xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 //===- MipsISelLowering.cpp - Mips DAG Lowering Implementation ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that Mips uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MipsISelLowering.h"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "MCTargetDesc/MipsInstPrinter.h"
17 #include "MCTargetDesc/MipsMCTargetDesc.h"
18 #include "MipsCCState.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsMachineFunction.h"
21 #include "MipsRegisterInfo.h"
22 #include "MipsSubtarget.h"
23 #include "MipsTargetMachine.h"
24 #include "MipsTargetObjectFile.h"
25 #include "llvm/ADT/APFloat.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/StringSwitch.h"
31 #include "llvm/CodeGen/CallingConvLower.h"
32 #include "llvm/CodeGen/FunctionLoweringInfo.h"
33 #include "llvm/CodeGen/ISDOpcodes.h"
34 #include "llvm/CodeGen/MachineBasicBlock.h"
35 #include "llvm/CodeGen/MachineFrameInfo.h"
36 #include "llvm/CodeGen/MachineFunction.h"
37 #include "llvm/CodeGen/MachineInstr.h"
38 #include "llvm/CodeGen/MachineInstrBuilder.h"
39 #include "llvm/CodeGen/MachineJumpTableInfo.h"
40 #include "llvm/CodeGen/MachineMemOperand.h"
41 #include "llvm/CodeGen/MachineOperand.h"
42 #include "llvm/CodeGen/MachineRegisterInfo.h"
43 #include "llvm/CodeGen/RuntimeLibcalls.h"
44 #include "llvm/CodeGen/SelectionDAG.h"
45 #include "llvm/CodeGen/SelectionDAGNodes.h"
46 #include "llvm/CodeGen/TargetFrameLowering.h"
47 #include "llvm/CodeGen/TargetInstrInfo.h"
48 #include "llvm/CodeGen/TargetRegisterInfo.h"
49 #include "llvm/CodeGen/ValueTypes.h"
50 #include "llvm/IR/CallingConv.h"
51 #include "llvm/IR/Constants.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/DebugLoc.h"
54 #include "llvm/IR/DerivedTypes.h"
55 #include "llvm/IR/Function.h"
56 #include "llvm/IR/GlobalValue.h"
57 #include "llvm/IR/Type.h"
58 #include "llvm/IR/Value.h"
59 #include "llvm/MC/MCContext.h"
60 #include "llvm/MC/MCRegisterInfo.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CodeGen.h"
63 #include "llvm/Support/CommandLine.h"
64 #include "llvm/Support/Compiler.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/MachineValueType.h"
67 #include "llvm/Support/MathExtras.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include "llvm/Target/TargetOptions.h"
70 #include <algorithm>
71 #include <cassert>
72 #include <cctype>
73 #include <cstdint>
74 #include <deque>
75 #include <iterator>
76 #include <utility>
77 #include <vector>
78 
79 using namespace llvm;
80 
81 #define DEBUG_TYPE "mips-lower"
82 
83 STATISTIC(NumTailCalls, "Number of tail calls");
84 
85 static cl::opt<bool>
86 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
87                cl::desc("MIPS: Don't trap on integer division by zero."),
88                cl::init(false));
89 
90 extern cl::opt<bool> EmitJalrReloc;
91 
92 static const MCPhysReg Mips64DPRegs[8] = {
93   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
94   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
95 };
96 
97 // The MIPS MSA ABI passes vector arguments in the integer register set.
98 // The number of integer registers used is dependant on the ABI used.
99 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
100                                                       CallingConv::ID CC,
101                                                       EVT VT) const {
102   if (!VT.isVector())
103     return getRegisterType(Context, VT);
104 
105   return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
106                                                            : MVT::i64;
107 }
108 
109 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
110                                                            CallingConv::ID CC,
111                                                            EVT VT) const {
112   if (VT.isVector())
113     return divideCeil(VT.getSizeInBits(), Subtarget.isABI_O32() ? 32 : 64);
114   return MipsTargetLowering::getNumRegisters(Context, VT);
115 }
116 
117 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
118     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
119     unsigned &NumIntermediates, MVT &RegisterVT) const {
120   // Break down vector types to either 2 i64s or 4 i32s.
121   RegisterVT = getRegisterTypeForCallingConv(Context, CC, VT);
122   IntermediateVT = RegisterVT;
123   NumIntermediates =
124       VT.getFixedSizeInBits() < RegisterVT.getFixedSizeInBits()
125           ? VT.getVectorNumElements()
126           : divideCeil(VT.getSizeInBits(), RegisterVT.getSizeInBits());
127   return NumIntermediates;
128 }
129 
130 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
131   MachineFunction &MF = DAG.getMachineFunction();
132   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
133   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
134 }
135 
136 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
137                                           SelectionDAG &DAG,
138                                           unsigned Flag) const {
139   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
140 }
141 
142 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
143                                           SelectionDAG &DAG,
144                                           unsigned Flag) const {
145   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
146 }
147 
148 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
149                                           SelectionDAG &DAG,
150                                           unsigned Flag) const {
151   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
152 }
153 
154 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
155                                           SelectionDAG &DAG,
156                                           unsigned Flag) const {
157   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
158 }
159 
160 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
161                                           SelectionDAG &DAG,
162                                           unsigned Flag) const {
163   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
164                                    N->getOffset(), Flag);
165 }
166 
167 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
168   switch ((MipsISD::NodeType)Opcode) {
169   case MipsISD::FIRST_NUMBER:      break;
170   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
171   case MipsISD::TailCall:          return "MipsISD::TailCall";
172   case MipsISD::Highest:           return "MipsISD::Highest";
173   case MipsISD::Higher:            return "MipsISD::Higher";
174   case MipsISD::Hi:                return "MipsISD::Hi";
175   case MipsISD::Lo:                return "MipsISD::Lo";
176   case MipsISD::GotHi:             return "MipsISD::GotHi";
177   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
178   case MipsISD::GPRel:             return "MipsISD::GPRel";
179   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
180   case MipsISD::Ret:               return "MipsISD::Ret";
181   case MipsISD::ERet:              return "MipsISD::ERet";
182   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
183   case MipsISD::FAbs:              return "MipsISD::FAbs";
184   case MipsISD::FMS:               return "MipsISD::FMS";
185   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
186   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
187   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
188   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
189   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
190   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
191   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
192   case MipsISD::MFHI:              return "MipsISD::MFHI";
193   case MipsISD::MFLO:              return "MipsISD::MFLO";
194   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
195   case MipsISD::Mult:              return "MipsISD::Mult";
196   case MipsISD::Multu:             return "MipsISD::Multu";
197   case MipsISD::MAdd:              return "MipsISD::MAdd";
198   case MipsISD::MAddu:             return "MipsISD::MAddu";
199   case MipsISD::MSub:              return "MipsISD::MSub";
200   case MipsISD::MSubu:             return "MipsISD::MSubu";
201   case MipsISD::DivRem:            return "MipsISD::DivRem";
202   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
203   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
204   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
205   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
206   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
207   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
208   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
209   case MipsISD::Sync:              return "MipsISD::Sync";
210   case MipsISD::Ext:               return "MipsISD::Ext";
211   case MipsISD::Ins:               return "MipsISD::Ins";
212   case MipsISD::CIns:              return "MipsISD::CIns";
213   case MipsISD::LWL:               return "MipsISD::LWL";
214   case MipsISD::LWR:               return "MipsISD::LWR";
215   case MipsISD::SWL:               return "MipsISD::SWL";
216   case MipsISD::SWR:               return "MipsISD::SWR";
217   case MipsISD::LDL:               return "MipsISD::LDL";
218   case MipsISD::LDR:               return "MipsISD::LDR";
219   case MipsISD::SDL:               return "MipsISD::SDL";
220   case MipsISD::SDR:               return "MipsISD::SDR";
221   case MipsISD::EXTP:              return "MipsISD::EXTP";
222   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
223   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
224   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
225   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
226   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
227   case MipsISD::SHILO:             return "MipsISD::SHILO";
228   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
229   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
230   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
231   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
232   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
233   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
234   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
235   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
236   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
237   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
238   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
239   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
240   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
241   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
242   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
243   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
244   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
245   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
246   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
247   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
248   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
249   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
250   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
251   case MipsISD::MULT:              return "MipsISD::MULT";
252   case MipsISD::MULTU:             return "MipsISD::MULTU";
253   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
254   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
255   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
256   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
257   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
258   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
259   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
260   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
261   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
262   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
263   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
264   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
265   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
266   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
267   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
268   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
269   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
270   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
271   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
272   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
273   case MipsISD::VNOR:              return "MipsISD::VNOR";
274   case MipsISD::VSHF:              return "MipsISD::VSHF";
275   case MipsISD::SHF:               return "MipsISD::SHF";
276   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
277   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
278   case MipsISD::ILVL:              return "MipsISD::ILVL";
279   case MipsISD::ILVR:              return "MipsISD::ILVR";
280   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
281   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
282   case MipsISD::INSVE:             return "MipsISD::INSVE";
283   }
284   return nullptr;
285 }
286 
287 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
288                                        const MipsSubtarget &STI)
289     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
290   // Mips does not have i1 type, so use i32 for
291   // setcc operations results (slt, sgt, ...).
292   setBooleanContents(ZeroOrOneBooleanContent);
293   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
294   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
295   // does. Integer booleans still use 0 and 1.
296   if (Subtarget.hasMips32r6())
297     setBooleanContents(ZeroOrOneBooleanContent,
298                        ZeroOrNegativeOneBooleanContent);
299 
300   // Load extented operations for i1 types must be promoted
301   for (MVT VT : MVT::integer_valuetypes()) {
302     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
303     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
304     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
305   }
306 
307   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
308   // for f32, f16
309   for (MVT VT : MVT::fp_valuetypes()) {
310     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
311     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
312   }
313 
314   // Set LoadExtAction for f16 vectors to Expand
315   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
316     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
317     if (F16VT.isValid())
318       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
319   }
320 
321   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
322   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
323 
324   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
325 
326   // Used by legalize types to correctly generate the setcc result.
327   // Without this, every float setcc comes with a AND/OR with the result,
328   // we don't want this, since the fpcmp result goes to a flag register,
329   // which is used implicitly by brcond and select operations.
330   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
331 
332   // Mips Custom Operations
333   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
334   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
335   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
336   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
337   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
338   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
339   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
340   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
341   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
342   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
343   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
344   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
345   setOperationAction(ISD::FABS,               MVT::f32,   Custom);
346   setOperationAction(ISD::FABS,               MVT::f64,   Custom);
347   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
348   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
349   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
350 
351   if (Subtarget.isGP64bit()) {
352     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
353     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
354     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
355     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
356     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
357     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
358     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
359     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
360     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
361     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
362     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
363     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
364   }
365 
366   if (!Subtarget.isGP64bit()) {
367     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
368     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
369     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
370   }
371 
372   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
373   if (Subtarget.isGP64bit())
374     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
375 
376   setOperationAction(ISD::SDIV, MVT::i32, Expand);
377   setOperationAction(ISD::SREM, MVT::i32, Expand);
378   setOperationAction(ISD::UDIV, MVT::i32, Expand);
379   setOperationAction(ISD::UREM, MVT::i32, Expand);
380   setOperationAction(ISD::SDIV, MVT::i64, Expand);
381   setOperationAction(ISD::SREM, MVT::i64, Expand);
382   setOperationAction(ISD::UDIV, MVT::i64, Expand);
383   setOperationAction(ISD::UREM, MVT::i64, Expand);
384 
385   // Operations not directly supported by Mips.
386   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
387   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
388   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
389   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
390   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
391   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
392   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
393   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
394   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
395   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
396   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
397   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
398   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
399   if (Subtarget.hasCnMips()) {
400     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
401     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
402   } else {
403     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
404     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
405   }
406   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
407   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
408   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
409   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
410   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
411   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
412 
413   if (!Subtarget.hasMips32r2())
414     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
415 
416   if (!Subtarget.hasMips64r2())
417     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
418 
419   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
420   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
421   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
422   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
423   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
424   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
425   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
426   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
427   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
428   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
429   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
430   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
431   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
432   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
433   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
434   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
435 
436   // Lower f16 conversion operations into library calls
437   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
438   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
439   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
440   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
441 
442   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
443 
444   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
445   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
446   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
447   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
448 
449   // Use the default for now
450   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
451   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
452 
453   if (!Subtarget.isGP64bit()) {
454     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
455     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
456   }
457 
458   if (!Subtarget.hasMips32r2()) {
459     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
460     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
461   }
462 
463   // MIPS16 lacks MIPS32's clz and clo instructions.
464   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
465     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
466   if (!Subtarget.hasMips64())
467     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
468 
469   if (!Subtarget.hasMips32r2())
470     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
471   if (!Subtarget.hasMips64r2())
472     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
473 
474   if (Subtarget.isGP64bit()) {
475     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
476     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
477     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
478     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
479   }
480 
481   setOperationAction(ISD::TRAP, MVT::Other, Legal);
482 
483   setTargetDAGCombine({ISD::SDIVREM, ISD::UDIVREM, ISD::SELECT, ISD::AND,
484                        ISD::OR, ISD::ADD, ISD::SUB, ISD::AssertZext, ISD::SHL});
485 
486   if (ABI.IsO32()) {
487     // These libcalls are not available in 32-bit.
488     setLibcallName(RTLIB::SHL_I128, nullptr);
489     setLibcallName(RTLIB::SRL_I128, nullptr);
490     setLibcallName(RTLIB::SRA_I128, nullptr);
491     setLibcallName(RTLIB::MUL_I128, nullptr);
492     setLibcallName(RTLIB::MULO_I64, nullptr);
493     setLibcallName(RTLIB::MULO_I128, nullptr);
494   }
495 
496   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
497 
498   // The arguments on the stack are defined in terms of 4-byte slots on O32
499   // and 8-byte slots on N32/N64.
500   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
501                                                             : Align(4));
502 
503   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
504 
505   MaxStoresPerMemcpy = 16;
506 
507   isMicroMips = Subtarget.inMicroMipsMode();
508 }
509 
510 const MipsTargetLowering *
511 MipsTargetLowering::create(const MipsTargetMachine &TM,
512                            const MipsSubtarget &STI) {
513   if (STI.inMips16Mode())
514     return createMips16TargetLowering(TM, STI);
515 
516   return createMipsSETargetLowering(TM, STI);
517 }
518 
519 // Create a fast isel object.
520 FastISel *
521 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
522                                   const TargetLibraryInfo *libInfo) const {
523   const MipsTargetMachine &TM =
524       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
525 
526   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
527   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
528                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
529                      !Subtarget.inMicroMipsMode();
530 
531   // Disable if either of the following is true:
532   // We do not generate PIC, the ABI is not O32, XGOT is being used.
533   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
534       Subtarget.useXGOT())
535     UseFastISel = false;
536 
537   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
538 }
539 
540 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
541                                            EVT VT) const {
542   if (!VT.isVector())
543     return MVT::i32;
544   return VT.changeVectorElementTypeToInteger();
545 }
546 
547 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
548                                     TargetLowering::DAGCombinerInfo &DCI,
549                                     const MipsSubtarget &Subtarget) {
550   if (DCI.isBeforeLegalizeOps())
551     return SDValue();
552 
553   EVT Ty = N->getValueType(0);
554   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
555   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
556   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
557                                                   MipsISD::DivRemU16;
558   SDLoc DL(N);
559 
560   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
561                                N->getOperand(0), N->getOperand(1));
562   SDValue InChain = DAG.getEntryNode();
563   SDValue InGlue = DivRem;
564 
565   // insert MFLO
566   if (N->hasAnyUseOfValue(0)) {
567     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
568                                             InGlue);
569     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
570     InChain = CopyFromLo.getValue(1);
571     InGlue = CopyFromLo.getValue(2);
572   }
573 
574   // insert MFHI
575   if (N->hasAnyUseOfValue(1)) {
576     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
577                                             HI, Ty, InGlue);
578     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
579   }
580 
581   return SDValue();
582 }
583 
584 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
585   switch (CC) {
586   default: llvm_unreachable("Unknown fp condition code!");
587   case ISD::SETEQ:
588   case ISD::SETOEQ: return Mips::FCOND_OEQ;
589   case ISD::SETUNE: return Mips::FCOND_UNE;
590   case ISD::SETLT:
591   case ISD::SETOLT: return Mips::FCOND_OLT;
592   case ISD::SETGT:
593   case ISD::SETOGT: return Mips::FCOND_OGT;
594   case ISD::SETLE:
595   case ISD::SETOLE: return Mips::FCOND_OLE;
596   case ISD::SETGE:
597   case ISD::SETOGE: return Mips::FCOND_OGE;
598   case ISD::SETULT: return Mips::FCOND_ULT;
599   case ISD::SETULE: return Mips::FCOND_ULE;
600   case ISD::SETUGT: return Mips::FCOND_UGT;
601   case ISD::SETUGE: return Mips::FCOND_UGE;
602   case ISD::SETUO:  return Mips::FCOND_UN;
603   case ISD::SETO:   return Mips::FCOND_OR;
604   case ISD::SETNE:
605   case ISD::SETONE: return Mips::FCOND_ONE;
606   case ISD::SETUEQ: return Mips::FCOND_UEQ;
607   }
608 }
609 
610 /// This function returns true if the floating point conditional branches and
611 /// conditional moves which use condition code CC should be inverted.
612 static bool invertFPCondCodeUser(Mips::CondCode CC) {
613   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
614     return false;
615 
616   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
617          "Illegal Condition Code");
618 
619   return true;
620 }
621 
622 // Creates and returns an FPCmp node from a setcc node.
623 // Returns Op if setcc is not a floating point comparison.
624 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
625   // must be a SETCC node
626   if (Op.getOpcode() != ISD::SETCC)
627     return Op;
628 
629   SDValue LHS = Op.getOperand(0);
630 
631   if (!LHS.getValueType().isFloatingPoint())
632     return Op;
633 
634   SDValue RHS = Op.getOperand(1);
635   SDLoc DL(Op);
636 
637   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
638   // node if necessary.
639   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
640 
641   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
642                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
643 }
644 
645 // Creates and returns a CMovFPT/F node.
646 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
647                             SDValue False, const SDLoc &DL) {
648   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
649   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
650   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
651 
652   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
653                      True.getValueType(), True, FCC0, False, Cond);
654 }
655 
656 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
657                                     TargetLowering::DAGCombinerInfo &DCI,
658                                     const MipsSubtarget &Subtarget) {
659   if (DCI.isBeforeLegalizeOps())
660     return SDValue();
661 
662   SDValue SetCC = N->getOperand(0);
663 
664   if ((SetCC.getOpcode() != ISD::SETCC) ||
665       !SetCC.getOperand(0).getValueType().isInteger())
666     return SDValue();
667 
668   SDValue False = N->getOperand(2);
669   EVT FalseTy = False.getValueType();
670 
671   if (!FalseTy.isInteger())
672     return SDValue();
673 
674   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
675 
676   // If the RHS (False) is 0, we swap the order of the operands
677   // of ISD::SELECT (obviously also inverting the condition) so that we can
678   // take advantage of conditional moves using the $0 register.
679   // Example:
680   //   return (a != 0) ? x : 0;
681   //     load $reg, x
682   //     movz $reg, $0, a
683   if (!FalseC)
684     return SDValue();
685 
686   const SDLoc DL(N);
687 
688   if (!FalseC->getZExtValue()) {
689     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
690     SDValue True = N->getOperand(1);
691 
692     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
693                          SetCC.getOperand(1),
694                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
695 
696     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
697   }
698 
699   // If both operands are integer constants there's a possibility that we
700   // can do some interesting optimizations.
