xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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/MachineValueType.h"
44 #include "llvm/CodeGen/RuntimeLibcalls.h"
45 #include "llvm/CodeGen/SelectionDAG.h"
46 #include "llvm/CodeGen/SelectionDAGNodes.h"
47 #include "llvm/CodeGen/TargetFrameLowering.h"
48 #include "llvm/CodeGen/TargetInstrInfo.h"
49 #include "llvm/CodeGen/TargetRegisterInfo.h"
50 #include "llvm/CodeGen/ValueTypes.h"
51 #include "llvm/IR/CallingConv.h"
52 #include "llvm/IR/Constants.h"
53 #include "llvm/IR/DataLayout.h"
54 #include "llvm/IR/DebugLoc.h"
55 #include "llvm/IR/DerivedTypes.h"
56 #include "llvm/IR/Function.h"
57 #include "llvm/IR/GlobalValue.h"
58 #include "llvm/IR/Type.h"
59 #include "llvm/IR/Value.h"
60 #include "llvm/MC/MCContext.h"
61 #include "llvm/MC/MCRegisterInfo.h"
62 #include "llvm/Support/Casting.h"
63 #include "llvm/Support/CodeGen.h"
64 #include "llvm/Support/CommandLine.h"
65 #include "llvm/Support/Compiler.h"
66 #include "llvm/Support/ErrorHandling.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   if (VT.isPow2VectorType() && VT.getVectorElementType().isRound())
106     return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
107                                                              : MVT::i64;
108   return getRegisterType(Context, VT.getVectorElementType());
109 }
110 
111 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
112                                                            CallingConv::ID CC,
113                                                            EVT VT) const {
114   if (VT.isVector()) {
115     if (VT.isPow2VectorType() && VT.getVectorElementType().isRound())
116       return divideCeil(VT.getSizeInBits(), Subtarget.isABI_O32() ? 32 : 64);
117     return VT.getVectorNumElements() *
118            getNumRegisters(Context, VT.getVectorElementType());
119   }
120   return MipsTargetLowering::getNumRegisters(Context, VT);
121 }
122 
123 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
124     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
125     unsigned &NumIntermediates, MVT &RegisterVT) const {
126   if (VT.isPow2VectorType()) {
127     IntermediateVT = getRegisterTypeForCallingConv(Context, CC, VT);
128     RegisterVT = IntermediateVT.getSimpleVT();
129     NumIntermediates = getNumRegistersForCallingConv(Context, CC, VT);
130     return NumIntermediates;
131   }
132   IntermediateVT = VT.getVectorElementType();
133   NumIntermediates = VT.getVectorNumElements();
134   RegisterVT = getRegisterType(Context, IntermediateVT);
135   return NumIntermediates * getNumRegisters(Context, IntermediateVT);
136 }
137 
138 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
139   MachineFunction &MF = DAG.getMachineFunction();
140   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
141   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
142 }
143 
144 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
145                                           SelectionDAG &DAG,
146                                           unsigned Flag) const {
147   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
148 }
149 
150 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
151                                           SelectionDAG &DAG,
152                                           unsigned Flag) const {
153   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
154 }
155 
156 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
157                                           SelectionDAG &DAG,
158                                           unsigned Flag) const {
159   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
160 }
161 
162 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
163                                           SelectionDAG &DAG,
164                                           unsigned Flag) const {
165   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
166 }
167 
168 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
169                                           SelectionDAG &DAG,
170                                           unsigned Flag) const {
171   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
172                                    N->getOffset(), Flag);
173 }
174 
175 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
176   switch ((MipsISD::NodeType)Opcode) {
177   case MipsISD::FIRST_NUMBER:      break;
178   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
179   case MipsISD::TailCall:          return "MipsISD::TailCall";
180   case MipsISD::Highest:           return "MipsISD::Highest";
181   case MipsISD::Higher:            return "MipsISD::Higher";
182   case MipsISD::Hi:                return "MipsISD::Hi";
183   case MipsISD::Lo:                return "MipsISD::Lo";
184   case MipsISD::GotHi:             return "MipsISD::GotHi";
185   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
186   case MipsISD::GPRel:             return "MipsISD::GPRel";
187   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
188   case MipsISD::Ret:               return "MipsISD::Ret";
189   case MipsISD::ERet:              return "MipsISD::ERet";
190   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
191   case MipsISD::FAbs:              return "MipsISD::FAbs";
192   case MipsISD::FMS:               return "MipsISD::FMS";
193   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
194   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
195   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
196   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
197   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
198   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
199   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
200   case MipsISD::MFHI:              return "MipsISD::MFHI";
201   case MipsISD::MFLO:              return "MipsISD::MFLO";
202   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
203   case MipsISD::Mult:              return "MipsISD::Mult";
204   case MipsISD::Multu:             return "MipsISD::Multu";
205   case MipsISD::MAdd:              return "MipsISD::MAdd";
206   case MipsISD::MAddu:             return "MipsISD::MAddu";
207   case MipsISD::MSub:              return "MipsISD::MSub";
208   case MipsISD::MSubu:             return "MipsISD::MSubu";
209   case MipsISD::DivRem:            return "MipsISD::DivRem";
210   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
211   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
212   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
213   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
214   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
215   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
216   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
217   case MipsISD::Sync:              return "MipsISD::Sync";
218   case MipsISD::Ext:               return "MipsISD::Ext";
219   case MipsISD::Ins:               return "MipsISD::Ins";
220   case MipsISD::CIns:              return "MipsISD::CIns";
221   case MipsISD::LWL:               return "MipsISD::LWL";
222   case MipsISD::LWR:               return "MipsISD::LWR";
223   case MipsISD::SWL:               return "MipsISD::SWL";
224   case MipsISD::SWR:               return "MipsISD::SWR";
225   case MipsISD::LDL:               return "MipsISD::LDL";
226   case MipsISD::LDR:               return "MipsISD::LDR";
227   case MipsISD::SDL:               return "MipsISD::SDL";
228   case MipsISD::SDR:               return "MipsISD::SDR";
229   case MipsISD::EXTP:              return "MipsISD::EXTP";
230   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
231   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
232   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
233   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
234   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
235   case MipsISD::SHILO:             return "MipsISD::SHILO";
236   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
237   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
238   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
239   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
240   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
241   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
242   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
243   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
244   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
245   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
246   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
247   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
248   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
249   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
250   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
251   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
252   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
253   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
254   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
255   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
256   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
257   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
258   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
259   case MipsISD::MULT:              return "MipsISD::MULT";
260   case MipsISD::MULTU:             return "MipsISD::MULTU";
261   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
262   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
263   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
264   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
265   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
266   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
267   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
268   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
269   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
270   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
271   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
272   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
273   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
274   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
275   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
276   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
277   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
278   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
279   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
280   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
281   case MipsISD::VNOR:              return "MipsISD::VNOR";
282   case MipsISD::VSHF:              return "MipsISD::VSHF";
283   case MipsISD::SHF:               return "MipsISD::SHF";
284   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
285   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
286   case MipsISD::ILVL:              return "MipsISD::ILVL";
287   case MipsISD::ILVR:              return "MipsISD::ILVR";
288   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
289   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
290   case MipsISD::INSVE:             return "MipsISD::INSVE";
291   }
292   return nullptr;
293 }
294 
295 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
296                                        const MipsSubtarget &STI)
297     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
298   // Mips does not have i1 type, so use i32 for
299   // setcc operations results (slt, sgt, ...).
300   setBooleanContents(ZeroOrOneBooleanContent);
301   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
302   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
303   // does. Integer booleans still use 0 and 1.
304   if (Subtarget.hasMips32r6())
305     setBooleanContents(ZeroOrOneBooleanContent,
306                        ZeroOrNegativeOneBooleanContent);
307 
308   // Load extented operations for i1 types must be promoted
309   for (MVT VT : MVT::integer_valuetypes()) {
310     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
311     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
312     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
313   }
314 
315   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
316   // for f32, f16
317   for (MVT VT : MVT::fp_valuetypes()) {
318     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
319     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
320   }
321 
322   // Set LoadExtAction for f16 vectors to Expand
323   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
324     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
325     if (F16VT.isValid())
326       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
327   }
328 
329   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
330   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
331 
332   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
333 
334   // Used by legalize types to correctly generate the setcc result.
335   // Without this, every float setcc comes with a AND/OR with the result,
336   // we don't want this, since the fpcmp result goes to a flag register,
337   // which is used implicitly by brcond and select operations.
338   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
339 
340   // Mips Custom Operations
341   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
342   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
343   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
344   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
345   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
346   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
347   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
348   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
349   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
350   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
351   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
352   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
353   setOperationAction(ISD::FABS,               MVT::f32,   Custom);
354   setOperationAction(ISD::FABS,               MVT::f64,   Custom);
355   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
356   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
357   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
358 
359   if (Subtarget.isGP64bit()) {
360     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
361     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
362     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
363     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
364     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
365     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
366     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
367     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
368     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
369     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
370     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
371     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
372   }
373 
374   if (!Subtarget.isGP64bit()) {
375     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
376     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
377     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
378   }
379 
380   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
381   if (Subtarget.isGP64bit())
382     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
383 
384   setOperationAction(ISD::SDIV, MVT::i32, Expand);
385   setOperationAction(ISD::SREM, MVT::i32, Expand);
386   setOperationAction(ISD::UDIV, MVT::i32, Expand);
387   setOperationAction(ISD::UREM, MVT::i32, Expand);
388   setOperationAction(ISD::SDIV, MVT::i64, Expand);
389   setOperationAction(ISD::SREM, MVT::i64, Expand);
390   setOperationAction(ISD::UDIV, MVT::i64, Expand);
391   setOperationAction(ISD::UREM, MVT::i64, Expand);
392 
393   // Operations not directly supported by Mips.
394   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
395   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
396   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
397   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
398   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
399   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
400   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
401   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
402   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
403   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
404   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
405   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
406   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
407   if (Subtarget.hasCnMips()) {
408     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
409     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
410   } else {
411     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
412     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
413   }
414   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
415   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
416   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
417   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
418   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
419   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
420 
421   if (!Subtarget.hasMips32r2())
422     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
423 
424   if (!Subtarget.hasMips64r2())
425     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
426 
427   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
428   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
429   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
430   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
431   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
432   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
433   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
434   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
435   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
436   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
437   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
438   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
439   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
440   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
441   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
442   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
443 
444   // Lower f16 conversion operations into library calls
445   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
446   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
447   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
448   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
449 
450   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
451 
452   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
453   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
454   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
455   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
456 
457   // Use the default for now
458   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
459   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
460 
461   if (!Subtarget.isGP64bit()) {
462     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
463     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
464   }
465 
466   if (!Subtarget.hasMips32r2()) {
467     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
468     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
469   }
470 
471   // MIPS16 lacks MIPS32's clz and clo instructions.