701   SDValue True = N->getOperand(1);
702   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
703 
704   if (!TrueC || !True.getValueType().isInteger())
705     return SDValue();
706 
707   // We'll also ignore MVT::i64 operands as this optimizations proves
708   // to be ineffective because of the required sign extensions as the result
709   // of a SETCC operator is always MVT::i32 for non-vector types.
710   if (True.getValueType() == MVT::i64)
711     return SDValue();
712 
713   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
714 
715   // 1)  (a < x) ? y : y-1
716   //  slti $reg1, a, x
717   //  addiu $reg2, $reg1, y-1
718   if (Diff == 1)
719     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
720 
721   // 2)  (a < x) ? y-1 : y
722   //  slti $reg1, a, x
723   //  xor $reg1, $reg1, 1
724   //  addiu $reg2, $reg1, y-1
725   if (Diff == -1) {
726     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
727     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
728                          SetCC.getOperand(1),
729                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
730     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
731   }
732 
733   // Could not optimize.
734   return SDValue();
735 }
736 
737 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
738                                     TargetLowering::DAGCombinerInfo &DCI,
739                                     const MipsSubtarget &Subtarget) {
740   if (DCI.isBeforeLegalizeOps())
741     return SDValue();
742 
743   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
744 
745   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
746   if (!FalseC || FalseC->getZExtValue())
747     return SDValue();
748 
749   // Since RHS (False) is 0, we swap the order of the True/False operands
750   // (obviously also inverting the condition) so that we can
751   // take advantage of conditional moves using the $0 register.
752   // Example:
753   //   return (a != 0) ? x : 0;
754   //     load $reg, x
755   //     movz $reg, $0, a
756   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
757                                                          MipsISD::CMovFP_T;
758 
759   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
760   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
761                      ValueIfFalse, FCC, ValueIfTrue, Glue);
762 }
763 
764 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
765                                  TargetLowering::DAGCombinerInfo &DCI,
766                                  const MipsSubtarget &Subtarget) {
767   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
768     return SDValue();
769 
770   SDValue FirstOperand = N->getOperand(0);
771   unsigned FirstOperandOpc = FirstOperand.getOpcode();
772   SDValue Mask = N->getOperand(1);
773   EVT ValTy = N->getValueType(0);
774   SDLoc DL(N);
775 
776   uint64_t Pos = 0;
777   unsigned SMPos, SMSize;
778   ConstantSDNode *CN;
779   SDValue NewOperand;
780   unsigned Opc;
781 
782   // Op's second operand must be a shifted mask.
783   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
784       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
785     return SDValue();
786 
787   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
788     // Pattern match EXT.
789     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
790     //  => ext $dst, $src, pos, size
791 
792     // The second operand of the shift must be an immediate.
793     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
794       return SDValue();
795 
796     Pos = CN->getZExtValue();
797 
798     // Return if the shifted mask does not start at bit 0 or the sum of its size
799     // and Pos exceeds the word's size.
800     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
801       return SDValue();
802 
803     Opc = MipsISD::Ext;
804     NewOperand = FirstOperand.getOperand(0);
805   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
806     // Pattern match CINS.
807     //  $dst = and (shl $src , pos), mask
808     //  => cins $dst, $src, pos, size
809     // mask is a shifted mask with consecutive 1's, pos = shift amount,
810     // size = population count.
811 
812     // The second operand of the shift must be an immediate.
813     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
814       return SDValue();
815 
816     Pos = CN->getZExtValue();
817 
818     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
819         Pos + SMSize > ValTy.getSizeInBits())
820       return SDValue();
821 
822     NewOperand = FirstOperand.getOperand(0);
823     // SMSize is 'location' (position) in this case, not size.
824     SMSize--;
825     Opc = MipsISD::CIns;
826   } else {
827     // Pattern match EXT.
828     //  $dst = and $src, (2**size - 1) , if size > 16
829     //  => ext $dst, $src, pos, size , pos = 0
830 
831     // If the mask is <= 0xffff, andi can be used instead.
832     if (CN->getZExtValue() <= 0xffff)
833       return SDValue();
834 
835     // Return if the mask doesn't start at position 0.
836     if (SMPos)
837       return SDValue();
838 
839     Opc = MipsISD::Ext;
840     NewOperand = FirstOperand;
841   }
842   return DAG.getNode(Opc, DL, ValTy, NewOperand,
843                      DAG.getConstant(Pos, DL, MVT::i32),
844                      DAG.getConstant(SMSize, DL, MVT::i32));
845 }
846 
847 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
848                                 TargetLowering::DAGCombinerInfo &DCI,
849                                 const MipsSubtarget &Subtarget) {
850   // Pattern match INS.
851   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
852   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
853   //  => ins $dst, $src, size, pos, $src1
854   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
855     return SDValue();
856 
857   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
858   unsigned SMPos0, SMSize0, SMPos1, SMSize1;
859   ConstantSDNode *CN, *CN1;
860 
861   // See if Op's first operand matches (and $src1 , mask0).
862   if (And0.getOpcode() != ISD::AND)
863     return SDValue();
864 
865   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
866       !isShiftedMask_64(~CN->getSExtValue(), SMPos0, SMSize0))
867     return SDValue();
868 
869   // See if Op's second operand matches (and (shl $src, pos), mask1).
870   if (And1.getOpcode() == ISD::AND &&
871       And1.getOperand(0).getOpcode() == ISD::SHL) {
872 
873     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
874         !isShiftedMask_64(CN->getZExtValue(), SMPos1, SMSize1))
875       return SDValue();
876 
877     // The shift masks must have the same position and size.
878     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
879       return SDValue();
880 
881     SDValue Shl = And1.getOperand(0);
882 
883     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
884       return SDValue();
885 
886     unsigned Shamt = CN->getZExtValue();
887 
888     // Return if the shift amount and the first bit position of mask are not the
889     // same.
890     EVT ValTy = N->getValueType(0);
891     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
892       return SDValue();
893 
894     SDLoc DL(N);
895     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
896                        DAG.getConstant(SMPos0, DL, MVT::i32),
897                        DAG.getConstant(SMSize0, DL, MVT::i32),
898                        And0.getOperand(0));
899   } else {
900     // Pattern match DINS.
901     //  $dst = or (and $src, mask0), mask1
902     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
903     //  => dins $dst, $src, pos, size
904     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
905         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
906          (SMSize0 + SMPos0 <= 32))) {
907       // Check if AND instruction has constant as argument
908       bool isConstCase = And1.getOpcode() != ISD::AND;
909       if (And1.getOpcode() == ISD::AND) {
910         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
911           return SDValue();
912       } else {
913         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
914           return SDValue();
915       }
916       // Don't generate INS if constant OR operand doesn't fit into bits
917       // cleared by constant AND operand.
918       if (CN->getSExtValue() & CN1->getSExtValue())
919         return SDValue();
920 
921       SDLoc DL(N);
922       EVT ValTy = N->getOperand(0)->getValueType(0);
923       SDValue Const1;
924       SDValue SrlX;
925       if (!isConstCase) {
926         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
927         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
928       }
929       return DAG.getNode(
930           MipsISD::Ins, DL, N->getValueType(0),
931           isConstCase
932               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
933               : SrlX,
934           DAG.getConstant(SMPos0, DL, MVT::i32),
935           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
936                                                         : SMSize0,
937                           DL, MVT::i32),
938           And0->getOperand(0));
939 
940     }
941     return SDValue();
942   }
943 }
944 
945 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
946                                        const MipsSubtarget &Subtarget) {
947   // ROOTNode must have a multiplication as an operand for the match to be
948   // successful.
949   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
950       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
951     return SDValue();
952 
953   // In the case where we have a multiplication as the left operand of
954   // of a subtraction, we can't combine into a MipsISD::MSub node as the
955   // the instruction definition of msub(u) places the multiplication on
956   // on the right.
957   if (ROOTNode->getOpcode() == ISD::SUB &&
958       ROOTNode->getOperand(0).getOpcode() == ISD::MUL)
959     return SDValue();
960 
961   // We don't handle vector types here.
962   if (ROOTNode->getValueType(0).isVector())
963     return SDValue();
964 
965   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
966   // arithmetic. E.g.
967   // (add (mul a b) c) =>
968   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
969   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
970   //   or
971   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
972   //
973   // The overhead of setting up the Hi/Lo registers and reassembling the
974   // result makes this a dubious optimzation for MIPS64. The core of the
975   // problem is that Hi/Lo contain the upper and lower 32 bits of the
976   // operand and result.
977   //
978   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
979   // density than doing it naively, 5 for MIPS64. Additionally, using
980   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
981   // extended operands, not true 64 bit values.
982   //
983   // FIXME: For the moment, disable this completely for MIPS64.
984   if (Subtarget.hasMips64())
985     return SDValue();
986 
987   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
988                      ? ROOTNode->getOperand(0)
989                      : ROOTNode->getOperand(1);
990 
991   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
992                      ? ROOTNode->getOperand(1)
993                      : ROOTNode->getOperand(0);
994 
995   // Transform this to a MADD only if the user of this node is the add.
996   // If there are other users of the mul, this function returns here.
997   if (!Mult.hasOneUse())
998     return SDValue();
999 
1000   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1001   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1002   // of the multiply must have 32 or more sign bits, otherwise we cannot
1003   // perform this optimization. We have to check this here as we're performing
1004   // this optimization pre-legalization.
1005   SDValue MultLHS = Mult->getOperand(0);
1006   SDValue MultRHS = Mult->getOperand(1);
1007 
1008   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1009                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1010   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1011                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1012 
1013   if (!IsSigned && !IsUnsigned)
1014     return SDValue();
1015 
1016   // Initialize accumulator.
1017   SDLoc DL(ROOTNode);
1018   SDValue TopHalf;
1019   SDValue BottomHalf;
1020   BottomHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1021                               CurDAG.getIntPtrConstant(0, DL));
1022 
1023   TopHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1024                            CurDAG.getIntPtrConstant(1, DL));
1025   SDValue ACCIn = CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped,
1026                                   BottomHalf,
1027                                   TopHalf);
1028 
1029   // Create MipsMAdd(u) / MipsMSub(u) node.
1030   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1031   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1032                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1033   SDValue MAddOps[3] = {
1034       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1035       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1036   EVT VTs[2] = {MVT::i32, MVT::i32};
1037   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1038 
1039   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1040   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1041   SDValue Combined =
1042       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1043   return Combined;
1044 }
1045 
1046 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1047                                  TargetLowering::DAGCombinerInfo &DCI,
1048                                  const MipsSubtarget &Subtarget) {
1049   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1050   if (DCI.isBeforeLegalizeOps()) {
1051     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1052         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1053       return performMADD_MSUBCombine(N, DAG, Subtarget);
1054 
1055     return SDValue();
1056   }
1057 
1058   return SDValue();
1059 }
1060 
1061 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1062                                  TargetLowering::DAGCombinerInfo &DCI,
1063                                  const MipsSubtarget &Subtarget) {
1064   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1065   if (DCI.isBeforeLegalizeOps()) {
1066     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1067         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1068       return performMADD_MSUBCombine(N, DAG, Subtarget);
1069 
1070     return SDValue();
1071   }
1072 
1073   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1074   SDValue Add = N->getOperand(1);
1075 
1076   if (Add.getOpcode() != ISD::ADD)
1077     return SDValue();
1078 
1079   SDValue Lo = Add.getOperand(1);
1080 
1081   if ((Lo.getOpcode() != MipsISD::Lo) ||
1082       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1083     return SDValue();
1084 
1085   EVT ValTy = N->getValueType(0);
1086   SDLoc DL(N);
1087 
1088   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1089                              Add.getOperand(0));
1090   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1091 }
1092 
1093 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1094                                  TargetLowering::DAGCombinerInfo &DCI,
1095                                  const MipsSubtarget &Subtarget) {
1096   // Pattern match CINS.
1097   //  $dst = shl (and $src , imm), pos
1098   //  => cins $dst, $src, pos, size
1099 
1100   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1101     return SDValue();
1102 
1103   SDValue FirstOperand = N->getOperand(0);
1104   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1105   SDValue SecondOperand = N->getOperand(1);
1106   EVT ValTy = N->getValueType(0);
1107   SDLoc DL(N);
1108 
1109   uint64_t Pos = 0;
1110   unsigned SMPos, SMSize;
1111   ConstantSDNode *CN;
1112   SDValue NewOperand;
1113 
1114   // The second operand of the shift must be an immediate.
1115   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1116     return SDValue();
1117 
1118   Pos = CN->getZExtValue();
1119 
1120   if (Pos >= ValTy.getSizeInBits())
1121     return SDValue();
1122 
1123   if (FirstOperandOpc != ISD::AND)
1124     return SDValue();
1125 
1126   // AND's second operand must be a shifted mask.
1127   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1128       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
1129     return SDValue();
1130 
1131   // Return if the shifted mask does not start at bit 0 or the sum of its size
1132   // and Pos exceeds the word's size.
1133   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1134     return SDValue();
1135 
1136   NewOperand = FirstOperand.getOperand(0);
1137   // SMSize is 'location' (position) in this case, not size.
1138   SMSize--;
1139 
1140   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1141                      DAG.getConstant(Pos, DL, MVT::i32),
1142                      DAG.getConstant(SMSize, DL, MVT::i32));
1143 }
1144 
1145 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1146   const {
1147   SelectionDAG &DAG = DCI.DAG;
1148   unsigned Opc = N->getOpcode();
1149 
1150   switch (Opc) {
1151   default: break;
1152   case ISD::SDIVREM:
1153   case ISD::UDIVREM:
1154     return performDivRemCombine(N, DAG, DCI, Subtarget);
1155   case ISD::SELECT:
1156     return performSELECTCombine(N, DAG, DCI, Subtarget);
1157   case MipsISD::CMovFP_F:
1158   case MipsISD::CMovFP_T:
1159     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1160   case ISD::AND:
1161     return performANDCombine(N, DAG, DCI, Subtarget);
1162   case ISD::OR:
1163     return performORCombine(N, DAG, DCI, Subtarget);
1164   case ISD::ADD:
1165     return performADDCombine(N, DAG, DCI, Subtarget);
1166   case ISD::SHL:
1167     return performSHLCombine(N, DAG, DCI, Subtarget);
1168   case ISD::SUB:
1169     return performSUBCombine(N, DAG, DCI, Subtarget);
1170   }
1171 
1172   return SDValue();
1173 }
1174 
1175 bool MipsTargetLowering::isCheapToSpeculateCttz(Type *Ty) const {
1176   return Subtarget.hasMips32();
1177 }
1178 
1179 bool MipsTargetLowering::isCheapToSpeculateCtlz(Type *Ty) const {
1180   return Subtarget.hasMips32();
1181 }
1182 
1183 bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
1184   // We can use ANDI+SLTIU as a bit test. Y contains the bit position.
1185   // For MIPSR2 or later, we may be able to use the `ext` instruction or its'
1186   // double-word variants.
1187   if (auto *C = dyn_cast<ConstantSDNode>(Y))
1188     return C->getAPIntValue().ule(15);
1189 
1190   return false;
1191 }
1192 
1193 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1194     const SDNode *N, CombineLevel Level) const {
1195   assert(((N->getOpcode() == ISD::SHL &&
1196            N->getOperand(0).getOpcode() == ISD::SRL) ||
1197           (N->getOpcode() == ISD::SRL &&
1198            N->getOperand(0).getOpcode() == ISD::SHL)) &&
1199          "Expected shift-shift mask");
1200 
1201   if (N->getOperand(0).getValueType().isVector())
1202     return false;
1203   return true;
1204 }
1205 
1206 void
1207 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1208                                        SmallVectorImpl<SDValue> &Results,
1209                                        SelectionDAG &DAG) const {
1210   return LowerOperationWrapper(N, Results, DAG);
1211 }
1212 
1213 SDValue MipsTargetLowering::
1214 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1215 {
1216   switch (Op.getOpcode())
1217   {
1218   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1219   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1220   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1221   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1222   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1223   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1224   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1225   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1226   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1227   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1228   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1229   case ISD::FABS:               return lowerFABS(Op, DAG);
1230   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1231   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1232   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1233   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1234   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1235   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1236   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1237   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1238   case ISD::STORE:              return lowerSTORE(Op, DAG);
1239   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1240   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1241   }
1242   return SDValue();
1243 }
1244 
1245 //===----------------------------------------------------------------------===//
1246 //  Lower helper functions
1247 //===----------------------------------------------------------------------===//
1248 
1249 // addLiveIn - This helper function adds the specified physical register to the
1250 // MachineFunction as a live in value.  It also creates a corresponding
1251 // virtual register for it.
1252 static unsigned
1253 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1254 {
1255   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1256   MF.getRegInfo().addLiveIn(PReg, VReg);
1257   return VReg;
1258 }
1259 
1260 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1261                                               MachineBasicBlock &MBB,
1262                                               const TargetInstrInfo &TII,
1263                                               bool Is64Bit, bool IsMicroMips) {
1264   if (NoZeroDivCheck)
1265     return &MBB;
1266 
1267   // Insert instruction "teq $divisor_reg, $zero, 7".
1268   MachineBasicBlock::iterator I(MI);
1269   MachineInstrBuilder MIB;
1270   MachineOperand &Divisor = MI.getOperand(2);
1271   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1272                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1273             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1274             .addReg(Mips::ZERO)
1275             .addImm(7);
1276 
1277   // Use the 32-bit sub-register if this is a 64-bit division.
1278   if (Is64Bit)
1279     MIB->getOperand(0).setSubReg(Mips::sub_32);
1280 
1281   // Clear Divisor's kill flag.
1282   Divisor.setIsKill(false);
1283 
1284   // We would normally delete the original instruction here but in this case
1285   // we only needed to inject an additional instruction rather than replace it.
1286 
1287   return &MBB;
1288 }
1289 
1290 MachineBasicBlock *
1291 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1292                                                 MachineBasicBlock *BB) const {
1293   switch (MI.getOpcode()) {
1294   default:
1295     llvm_unreachable("Unexpected instr type to insert");
1296   case Mips::ATOMIC_LOAD_ADD_I8:
1297     return emitAtomicBinaryPartword(MI, BB, 1);
1298   case Mips::ATOMIC_LOAD_ADD_I16:
1299     return emitAtomicBinaryPartword(MI, BB, 2);
1300   case Mips::ATOMIC_LOAD_ADD_I32:
1301     return emitAtomicBinary(MI, BB);
1302   case Mips::ATOMIC_LOAD_ADD_I64:
1303     return emitAtomicBinary(MI, BB);
1304 
1305   case Mips::ATOMIC_LOAD_AND_I8:
1306     return emitAtomicBinaryPartword(MI, BB, 1);
1307   case Mips::ATOMIC_LOAD_AND_I16:
1308     return emitAtomicBinaryPartword(MI, BB, 2);
1309   case Mips::ATOMIC_LOAD_AND_I32:
1310     return emitAtomicBinary(MI, BB);
1311   case Mips::ATOMIC_LOAD_AND_I64:
1312     return emitAtomicBinary(MI, BB);
1313 
1314   case Mips::ATOMIC_LOAD_OR_I8:
1315     return emitAtomicBinaryPartword(MI, BB, 1);
1316   case Mips::ATOMIC_LOAD_OR_I16:
1317     return emitAtomicBinaryPartword(MI, BB, 2);
1318   case Mips::ATOMIC_LOAD_OR_I32:
1319     return emitAtomicBinary(MI, BB);
1320   case Mips::ATOMIC_LOAD_OR_I64:
1321     return emitAtomicBinary(MI, BB);
1322 
1323   case Mips::ATOMIC_LOAD_XOR_I8:
1324     return emitAtomicBinaryPartword(MI, BB, 1);
1325   case Mips::ATOMIC_LOAD_XOR_I16:
1326     return emitAtomicBinaryPartword(MI, BB, 2);
1327   case Mips::ATOMIC_LOAD_XOR_I32:
1328     return emitAtomicBinary(MI, BB);
1329   case Mips::ATOMIC_LOAD_XOR_I64:
1330     return emitAtomicBinary(MI, BB);
1331 
1332   case Mips::ATOMIC_LOAD_NAND_I8:
1333     return emitAtomicBinaryPartword(MI, BB, 1);
1334   case Mips::ATOMIC_LOAD_NAND_I16:
1335     return emitAtomicBinaryPartword(MI, BB, 2);
1336   case Mips::ATOMIC_LOAD_NAND_I32:
1337     return emitAtomicBinary(MI, BB);
1338   case Mips::ATOMIC_LOAD_NAND_I64:
1339     return emitAtomicBinary(MI, BB);
1340 
1341   case Mips::ATOMIC_LOAD_SUB_I8:
1342     return emitAtomicBinaryPartword(MI, BB, 1);
1343   case Mips::ATOMIC_LOAD_SUB_I16:
1344     return emitAtomicBinaryPartword(MI, BB, 2);
1345   case Mips::ATOMIC_LOAD_SUB_I32:
1346     return emitAtomicBinary(MI, BB);
1347   case Mips::ATOMIC_LOAD_SUB_I64:
1348     return emitAtomicBinary(MI, BB);
1349 
1350   case Mips::ATOMIC_SWAP_I8:
1351     return emitAtomicBinaryPartword(MI, BB, 1);
1352   case Mips::ATOMIC_SWAP_I16:
1353     return emitAtomicBinaryPartword(MI, BB, 2);
1354   case Mips::ATOMIC_SWAP_I32:
1355     return emitAtomicBinary(MI, BB);
1356   case Mips::ATOMIC_SWAP_I64:
1357     return emitAtomicBinary(MI, BB);
1358 
1359   case Mips::ATOMIC_CMP_SWAP_I8:
1360     return emitAtomicCmpSwapPartword(MI, BB, 1);
1361   case Mips::ATOMIC_CMP_SWAP_I16:
1362     return emitAtomicCmpSwapPartword(MI, BB, 2);
1363   case Mips::ATOMIC_CMP_SWAP_I32:
1364     return emitAtomicCmpSwap(MI, BB);
1365   case Mips::ATOMIC_CMP_SWAP_I64:
1366     return emitAtomicCmpSwap(MI, BB);
1367 
1368   case Mips::ATOMIC_LOAD_MIN_I8:
1369     return emitAtomicBinaryPartword(MI, BB, 1);
1370   case Mips::ATOMIC_LOAD_MIN_I16:
1371     return emitAtomicBinaryPartword(MI, BB, 2);
1372   case Mips::ATOMIC_LOAD_MIN_I32:
1373     return emitAtomicBinary(MI, BB);
1374   case Mips::ATOMIC_LOAD_MIN_I64:
1375     return emitAtomicBinary(MI, BB);
1376 
1377   case Mips::ATOMIC_LOAD_MAX_I8:
1378     return emitAtomicBinaryPartword(MI, BB, 1);
1379   case Mips::ATOMIC_LOAD_MAX_I16:
1380     return emitAtomicBinaryPartword(MI, BB, 2);
1381   case Mips::ATOMIC_LOAD_MAX_I32:
1382     return emitAtomicBinary(MI, BB);
1383   case Mips::ATOMIC_LOAD_MAX_I64:
1384     return emitAtomicBinary(MI, BB);
1385 
1386   case Mips::ATOMIC_LOAD_UMIN_I8:
1387     return emitAtomicBinaryPartword(MI, BB, 1);
1388   case Mips::ATOMIC_LOAD_UMIN_I16:
1389     return emitAtomicBinaryPartword(MI, BB, 2);
1390   case Mips::ATOMIC_LOAD_UMIN_I32:
1391     return emitAtomicBinary(MI, BB);
1392   case Mips::ATOMIC_LOAD_UMIN_I64:
1393     return emitAtomicBinary(MI, BB);
1394 
1395   case Mips::ATOMIC_LOAD_UMAX_I8:
1396     return emitAtomicBinaryPartword(MI, BB, 1);
1397   case Mips::ATOMIC_LOAD_UMAX_I16:
1398     return emitAtomicBinaryPartword(MI, BB, 2);
1399   case Mips::ATOMIC_LOAD_UMAX_I32:
1400     return emitAtomicBinary(MI, BB);
1401   case Mips::ATOMIC_LOAD_UMAX_I64:
1402     return emitAtomicBinary(MI, BB);
1403 
1404   case Mips::PseudoSDIV:
1405   case Mips::PseudoUDIV:
1406   case Mips::DIV:
1407   case Mips::DIVU:
1408   case Mips::MOD:
1409   case Mips::MODU:
1410     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1411                                false);
1412   case Mips::SDIV_MM_Pseudo:
1413   case Mips::UDIV_MM_Pseudo:
1414   case Mips::SDIV_MM:
1415   case Mips::UDIV_MM:
1416   case Mips::DIV_MMR6:
1417   case Mips::DIVU_MMR6:
1418   case Mips::MOD_MMR6:
1419   case Mips::MODU_MMR6:
1420     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1421   case Mips::PseudoDSDIV:
1422   case Mips::PseudoDUDIV:
1423   case Mips::DDIV:
1424   case Mips::DDIVU:
1425   case Mips::DMOD:
1426   case Mips::DMODU:
1427     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1428 
1429   case Mips::PseudoSELECT_I:
1430   case Mips::PseudoSELECT_I64:
1431   case Mips::PseudoSELECT_S:
1432   case Mips::PseudoSELECT_D32:
1433   case Mips::PseudoSELECT_D64:
1434     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1435   case Mips::PseudoSELECTFP_F_I:
1436   case Mips::PseudoSELECTFP_F_I64:
1437   case Mips::PseudoSELECTFP_F_S:
1438   case Mips::PseudoSELECTFP_F_D32:
1439   case Mips::PseudoSELECTFP_F_D64:
1440     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1441   case Mips::PseudoSELECTFP_T_I:
1442   case Mips::PseudoSELECTFP_T_I64:
1443   case Mips::PseudoSELECTFP_T_S:
1444   case Mips::PseudoSELECTFP_T_D32:
1445   case Mips::PseudoSELECTFP_T_D64:
1446     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1447   case Mips::PseudoD_SELECT_I:
1448   case Mips::PseudoD_SELECT_I64:
1449     return emitPseudoD_SELECT(MI, BB);
1450   case Mips::LDR_W:
1451     return emitLDR_W(MI, BB);
1452   case Mips::LDR_D:
1453     return emitLDR_D(MI, BB);
1454   case Mips::STR_W:
1455     return emitSTR_W(MI, BB);
1456   case Mips::STR_D:
1457     return emitSTR_D(MI, BB);
1458   }
1459 }
1460 
1461 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1462 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1463 MachineBasicBlock *
1464 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1465                                      MachineBasicBlock *BB) const {
1466 
1467   MachineFunction *MF = BB->getParent();
1468   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1469   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1470   DebugLoc DL = MI.getDebugLoc();
1471 
1472   unsigned AtomicOp;
1473   bool NeedsAdditionalReg = false;
1474   switch (MI.getOpcode()) {
1475   case Mips::ATOMIC_LOAD_ADD_I32:
1476     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1477     break;
1478   case Mips::ATOMIC_LOAD_SUB_I32:
1479     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1480     break;
1481   case Mips::ATOMIC_LOAD_AND_I32:
1482     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1483     break;
1484   case Mips::ATOMIC_LOAD_OR_I32:
1485     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1486     break;
1487   case Mips::ATOMIC_LOAD_XOR_I32:
1488     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1489     break;
1490   case Mips::ATOMIC_LOAD_NAND_I32:
1491     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1492     break;
1493   case Mips::ATOMIC_SWAP_I32:
1494     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1495     break;
1496   case Mips::ATOMIC_LOAD_ADD_I64:
1497     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1498     break;
1499   case Mips::ATOMIC_LOAD_SUB_I64:
1500     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1501     break;
1502   case Mips::ATOMIC_LOAD_AND_I64:
1503     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1504     break;
1505   case Mips::ATOMIC_LOAD_OR_I64:
1506     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1507     break;
1508   case Mips::ATOMIC_LOAD_XOR_I64:
1509     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1510     break;
1511   case Mips::ATOMIC_LOAD_NAND_I64:
1512     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1513     break;
1514   case Mips::ATOMIC_SWAP_I64:
1515     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1516     break;
1517   case Mips::ATOMIC_LOAD_MIN_I32:
1518     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1519     NeedsAdditionalReg = true;
1520     break;
1521   case Mips::ATOMIC_LOAD_MAX_I32:
1522     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1523     NeedsAdditionalReg = true;
1524     break;
1525   case Mips::ATOMIC_LOAD_UMIN_I32:
1526     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1527     NeedsAdditionalReg = true;
1528     break;
1529   case Mips::ATOMIC_LOAD_UMAX_I32:
1530     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1531     NeedsAdditionalReg = true;
1532     break;
1533   case Mips::ATOMIC_LOAD_MIN_I64:
1534     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1535     NeedsAdditionalReg = true;
1536     break;
1537   case Mips::ATOMIC_LOAD_MAX_I64:
1538     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1539     NeedsAdditionalReg = true;
1540     break;
1541   case Mips::ATOMIC_LOAD_UMIN_I64:
1542     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1543     NeedsAdditionalReg = true;
1544     break;
1545   case Mips::ATOMIC_LOAD_UMAX_I64:
1546     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1547     NeedsAdditionalReg = true;
1548     break;
1549   default:
1550     llvm_unreachable("Unknown pseudo atomic for replacement!");
1551   }
1552 
1553   Register OldVal = MI.getOperand(0).getReg();
1554   Register Ptr = MI.getOperand(1).getReg();
1555   Register Incr = MI.getOperand(2).getReg();
1556   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1557 
1558   MachineBasicBlock::iterator II(MI);
1559 
1560   // The scratch registers here with the EarlyClobber | Define | Implicit
1561   // flags is used to persuade the register allocator and the machine
1562   // verifier to accept the usage of this register. This has to be a real
1563   // register which has an UNDEF value but is dead after the instruction which
1564   // is unique among the registers chosen for the instruction.
1565 
1566   // The EarlyClobber flag has the semantic properties that the operand it is
1567   // attached to is clobbered before the rest of the inputs are read. Hence it
1568   // must be unique among the operands to the instruction.
1569   // The Define flag is needed to coerce the machine verifier that an Undef
1570   // value isn't a problem.
1571   // The Dead flag is needed as the value in scratch isn't used by any other
1572   // instruction. Kill isn't used as Dead is more precise.
1573   // The implicit flag is here due to the interaction between the other flags
1574   // and the machine verifier.
1575 
1576   // For correctness purpose, a new pseudo is introduced here. We need this
1577   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1578   // that is spread over >1 basic blocks. A register allocator which
1579   // introduces (or any codegen infact) a store, can violate the expectations
1580   // of the hardware.
1581   //
1582   // An atomic read-modify-write sequence starts with a linked load
1583   // instruction and ends with a store conditional instruction. The atomic
1584   // read-modify-write sequence fails if any of the following conditions
1585   // occur between the execution of ll and sc:
1586   //   * A coherent store is completed by another process or coherent I/O
1587   //     module into the block of synchronizable physical memory containing
1588   //     the word. The size and alignment of the block is
1589   //     implementation-dependent.
1590   //   * A coherent store is executed between an LL and SC sequence on the
1591   //     same processor to the block of synchornizable physical memory
1592   //     containing the word.
1593   //
1594 
1595   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1596   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1597 
1598   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1599   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1600 
1601   MachineInstrBuilder MIB =
1602       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1603           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1604           .addReg(PtrCopy)
1605           .addReg(IncrCopy)
1606           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1607                                RegState::Implicit | RegState::Dead);
1608   if (NeedsAdditionalReg) {
1609     Register Scratch2 =
1610         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1611     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1612                              RegState::Implicit | RegState::Dead);
1613   }
1614 
1615   MI.eraseFromParent();
1616 
1617   return BB;
1618 }
1619 
1620 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1621     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1622     unsigned SrcReg) const {
1623   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1624   const DebugLoc &DL = MI.getDebugLoc();
1625 
1626   if (Subtarget.hasMips32r2() && Size == 1) {
1627     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1628     return BB;
1629   }
1630 
1631   if (Subtarget.hasMips32r2() && Size == 2) {
1632     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1633     return BB;
1634   }
1635 
1636   MachineFunction *MF = BB->getParent();
1637   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1638   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1639   Register ScrReg = RegInfo.createVirtualRegister(RC);
1640 
1641   assert(Size < 32);
1642   int64_t ShiftImm = 32 - (Size * 8);
1643 
1644   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1645   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1646 
1647   return BB;
1648 }
1649 
1650 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1651     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1652   assert((Size == 1 || Size == 2) &&
1653          "Unsupported size for EmitAtomicBinaryPartial.");
1654 
1655   MachineFunction *MF = BB->getParent();
1656   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1657   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1658   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1659   const TargetRegisterClass *RCp =
1660     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1661   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1662   DebugLoc DL = MI.getDebugLoc();
1663 
1664   Register Dest = MI.getOperand(0).getReg();
1665   Register Ptr = MI.getOperand(1).getReg();
1666   Register Incr = MI.getOperand(2).getReg();
1667 
1668   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1669   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1670   Register Mask = RegInfo.createVirtualRegister(RC);
1671   Register Mask2 = RegInfo.createVirtualRegister(RC);
1672   Register Incr2 = RegInfo.createVirtualRegister(RC);
1673   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1674   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1675   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1676   Register Scratch = RegInfo.createVirtualRegister(RC);
1677   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1678   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1679 
1680   unsigned AtomicOp = 0;
1681   bool NeedsAdditionalReg = false;
1682   switch (MI.getOpcode()) {
1683   case Mips::ATOMIC_LOAD_NAND_I8:
1684     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1685     break;
1686   case Mips::ATOMIC_LOAD_NAND_I16:
1687     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1688     break;
1689   case Mips::ATOMIC_SWAP_I8:
1690     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1691     break;
1692   case Mips::ATOMIC_SWAP_I16:
1693     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1694     break;
1695   case Mips::ATOMIC_LOAD_ADD_I8:
1696     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1697     break;
1698   case Mips::ATOMIC_LOAD_ADD_I16:
1699     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1700     break;
1701   case Mips::ATOMIC_LOAD_SUB_I8:
1702     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1703     break;
1704   case Mips::ATOMIC_LOAD_SUB_I16:
1705     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1706     break;
1707   case Mips::ATOMIC_LOAD_AND_I8:
1708     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1709     break;
1710   case Mips::ATOMIC_LOAD_AND_I16:
1711     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1712     break;
1713   case Mips::ATOMIC_LOAD_OR_I8:
1714     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1715     break;
1716   case Mips::ATOMIC_LOAD_OR_I16:
1717     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1718     break;
1719   case Mips::ATOMIC_LOAD_XOR_I8:
1720     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1721     break;
1722   case Mips::ATOMIC_LOAD_XOR_I16:
1723     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1724     break;
1725   case Mips::ATOMIC_LOAD_MIN_I8:
1726     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1727     NeedsAdditionalReg = true;
1728     break;
1729   case Mips::ATOMIC_LOAD_MIN_I16:
1730     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1731     NeedsAdditionalReg = true;
1732     break;
1733   case Mips::ATOMIC_LOAD_MAX_I8:
1734     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1735     NeedsAdditionalReg = true;
1736     break;
1737   case Mips::ATOMIC_LOAD_MAX_I16:
1738     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1739     NeedsAdditionalReg = true;
1740     break;
1741   case Mips::ATOMIC_LOAD_UMIN_I8:
1742     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1743     NeedsAdditionalReg = true;
1744     break;
1745   case Mips::ATOMIC_LOAD_UMIN_I16:
1746     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1747     NeedsAdditionalReg = true;
1748     break;
1749   case Mips::ATOMIC_LOAD_UMAX_I8:
1750     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1751     NeedsAdditionalReg = true;
1752     break;
1753   case Mips::ATOMIC_LOAD_UMAX_I16:
1754     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1755     NeedsAdditionalReg = true;
1756     break;
1757   default:
1758     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1759   }
1760 
1761   // insert new blocks after the current block
1762   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1763   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1764   MachineFunction::iterator It = ++BB->getIterator();
1765   MF->insert(It, exitMBB);
1766 
1767   // Transfer the remainder of BB and its successor edges to exitMBB.
1768   exitMBB->splice(exitMBB->begin(), BB,
1769                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1770   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1771 
1772   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1773 
1774   //  thisMBB:
1775   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1776   //    and     alignedaddr,ptr,masklsb2
1777   //    andi    ptrlsb2,ptr,3
1778   //    sll     shiftamt,ptrlsb2,3
1779   //    ori     maskupper,$0,255               # 0xff
1780   //    sll     mask,maskupper,shiftamt
1781   //    nor     mask2,$0,mask
1782   //    sll     incr2,incr,shiftamt
1783 
1784   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1785   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1786     .addReg(ABI.GetNullPtr()).addImm(-4);
1787   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1788     .addReg(Ptr).addReg(MaskLSB2);
1789   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1790       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1791   if (Subtarget.isLittle()) {
1792     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1793   } else {
1794     Register Off = RegInfo.createVirtualRegister(RC);
1795     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1796       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1797     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1798   }
1799   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1800     .addReg(Mips::ZERO).addImm(MaskImm);
1801   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1802     .addReg(MaskUpper).addReg(ShiftAmt);
1803   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1804   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1805 
1806 
1807   // The purposes of the flags on the scratch registers is explained in
1808   // emitAtomicBinary. In summary, we need a scratch register which is going to
1809   // be undef, that is unique among registers chosen for the instruction.
1810 
1811   MachineInstrBuilder MIB =
1812       BuildMI(BB, DL, TII->get(AtomicOp))
1813           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1814           .addReg(AlignedAddr)
1815           .addReg(Incr2)
1816           .addReg(Mask)
1817           .addReg(Mask2)
1818           .addReg(ShiftAmt)
1819           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1820                                RegState::Dead | RegState::Implicit)
1821           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1822                                 RegState::Dead | RegState::Implicit)
1823           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1824                                 RegState::Dead | RegState::Implicit);
1825   if (NeedsAdditionalReg) {
1826     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1827     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1828                              RegState::Dead | RegState::Implicit);
1829   }
1830 
1831   MI.eraseFromParent(); // The instruction is gone now.
1832 
1833   return exitMBB;
1834 }
1835 
1836 // Lower atomic compare and swap to a pseudo instruction, taking care to
1837 // define a scratch register for the pseudo instruction's expansion. The
1838 // instruction is expanded after the register allocator as to prevent
1839 // the insertion of stores between the linked load and the store conditional.