472   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
473     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
474   if (!Subtarget.hasMips64())
475     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
476 
477   if (!Subtarget.hasMips32r2())
478     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
479   if (!Subtarget.hasMips64r2())
480     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
481 
482   if (Subtarget.isGP64bit()) {
483     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
484     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
485     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
486     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
487   }
488 
489   setOperationAction(ISD::TRAP, MVT::Other, Legal);
490 
491   setTargetDAGCombine({ISD::SDIVREM, ISD::UDIVREM, ISD::SELECT, ISD::AND,
492                        ISD::OR, ISD::ADD, ISD::SUB, ISD::AssertZext, ISD::SHL});
493 
494   if (ABI.IsO32()) {
495     // These libcalls are not available in 32-bit.
496     setLibcallName(RTLIB::SHL_I128, nullptr);
497     setLibcallName(RTLIB::SRL_I128, nullptr);
498     setLibcallName(RTLIB::SRA_I128, nullptr);
499     setLibcallName(RTLIB::MUL_I128, nullptr);
500     setLibcallName(RTLIB::MULO_I64, nullptr);
501     setLibcallName(RTLIB::MULO_I128, nullptr);
502   }
503 
504   if (Subtarget.isGP64bit())
505     setMaxAtomicSizeInBitsSupported(64);
506   else
507     setMaxAtomicSizeInBitsSupported(32);
508 
509   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
510 
511   // The arguments on the stack are defined in terms of 4-byte slots on O32
512   // and 8-byte slots on N32/N64.
513   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
514                                                             : Align(4));
515 
516   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
517 
518   MaxStoresPerMemcpy = 16;
519 
520   isMicroMips = Subtarget.inMicroMipsMode();
521 }
522 
523 const MipsTargetLowering *
524 MipsTargetLowering::create(const MipsTargetMachine &TM,
525                            const MipsSubtarget &STI) {
526   if (STI.inMips16Mode())
527     return createMips16TargetLowering(TM, STI);
528 
529   return createMipsSETargetLowering(TM, STI);
530 }
531 
532 // Create a fast isel object.
533 FastISel *
534 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
535                                   const TargetLibraryInfo *libInfo) const {
536   const MipsTargetMachine &TM =
537       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
538 
539   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
540   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
541                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
542                      !Subtarget.inMicroMipsMode();
543 
544   // Disable if either of the following is true:
545   // We do not generate PIC, the ABI is not O32, XGOT is being used.
546   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
547       Subtarget.useXGOT())
548     UseFastISel = false;
549 
550   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
551 }
552 
553 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
554                                            EVT VT) const {
555   if (!VT.isVector())
556     return MVT::i32;
557   return VT.changeVectorElementTypeToInteger();
558 }
559 
560 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
561                                     TargetLowering::DAGCombinerInfo &DCI,
562                                     const MipsSubtarget &Subtarget) {
563   if (DCI.isBeforeLegalizeOps())
564     return SDValue();
565 
566   EVT Ty = N->getValueType(0);
567   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
568   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
569   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
570                                                   MipsISD::DivRemU16;
571   SDLoc DL(N);
572 
573   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
574                                N->getOperand(0), N->getOperand(1));
575   SDValue InChain = DAG.getEntryNode();
576   SDValue InGlue = DivRem;
577 
578   // insert MFLO
579   if (N->hasAnyUseOfValue(0)) {
580     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
581                                             InGlue);
582     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
583     InChain = CopyFromLo.getValue(1);
584     InGlue = CopyFromLo.getValue(2);
585   }
586 
587   // insert MFHI
588   if (N->hasAnyUseOfValue(1)) {
589     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
590                                             HI, Ty, InGlue);
591     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
592   }
593 
594   return SDValue();
595 }
596 
597 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
598   switch (CC) {
599   default: llvm_unreachable("Unknown fp condition code!");
600   case ISD::SETEQ:
601   case ISD::SETOEQ: return Mips::FCOND_OEQ;
602   case ISD::SETUNE: return Mips::FCOND_UNE;
603   case ISD::SETLT:
604   case ISD::SETOLT: return Mips::FCOND_OLT;
605   case ISD::SETGT:
606   case ISD::SETOGT: return Mips::FCOND_OGT;
607   case ISD::SETLE:
608   case ISD::SETOLE: return Mips::FCOND_OLE;
609   case ISD::SETGE:
610   case ISD::SETOGE: return Mips::FCOND_OGE;
611   case ISD::SETULT: return Mips::FCOND_ULT;
612   case ISD::SETULE: return Mips::FCOND_ULE;
613   case ISD::SETUGT: return Mips::FCOND_UGT;
614   case ISD::SETUGE: return Mips::FCOND_UGE;
615   case ISD::SETUO:  return Mips::FCOND_UN;
616   case ISD::SETO:   return Mips::FCOND_OR;
617   case ISD::SETNE:
618   case ISD::SETONE: return Mips::FCOND_ONE;
619   case ISD::SETUEQ: return Mips::FCOND_UEQ;
620   }
621 }
622 
623 /// This function returns true if the floating point conditional branches and
624 /// conditional moves which use condition code CC should be inverted.