1840 
1841 MachineBasicBlock *
1842 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1843                                       MachineBasicBlock *BB) const {
1844 
1845   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1846           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1847          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1848 
1849   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1850 
1851   MachineFunction *MF = BB->getParent();
1852   MachineRegisterInfo &MRI = MF->getRegInfo();
1853   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1854   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1855   DebugLoc DL = MI.getDebugLoc();
1856 
1857   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1858                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1859                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1860   Register Dest = MI.getOperand(0).getReg();
1861   Register Ptr = MI.getOperand(1).getReg();
1862   Register OldVal = MI.getOperand(2).getReg();
1863   Register NewVal = MI.getOperand(3).getReg();
1864 
1865   Register Scratch = MRI.createVirtualRegister(RC);
1866   MachineBasicBlock::iterator II(MI);
1867 
1868   // We need to create copies of the various registers and kill them at the
1869   // atomic pseudo. If the copies are not made, when the atomic is expanded
1870   // after fast register allocation, the spills will end up outside of the
1871   // blocks that their values are defined in, causing livein errors.
1872 
1873   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1874   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1875   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1876 
1877   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1878   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1879   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1880 
1881   // The purposes of the flags on the scratch registers is explained in
1882   // emitAtomicBinary. In summary, we need a scratch register which is going to
1883   // be undef, that is unique among registers chosen for the instruction.
1884 
1885   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1886       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1887       .addReg(PtrCopy, RegState::Kill)
1888       .addReg(OldValCopy, RegState::Kill)
1889       .addReg(NewValCopy, RegState::Kill)
1890       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1891                            RegState::Dead | RegState::Implicit);
1892 
1893   MI.eraseFromParent(); // The instruction is gone now.
1894 
1895   return BB;
1896 }
1897 
1898 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1899     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1900   assert((Size == 1 || Size == 2) &&
1901       "Unsupported size for EmitAtomicCmpSwapPartial.");
1902 
1903   MachineFunction *MF = BB->getParent();
1904   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1905   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1906   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1907   const TargetRegisterClass *RCp =
1908     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1909   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1910   DebugLoc DL = MI.getDebugLoc();
1911 
1912   Register Dest = MI.getOperand(0).getReg();
1913   Register Ptr = MI.getOperand(1).getReg();
1914   Register CmpVal = MI.getOperand(2).getReg();
1915   Register NewVal = MI.getOperand(3).getReg();
1916 
1917   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1918   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1919   Register Mask = RegInfo.createVirtualRegister(RC);
1920   Register Mask2 = RegInfo.createVirtualRegister(RC);
1921   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1922   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1923   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1924   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1925   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1926   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1927   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1928   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1929                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
1930                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
1931 
1932   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
1933   // flags are used to coerce the register allocator and the machine verifier to
1934   // accept the usage of these registers.
1935   // The EarlyClobber flag has the semantic properties that the operand it is
1936   // attached to is clobbered before the rest of the inputs are read. Hence it
1937   // must be unique among the operands to the instruction.
1938   // The Define flag is needed to coerce the machine verifier that an Undef
1939   // value isn't a problem.
1940   // The Dead flag is needed as the value in scratch isn't used by any other
1941   // instruction. Kill isn't used as Dead is more precise.
1942   Register Scratch = RegInfo.createVirtualRegister(RC);
1943   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1944 
1945   // insert new blocks after the current block
1946   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1947   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1948   MachineFunction::iterator It = ++BB->getIterator();
1949   MF->insert(It, exitMBB);
1950 
1951   // Transfer the remainder of BB and its successor edges to exitMBB.
1952   exitMBB->splice(exitMBB->begin(), BB,
1953                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1954   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1955 
1956   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1957 
1958   //  thisMBB:
1959   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1960   //    and     alignedaddr,ptr,masklsb2
1961   //    andi    ptrlsb2,ptr,3
1962   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1963   //    sll     shiftamt,ptrlsb2,3
1964   //    ori     maskupper,$0,255               # 0xff
1965   //    sll     mask,maskupper,shiftamt
1966   //    nor     mask2,$0,mask
1967   //    andi    maskedcmpval,cmpval,255
1968   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1969   //    andi    maskednewval,newval,255
1970   //    sll     shiftednewval,maskednewval,shiftamt
1971   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1972   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1973     .addReg(ABI.GetNullPtr()).addImm(-4);
1974   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1975     .addReg(Ptr).addReg(MaskLSB2);
1976   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1977       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1978   if (Subtarget.isLittle()) {
1979     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1980   } else {
1981     Register Off = RegInfo.createVirtualRegister(RC);
1982     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1983       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1984     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1985   }
1986   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1987     .addReg(Mips::ZERO).addImm(MaskImm);
1988   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1989     .addReg(MaskUpper).addReg(ShiftAmt);
1990   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1991   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1992     .addReg(CmpVal).addImm(MaskImm);
1993   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1994     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1995   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1996     .addReg(NewVal).addImm(MaskImm);
1997   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1998     .addReg(MaskedNewVal).addReg(ShiftAmt);
1999 
2000   // The purposes of the flags on the scratch registers are explained in
2001   // emitAtomicBinary. In summary, we need a scratch register which is going to
2002   // be undef, that is unique among the register chosen for the instruction.
2003 
2004   BuildMI(BB, DL, TII->get(AtomicOp))
2005       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2006       .addReg(AlignedAddr)
2007       .addReg(Mask)
2008       .addReg(ShiftedCmpVal)
2009       .addReg(Mask2)
2010       .addReg(ShiftedNewVal)
2011       .addReg(ShiftAmt)
2012       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2013                            RegState::Dead | RegState::Implicit)
2014       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2015                             RegState::Dead | RegState::Implicit);
2016 
2017   MI.eraseFromParent(); // The instruction is gone now.
2018 
2019   return exitMBB;
2020 }
2021 
2022 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2023   // The first operand is the chain, the second is the condition, the third is
2024   // the block to branch to if the condition is true.
2025   SDValue Chain = Op.getOperand(0);
2026   SDValue Dest = Op.getOperand(2);
2027   SDLoc DL(Op);
2028 
2029   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2030   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2031 
2032   // Return if flag is not set by a floating point comparison.
2033   if (CondRes.getOpcode() != MipsISD::FPCmp)
2034     return Op;
2035 
2036   SDValue CCNode  = CondRes.getOperand(2);
2037   Mips::CondCode CC =
2038     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
2039   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2040   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2041   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2042   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2043                      FCC0, Dest, CondRes);
2044 }
2045 
2046 SDValue MipsTargetLowering::
2047 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2048 {
2049   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2050   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2051 
2052   // Return if flag is not set by a floating point comparison.
2053   if (Cond.getOpcode() != MipsISD::FPCmp)
2054     return Op;
2055 
2056   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2057                       SDLoc(Op));
2058 }
2059 
2060 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2061   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2062   SDValue Cond = createFPCmp(DAG, Op);
2063 
2064   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2065          "Floating point operand expected.");
2066 
2067   SDLoc DL(Op);
2068   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2069   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2070 
2071   return createCMovFP(DAG, Cond, True, False, DL);
2072 }
2073 
2074 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2075                                                SelectionDAG &DAG) const {
2076   EVT Ty = Op.getValueType();
2077   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2078   const GlobalValue *GV = N->getGlobal();
2079 
2080   if (!isPositionIndependent()) {
2081     const MipsTargetObjectFile *TLOF =
2082         static_cast<const MipsTargetObjectFile *>(
2083             getTargetMachine().getObjFileLowering());
2084     const GlobalObject *GO = GV->getAliaseeObject();
2085     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2086       // %gp_rel relocation
2087       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2088 
2089                                 // %hi/%lo relocation
2090     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2091                                 // %highest/%higher/%hi/%lo relocation
2092                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2093   }
2094 
2095   // Every other architecture would use shouldAssumeDSOLocal in here, but
2096   // mips is special.
2097   // * In PIC code mips requires got loads even for local statics!
2098   // * To save on got entries, for local statics the got entry contains the
2099   //   page and an additional add instruction takes care of the low bits.
2100   // * It is legal to access a hidden symbol with a non hidden undefined,
2101   //   so one cannot guarantee that all access to a hidden symbol will know
2102   //   it is hidden.
2103   // * Mips linkers don't support creating a page and a full got entry for
2104   //   the same symbol.
2105   // * Given all that, we have to use a full got entry for hidden symbols :-(
2106   if (GV->hasLocalLinkage())
2107     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2108 
2109   if (Subtarget.useXGOT())
2110     return getAddrGlobalLargeGOT(
2111         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2112         DAG.getEntryNode(),
2113         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2114 
2115   return getAddrGlobal(
2116       N, SDLoc(N), Ty, DAG,
2117       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2118       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2119 }
2120 
2121 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2122                                               SelectionDAG &DAG) const {
2123   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2124   EVT Ty = Op.getValueType();
2125 
2126   if (!isPositionIndependent())
2127     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2128                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2129 
2130   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2131 }
2132 
2133 SDValue MipsTargetLowering::
2134 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2135 {
2136   // If the relocation model is PIC, use the General Dynamic TLS Model or
2137   // Local Dynamic TLS model, otherwise use the Initial Exec or
2138   // Local Exec TLS Model.
2139 
2140   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2141   if (DAG.getTarget().useEmulatedTLS())
2142     return LowerToTLSEmulatedModel(GA, DAG);
2143 
2144   SDLoc DL(GA);
2145   const GlobalValue *GV = GA->getGlobal();
2146   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2147 
2148   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2149 
2150   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2151     // General Dynamic and Local Dynamic TLS Model.
2152     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2153                                                       : MipsII::MO_TLSGD;
2154 
2155     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2156     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2157                                    getGlobalReg(DAG, PtrVT), TGA);
2158     unsigned PtrSize = PtrVT.getSizeInBits();
2159     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2160 
2161     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2162 
2163     ArgListTy Args;
2164     ArgListEntry Entry;
2165     Entry.Node = Argument;
2166     Entry.Ty = PtrTy;
2167     Args.push_back(Entry);
2168 
2169     TargetLowering::CallLoweringInfo CLI(DAG);
2170     CLI.setDebugLoc(DL)
2171         .setChain(DAG.getEntryNode())
2172         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2173     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2174 
2175     SDValue Ret = CallResult.first;
2176 
2177     if (model != TLSModel::LocalDynamic)
2178       return Ret;
2179 
2180     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2181                                                MipsII::MO_DTPREL_HI);
2182     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2183     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2184                                                MipsII::MO_DTPREL_LO);
2185     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2186     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2187     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2188   }
2189 
2190   SDValue Offset;
2191   if (model == TLSModel::InitialExec) {
2192     // Initial Exec TLS Model
2193     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2194                                              MipsII::MO_GOTTPREL);
2195     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2196                       TGA);
2197     Offset =
2198         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2199   } else {
2200     // Local Exec TLS Model
2201     assert(model == TLSModel::LocalExec);
2202     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2203                                                MipsII::MO_TPREL_HI);
2204     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2205                                                MipsII::MO_TPREL_LO);
2206     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2207     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2208     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2209   }
2210 
2211   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2212   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2213 }
2214 
2215 SDValue MipsTargetLowering::
2216 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2217 {
2218   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2219   EVT Ty = Op.getValueType();
2220 
2221   if (!isPositionIndependent())
2222     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2223                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2224 
2225   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2226 }
2227 
2228 SDValue MipsTargetLowering::
2229 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2230 {
2231   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2232   EVT Ty = Op.getValueType();
2233 
2234   if (!isPositionIndependent()) {
2235     const MipsTargetObjectFile *TLOF =
2236         static_cast<const MipsTargetObjectFile *>(
2237             getTargetMachine().getObjFileLowering());
2238 
2239     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2240                                        getTargetMachine()))
2241       // %gp_rel relocation
2242       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2243 
2244     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2245                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2246   }
2247 
2248  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2249 }
2250 
2251 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2252   MachineFunction &MF = DAG.getMachineFunction();
2253   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2254 
2255   SDLoc DL(Op);
2256   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2257                                  getPointerTy(MF.getDataLayout()));
2258 
2259   // vastart just stores the address of the VarArgsFrameIndex slot into the
2260   // memory location argument.
2261   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2262   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2263                       MachinePointerInfo(SV));
2264 }
2265 
2266 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2267   SDNode *Node = Op.getNode();
2268   EVT VT = Node->getValueType(0);
2269   SDValue Chain = Node->getOperand(0);
2270   SDValue VAListPtr = Node->getOperand(1);
2271   const Align Align =
2272       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2273   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2274   SDLoc DL(Node);
2275   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2276 
2277   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2278                                    VAListPtr, MachinePointerInfo(SV));
2279   SDValue VAList = VAListLoad;
2280 
2281   // Re-align the pointer if necessary.
2282   // It should only ever be necessary for 64-bit types on O32 since the minimum
2283   // argument alignment is the same as the maximum type alignment for N32/N64.
2284   //
2285   // FIXME: We currently align too often. The code generator doesn't notice
2286   //        when the pointer is still aligned from the last va_arg (or pair of
2287   //        va_args for the i64 on O32 case).
2288   if (Align > getMinStackArgumentAlignment()) {
2289     VAList = DAG.getNode(
2290         ISD::ADD, DL, VAList.getValueType(), VAList,
2291         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2292 
2293     VAList = DAG.getNode(
2294         ISD::AND, DL, VAList.getValueType(), VAList,
2295         DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
2296   }
2297 
2298   // Increment the pointer, VAList, to the next vaarg.
2299   auto &TD = DAG.getDataLayout();
2300   unsigned ArgSizeInBytes =
2301       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2302   SDValue Tmp3 =
2303       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2304                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2305                                   DL, VAList.getValueType()));
2306   // Store the incremented VAList to the legalized pointer
2307   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2308                        MachinePointerInfo(SV));
2309 
2310   // In big-endian mode we must adjust the pointer when the load size is smaller
2311   // than the argument slot size. We must also reduce the known alignment to
2312   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2313   // the correct half of the slot, and reduce the alignment from 8 (slot
2314   // alignment) down to 4 (type alignment).
2315   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2316     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2317     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2318                          DAG.getIntPtrConstant(Adjustment, DL));
2319   }
2320   // Load the actual argument out of the pointer VAList
2321   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2322 }
2323 
2324 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2325                                 bool HasExtractInsert) {
2326   EVT TyX = Op.getOperand(0).getValueType();
2327   EVT TyY = Op.getOperand(1).getValueType();
2328   SDLoc DL(Op);
2329   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2330   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2331   SDValue Res;
2332 
2333   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2334   // to i32.
2335   SDValue X = (TyX == MVT::f32) ?
2336     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2337     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2338                 Const1);
2339   SDValue Y = (TyY == MVT::f32) ?
2340     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2341     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2342                 Const1);
2343 
2344   if (HasExtractInsert) {
2345     // ext  E, Y, 31, 1  ; extract bit31 of Y
2346     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2347     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2348     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2349   } else {
2350     // sll SllX, X, 1
2351     // srl SrlX, SllX, 1
2352     // srl SrlY, Y, 31
2353     // sll SllY, SrlX, 31
2354     // or  Or, SrlX, SllY
2355     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2356     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2357     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2358     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2359     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2360   }
2361 
2362   if (TyX == MVT::f32)
2363     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2364 
2365   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2366                              Op.getOperand(0),
2367                              DAG.getConstant(0, DL, MVT::i32));
2368   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2369 }
2370 
2371 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2372                                 bool HasExtractInsert) {
2373   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2374   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2375   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2376   SDLoc DL(Op);
2377   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2378 
2379   // Bitcast to integer nodes.
2380   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2381   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2382 
2383   if (HasExtractInsert) {
2384     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2385     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2386     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2387                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2388 
2389     if (WidthX > WidthY)
2390       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2391     else if (WidthY > WidthX)
2392       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2393 
2394     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2395                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2396                             X);
2397     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2398   }
2399 
2400   // (d)sll SllX, X, 1
2401   // (d)srl SrlX, SllX, 1
2402   // (d)srl SrlY, Y, width(Y)-1
2403   // (d)sll SllY, SrlX, width(Y)-1
2404   // or     Or, SrlX, SllY
2405   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2406   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2407   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2408                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2409 
2410   if (WidthX > WidthY)
2411     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2412   else if (WidthY > WidthX)
2413     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2414 
2415   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2416                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2417   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2418   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2419 }
2420 
2421 SDValue
2422 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2423   if (Subtarget.isGP64bit())
2424     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2425 
2426   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2427 }
2428 
2429 SDValue MipsTargetLowering::lowerFABS32(SDValue Op, SelectionDAG &DAG,
2430                                         bool HasExtractInsert) const {
2431   SDLoc DL(Op);
2432   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2433 
2434   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2435     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2436 
2437   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2438   // to i32.
2439   SDValue X = (Op.getValueType() == MVT::f32)
2440                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2441                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2442                                 Op.getOperand(0), Const1);
2443 
2444   // Clear MSB.
2445   if (HasExtractInsert)
2446     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2447                       DAG.getRegister(Mips::ZERO, MVT::i32),
2448                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2449   else {
2450     // TODO: Provide DAG patterns which transform (and x, cst)
2451     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2452     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2453     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2454   }
2455 
2456   if (Op.getValueType() == MVT::f32)
2457     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2458 
2459   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2460   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2461   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2462   // place.
2463   SDValue LowX =
2464       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2465                   DAG.getConstant(0, DL, MVT::i32));
2466   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2467 }
2468 
2469 SDValue MipsTargetLowering::lowerFABS64(SDValue Op, SelectionDAG &DAG,
2470                                         bool HasExtractInsert) const {
2471   SDLoc DL(Op);
2472   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2473 
2474   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2475     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2476 
2477   // Bitcast to integer node.
2478   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2479 
2480   // Clear MSB.
2481   if (HasExtractInsert)
2482     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2483                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2484                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2485   else {
2486     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2487     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2488   }
2489 
2490   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2491 }
2492 
2493 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2494   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2495     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2496 
2497   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2498 }
2499 
2500 SDValue MipsTargetLowering::
2501 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2502   // check the depth
2503   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2504     DAG.getContext()->emitError(
2505         "return address can be determined only for current frame");
2506     return SDValue();
2507   }
2508 
2509   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2510   MFI.setFrameAddressIsTaken(true);
2511   EVT VT = Op.getValueType();
2512   SDLoc DL(Op);
2513   SDValue FrameAddr = DAG.getCopyFromReg(
2514       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2515   return FrameAddr;
2516 }
2517 
2518 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2519                                             SelectionDAG &DAG) const {
2520   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2521     return SDValue();
2522 
2523   // check the depth
2524   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2525     DAG.getContext()->emitError(
2526         "return address can be determined only for current frame");
2527     return SDValue();
2528   }
2529 
2530   MachineFunction &MF = DAG.getMachineFunction();
2531   MachineFrameInfo &MFI = MF.getFrameInfo();
2532   MVT VT = Op.getSimpleValueType();
2533   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2534   MFI.setReturnAddressIsTaken(true);
2535 
2536   // Return RA, which contains the return address. Mark it an implicit live-in.
2537   Register Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2538   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2539 }
2540 
2541 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2542 // generated from __builtin_eh_return (offset, handler)
2543 // The effect of this is to adjust the stack pointer by "offset"
2544 // and then branch to "handler".
2545 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2546                                                                      const {
2547   MachineFunction &MF = DAG.getMachineFunction();
2548   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2549 
2550   MipsFI->setCallsEhReturn();
2551   SDValue Chain     = Op.getOperand(0);
2552   SDValue Offset    = Op.getOperand(1);
2553   SDValue Handler   = Op.getOperand(2);
2554   SDLoc DL(Op);
2555   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2556 
2557   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2558   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2559   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2560   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2561   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2562   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2563   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2564                      DAG.getRegister(OffsetReg, Ty),
2565                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2566                      Chain.getValue(1));
2567 }
2568 
2569 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2570                                               SelectionDAG &DAG) const {
2571   // FIXME: Need pseudo-fence for 'singlethread' fences
2572   // FIXME: Set SType for weaker fences where supported/appropriate.
2573   unsigned SType = 0;
2574   SDLoc DL(Op);
2575   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2576                      DAG.getConstant(SType, DL, MVT::i32));
2577 }
2578 
2579 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2580                                                 SelectionDAG &DAG) const {
2581   SDLoc DL(Op);
2582   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2583 
2584   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2585   SDValue Shamt = Op.getOperand(2);
2586   // if shamt < (VT.bits):
2587   //  lo = (shl lo, shamt)
2588   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2589   // else:
2590   //  lo = 0
2591   //  hi = (shl lo, shamt[4:0])
2592   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2593                             DAG.getConstant(-1, DL, MVT::i32));
2594   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2595                                       DAG.getConstant(1, DL, VT));
2596   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2597   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2598   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2599   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2600   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2601                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2602   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2603                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2604   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2605 
2606   SDValue Ops[2] = {Lo, Hi};
2607   return DAG.getMergeValues(Ops, DL);
2608 }
2609 
2610 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2611                                                  bool IsSRA) const {
2612   SDLoc DL(Op);
2613   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2614   SDValue Shamt = Op.getOperand(2);
2615   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2616 
2617   // if shamt < (VT.bits):
2618   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2619   //  if isSRA:
2620   //    hi = (sra hi, shamt)
2621   //  else:
2622   //    hi = (srl hi, shamt)
2623   // else:
2624   //  if isSRA:
2625   //   lo = (sra hi, shamt[4:0])
2626   //   hi = (sra hi, 31)
2627   //  else:
2628   //   lo = (srl hi, shamt[4:0])
2629   //   hi = 0
2630   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2631                             DAG.getConstant(-1, DL, MVT::i32));
2632   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2633                                      DAG.getConstant(1, DL, VT));
2634   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2635   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2636   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2637   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2638                                      DL, VT, Hi, Shamt);
2639   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2640                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2641   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2642                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2643 
2644   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2645     SDVTList VTList = DAG.getVTList(VT, VT);
2646     return DAG.getNode(Subtarget.isGP64bit() ? Mips::PseudoD_SELECT_I64
2647                                              : Mips::PseudoD_SELECT_I,
2648                        DL, VTList, Cond, ShiftRightHi,
2649                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2650                        ShiftRightHi);
2651   }
2652 
2653   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2654   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2655                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2656 
2657   SDValue Ops[2] = {Lo, Hi};
2658   return DAG.getMergeValues(Ops, DL);
2659 }
2660 
2661 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2662                             SDValue Chain, SDValue Src, unsigned Offset) {
2663   SDValue Ptr = LD->getBasePtr();
2664   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2665   EVT BasePtrVT = Ptr.getValueType();
2666   SDLoc DL(LD);
2667   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2668 
2669   if (Offset)
2670     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2671                       DAG.getConstant(Offset, DL, BasePtrVT));
2672 
2673   SDValue Ops[] = { Chain, Ptr, Src };
2674   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2675                                  LD->getMemOperand());
2676 }
2677 
2678 // Expand an unaligned 32 or 64-bit integer load node.
2679 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2680   LoadSDNode *LD = cast<LoadSDNode>(Op);
2681   EVT MemVT = LD->getMemoryVT();
2682 
2683   if (Subtarget.systemSupportsUnalignedAccess())
2684     return Op;
2685 
2686   // Return if load is aligned or if MemVT is neither i32 nor i64.
2687   if ((LD->getAlign().value() >= (MemVT.getSizeInBits() / 8)) ||
2688       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2689     return SDValue();
2690 
2691   bool IsLittle = Subtarget.isLittle();
2692   EVT VT = Op.getValueType();
2693   ISD::LoadExtType ExtType = LD->getExtensionType();
2694   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2695 
2696   assert((VT == MVT::i32) || (VT == MVT::i64));
2697 
2698   // Expand
2699   //  (set dst, (i64 (load baseptr)))
2700   // to
2701   //  (set tmp, (ldl (add baseptr, 7), undef))
2702   //  (set dst, (ldr baseptr, tmp))
2703   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2704     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2705                                IsLittle ? 7 : 0);
2706     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2707                         IsLittle ? 0 : 7);
2708   }
2709 
2710   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2711                              IsLittle ? 3 : 0);
2712   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2713                              IsLittle ? 0 : 3);
2714 
2715   // Expand
2716   //  (set dst, (i32 (load baseptr))) or
2717   //  (set dst, (i64 (sextload baseptr))) or
2718   //  (set dst, (i64 (extload baseptr)))
2719   // to
2720   //  (set tmp, (lwl (add baseptr, 3), undef))
2721   //  (set dst, (lwr baseptr, tmp))
2722   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2723       (ExtType == ISD::EXTLOAD))
2724     return LWR;
2725 
2726   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2727 
2728   // Expand
2729   //  (set dst, (i64 (zextload baseptr)))
2730   // to
2731   //  (set tmp0, (lwl (add baseptr, 3), undef))
2732   //  (set tmp1, (lwr baseptr, tmp0))
2733   //  (set tmp2, (shl tmp1, 32))
2734   //  (set dst, (srl tmp2, 32))
2735   SDLoc DL(LD);
2736   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2737   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2738   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2739   SDValue Ops[] = { SRL, LWR.getValue(1) };
2740   return DAG.getMergeValues(Ops, DL);
2741 }
2742 
2743 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2744                              SDValue Chain, unsigned Offset) {
2745   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2746   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2747   SDLoc DL(SD);
2748   SDVTList VTList = DAG.getVTList(MVT::Other);
2749 
2750   if (Offset)
2751     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2752                       DAG.getConstant(Offset, DL, BasePtrVT));
2753 
2754   SDValue Ops[] = { Chain, Value, Ptr };
2755   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2756                                  SD->getMemOperand());
2757 }
2758 
2759 // Expand an unaligned 32 or 64-bit integer store node.
2760 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2761                                       bool IsLittle) {
2762   SDValue Value = SD->getValue(), Chain = SD->getChain();
2763   EVT VT = Value.getValueType();
2764 
2765   // Expand
2766   //  (store val, baseptr) or
2767   //  (truncstore val, baseptr)
2768   // to
2769   //  (swl val, (add baseptr, 3))
2770   //  (swr val, baseptr)
2771   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2772     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2773                                 IsLittle ? 3 : 0);
2774     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2775   }
2776 
2777   assert(VT == MVT::i64);
2778 
2779   // Expand
2780   //  (store val, baseptr)
2781   // to
2782   //  (sdl val, (add baseptr, 7))
2783   //  (sdr val, baseptr)
2784   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2785   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2786 }
2787 
2788 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2789 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2790                                      bool SingleFloat) {
2791   SDValue Val = SD->getValue();
2792 
2793   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2794       (Val.getValueSizeInBits() > 32 && SingleFloat))
2795     return SDValue();
2796 
2797   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2798   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2799                            Val.getOperand(0));
2800   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2801                       SD->getPointerInfo(), SD->getAlign(),
2802                       SD->getMemOperand()->getFlags());
2803 }
2804 
2805 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2806   StoreSDNode *SD = cast<StoreSDNode>(Op);
2807   EVT MemVT = SD->getMemoryVT();
2808 
2809   // Lower unaligned integer stores.
2810   if (!Subtarget.systemSupportsUnalignedAccess() &&
2811       (SD->getAlign().value() < (MemVT.getSizeInBits() / 8)) &&
2812       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2813     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2814 
2815   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2816 }
2817 
2818 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2819                                               SelectionDAG &DAG) const {
2820 
2821   // Return a fixed StackObject with offset 0 which points to the old stack
2822   // pointer.
2823   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2824   EVT ValTy = Op->getValueType(0);
2825   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2826   return DAG.getFrameIndex(FI, ValTy);
2827 }
2828 
2829 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2830                                             SelectionDAG &DAG) const {
2831   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2832     return SDValue();
2833 
2834   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2835   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2836                               Op.getOperand(0));
2837   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2838 }
2839 
2840 //===----------------------------------------------------------------------===//
2841 //                      Calling Convention Implementation
2842 //===----------------------------------------------------------------------===//
2843 
2844 //===----------------------------------------------------------------------===//
2845 // TODO: Implement a generic logic using tblgen that can support this.
2846 // Mips O32 ABI rules:
2847 // ---
2848 // i32 - Passed in A0, A1, A2, A3 and stack
2849 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2850 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2851 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2852 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2853 //       not used, it must be shadowed. If only A3 is available, shadow it and
2854 //       go to stack.
2855 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2856 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2857 //         with the remainder spilled to the stack.
2858 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2859 //         spilling the remainder to the stack.
2860 //
2861 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2862 //===----------------------------------------------------------------------===//
2863 
2864 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2865                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2866                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2867   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2868       State.getMachineFunction().getSubtarget());
2869 
2870   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2871 
2872   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2873 
2874   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2875 
2876   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2877 
2878   // Do not process byval args here.
2879   if (ArgFlags.isByVal())
2880     return true;
2881 
2882   // Promote i8 and i16
2883   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2884     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2885       LocVT = MVT::i32;
2886       if (ArgFlags.isSExt())
2887         LocInfo = CCValAssign::SExtUpper;
2888       else if (ArgFlags.isZExt())
2889         LocInfo = CCValAssign::ZExtUpper;
2890       else
2891         LocInfo = CCValAssign::AExtUpper;
2892     }
2893   }
2894 
2895   // Promote i8 and i16
2896   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2897     LocVT = MVT::i32;
2898     if (ArgFlags.isSExt())
2899       LocInfo = CCValAssign::SExt;
2900     else if (ArgFlags.isZExt())
2901       LocInfo = CCValAssign::ZExt;
2902     else
2903       LocInfo = CCValAssign::AExt;
2904   }
2905 
2906   unsigned Reg;
2907 
2908   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2909   // is true: function is vararg, argument is 3rd or higher, there is previous
2910   // argument which is not f32 or f64.
2911   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2912                                 State.getFirstUnallocated(F32Regs) != ValNo;
2913   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
2914   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
2915   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2916 
2917   // The MIPS vector ABI for floats passes them in a pair of registers
2918   if (ValVT == MVT::i32 && isVectorFloat) {
2919     // This is the start of an vector that was scalarized into an unknown number
2920     // of components. It doesn't matter how many there are. Allocate one of the
2921     // notional 8 byte aligned registers which map onto the argument stack, and
2922     // shadow the register lost to alignment requirements.
2923     if (ArgFlags.isSplit()) {
2924       Reg = State.AllocateReg(FloatVectorIntRegs);
2925       if (Reg == Mips::A2)
2926         State.AllocateReg(Mips::A1);
2927       else if (Reg == 0)
2928         State.AllocateReg(Mips::A3);
2929     } else {
2930       // If we're an intermediate component of the split, we can just attempt to
2931       // allocate a register directly.
2932       Reg = State.AllocateReg(IntRegs);
2933     }
2934   } else if (ValVT == MVT::i32 ||
2935              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2936     Reg = State.AllocateReg(IntRegs);
2937     // If this is the first part of an i64 arg,
2938     // the allocated register must be either A0 or A2.
2939     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2940       Reg = State.AllocateReg(IntRegs);
2941     LocVT = MVT::i32;
2942   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2943     LocVT = MVT::i32;
2944 
2945     // Allocate int register and shadow next int register. If first
2946     // available register is Mips::A1 or Mips::A3, shadow it too.
2947     Reg = State.AllocateReg(IntRegs);
2948     if (Reg == Mips::A1 || Reg == Mips::A3)
2949       Reg = State.AllocateReg(IntRegs);
2950 
2951     if (Reg) {
2952       State.addLoc(
2953           CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2954       MCRegister HiReg = State.AllocateReg(IntRegs);
2955       assert(HiReg);
2956       State.addLoc(
2957           CCValAssign::getCustomReg(ValNo, ValVT, HiReg, LocVT, LocInfo));
2958       return false;
2959     }
2960   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2961     // we are guaranteed to find an available float register
2962     if (ValVT == MVT::f32) {
2963       Reg = State.AllocateReg(F32Regs);
2964       // Shadow int register
2965       State.AllocateReg(IntRegs);
2966     } else {
2967       Reg = State.AllocateReg(F64Regs);
2968       // Shadow int registers
2969       unsigned Reg2 = State.AllocateReg(IntRegs);
2970       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2971         State.AllocateReg(IntRegs);
2972       State.AllocateReg(IntRegs);
2973     }
2974   } else
2975     llvm_unreachable("Cannot handle this ValVT.");
2976 
2977   if (!Reg) {
2978     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2979     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2980   } else
2981     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2982 
2983   return false;
2984 }
2985 
2986 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2987                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2988                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2989   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2990 
2991   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2992 }
2993 
2994 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2995                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2996                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2997   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2998 
2999   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
3000 }
3001 
3002 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
3003                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
3004                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
3005 
3006 #include "MipsGenCallingConv.inc"
3007 
3008  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
3009    return CC_Mips_FixedArg;
3010  }
3011 
3012  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3013    return RetCC_Mips;
3014  }
3015 //===----------------------------------------------------------------------===//
3016 //                  Call Calling Convention Implementation
3017 //===----------------------------------------------------------------------===//
3018 
3019 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3020                                            SDValue Chain, SDValue Arg,
3021                                            const SDLoc &DL, bool IsTailCall,
3022                                            SelectionDAG &DAG) const {
3023   if (!IsTailCall) {
3024     SDValue PtrOff =
3025         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3026                     DAG.getIntPtrConstant(Offset, DL));
3027     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3028   }
3029 
3030   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3031   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3032   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3033   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(), MaybeAlign(),
3034                       MachineMemOperand::MOVolatile);
3035 }
3036 
3037 void MipsTargetLowering::
3038 getOpndList(SmallVectorImpl<SDValue> &Ops,
3039             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3040             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3041             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3042             SDValue Chain) const {
3043   // Insert node "GP copy globalreg" before call to function.
3044   //
3045   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3046   // in PIC mode) allow symbols to be resolved via lazy binding.
3047   // The lazy binding stub requires GP to point to the GOT.
3048   // Note that we don't need GP to point to the GOT for indirect calls
3049   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3050   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3051   // used for the function (that is, Mips linker doesn't generate lazy binding
3052   // stub for a function whose address is taken in the program).
3053   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3054     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3055     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3056     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3057   }
3058 
3059   // Build a sequence of copy-to-reg nodes chained together with token
3060   // chain and flag operands which copy the outgoing args into registers.
3061   // The InFlag in necessary since all emitted instructions must be
3062   // stuck together.
3063   SDValue InFlag;
3064 
3065   for (auto &R : RegsToPass) {
3066     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, R.first, R.second, InFlag);
3067     InFlag = Chain.getValue(1);
3068   }
3069 
3070   // Add argument registers to the end of the list so that they are
3071   // known live into the call.
3072   for (auto &R : RegsToPass)
3073     Ops.push_back(CLI.DAG.getRegister(R.first, R.second.getValueType()));
3074 
3075   // Add a register mask operand representing the call-preserved registers.
3076   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3077   const uint32_t *Mask =
3078       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3079   assert(Mask && "Missing call preserved mask for calling convention");
3080   if (Subtarget.inMips16HardFloat()) {
3081     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3082       StringRef Sym = G->getGlobal()->getName();
3083       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3084       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3085         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3086       }
3087     }
3088   }
3089   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3090 
3091   if (InFlag.getNode())
3092     Ops.push_back(InFlag);
3093 }
3094 
3095 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3096                                                        SDNode *Node) const {
3097   switch (MI.getOpcode()) {
3098     default:
3099       return;
3100     case Mips::JALR:
3101     case Mips::JALRPseudo:
3102     case Mips::JALR64:
3103     case Mips::JALR64Pseudo:
3104     case Mips::JALR16_MM:
3105     case Mips::JALRC16_MMR6:
3106     case Mips::TAILCALLREG:
3107     case Mips::TAILCALLREG64:
3108     case Mips::TAILCALLR6REG:
3109     case Mips::TAILCALL64R6REG:
3110     case Mips::TAILCALLREG_MM:
3111     case Mips::TAILCALLREG_MMR6: {
3112       if (!EmitJalrReloc ||
3113           Subtarget.inMips16Mode() ||
3114           !isPositionIndependent() ||
3115           Node->getNumOperands() < 1 ||
3116           Node->getOperand(0).getNumOperands() < 2) {
3117         return;
3118       }
3119       // We are after the callee address, set by LowerCall().
3120       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3121       // symbol.
3122       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3123       StringRef Sym;
3124       if (const GlobalAddressSDNode *G =
3125               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3126         // We must not emit the R_MIPS_JALR relocation against data symbols
3127         // since this will cause run-time crashes if the linker replaces the
3128         // call instruction with a relative branch to the data symbol.
3129         if (!isa<Function>(G->getGlobal())) {
3130           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3131                             << G->getGlobal()->getName() << "\n");
3132           return;
3133         }
3134         Sym = G->getGlobal()->getName();
3135       }
3136       else if (const ExternalSymbolSDNode *ES =
3137                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3138         Sym = ES->getSymbol();
3139       }
3140 
3141       if (Sym.empty())
3142         return;
3143 
3144       MachineFunction *MF = MI.getParent()->getParent();
3145       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3146       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3147       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3148     }
3149   }
3150 }
3151 
3152 /// LowerCall - functions arguments are copied from virtual regs to
3153 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3154 SDValue
3155 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3156                               SmallVectorImpl<SDValue> &InVals) const {
3157   SelectionDAG &DAG                     = CLI.DAG;
3158   SDLoc DL                              = CLI.DL;
3159   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3160   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3161   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3162   SDValue Chain                         = CLI.Chain;
3163   SDValue Callee                        = CLI.Callee;
3164   bool &IsTailCall                      = CLI.IsTailCall;
3165   CallingConv::ID CallConv              = CLI.CallConv;
3166   bool IsVarArg                         = CLI.IsVarArg;
3167 
3168   MachineFunction &MF = DAG.getMachineFunction();
3169   MachineFrameInfo &MFI = MF.getFrameInfo();
3170   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3171   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3172   bool IsPIC = isPositionIndependent();
3173 
3174   // Analyze operands of the call, assigning locations to each operand.
3175   SmallVector<CCValAssign, 16> ArgLocs;
3176   MipsCCState CCInfo(
3177       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3178       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3179 
3180   const ExternalSymbolSDNode *ES =
3181       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3182 
3183   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3184   // is during the lowering of a call with a byval argument which produces
3185   // a call to memcpy. For the O32 case, this causes the caller to allocate
3186   // stack space for the reserved argument area for the callee, then recursively
3187   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3188   // ABIs mandate that the callee allocates the reserved argument area. We do
3189   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3190   //
3191   // If the callee has a byval argument and memcpy is used, we are mandated
3192   // to already have produced a reserved argument area for the callee for O32.