625 static bool invertFPCondCodeUser(Mips::CondCode CC) {
626   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
627     return false;
628 
629   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
630          "Illegal Condition Code");
631 
632   return true;
633 }
634 
635 // Creates and returns an FPCmp node from a setcc node.
636 // Returns Op if setcc is not a floating point comparison.
637 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
638   // must be a SETCC node
639   if (Op.getOpcode() != ISD::SETCC)
640     return Op;
641 
642   SDValue LHS = Op.getOperand(0);
643 
644   if (!LHS.getValueType().isFloatingPoint())
645     return Op;
646 
647   SDValue RHS = Op.getOperand(1);
648   SDLoc DL(Op);
649 
650   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
651   // node if necessary.
652   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
653 
654   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
655                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
656 }
657 
658 // Creates and returns a CMovFPT/F node.
659 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
660                             SDValue False, const SDLoc &DL) {
661   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
662   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
663   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
664 
665   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
666                      True.getValueType(), True, FCC0, False, Cond);
667 }
668 
669 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
670                                     TargetLowering::DAGCombinerInfo &DCI,
671                                     const MipsSubtarget &Subtarget) {
672   if (DCI.isBeforeLegalizeOps())
673     return SDValue();
674 
675   SDValue SetCC = N->getOperand(0);
676 
677   if ((SetCC.getOpcode() != ISD::SETCC) ||
678       !SetCC.getOperand(0).getValueType().isInteger())
679     return SDValue();
680 
681   SDValue False = N->getOperand(2);
682   EVT FalseTy = False.getValueType();
683 
684   if (!FalseTy.isInteger())
685     return SDValue();
686 
687   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
688 
689   // If the RHS (False) is 0, we swap the order of the operands
690   // of ISD::SELECT (obviously also inverting the condition) so that we can
691   // take advantage of conditional moves using the $0 register.
692   // Example:
693   //   return (a != 0) ? x : 0;
694   //     load $reg, x
695   //     movz $reg, $0, a
696   if (!FalseC)
697     return SDValue();
698 
699   const SDLoc DL(N);
700 
701   if (!FalseC->getZExtValue()) {
702     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
703     SDValue True = N->getOperand(1);
704 
705     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
706                          SetCC.getOperand(1),
707                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
708 
709     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
710   }
711 
712   // If both operands are integer constants there's a possibility that we
713   // can do some interesting optimizations.
714   SDValue True = N->getOperand(1);
715   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
716 
717   if (!TrueC || !True.getValueType().isInteger())
718     return SDValue();
719 
720   // We'll also ignore MVT::i64 operands as this optimizations proves
721   // to be ineffective because of the required sign extensions as the result
722   // of a SETCC operator is always MVT::i32 for non-vector types.
723   if (True.getValueType() == MVT::i64)
724     return SDValue();
725 
726   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
727 
728   // 1)  (a < x) ? y : y-1
729   //  slti $reg1, a, x
730   //  addiu $reg2, $reg1, y-1
731   if (Diff == 1)
732     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
733 
734   // 2)  (a < x) ? y-1 : y
735   //  slti $reg1, a, x
736   //  xor $reg1, $reg1, 1
737   //  addiu $reg2, $reg1, y-1
738   if (Diff == -1) {
739     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
740     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
741                          SetCC.getOperand(1),
742                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
743     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
744   }
745 
746   // Could not optimize.
747   return SDValue();
748 }
749 
750 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
751                                     TargetLowering::DAGCombinerInfo &DCI,
752                                     const MipsSubtarget &Subtarget) {
753   if (DCI.isBeforeLegalizeOps())
754     return SDValue();
755 
756   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
757 
758   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
759   if (!FalseC || FalseC->getZExtValue())
760     return SDValue();
761 
762   // Since RHS (False) is 0, we swap the order of the True/False operands
763   // (obviously also inverting the condition) so that we can
764   // take advantage of conditional moves using the $0 register.
765   // Example:
766   //   return (a != 0) ? x : 0;
767   //     load $reg, x
768   //     movz $reg, $0, a
769   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
770                                                          MipsISD::CMovFP_T;
771 
772   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
773   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
774                      ValueIfFalse, FCC, ValueIfTrue, Glue);
775 }
776 
777 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
778                                  TargetLowering::DAGCombinerInfo &DCI,
779                                  const MipsSubtarget &Subtarget) {
780   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
781     return SDValue();
782 
783   SDValue FirstOperand = N->getOperand(0);
784   unsigned FirstOperandOpc = FirstOperand.getOpcode();
785   SDValue Mask = N->getOperand(1);
786   EVT ValTy = N->getValueType(0);
787   SDLoc DL(N);
788 
789   uint64_t Pos = 0;
790   unsigned SMPos, SMSize;
791   ConstantSDNode *CN;
792   SDValue NewOperand;
793   unsigned Opc;
794 
795   // Op's second operand must be a shifted mask.
796   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
797       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
798     return SDValue();
799 
800   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
801     // Pattern match EXT.
802     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
803     //  => ext $dst, $src, pos, size
804 
805     // The second operand of the shift must be an immediate.