3193   // Therefore, the reserved argument area can be reused for both calls.
3194   //
3195   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3196   // present, as we have yet to hook that node onto the chain.
3197   //
3198   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3199   // case. GCC does a similar trick, in that wherever possible, it calculates
3200   // the maximum out going argument area (including the reserved area), and
3201   // preallocates the stack space on entrance to the caller.
3202   //
3203   // FIXME: We should do the same for efficiency and space.
3204 
3205   // Note: The check on the calling convention below must match
3206   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3207   bool MemcpyInByVal = ES &&
3208                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
3209                        CallConv != CallingConv::Fast &&
3210                        Chain.getOpcode() == ISD::CALLSEQ_START;
3211 
3212   // Allocate the reserved argument area. It seems strange to do this from the
3213   // caller side but removing it breaks the frame size calculation.
3214   unsigned ReservedArgArea =
3215       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3216   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3217 
3218   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3219                              ES ? ES->getSymbol() : nullptr);
3220 
3221   // Get a count of how many bytes are to be pushed on the stack.
3222   unsigned NextStackOffset = CCInfo.getNextStackOffset();
3223 
3224   // Call site info for function parameters tracking.
3225   MachineFunction::CallSiteInfo CSInfo;
3226 
3227   // Check if it's really possible to do a tail call. Restrict it to functions
3228   // that are part of this compilation unit.
3229   bool InternalLinkage = false;
3230   if (IsTailCall) {
3231     IsTailCall = isEligibleForTailCallOptimization(
3232         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
3233      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3234       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3235       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3236                      G->getGlobal()->hasPrivateLinkage() ||
3237                      G->getGlobal()->hasHiddenVisibility() ||
3238                      G->getGlobal()->hasProtectedVisibility());
3239      }
3240   }
3241   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3242     report_fatal_error("failed to perform tail call elimination on a call "
3243                        "site marked musttail");
3244 
3245   if (IsTailCall)
3246     ++NumTailCalls;
3247 
3248   // Chain is the output chain of the last Load/Store or CopyToReg node.
3249   // ByValChain is the output chain of the last Memcpy node created for copying
3250   // byval arguments to the stack.
3251   unsigned StackAlignment = TFL->getStackAlignment();
3252   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
3253 
3254   if (!(IsTailCall || MemcpyInByVal))
3255     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffset, 0, DL);
3256 
3257   SDValue StackPtr =
3258       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3259                          getPointerTy(DAG.getDataLayout()));
3260 
3261   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3262   SmallVector<SDValue, 8> MemOpChains;
3263 
3264   CCInfo.rewindByValRegsInfo();
3265 
3266   // Walk the register/memloc assignments, inserting copies/loads.
3267   for (unsigned i = 0, e = ArgLocs.size(), OutIdx = 0; i != e; ++i, ++OutIdx) {
3268     SDValue Arg = OutVals[OutIdx];
3269     CCValAssign &VA = ArgLocs[i];
3270     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3271     ISD::ArgFlagsTy Flags = Outs[OutIdx].Flags;
3272     bool UseUpperBits = false;
3273 
3274     // ByVal Arg.
3275     if (Flags.isByVal()) {
3276       unsigned FirstByValReg, LastByValReg;
3277       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3278       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3279 
3280       assert(Flags.getByValSize() &&
3281              "ByVal args of size 0 should have been ignored by front-end.");
3282       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3283       assert(!IsTailCall &&
3284              "Do not tail-call optimize if there is a byval argument.");
3285       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3286                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3287                    VA);
3288       CCInfo.nextInRegsParam();
3289       continue;
3290     }
3291 
3292     // Promote the value if needed.
3293     switch (VA.getLocInfo()) {
3294     default:
3295       llvm_unreachable("Unknown loc info!");
3296     case CCValAssign::Full:
3297       if (VA.isRegLoc()) {
3298         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3299             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3300             (ValVT == MVT::i64 && LocVT == MVT::f64))
3301           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3302         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3303           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3304                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3305           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3306                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3307           if (!Subtarget.isLittle())
3308             std::swap(Lo, Hi);
3309 
3310           assert(VA.needsCustom());
3311 
3312           Register LocRegLo = VA.getLocReg();
3313           Register LocRegHigh = ArgLocs[++i].getLocReg();
3314           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3315           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3316           continue;
3317         }
3318       }
3319       break;
3320     case CCValAssign::BCvt:
3321       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3322       break;
3323     case CCValAssign::SExtUpper:
3324       UseUpperBits = true;
3325       [[fallthrough]];
3326     case CCValAssign::SExt:
3327       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3328       break;
3329     case CCValAssign::ZExtUpper:
3330       UseUpperBits = true;
3331       [[fallthrough]];
3332     case CCValAssign::ZExt:
3333       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3334       break;
3335     case CCValAssign::AExtUpper:
3336       UseUpperBits = true;
3337       [[fallthrough]];
3338     case CCValAssign::AExt:
3339       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3340       break;
3341     }
3342 
3343     if (UseUpperBits) {
3344       unsigned ValSizeInBits = Outs[OutIdx].ArgVT.getSizeInBits();
3345       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3346       Arg = DAG.getNode(
3347           ISD::SHL, DL, VA.getLocVT(), Arg,
3348           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3349     }
3350 
3351     // Arguments that can be passed on register must be kept at
3352     // RegsToPass vector
3353     if (VA.isRegLoc()) {
3354       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3355 
3356       // If the parameter is passed through reg $D, which splits into
3357       // two physical registers, avoid creating call site info.
3358       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3359         continue;
3360 
3361       // Collect CSInfo about which register passes which parameter.
3362       const TargetOptions &Options = DAG.getTarget().Options;
3363       if (Options.SupportsDebugEntryValues)
3364         CSInfo.emplace_back(VA.getLocReg(), i);
3365 
3366       continue;
3367     }
3368 
3369     // Register can't get to this point...
3370     assert(VA.isMemLoc());
3371 
3372     // emit ISD::STORE whichs stores the
3373     // parameter value to a stack Location
3374     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3375                                          Chain, Arg, DL, IsTailCall, DAG));
3376   }
3377 
3378   // Transform all store nodes into one single node because all store
3379   // nodes are independent of each other.
3380   if (!MemOpChains.empty())
3381     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3382 
3383   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3384   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3385   // node so that legalize doesn't hack it.
3386 
3387   EVT Ty = Callee.getValueType();
3388   bool GlobalOrExternal = false, IsCallReloc = false;
3389 
3390   // The long-calls feature is ignored in case of PIC.
3391   // While we do not support -mshared / -mno-shared properly,
3392   // ignore long-calls in case of -mabicalls too.
3393   if (!Subtarget.isABICalls() && !IsPIC) {
3394     // If the function should be called using "long call",
3395     // get its address into a register to prevent using
3396     // of the `jal` instruction for the direct call.
3397     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3398       if (Subtarget.useLongCalls())
3399         Callee = Subtarget.hasSym32()
3400                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3401                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3402     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3403       bool UseLongCalls = Subtarget.useLongCalls();
3404       // If the function has long-call/far/near attribute
3405       // it overrides command line switch pased to the backend.
3406       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3407         if (F->hasFnAttribute("long-call"))
3408           UseLongCalls = true;
3409         else if (F->hasFnAttribute("short-call"))
3410           UseLongCalls = false;
3411       }
3412       if (UseLongCalls)
3413         Callee = Subtarget.hasSym32()
3414                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3415                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3416     }
3417   }
3418 
3419   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3420     if (IsPIC) {
3421       const GlobalValue *Val = G->getGlobal();
3422       InternalLinkage = Val->hasInternalLinkage();
3423 
3424       if (InternalLinkage)
3425         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3426       else if (Subtarget.useXGOT()) {
3427         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3428                                        MipsII::MO_CALL_LO16, Chain,
3429                                        FuncInfo->callPtrInfo(MF, Val));
3430         IsCallReloc = true;
3431       } else {
3432         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3433                                FuncInfo->callPtrInfo(MF, Val));
3434         IsCallReloc = true;
3435       }
3436     } else
3437       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3438                                           getPointerTy(DAG.getDataLayout()), 0,
3439                                           MipsII::MO_NO_FLAG);
3440     GlobalOrExternal = true;
3441   }
3442   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3443     const char *Sym = S->getSymbol();
3444 
3445     if (!IsPIC) // static
3446       Callee = DAG.getTargetExternalSymbol(
3447           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3448     else if (Subtarget.useXGOT()) {
3449       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3450                                      MipsII::MO_CALL_LO16, Chain,
3451                                      FuncInfo->callPtrInfo(MF, Sym));
3452       IsCallReloc = true;
3453     } else { // PIC
3454       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3455                              FuncInfo->callPtrInfo(MF, Sym));
3456       IsCallReloc = true;
3457     }
3458 
3459     GlobalOrExternal = true;
3460   }
3461 
3462   SmallVector<SDValue, 8> Ops(1, Chain);
3463   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3464 
3465   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3466               IsCallReloc, CLI, Callee, Chain);
3467 
3468   if (IsTailCall) {
3469     MF.getFrameInfo().setHasTailCall();
3470     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3471     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3472     return Ret;
3473   }
3474 
3475   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3476   SDValue InFlag = Chain.getValue(1);
3477 
3478   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3479 
3480   // Create the CALLSEQ_END node in the case of where it is not a call to
3481   // memcpy.
3482   if (!(MemcpyInByVal)) {
3483     Chain = DAG.getCALLSEQ_END(Chain, NextStackOffset, 0, InFlag, DL);
3484     InFlag = Chain.getValue(1);
3485   }
3486 
3487   // Handle result values, copying them out of physregs into vregs that we
3488   // return.
3489   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
3490                          InVals, CLI);
3491 }
3492 
3493 /// LowerCallResult - Lower the result values of a call into the
3494 /// appropriate copies out of appropriate physical registers.
3495 SDValue MipsTargetLowering::LowerCallResult(
3496     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
3497     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3498     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3499     TargetLowering::CallLoweringInfo &CLI) const {
3500   // Assign locations to each value returned by this call.
3501   SmallVector<CCValAssign, 16> RVLocs;
3502   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3503                      *DAG.getContext());
3504 
3505   const ExternalSymbolSDNode *ES =
3506       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3507   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3508                            ES ? ES->getSymbol() : nullptr);
3509 
3510   // Copy all of the result registers out of their specified physreg.
3511   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3512     CCValAssign &VA = RVLocs[i];
3513     assert(VA.isRegLoc() && "Can only return in registers!");
3514 
3515     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3516                                      RVLocs[i].getLocVT(), InFlag);
3517     Chain = Val.getValue(1);
3518     InFlag = Val.getValue(2);
3519 
3520     if (VA.isUpperBitsInLoc()) {
3521       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3522       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3523       unsigned Shift =
3524           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3525       Val = DAG.getNode(
3526           Shift, DL, VA.getLocVT(), Val,
3527           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3528     }
3529 
3530     switch (VA.getLocInfo()) {
3531     default:
3532       llvm_unreachable("Unknown loc info!");
3533     case CCValAssign::Full:
3534       break;
3535     case CCValAssign::BCvt:
3536       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3537       break;
3538     case CCValAssign::AExt:
3539     case CCValAssign::AExtUpper:
3540       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3541       break;
3542     case CCValAssign::ZExt:
3543     case CCValAssign::ZExtUpper:
3544       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3545                         DAG.getValueType(VA.getValVT()));
3546       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3547       break;
3548     case CCValAssign::SExt:
3549     case CCValAssign::SExtUpper:
3550       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3551                         DAG.getValueType(VA.getValVT()));
3552       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3553       break;
3554     }
3555 
3556     InVals.push_back(Val);
3557   }
3558 
3559   return Chain;
3560 }
3561 
3562 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3563                                       EVT ArgVT, const SDLoc &DL,
3564                                       SelectionDAG &DAG) {
3565   MVT LocVT = VA.getLocVT();
3566   EVT ValVT = VA.getValVT();
3567 
3568   // Shift into the upper bits if necessary.
3569   switch (VA.getLocInfo()) {
3570   default:
3571     break;
3572   case CCValAssign::AExtUpper:
3573   case CCValAssign::SExtUpper:
3574   case CCValAssign::ZExtUpper: {
3575     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3576     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3577     unsigned Opcode =
3578         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3579     Val = DAG.getNode(
3580         Opcode, DL, VA.getLocVT(), Val,
3581         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3582     break;
3583   }
3584   }
3585 
3586   // If this is an value smaller than the argument slot size (32-bit for O32,
3587   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3588   // size. Extract the value and insert any appropriate assertions regarding
3589   // sign/zero extension.
3590   switch (VA.getLocInfo()) {
3591   default:
3592     llvm_unreachable("Unknown loc info!");
3593   case CCValAssign::Full:
3594     break;
3595   case CCValAssign::AExtUpper:
3596   case CCValAssign::AExt:
3597     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3598     break;
3599   case CCValAssign::SExtUpper:
3600   case CCValAssign::SExt:
3601     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3602     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3603     break;
3604   case CCValAssign::ZExtUpper:
3605   case CCValAssign::ZExt:
3606     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3607     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3608     break;
3609   case CCValAssign::BCvt:
3610     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3611     break;
3612   }
3613 
3614   return Val;
3615 }
3616 
3617 //===----------------------------------------------------------------------===//
3618 //             Formal Arguments Calling Convention Implementation
3619 //===----------------------------------------------------------------------===//
3620 /// LowerFormalArguments - transform physical registers into virtual registers
3621 /// and generate load operations for arguments places on the stack.
3622 SDValue MipsTargetLowering::LowerFormalArguments(
3623     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3624     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3625     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3626   MachineFunction &MF = DAG.getMachineFunction();
3627   MachineFrameInfo &MFI = MF.getFrameInfo();
3628   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3629 
3630   MipsFI->setVarArgsFrameIndex(0);
3631 
3632   // Used with vargs to acumulate store chains.
3633   std::vector<SDValue> OutChains;
3634 
3635   // Assign locations to all of the incoming arguments.
3636   SmallVector<CCValAssign, 16> ArgLocs;
3637   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3638                      *DAG.getContext());
3639   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3640   const Function &Func = DAG.getMachineFunction().getFunction();
3641   Function::const_arg_iterator FuncArg = Func.arg_begin();
3642 
3643   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3644     report_fatal_error(
3645         "Functions with the interrupt attribute cannot have arguments!");
3646 
3647   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3648   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3649                            CCInfo.getInRegsParamsCount() > 0);
3650 
3651   unsigned CurArgIdx = 0;
3652   CCInfo.rewindByValRegsInfo();
3653 
3654   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3655     CCValAssign &VA = ArgLocs[i];
3656     if (Ins[InsIdx].isOrigArg()) {
3657       std::advance(FuncArg, Ins[InsIdx].getOrigArgIndex() - CurArgIdx);
3658       CurArgIdx = Ins[InsIdx].getOrigArgIndex();
3659     }
3660     EVT ValVT = VA.getValVT();
3661     ISD::ArgFlagsTy Flags = Ins[InsIdx].Flags;
3662     bool IsRegLoc = VA.isRegLoc();
3663 
3664     if (Flags.isByVal()) {
3665       assert(Ins[InsIdx].isOrigArg() && "Byval arguments cannot be implicit");
3666       unsigned FirstByValReg, LastByValReg;
3667       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3668       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3669 
3670       assert(Flags.getByValSize() &&
3671              "ByVal args of size 0 should have been ignored by front-end.");
3672       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3673       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3674                     FirstByValReg, LastByValReg, VA, CCInfo);
3675       CCInfo.nextInRegsParam();
3676       continue;
3677     }
3678 
3679     // Arguments stored on registers
3680     if (IsRegLoc) {
3681       MVT RegVT = VA.getLocVT();
3682       Register ArgReg = VA.getLocReg();
3683       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3684 
3685       // Transform the arguments stored on
3686       // physical registers into virtual ones
3687       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3688       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3689 
3690       ArgValue =
3691           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3692 
3693       // Handle floating point arguments passed in integer registers and
3694       // long double arguments passed in floating point registers.
3695       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3696           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3697           (RegVT == MVT::f64 && ValVT == MVT::i64))
3698         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3699       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3700                ValVT == MVT::f64) {
3701         assert(VA.needsCustom() && "Expected custom argument for f64 split");
3702         CCValAssign &NextVA = ArgLocs[++i];
3703         unsigned Reg2 =
3704             addLiveIn(DAG.getMachineFunction(), NextVA.getLocReg(), RC);
3705         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3706         if (!Subtarget.isLittle())
3707           std::swap(ArgValue, ArgValue2);
3708         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3709                                ArgValue, ArgValue2);
3710       }
3711 
3712       InVals.push_back(ArgValue);
3713     } else { // VA.isRegLoc()
3714       MVT LocVT = VA.getLocVT();
3715 
3716       assert(!VA.needsCustom() && "unexpected custom memory argument");
3717 
3718       if (ABI.IsO32()) {
3719         // We ought to be able to use LocVT directly but O32 sets it to i32
3720         // when allocating floating point values to integer registers.
3721         // This shouldn't influence how we load the value into registers unless
3722         // we are targeting softfloat.
3723         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3724           LocVT = VA.getValVT();
3725       }
3726 
3727       // Only arguments pased on the stack should make it here.
3728       assert(VA.isMemLoc());
3729 
3730       // The stack pointer offset is relative to the caller stack frame.
3731       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3732                                      VA.getLocMemOffset(), true);
3733 
3734       // Create load nodes to retrieve arguments from the stack
3735       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3736       SDValue ArgValue = DAG.getLoad(
3737           LocVT, DL, Chain, FIN,
3738           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3739       OutChains.push_back(ArgValue.getValue(1));
3740 
3741       ArgValue =
3742           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3743 
3744       InVals.push_back(ArgValue);
3745     }
3746   }
3747 
3748   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3749 
3750     if (ArgLocs[i].needsCustom()) {
3751       ++i;
3752       continue;
3753     }
3754 
3755     // The mips ABIs for returning structs by value requires that we copy
3756     // the sret argument into $v0 for the return. Save the argument into
3757     // a virtual register so that we can access it from the return points.
3758     if (Ins[InsIdx].Flags.isSRet()) {
3759       unsigned Reg = MipsFI->getSRetReturnReg();
3760       if (!Reg) {
3761         Reg = MF.getRegInfo().createVirtualRegister(
3762             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3763         MipsFI->setSRetReturnReg(Reg);
3764       }
3765       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3766       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3767       break;
3768     }
3769   }
3770 
3771   if (IsVarArg)
3772     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3773 
3774   // All stores are grouped in one node to allow the matching between
3775   // the size of Ins and InVals. This only happens when on varg functions
3776   if (!OutChains.empty()) {
3777     OutChains.push_back(Chain);
3778     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3779   }
3780 
3781   return Chain;
3782 }
3783 
3784 //===----------------------------------------------------------------------===//
3785 //               Return Value Calling Convention Implementation
3786 //===----------------------------------------------------------------------===//
3787 
3788 bool
3789 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3790                                    MachineFunction &MF, bool IsVarArg,
3791                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3792                                    LLVMContext &Context) const {
3793   SmallVector<CCValAssign, 16> RVLocs;
3794   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3795   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3796 }
3797 
3798 bool MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type,
3799                                                        bool IsSigned) const {
3800   if ((ABI.IsN32() || ABI.IsN64()) && Type == MVT::i32)
3801       return true;
3802 
3803   return IsSigned;
3804 }
3805 
3806 SDValue
3807 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3808                                          const SDLoc &DL,
3809                                          SelectionDAG &DAG) const {
3810   MachineFunction &MF = DAG.getMachineFunction();
3811   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3812 
3813   MipsFI->setISR();
3814 
3815   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3816 }
3817 
3818 SDValue
3819 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3820                                 bool IsVarArg,
3821                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3822                                 const SmallVectorImpl<SDValue> &OutVals,
3823                                 const SDLoc &DL, SelectionDAG &DAG) const {
3824   // CCValAssign - represent the assignment of
3825   // the return value to a location
3826   SmallVector<CCValAssign, 16> RVLocs;
3827   MachineFunction &MF = DAG.getMachineFunction();
3828 
3829   // CCState - Info about the registers and stack slot.
3830   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3831 
3832   // Analyze return values.
3833   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3834 
3835   SDValue Flag;
3836   SmallVector<SDValue, 4> RetOps(1, Chain);
3837 
3838   // Copy the result values into the output registers.
3839   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3840     SDValue Val = OutVals[i];
3841     CCValAssign &VA = RVLocs[i];
3842     assert(VA.isRegLoc() && "Can only return in registers!");
3843     bool UseUpperBits = false;
3844 
3845     switch (VA.getLocInfo()) {
3846     default:
3847       llvm_unreachable("Unknown loc info!");
3848     case CCValAssign::Full:
3849       break;
3850     case CCValAssign::BCvt:
3851       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3852       break;
3853     case CCValAssign::AExtUpper:
3854       UseUpperBits = true;
3855       [[fallthrough]];
3856     case CCValAssign::AExt:
3857       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3858       break;
3859     case CCValAssign::ZExtUpper:
3860       UseUpperBits = true;
3861       [[fallthrough]];
3862     case CCValAssign::ZExt:
3863       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3864       break;
3865     case CCValAssign::SExtUpper:
3866       UseUpperBits = true;
3867       [[fallthrough]];
3868     case CCValAssign::SExt:
3869       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3870       break;
3871     }
3872 
3873     if (UseUpperBits) {
3874       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3875       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3876       Val = DAG.getNode(
3877           ISD::SHL, DL, VA.getLocVT(), Val,
3878           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3879     }
3880 
3881     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3882 
3883     // Guarantee that all emitted copies are stuck together with flags.
3884     Flag = Chain.getValue(1);
3885     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3886   }
3887 
3888   // The mips ABIs for returning structs by value requires that we copy
3889   // the sret argument into $v0 for the return. We saved the argument into
3890   // a virtual register in the entry block, so now we copy the value out
3891   // and into $v0.
3892   if (MF.getFunction().hasStructRetAttr()) {
3893     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3894     unsigned Reg = MipsFI->getSRetReturnReg();
3895 
3896     if (!Reg)
3897       llvm_unreachable("sret virtual register not created in the entry block");
3898     SDValue Val =
3899         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3900     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3901 
3902     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3903     Flag = Chain.getValue(1);
3904     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3905   }
3906 
3907   RetOps[0] = Chain;  // Update chain.
3908 
3909   // Add the flag if we have it.
3910   if (Flag.getNode())
3911     RetOps.push_back(Flag);
3912 
3913   // ISRs must use "eret".
3914   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
3915     return LowerInterruptReturn(RetOps, DL, DAG);
3916 
3917   // Standard return on Mips is a "jr $ra"
3918   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3919 }
3920 
3921 //===----------------------------------------------------------------------===//
3922 //                           Mips Inline Assembly Support
3923 //===----------------------------------------------------------------------===//
3924 
3925 /// getConstraintType - Given a constraint letter, return the type of
3926 /// constraint it is for this target.
3927 MipsTargetLowering::ConstraintType
3928 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3929   // Mips specific constraints
3930   // GCC config/mips/constraints.md
3931   //
3932   // 'd' : An address register. Equivalent to r
3933   //       unless generating MIPS16 code.
3934   // 'y' : Equivalent to r; retained for
3935   //       backwards compatibility.
3936   // 'c' : A register suitable for use in an indirect
3937   //       jump. This will always be $25 for -mabicalls.
3938   // 'l' : The lo register. 1 word storage.
3939   // 'x' : The hilo register pair. Double word storage.
3940   if (Constraint.size() == 1) {
3941     switch (Constraint[0]) {
3942       default : break;
3943       case 'd':
3944       case 'y':
3945       case 'f':
3946       case 'c':
3947       case 'l':
3948       case 'x':
3949         return C_RegisterClass;
3950       case 'R':
3951         return C_Memory;
3952     }
3953   }
3954 
3955   if (Constraint == "ZC")
3956     return C_Memory;
3957 
3958   return TargetLowering::getConstraintType(Constraint);
3959 }
3960 
3961 /// Examine constraint type and operand type and determine a weight value.
3962 /// This object must already have been set up with the operand type
3963 /// and the current alternative constraint selected.
3964 TargetLowering::ConstraintWeight
3965 MipsTargetLowering::getSingleConstraintMatchWeight(
3966     AsmOperandInfo &info, const char *constraint) const {
3967   ConstraintWeight weight = CW_Invalid;
3968   Value *CallOperandVal = info.CallOperandVal;
3969     // If we don't have a value, we can't do a match,
3970     // but allow it at the lowest weight.
3971   if (!CallOperandVal)
3972     return CW_Default;
3973   Type *type = CallOperandVal->getType();
3974   // Look at the constraint type.
3975   switch (*constraint) {
3976   default:
3977     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3978     break;
3979   case 'd':
3980   case 'y':
3981     if (type->isIntegerTy())
3982       weight = CW_Register;
3983     break;
3984   case 'f': // FPU or MSA register
3985     if (Subtarget.hasMSA() && type->isVectorTy() &&
3986         type->getPrimitiveSizeInBits().getFixedValue() == 128)
3987       weight = CW_Register;
3988     else if (type->isFloatTy())
3989       weight = CW_Register;
3990     break;
3991   case 'c': // $25 for indirect jumps
3992   case 'l': // lo register
3993   case 'x': // hilo register pair
3994     if (type->isIntegerTy())
3995       weight = CW_SpecificReg;
3996     break;
3997   case 'I': // signed 16 bit immediate
3998   case 'J': // integer zero
3999   case 'K': // unsigned 16 bit immediate
4000   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4001   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4002   case 'O': // signed 15 bit immediate (+- 16383)
4003   case 'P': // immediate in the range of 65535 to 1 (inclusive)
4004     if (isa<ConstantInt>(CallOperandVal))
4005       weight = CW_Constant;
4006     break;
4007   case 'R':
4008     weight = CW_Memory;
4009     break;
4010   }
4011   return weight;
4012 }
4013 
4014 /// This is a helper function to parse a physical register string and split it
4015 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
4016 /// that is returned indicates whether parsing was successful. The second flag
4017 /// is true if the numeric part exists.
4018 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
4019                                               unsigned long long &Reg) {
4020   if (C.front() != '{' || C.back() != '}')
4021     return std::make_pair(false, false);
4022 
4023   // Search for the first numeric character.
4024   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
4025   I = std::find_if(B, E, isdigit);
4026 
4027   Prefix = StringRef(B, I - B);
4028 
4029   // The second flag is set to false if no numeric characters were found.
4030   if (I == E)
4031     return std::make_pair(true, false);
4032 
4033   // Parse the numeric characters.
4034   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
4035                         true);
4036 }
4037 
4038 EVT MipsTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
4039                                             ISD::NodeType) const {
4040   bool Cond = !Subtarget.isABI_O32() && VT.getSizeInBits() == 32;
4041   EVT MinVT = getRegisterType(Context, Cond ? MVT::i64 : MVT::i32);
4042   return VT.bitsLT(MinVT) ? MinVT : VT;
4043 }
4044 
4045 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
4046 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
4047   const TargetRegisterInfo *TRI =
4048       Subtarget.getRegisterInfo();
4049   const TargetRegisterClass *RC;
4050   StringRef Prefix;
4051   unsigned long long Reg;
4052 
4053   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
4054 
4055   if (!R.first)
4056     return std::make_pair(0U, nullptr);
4057 
4058   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
4059     // No numeric characters follow "hi" or "lo".
4060     if (R.second)
4061       return std::make_pair(0U, nullptr);
4062 
4063     RC = TRI->getRegClass(Prefix == "hi" ?
4064                           Mips::HI32RegClassID : Mips::LO32RegClassID);
4065     return std::make_pair(*(RC->begin()), RC);
4066   } else if (Prefix.startswith("$msa")) {
4067     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
4068 
4069     // No numeric characters follow the name.
4070     if (R.second)
4071       return std::make_pair(0U, nullptr);
4072 
4073     Reg = StringSwitch<unsigned long long>(Prefix)
4074               .Case("$msair", Mips::MSAIR)
4075               .Case("$msacsr", Mips::MSACSR)
4076               .Case("$msaaccess", Mips::MSAAccess)
4077               .Case("$msasave", Mips::MSASave)
4078               .Case("$msamodify", Mips::MSAModify)
4079               .Case("$msarequest", Mips::MSARequest)
4080               .Case("$msamap", Mips::MSAMap)
4081               .Case("$msaunmap", Mips::MSAUnmap)
4082               .Default(0);
4083 
4084     if (!Reg)
4085       return std::make_pair(0U, nullptr);
4086 
4087     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
4088     return std::make_pair(Reg, RC);
4089   }
4090 
4091   if (!R.second)
4092     return std::make_pair(0U, nullptr);
4093 
4094   if (Prefix == "$f") { // Parse $f0-$f31.
4095     // If the size of FP registers is 64-bit or Reg is an even number, select
4096     // the 64-bit register class. Otherwise, select the 32-bit register class.
4097     if (VT == MVT::Other)
4098       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
4099 
4100     RC = getRegClassFor(VT);
4101 
4102     if (RC == &Mips::AFGR64RegClass) {
4103       assert(Reg % 2 == 0);
4104       Reg >>= 1;
4105     }
4106   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
4107     RC = TRI->getRegClass(Mips::FCCRegClassID);
4108   else if (Prefix == "$w") { // Parse $w0-$w31.
4109     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
4110   } else { // Parse $0-$31.
4111     assert(Prefix == "$");
4112     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
4113   }
4114 
4115   assert(Reg < RC->getNumRegs());
4116   return std::make_pair(*(RC->begin() + Reg), RC);
4117 }
4118 
4119 /// Given a register class constraint, like 'r', if this corresponds directly
4120 /// to an LLVM register class, return a register of 0 and the register class
4121 /// pointer.
4122 std::pair<unsigned, const TargetRegisterClass *>
4123 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
4124                                                  StringRef Constraint,
4125                                                  MVT VT) const {
4126   if (Constraint.size() == 1) {
4127     switch (Constraint[0]) {
4128     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
4129     case 'y': // Same as 'r'. Exists for compatibility.
4130     case 'r':
4131       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8 || VT == MVT::i1) {
4132         if (Subtarget.inMips16Mode())
4133           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
4134         return std::make_pair(0U, &Mips::GPR32RegClass);
4135       }
4136       if (VT == MVT::i64 && !Subtarget.isGP64bit())
4137         return std::make_pair(0U, &Mips::GPR32RegClass);
4138       if (VT == MVT::i64 && Subtarget.isGP64bit())
4139         return std::make_pair(0U, &Mips::GPR64RegClass);
4140       // This will generate an error message
4141       return std::make_pair(0U, nullptr);
4142     case 'f': // FPU or MSA register
4143       if (VT == MVT::v16i8)
4144         return std::make_pair(0U, &Mips::MSA128BRegClass);
4145       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
4146         return std::make_pair(0U, &Mips::MSA128HRegClass);
4147       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
4148         return std::make_pair(0U, &Mips::MSA128WRegClass);
4149       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
4150         return std::make_pair(0U, &Mips::MSA128DRegClass);
4151       else if (VT == MVT::f32)
4152         return std::make_pair(0U, &Mips::FGR32RegClass);
4153       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
4154         if (Subtarget.isFP64bit())
4155           return std::make_pair(0U, &Mips::FGR64RegClass);
4156         return std::make_pair(0U, &Mips::AFGR64RegClass);
4157       }
4158       break;
4159     case 'c': // register suitable for indirect jump
4160       if (VT == MVT::i32)
4161         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
4162       if (VT == MVT::i64)
4163         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
4164       // This will generate an error message
4165       return std::make_pair(0U, nullptr);
4166     case 'l': // use the `lo` register to store values
4167               // that are no bigger than a word
4168       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
4169         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
4170       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
4171     case 'x': // use the concatenated `hi` and `lo` registers
4172               // to store doubleword values
4173       // Fixme: Not triggering the use of both hi and low
4174       // This will generate an error message
4175       return std::make_pair(0U, nullptr);
4176     }
4177   }
4178 
4179   if (!Constraint.empty()) {
4180     std::pair<unsigned, const TargetRegisterClass *> R;
4181     R = parseRegForInlineAsmConstraint(Constraint, VT);
4182 
4183     if (R.second)
4184       return R;
4185   }
4186 
4187   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
4188 }
4189 
4190 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
4191 /// vector.  If it is invalid, don't add anything to Ops.
4192 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
4193                                                      std::string &Constraint,
4194                                                      std::vector<SDValue>&Ops,
4195                                                      SelectionDAG &DAG) const {
4196   SDLoc DL(Op);
4197   SDValue Result;
4198 
4199   // Only support length 1 constraints for now.
4200   if (Constraint.length() > 1) return;
4201 
4202   char ConstraintLetter = Constraint[0];
4203   switch (ConstraintLetter) {
4204   default: break; // This will fall through to the generic implementation
4205   case 'I': // Signed 16 bit constant
4206     // If this fails, the parent routine will give an error
4207     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4208       EVT Type = Op.getValueType();
4209       int64_t Val = C->getSExtValue();
4210       if (isInt<16>(Val)) {
4211         Result = DAG.getTargetConstant(Val, DL, Type);
4212         break;
4213       }
4214     }
4215     return;
4216   case 'J': // integer zero
4217     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4218       EVT Type = Op.getValueType();
4219       int64_t Val = C->getZExtValue();
4220       if (Val == 0) {
4221         Result = DAG.getTargetConstant(0, DL, Type);
4222         break;
4223       }
4224     }
4225     return;
4226   case 'K': // unsigned 16 bit immediate
4227     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4228       EVT Type = Op.getValueType();
4229       uint64_t Val = (uint64_t)C->getZExtValue();
4230       if (isUInt<16>(Val)) {
4231         Result = DAG.getTargetConstant(Val, DL, Type);
4232         break;
4233       }
4234     }
4235     return;
4236   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4237     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4238       EVT Type = Op.getValueType();
4239       int64_t Val = C->getSExtValue();
4240       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4241         Result = DAG.getTargetConstant(Val, DL, Type);
4242         break;
4243       }
4244     }
4245     return;
4246   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4247     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4248       EVT Type = Op.getValueType();
4249       int64_t Val = C->getSExtValue();
4250       if ((Val >= -65535) && (Val <= -1)) {
4251         Result = DAG.getTargetConstant(Val, DL, Type);
4252         break;
4253       }
4254     }
4255     return;
4256   case 'O': // signed 15 bit immediate
4257     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4258       EVT Type = Op.getValueType();
4259       int64_t Val = C->getSExtValue();
4260       if ((isInt<15>(Val))) {
4261         Result = DAG.getTargetConstant(Val, DL, Type);
4262         break;
4263       }
4264     }
4265     return;
4266   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4267     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4268       EVT Type = Op.getValueType();
4269       int64_t Val = C->getSExtValue();
4270       if ((Val <= 65535) && (Val >= 1)) {
4271         Result = DAG.getTargetConstant(Val, DL, Type);
4272         break;
4273       }
4274     }
4275     return;
4276   }
4277 
4278   if (Result.getNode()) {
4279     Ops.push_back(Result);
4280     return;
4281   }
4282 
4283   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4284 }
4285 
4286 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4287                                                const AddrMode &AM, Type *Ty,
4288                                                unsigned AS,
4289                                                Instruction *I) const {
4290   // No global is ever allowed as a base.
4291   if (AM.BaseGV)
4292     return false;
4293 
4294   switch (AM.Scale) {
4295   case 0: // "r+i" or just "i", depending on HasBaseReg.
4296     break;
4297   case 1:
4298     if (!AM.HasBaseReg) // allow "r+i".
4299       break;
4300     return false; // disallow "r+r" or "r+r+i".
4301   default:
4302     return false;
4303   }
4304 
4305   return true;
4306 }
4307 
4308 bool
4309 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4310   // The Mips target isn't yet aware of offsets.
4311   return false;
4312 }
4313 
4314 EVT MipsTargetLowering::getOptimalMemOpType(
4315     const MemOp &Op, const AttributeList &FuncAttributes) const {
4316   if (Subtarget.hasMips64())
4317     return MVT::i64;
4318 
4319   return MVT::i32;
4320 }
4321 
4322 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4323                                       bool ForCodeSize) const {
4324   if (VT != MVT::f32 && VT != MVT::f64)
4325     return false;
4326   if (Imm.isNegZero())
4327     return false;
4328   return Imm.isZero();
4329 }
4330 
4331 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4332 
4333   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4334   if (ABI.IsN64() && isPositionIndependent())
4335     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4336 
4337   return TargetLowering::getJumpTableEncoding();
4338 }
4339 
4340 bool MipsTargetLowering::useSoftFloat() const {
4341   return Subtarget.useSoftFloat();
4342 }
4343 
4344 void MipsTargetLowering::copyByValRegs(
4345     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4346     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4347     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4348     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4349     MipsCCState &State) const {
4350   MachineFunction &MF = DAG.getMachineFunction();
4351   MachineFrameInfo &MFI = MF.getFrameInfo();
4352   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4353   unsigned NumRegs = LastReg - FirstReg;
4354   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4355   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4356   int FrameObjOffset;
4357   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4358 
4359   if (RegAreaSize)
4360     FrameObjOffset =
4361         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4362         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4363   else
4364     FrameObjOffset = VA.getLocMemOffset();
4365 
4366   // Create frame object.
4367   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4368   // Make the fixed object stored to mutable so that the load instructions
4369   // referencing it have their memory dependencies added.
4370   // Set the frame object as isAliased which clears the underlying objects
4371   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4372   // stores as dependencies for loads referencing this fixed object.
4373   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4374   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4375   InVals.push_back(FIN);
4376 
4377   if (!NumRegs)
4378     return;
4379 
4380   // Copy arg registers.
4381   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4382   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4383 
4384   for (unsigned I = 0; I < NumRegs; ++I) {
4385     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4386     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4387     unsigned Offset = I * GPRSizeInBytes;
4388     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4389                                    DAG.getConstant(Offset, DL, PtrTy));
4390     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4391                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4392     OutChains.push_back(Store);
4393   }
4394 }
4395 
4396 // Copy byVal arg to registers and stack.