806     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
807       return SDValue();
808 
809     Pos = CN->getZExtValue();
810 
811     // Return if the shifted mask does not start at bit 0 or the sum of its size
812     // and Pos exceeds the word's size.
813     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
814       return SDValue();
815 
816     Opc = MipsISD::Ext;
817     NewOperand = FirstOperand.getOperand(0);
818   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
819     // Pattern match CINS.
820     //  $dst = and (shl $src , pos), mask
821     //  => cins $dst, $src, pos, size
822     // mask is a shifted mask with consecutive 1's, pos = shift amount,
823     // size = population count.
824 
825     // The second operand of the shift must be an immediate.
826     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
827       return SDValue();
828 
829     Pos = CN->getZExtValue();
830 
831     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
832         Pos + SMSize > ValTy.getSizeInBits())
833       return SDValue();
834 
835     NewOperand = FirstOperand.getOperand(0);
836     // SMSize is 'location' (position) in this case, not size.
837     SMSize--;
838     Opc = MipsISD::CIns;
839   } else {
840     // Pattern match EXT.
841     //  $dst = and $src, (2**size - 1) , if size > 16
842     //  => ext $dst, $src, pos, size , pos = 0
843 
844     // If the mask is <= 0xffff, andi can be used instead.
845     if (CN->getZExtValue() <= 0xffff)
846       return SDValue();
847 
848     // Return if the mask doesn't start at position 0.
849     if (SMPos)
850       return SDValue();
851 
852     Opc = MipsISD::Ext;
853     NewOperand = FirstOperand;
854   }
855   return DAG.getNode(Opc, DL, ValTy, NewOperand,
856                      DAG.getConstant(Pos, DL, MVT::i32),
857                      DAG.getConstant(SMSize, DL, MVT::i32));
858 }
859 
860 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
861                                 TargetLowering::DAGCombinerInfo &DCI,
862                                 const MipsSubtarget &Subtarget) {
863   // Pattern match INS.
864   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
865   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
866   //  => ins $dst, $src, size, pos, $src1
867   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
868     return SDValue();
869 
870   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
871   unsigned SMPos0, SMSize0, SMPos1, SMSize1;
872   ConstantSDNode *CN, *CN1;
873 
874   // See if Op's first operand matches (and $src1 , mask0).
875   if (And0.getOpcode() != ISD::AND)
876     return SDValue();
877 
878   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
879       !isShiftedMask_64(~CN->getSExtValue(), SMPos0, SMSize0))
880     return SDValue();
881 
882   // See if Op's second operand matches (and (shl $src, pos), mask1).
883   if (And1.getOpcode() == ISD::AND &&
884       And1.getOperand(0).getOpcode() == ISD::SHL) {
885 
886     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
887         !isShiftedMask_64(CN->getZExtValue(), SMPos1, SMSize1))
888       return SDValue();
889 
890     // The shift masks must have the same position and size.
891     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
892       return SDValue();
893 
894     SDValue Shl = And1.getOperand(0);
895 
896     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
897       return SDValue();
898 
899     unsigned Shamt = CN->getZExtValue();
900 
901     // Return if the shift amount and the first bit position of mask are not the
902     // same.
903     EVT ValTy = N->getValueType(0);
904     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
905       return SDValue();
906 
907     SDLoc DL(N);
908     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
909                        DAG.getConstant(SMPos0, DL, MVT::i32),
910                        DAG.getConstant(SMSize0, DL, MVT::i32),
911                        And0.getOperand(0));
912   } else {
913     // Pattern match DINS.
914     //  $dst = or (and $src, mask0), mask1
915     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
916     //  => dins $dst, $src, pos, size
917     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
918         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
919          (SMSize0 + SMPos0 <= 32))) {
920       // Check if AND instruction has constant as argument
921       bool isConstCase = And1.getOpcode() != ISD::AND;
922       if (And1.getOpcode() == ISD::AND) {
923         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
924           return SDValue();
925       } else {
926         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
927           return SDValue();
928       }
929       // Don't generate INS if constant OR operand doesn't fit into bits
930       // cleared by constant AND operand.
931       if (CN->getSExtValue() & CN1->getSExtValue())
932         return SDValue();
933 
934       SDLoc DL(N);
935       EVT ValTy = N->getOperand(0)->getValueType(0);
936       SDValue Const1;
937       SDValue SrlX;
938       if (!isConstCase) {
939         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
940         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
941       }
942       return DAG.getNode(
943           MipsISD::Ins, DL, N->getValueType(0),
944           isConstCase
945               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
946               : SrlX,
947           DAG.getConstant(SMPos0, DL, MVT::i32),
948           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
949                                                         : SMSize0,
950                           DL, MVT::i32),
951           And0->getOperand(0));
952 
953     }
954     return SDValue();
955   }
956 }
957 
958 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
959                                        const MipsSubtarget &Subtarget) {
960   // ROOTNode must have a multiplication as an operand for the match to be
961   // successful.
962   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
963       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
964     return SDValue();
965 
966   // In the case where we have a multiplication as the left operand of
967   // of a subtraction, we can't combine into a MipsISD::MSub node as the
968   // the instruction definition of msub(u) places the multiplication on
969   // on the right.
970   if (ROOTNode->getOpcode() == ISD::SUB &&
971       ROOTNode->getOperand(0).getOpcode() == ISD::MUL)
972     return SDValue();
973 
974   // We don't handle vector types here.