4397 void MipsTargetLowering::passByValArg(
4398     SDValue Chain, const SDLoc &DL,
4399     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4400     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4401     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4402     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4403     const CCValAssign &VA) const {
4404   unsigned ByValSizeInBytes = Flags.getByValSize();
4405   unsigned OffsetInBytes = 0; // From beginning of struct
4406   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4407   Align Alignment =
4408       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4409   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4410       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4411   unsigned NumRegs = LastReg - FirstReg;
4412 
4413   if (NumRegs) {
4414     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4415     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4416     unsigned I = 0;
4417 
4418     // Copy words to registers.
4419     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4420       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4421                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4422       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4423                                     MachinePointerInfo(), Alignment);
4424       MemOpChains.push_back(LoadVal.getValue(1));
4425       unsigned ArgReg = ArgRegs[FirstReg + I];
4426       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4427     }
4428 
4429     // Return if the struct has been fully copied.
4430     if (ByValSizeInBytes == OffsetInBytes)
4431       return;
4432 
4433     // Copy the remainder of the byval argument with sub-word loads and shifts.
4434     if (LeftoverBytes) {
4435       SDValue Val;
4436 
4437       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4438            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4439         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4440 
4441         if (RemainingSizeInBytes < LoadSizeInBytes)
4442           continue;
4443 
4444         // Load subword.
4445         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4446                                       DAG.getConstant(OffsetInBytes, DL,
4447                                                       PtrTy));
4448         SDValue LoadVal = DAG.getExtLoad(
4449             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4450             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4451         MemOpChains.push_back(LoadVal.getValue(1));
4452 
4453         // Shift the loaded value.
4454         unsigned Shamt;
4455 
4456         if (isLittle)
4457           Shamt = TotalBytesLoaded * 8;
4458         else
4459           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4460 
4461         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4462                                     DAG.getConstant(Shamt, DL, MVT::i32));
4463 
4464         if (Val.getNode())
4465           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4466         else
4467           Val = Shift;
4468 
4469         OffsetInBytes += LoadSizeInBytes;
4470         TotalBytesLoaded += LoadSizeInBytes;
4471         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4472       }
4473 
4474       unsigned ArgReg = ArgRegs[FirstReg + I];
4475       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4476       return;
4477     }
4478   }
4479 
4480   // Copy remainder of byval arg to it with memcpy.
4481   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4482   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4483                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4484   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4485                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4486   Chain = DAG.getMemcpy(
4487       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4488       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4489       /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
4490   MemOpChains.push_back(Chain);
4491 }
4492 
4493 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4494                                          SDValue Chain, const SDLoc &DL,
4495                                          SelectionDAG &DAG,
4496                                          CCState &State) const {
4497   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4498   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4499   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4500   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4501   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4502   MachineFunction &MF = DAG.getMachineFunction();
4503   MachineFrameInfo &MFI = MF.getFrameInfo();
4504   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4505 
4506   // Offset of the first variable argument from stack pointer.
4507   int VaArgOffset;
4508 
4509   if (ArgRegs.size() == Idx)
4510     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
4511   else {
4512     VaArgOffset =
4513         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4514         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4515   }
4516 
4517   // Record the frame index of the first variable argument
4518   // which is a value necessary to VASTART.
4519   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4520   MipsFI->setVarArgsFrameIndex(FI);
4521 
4522   // Copy the integer registers that have not been used for argument passing
4523   // to the argument register save area. For O32, the save area is allocated
4524   // in the caller's stack frame, while for N32/64, it is allocated in the
4525   // callee's stack frame.
4526   for (unsigned I = Idx; I < ArgRegs.size();
4527        ++I, VaArgOffset += RegSizeInBytes) {
4528     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4529     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4530     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4531     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4532     SDValue Store =
4533         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4534     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4535         (Value *)nullptr);
4536     OutChains.push_back(Store);
4537   }
4538 }
4539 
4540 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4541                                      Align Alignment) const {
4542   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4543 
4544   assert(Size && "Byval argument's size shouldn't be 0.");
4545 
4546   Alignment = std::min(Alignment, TFL->getStackAlign());
4547 
4548   unsigned FirstReg = 0;
4549   unsigned NumRegs = 0;
4550 
4551   if (State->getCallingConv() != CallingConv::Fast) {
4552     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4553     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4554     // FIXME: The O32 case actually describes no shadow registers.
4555     const MCPhysReg *ShadowRegs =
4556         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4557 
4558     // We used to check the size as well but we can't do that anymore since
4559     // CCState::HandleByVal() rounds up the size after calling this function.
4560     assert(
4561         Alignment >= Align(RegSizeInBytes) &&
4562         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4563 
4564     FirstReg = State->getFirstUnallocated(IntArgRegs);
4565 
4566     // If Alignment > RegSizeInBytes, the first arg register must be even.
4567     // FIXME: This condition happens to do the right thing but it's not the
4568     //        right way to test it. We want to check that the stack frame offset
4569     //        of the register is aligned.
4570     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4571       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4572       ++FirstReg;
4573     }
4574 
4575     // Mark the registers allocated.
4576     Size = alignTo(Size, RegSizeInBytes);
4577     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4578          Size -= RegSizeInBytes, ++I, ++NumRegs)
4579       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4580   }
4581 
4582   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4583 }
4584 
4585 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4586                                                         MachineBasicBlock *BB,
4587                                                         bool isFPCmp,
4588                                                         unsigned Opc) const {
4589   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4590          "Subtarget already supports SELECT nodes with the use of"
4591          "conditional-move instructions.");
4592 
4593   const TargetInstrInfo *TII =
4594       Subtarget.getInstrInfo();
4595   DebugLoc DL = MI.getDebugLoc();
4596 
4597   // To "insert" a SELECT instruction, we actually have to insert the
4598   // diamond control-flow pattern.  The incoming instruction knows the
4599   // destination vreg to set, the condition code register to branch on, the
4600   // true/false values to select between, and a branch opcode to use.
4601   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4602   MachineFunction::iterator It = ++BB->getIterator();
4603 
4604   //  thisMBB:
4605   //  ...
4606   //   TrueVal = ...
4607   //   setcc r1, r2, r3
4608   //   bNE   r1, r0, copy1MBB
4609   //   fallthrough --> copy0MBB
4610   MachineBasicBlock *thisMBB  = BB;
4611   MachineFunction *F = BB->getParent();
4612   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4613   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4614   F->insert(It, copy0MBB);
4615   F->insert(It, sinkMBB);
4616 
4617   // Transfer the remainder of BB and its successor edges to sinkMBB.
4618   sinkMBB->splice(sinkMBB->begin(), BB,
4619                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4620   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4621 
4622   // Next, add the true and fallthrough blocks as its successors.
4623   BB->addSuccessor(copy0MBB);
4624   BB->addSuccessor(sinkMBB);
4625 
4626   if (isFPCmp) {
4627     // bc1[tf] cc, sinkMBB
4628     BuildMI(BB, DL, TII->get(Opc))
4629         .addReg(MI.getOperand(1).getReg())
4630         .addMBB(sinkMBB);
4631   } else {
4632     // bne rs, $0, sinkMBB
4633     BuildMI(BB, DL, TII->get(Opc))
4634         .addReg(MI.getOperand(1).getReg())
4635         .addReg(Mips::ZERO)
4636         .addMBB(sinkMBB);
4637   }
4638 
4639   //  copy0MBB:
4640   //   %FalseValue = ...
4641   //   # fallthrough to sinkMBB
4642   BB = copy0MBB;
4643 
4644   // Update machine-CFG edges
4645   BB->addSuccessor(sinkMBB);
4646 
4647   //  sinkMBB:
4648   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4649   //  ...
4650   BB = sinkMBB;
4651 
4652   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4653       .addReg(MI.getOperand(2).getReg())
4654       .addMBB(thisMBB)
4655       .addReg(MI.getOperand(3).getReg())
4656       .addMBB(copy0MBB);
4657 
4658   MI.eraseFromParent(); // The pseudo instruction is gone now.
4659 
4660   return BB;
4661 }
4662 
4663 MachineBasicBlock *
4664 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4665                                        MachineBasicBlock *BB) const {
4666   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4667          "Subtarget already supports SELECT nodes with the use of"
4668          "conditional-move instructions.");
4669 
4670   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4671   DebugLoc DL = MI.getDebugLoc();
4672 
4673   // D_SELECT substitutes two SELECT nodes that goes one after another and
4674   // have the same condition operand. On machines which don't have
4675   // conditional-move instruction, it reduces unnecessary branch instructions
4676   // which are result of using two diamond patterns that are result of two
4677   // SELECT pseudo instructions.
4678   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4679   MachineFunction::iterator It = ++BB->getIterator();
4680 
4681   //  thisMBB:
4682   //  ...
4683   //   TrueVal = ...
4684   //   setcc r1, r2, r3
4685   //   bNE   r1, r0, copy1MBB
4686   //   fallthrough --> copy0MBB
4687   MachineBasicBlock *thisMBB = BB;
4688   MachineFunction *F = BB->getParent();
4689   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4690   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4691   F->insert(It, copy0MBB);
4692   F->insert(It, sinkMBB);
4693 
4694   // Transfer the remainder of BB and its successor edges to sinkMBB.
4695   sinkMBB->splice(sinkMBB->begin(), BB,
4696                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4697   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4698 
4699   // Next, add the true and fallthrough blocks as its successors.
4700   BB->addSuccessor(copy0MBB);
4701   BB->addSuccessor(sinkMBB);
4702 
4703   // bne rs, $0, sinkMBB
4704   BuildMI(BB, DL, TII->get(Mips::BNE))
4705       .addReg(MI.getOperand(2).getReg())
4706       .addReg(Mips::ZERO)
4707       .addMBB(sinkMBB);
4708 
4709   //  copy0MBB:
4710   //   %FalseValue = ...
4711   //   # fallthrough to sinkMBB
4712   BB = copy0MBB;
4713 
4714   // Update machine-CFG edges
4715   BB->addSuccessor(sinkMBB);
4716 
4717   //  sinkMBB:
4718   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4719   //  ...
4720   BB = sinkMBB;
4721 
4722   // Use two PHI nodes to select two reults
4723   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4724       .addReg(MI.getOperand(3).getReg())
4725       .addMBB(thisMBB)
4726       .addReg(MI.getOperand(5).getReg())
4727       .addMBB(copy0MBB);
4728   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4729       .addReg(MI.getOperand(4).getReg())
4730       .addMBB(thisMBB)
4731       .addReg(MI.getOperand(6).getReg())
4732       .addMBB(copy0MBB);
4733 
4734   MI.eraseFromParent(); // The pseudo instruction is gone now.
4735 
4736   return BB;
4737 }
4738 
4739 // FIXME? Maybe this could be a TableGen attribute on some registers and
4740 // this table could be generated automatically from RegInfo.
4741 Register
4742 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4743                                       const MachineFunction &MF) const {
4744   // The Linux kernel uses $28 and sp.
4745   if (Subtarget.isGP64bit()) {
4746     Register Reg = StringSwitch<Register>(RegName)
4747                        .Case("$28", Mips::GP_64)
4748                        .Case("sp", Mips::SP_64)
4749                        .Default(Register());
4750     if (Reg)
4751       return Reg;
4752   } else {
4753     Register Reg = StringSwitch<Register>(RegName)
4754                        .Case("$28", Mips::GP)
4755                        .Case("sp", Mips::SP)
4756                        .Default(Register());
4757     if (Reg)
4758       return Reg;
4759   }
4760   report_fatal_error("Invalid register name global variable");
4761 }
4762 
4763 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4764                                                  MachineBasicBlock *BB) const {
4765   MachineFunction *MF = BB->getParent();
4766   MachineRegisterInfo &MRI = MF->getRegInfo();
4767   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4768   const bool IsLittle = Subtarget.isLittle();
4769   DebugLoc DL = MI.getDebugLoc();
4770 
4771   Register Dest = MI.getOperand(0).getReg();
4772   Register Address = MI.getOperand(1).getReg();
4773   unsigned Imm = MI.getOperand(2).getImm();
4774 
4775   MachineBasicBlock::iterator I(MI);
4776 
4777   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4778     // Mips release 6 can load from adress that is not naturally-aligned.
4779     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4780     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4781         .addDef(Temp)
4782         .addUse(Address)
4783         .addImm(Imm);
4784     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4785   } else {
4786     // Mips release 5 needs to use instructions that can load from an unaligned
4787     // memory address.
4788     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4789     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4790     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4791     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4792     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4793         .addDef(LoadHalf)
4794         .addUse(Address)
4795         .addImm(Imm + (IsLittle ? 0 : 3))
4796         .addUse(Undef);
4797     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4798         .addDef(LoadFull)
4799         .addUse(Address)
4800         .addImm(Imm + (IsLittle ? 3 : 0))
4801         .addUse(LoadHalf);
4802     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4803   }
4804 
4805   MI.eraseFromParent();
4806   return BB;
4807 }
4808 
4809 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4810                                                  MachineBasicBlock *BB) const {
4811   MachineFunction *MF = BB->getParent();
4812   MachineRegisterInfo &MRI = MF->getRegInfo();
4813   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4814   const bool IsLittle = Subtarget.isLittle();
4815   DebugLoc DL = MI.getDebugLoc();
4816 
4817   Register Dest = MI.getOperand(0).getReg();
4818   Register Address = MI.getOperand(1).getReg();
4819   unsigned Imm = MI.getOperand(2).getImm();
4820 
4821   MachineBasicBlock::iterator I(MI);
4822 
4823   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4824     // Mips release 6 can load from adress that is not naturally-aligned.
4825     if (Subtarget.isGP64bit()) {
4826       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4827       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4828           .addDef(Temp)
4829           .addUse(Address)
4830           .addImm(Imm);
4831       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4832     } else {
4833       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4834       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4835       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4836       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4837           .addDef(Lo)
4838           .addUse(Address)
4839           .addImm(Imm + (IsLittle ? 0 : 4));
4840       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4841           .addDef(Hi)
4842           .addUse(Address)
4843           .addImm(Imm + (IsLittle ? 4 : 0));
4844       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4845       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4846           .addUse(Wtemp)
4847           .addUse(Hi)
4848           .addImm(1);
4849     }
4850   } else {
4851     // Mips release 5 needs to use instructions that can load from an unaligned
4852     // memory address.
4853     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4854     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4855     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4856     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4857     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4858     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4859     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4860     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4861     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4862         .addDef(LoHalf)
4863         .addUse(Address)
4864         .addImm(Imm + (IsLittle ? 0 : 7))
4865         .addUse(LoUndef);
4866     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4867         .addDef(LoFull)
4868         .addUse(Address)
4869         .addImm(Imm + (IsLittle ? 3 : 4))
4870         .addUse(LoHalf);
4871     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4872     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4873         .addDef(HiHalf)
4874         .addUse(Address)
4875         .addImm(Imm + (IsLittle ? 4 : 3))
4876         .addUse(HiUndef);
4877     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4878         .addDef(HiFull)
4879         .addUse(Address)
4880         .addImm(Imm + (IsLittle ? 7 : 0))
4881         .addUse(HiHalf);
4882     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4883     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4884         .addUse(Wtemp)
4885         .addUse(HiFull)
4886         .addImm(1);
4887   }
4888 
4889   MI.eraseFromParent();
4890   return BB;
4891 }
4892 
4893 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4894                                                  MachineBasicBlock *BB) const {
4895   MachineFunction *MF = BB->getParent();
4896   MachineRegisterInfo &MRI = MF->getRegInfo();
4897   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4898   const bool IsLittle = Subtarget.isLittle();
4899   DebugLoc DL = MI.getDebugLoc();
4900 
4901   Register StoreVal = MI.getOperand(0).getReg();
4902   Register Address = MI.getOperand(1).getReg();
4903   unsigned Imm = MI.getOperand(2).getImm();
4904 
4905   MachineBasicBlock::iterator I(MI);
4906 
4907   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4908     // Mips release 6 can store to adress that is not naturally-aligned.
4909     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4910     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4911     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
4912     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4913         .addDef(Tmp)
4914         .addUse(BitcastW)
4915         .addImm(0);
4916     BuildMI(*BB, I, DL, TII->get(Mips::SW))
4917         .addUse(Tmp)
4918         .addUse(Address)
4919         .addImm(Imm);
4920   } else {
4921     // Mips release 5 needs to use instructions that can store to an unaligned
4922     // memory address.
4923     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4924     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4925         .addDef(Tmp)
4926         .addUse(StoreVal)
4927         .addImm(0);
4928     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4929         .addUse(Tmp)
4930         .addUse(Address)
4931         .addImm(Imm + (IsLittle ? 0 : 3));
4932     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
4933         .addUse(Tmp)
4934         .addUse(Address)
4935         .addImm(Imm + (IsLittle ? 3 : 0));
4936   }
4937 
4938   MI.eraseFromParent();
4939 
4940   return BB;
4941 }
4942 
4943 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
4944                                                  MachineBasicBlock *BB) const {
4945   MachineFunction *MF = BB->getParent();
4946   MachineRegisterInfo &MRI = MF->getRegInfo();
4947   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4948   const bool IsLittle = Subtarget.isLittle();
4949   DebugLoc DL = MI.getDebugLoc();
4950 
4951   Register StoreVal = MI.getOperand(0).getReg();
4952   Register Address = MI.getOperand(1).getReg();
4953   unsigned Imm = MI.getOperand(2).getImm();
4954 
4955   MachineBasicBlock::iterator I(MI);
4956 
4957   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4958     // Mips release 6 can store to adress that is not naturally-aligned.
4959     if (Subtarget.isGP64bit()) {
4960       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
4961       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4962       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4963           .addDef(BitcastD)
4964           .addUse(StoreVal);
4965       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
4966           .addDef(Lo)
4967           .addUse(BitcastD)
4968           .addImm(0);
4969       BuildMI(*BB, I, DL, TII->get(Mips::SD))
4970           .addUse(Lo)
4971           .addUse(Address)
4972           .addImm(Imm);
4973     } else {
4974       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4975       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4976       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4977       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4978           .addDef(BitcastW)
4979           .addUse(StoreVal);
4980       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4981           .addDef(Lo)
4982           .addUse(BitcastW)
4983           .addImm(0);
4984       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4985           .addDef(Hi)
4986           .addUse(BitcastW)
4987           .addImm(1);
4988       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4989           .addUse(Lo)
4990           .addUse(Address)
4991           .addImm(Imm + (IsLittle ? 0 : 4));
4992       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4993           .addUse(Hi)
4994           .addUse(Address)
4995           .addImm(Imm + (IsLittle ? 4 : 0));
4996     }
4997   } else {
4998     // Mips release 5 needs to use instructions that can store to an unaligned
4999     // memory address.
5000     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
5001     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5002     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5003     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
5004     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5005         .addDef(Lo)
5006         .addUse(Bitcast)
5007         .addImm(0);
5008     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5009         .addDef(Hi)
5010         .addUse(Bitcast)
5011         .addImm(1);
5012     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5013         .addUse(Lo)
5014         .addUse(Address)
5015         .addImm(Imm + (IsLittle ? 0 : 3));
5016     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5017         .addUse(Lo)
5018         .addUse(Address)
5019         .addImm(Imm + (IsLittle ? 3 : 0));
5020     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5021         .addUse(Hi)
5022         .addUse(Address)
5023         .addImm(Imm + (IsLittle ? 4 : 7));
5024     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5025         .addUse(Hi)
5026         .addUse(Address)
5027         .addImm(Imm + (IsLittle ? 7 : 4));
5028   }
5029 
5030   MI.eraseFromParent();
5031   return BB;
5032 }
5033