975   if (ROOTNode->getValueType(0).isVector())
976     return SDValue();
977 
978   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
979   // arithmetic. E.g.
980   // (add (mul a b) c) =>
981   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
982   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
983   //   or
984   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
985   //
986   // The overhead of setting up the Hi/Lo registers and reassembling the
987   // result makes this a dubious optimzation for MIPS64. The core of the
988   // problem is that Hi/Lo contain the upper and lower 32 bits of the
989   // operand and result.
990   //
991   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
992   // density than doing it naively, 5 for MIPS64. Additionally, using
993   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
994   // extended operands, not true 64 bit values.
995   //
996   // FIXME: For the moment, disable this completely for MIPS64.
997   if (Subtarget.hasMips64())
998     return SDValue();
999 
1000   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1001                      ? ROOTNode->getOperand(0)
1002                      : ROOTNode->getOperand(1);
1003 
1004   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1005                      ? ROOTNode->getOperand(1)
1006                      : ROOTNode->getOperand(0);
1007 
1008   // Transform this to a MADD only if the user of this node is the add.
1009   // If there are other users of the mul, this function returns here.
1010   if (!Mult.hasOneUse())
1011     return SDValue();
1012 
1013   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1014   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1015   // of the multiply must have 32 or more sign bits, otherwise we cannot
1016   // perform this optimization. We have to check this here as we're performing
1017   // this optimization pre-legalization.
1018   SDValue MultLHS = Mult->getOperand(0);
1019   SDValue MultRHS = Mult->getOperand(1);
1020 
1021   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1022                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1023   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1024                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1025 
1026   if (!IsSigned && !IsUnsigned)
1027     return SDValue();
1028 
1029   // Initialize accumulator.
1030   SDLoc DL(ROOTNode);
1031   SDValue BottomHalf, TopHalf;
1032   std::tie(BottomHalf, TopHalf) =
1033       CurDAG.SplitScalar(AddOperand, DL, MVT::i32, MVT::i32);
1034   SDValue ACCIn =
1035       CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped, BottomHalf, TopHalf);
1036 
1037   // Create MipsMAdd(u) / MipsMSub(u) node.
1038   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1039   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1040                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1041   SDValue MAddOps[3] = {
1042       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1043       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1044   EVT VTs[2] = {MVT::i32, MVT::i32};
1045   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1046 
1047   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1048   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1049   SDValue Combined =
1050       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1051   return Combined;
1052 }
1053 
1054 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1055                                  TargetLowering::DAGCombinerInfo &DCI,
1056                                  const MipsSubtarget &Subtarget) {
1057   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1058   if (DCI.isBeforeLegalizeOps()) {
1059     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1060         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1061       return performMADD_MSUBCombine(N, DAG, Subtarget);
1062 
1063     return SDValue();
1064   }
1065 
1066   return SDValue();
1067 }
1068 
1069 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1070                                  TargetLowering::DAGCombinerInfo &DCI,
1071                                  const MipsSubtarget &Subtarget) {
1072   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1073   if (DCI.isBeforeLegalizeOps()) {
1074     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1075         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1076       return performMADD_MSUBCombine(N, DAG, Subtarget);
1077 
1078     return SDValue();
1079   }
1080 
1081   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1082   SDValue Add = N->getOperand(1);
1083 
1084   if (Add.getOpcode() != ISD::ADD)
1085     return SDValue();
1086 
1087   SDValue Lo = Add.getOperand(1);
1088 
1089   if ((Lo.getOpcode() != MipsISD::Lo) ||
1090       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1091     return SDValue();
1092 
1093   EVT ValTy = N->getValueType(0);
1094   SDLoc DL(N);
1095 
1096   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1097                              Add.getOperand(0));
1098   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1099 }
1100 
1101 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1102                                  TargetLowering::DAGCombinerInfo &DCI,
1103                                  const MipsSubtarget &Subtarget) {
1104   // Pattern match CINS.
1105   //  $dst = shl (and $src , imm), pos
1106   //  => cins $dst, $src, pos, size
1107 
1108   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1109     return SDValue();
1110 
1111   SDValue FirstOperand = N->getOperand(0);
1112   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1113   SDValue SecondOperand = N->getOperand(1);
1114   EVT ValTy = N->getValueType(0);
1115   SDLoc DL(N);
1116 
1117   uint64_t Pos = 0;
1118   unsigned SMPos, SMSize;
1119   ConstantSDNode *CN;
1120   SDValue NewOperand;
1121 
1122   // The second operand of the shift must be an immediate.
1123   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1124     return SDValue();
1125 
1126   Pos = CN->getZExtValue();
1127 
1128   if (Pos >= ValTy.getSizeInBits())
1129     return SDValue();
1130 
1131   if (FirstOperandOpc != ISD::AND)
1132     return SDValue();
1133 
1134   // AND's second operand must be a shifted mask.
1135   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1136       !isShiftedMask_64(CN->getZExtValue(), SMPos, SMSize))
1137     return SDValue();
1138 
1139   // Return if the shifted mask does not start at bit 0 or the sum of its size
1140   // and Pos exceeds the word's size.
1141   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1142     return SDValue();
1143 
1144   NewOperand = FirstOperand.getOperand(0);
1145   // SMSize is 'location' (position) in this case, not size.
1146   SMSize--;
1147 
1148   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1149                      DAG.getConstant(Pos, DL, MVT::i32),
1150                      DAG.getConstant(SMSize, DL, MVT::i32));
1151 }
1152 
1153 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1154   const {
1155   SelectionDAG &DAG = DCI.DAG;
1156   unsigned Opc = N->getOpcode();
1157 
1158   switch (Opc) {
1159   default: break;
1160   case ISD::SDIVREM:
1161   case ISD::UDIVREM:
1162     return performDivRemCombine(N, DAG, DCI, Subtarget);
1163   case ISD::SELECT:
1164     return performSELECTCombine(N, DAG, DCI, Subtarget);
1165   case MipsISD::CMovFP_F:
1166   case MipsISD::CMovFP_T:
1167     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1168   case ISD::AND:
1169     return performANDCombine(N, DAG, DCI, Subtarget);
1170   case ISD::OR:
1171     return performORCombine(N, DAG, DCI, Subtarget);
1172   case ISD::ADD:
1173     return performADDCombine(N, DAG, DCI, Subtarget);
1174   case ISD::SHL:
1175     return performSHLCombine(N, DAG, DCI, Subtarget);
1176   case ISD::SUB:
1177     return performSUBCombine(N, DAG, DCI, Subtarget);
1178   }
1179 
1180   return SDValue();
1181 }
1182 
1183 bool MipsTargetLowering::isCheapToSpeculateCttz(Type *Ty) const {
1184   return Subtarget.hasMips32();
1185 }
1186 
1187 bool MipsTargetLowering::isCheapToSpeculateCtlz(Type *Ty) const {
1188   return Subtarget.hasMips32();
1189 }
1190 
1191 bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
1192   // We can use ANDI+SLTIU as a bit test. Y contains the bit position.
1193   // For MIPSR2 or later, we may be able to use the `ext` instruction or its'
1194   // double-word variants.
1195   if (auto *C = dyn_cast<ConstantSDNode>(Y))
1196     return C->getAPIntValue().ule(15);
1197 
1198   return false;
1199 }
1200 
1201 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1202     const SDNode *N, CombineLevel Level) const {
1203   assert(((N->getOpcode() == ISD::SHL &&
1204            N->getOperand(0).getOpcode() == ISD::SRL) ||
1205           (N->getOpcode() == ISD::SRL &&
1206            N->getOperand(0).getOpcode() == ISD::SHL)) &&
1207          "Expected shift-shift mask");
1208 
1209   if (N->getOperand(0).getValueType().isVector())
1210     return false;
1211   return true;
1212 }
1213 
1214 void
1215 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1216                                        SmallVectorImpl<SDValue> &Results,
1217                                        SelectionDAG &DAG) const {
1218   return LowerOperationWrapper(N, Results, DAG);
1219 }
1220 
1221 SDValue MipsTargetLowering::
1222 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1223 {
1224   switch (Op.getOpcode())
1225   {
1226   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1227   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1228   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1229   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1230   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1231   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1232   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1233   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1234   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1235   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1236   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1237   case ISD::FABS:               return lowerFABS(Op, DAG);
1238   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1239   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1240   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1241   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1242   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1243   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1244   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1245   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1246   case ISD::STORE:              return lowerSTORE(Op, DAG);
1247   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1248   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1249   }
1250   return SDValue();
1251 }
1252 
1253 //===----------------------------------------------------------------------===//
1254 //  Lower helper functions
1255 //===----------------------------------------------------------------------===//
1256 
1257 // addLiveIn - This helper function adds the specified physical register to the
1258 // MachineFunction as a live in value.  It also creates a corresponding
1259 // virtual register for it.
1260 static unsigned
1261 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1262 {
1263   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1264   MF.getRegInfo().addLiveIn(PReg, VReg);
1265   return VReg;
1266 }
1267 
1268 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1269                                               MachineBasicBlock &MBB,
1270                                               const TargetInstrInfo &TII,
1271                                               bool Is64Bit, bool IsMicroMips) {
1272   if (NoZeroDivCheck)
1273     return &MBB;
1274 
1275   // Insert instruction "teq $divisor_reg, $zero, 7".
1276   MachineBasicBlock::iterator I(MI);
1277   MachineInstrBuilder MIB;
1278   MachineOperand &Divisor = MI.getOperand(2);
1279   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1280                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1281             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1282             .addReg(Mips::ZERO)
1283             .addImm(7);
1284 
1285   // Use the 32-bit sub-register if this is a 64-bit division.
1286   if (Is64Bit)
1287     MIB->getOperand(0).setSubReg(Mips::sub_32);
1288 
1289   // Clear Divisor's kill flag.
1290   Divisor.setIsKill(false);
1291 
1292   // We would normally delete the original instruction here but in this case
1293   // we only needed to inject an additional instruction rather than replace it.
1294 
1295   return &MBB;
1296 }
1297 
1298 MachineBasicBlock *
1299 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1300                                                 MachineBasicBlock *BB) const {
1301   switch (MI.getOpcode()) {
1302   default:
1303     llvm_unreachable("Unexpected instr type to insert");
1304   case Mips::ATOMIC_LOAD_ADD_I8:
1305     return emitAtomicBinaryPartword(MI, BB, 1);
1306   case Mips::ATOMIC_LOAD_ADD_I16:
1307     return emitAtomicBinaryPartword(MI, BB, 2);
1308   case Mips::ATOMIC_LOAD_ADD_I32:
1309     return emitAtomicBinary(MI, BB);
1310   case Mips::ATOMIC_LOAD_ADD_I64:
1311     return emitAtomicBinary(MI, BB);
1312 
1313   case Mips::ATOMIC_LOAD_AND_I8:
1314     return emitAtomicBinaryPartword(MI, BB, 1);
1315   case Mips::ATOMIC_LOAD_AND_I16:
1316     return emitAtomicBinaryPartword(MI, BB, 2);
1317   case Mips::ATOMIC_LOAD_AND_I32:
1318     return emitAtomicBinary(MI, BB);
1319   case Mips::ATOMIC_LOAD_AND_I64:
1320     return emitAtomicBinary(MI, BB);
1321 
1322   case Mips::ATOMIC_LOAD_OR_I8:
1323     return emitAtomicBinaryPartword(MI, BB, 1);
1324   case Mips::ATOMIC_LOAD_OR_I16:
1325     return emitAtomicBinaryPartword(MI, BB, 2);
1326   case Mips::ATOMIC_LOAD_OR_I32:
1327     return emitAtomicBinary(MI, BB);
1328   case Mips::ATOMIC_LOAD_OR_I64:
1329     return emitAtomicBinary(MI, BB);
1330 
1331   case Mips::ATOMIC_LOAD_XOR_I8:
1332     return emitAtomicBinaryPartword(MI, BB, 1);
1333   case Mips::ATOMIC_LOAD_XOR_I16:
1334     return emitAtomicBinaryPartword(MI, BB, 2);
1335   case Mips::ATOMIC_LOAD_XOR_I32:
1336     return emitAtomicBinary(MI, BB);
1337   case Mips::ATOMIC_LOAD_XOR_I64:
1338     return emitAtomicBinary(MI, BB);
1339 
1340   case Mips::ATOMIC_LOAD_NAND_I8:
1341     return emitAtomicBinaryPartword(MI, BB, 1);
1342   case Mips::ATOMIC_LOAD_NAND_I16:
1343     return emitAtomicBinaryPartword(MI, BB, 2);
1344   case Mips::ATOMIC_LOAD_NAND_I32:
1345     return emitAtomicBinary(MI, BB);
1346   case Mips::ATOMIC_LOAD_NAND_I64:
1347     return emitAtomicBinary(MI, BB);
1348 
1349   case Mips::ATOMIC_LOAD_SUB_I8:
1350     return emitAtomicBinaryPartword(MI, BB, 1);
1351   case Mips::ATOMIC_LOAD_SUB_I16:
1352     return emitAtomicBinaryPartword(MI, BB, 2);
1353   case Mips::ATOMIC_LOAD_SUB_I32:
1354     return emitAtomicBinary(MI, BB);
1355   case Mips::ATOMIC_LOAD_SUB_I64:
1356     return emitAtomicBinary(MI, BB);
1357 
1358   case Mips::ATOMIC_SWAP_I8:
1359     return emitAtomicBinaryPartword(MI, BB, 1);
1360   case Mips::ATOMIC_SWAP_I16:
1361     return emitAtomicBinaryPartword(MI, BB, 2);
1362   case Mips::ATOMIC_SWAP_I32:
1363     return emitAtomicBinary(MI, BB);
1364   case Mips::ATOMIC_SWAP_I64:
1365     return emitAtomicBinary(MI, BB);
1366 
1367   case Mips::ATOMIC_CMP_SWAP_I8:
1368     return emitAtomicCmpSwapPartword(MI, BB, 1);
1369   case Mips::ATOMIC_CMP_SWAP_I16:
1370     return emitAtomicCmpSwapPartword(MI, BB, 2);
1371   case Mips::ATOMIC_CMP_SWAP_I32:
1372     return emitAtomicCmpSwap(MI, BB);
1373   case Mips::ATOMIC_CMP_SWAP_I64:
1374     return emitAtomicCmpSwap(MI, BB);
1375 
1376   case Mips::ATOMIC_LOAD_MIN_I8:
1377     return emitAtomicBinaryPartword(MI, BB, 1);
1378   case Mips::ATOMIC_LOAD_MIN_I16:
1379     return emitAtomicBinaryPartword(MI, BB, 2);
1380   case Mips::ATOMIC_LOAD_MIN_I32:
1381     return emitAtomicBinary(MI, BB);
1382   case Mips::ATOMIC_LOAD_MIN_I64:
1383     return emitAtomicBinary(MI, BB);
1384 
1385   case Mips::ATOMIC_LOAD_MAX_I8:
1386     return emitAtomicBinaryPartword(MI, BB, 1);
1387   case Mips::ATOMIC_LOAD_MAX_I16:
1388     return emitAtomicBinaryPartword(MI, BB, 2);
1389   case Mips::ATOMIC_LOAD_MAX_I32:
1390     return emitAtomicBinary(MI, BB);
1391   case Mips::ATOMIC_LOAD_MAX_I64:
1392     return emitAtomicBinary(MI, BB);
1393 
1394   case Mips::ATOMIC_LOAD_UMIN_I8:
1395     return emitAtomicBinaryPartword(MI, BB, 1);
1396   case Mips::ATOMIC_LOAD_UMIN_I16:
1397     return emitAtomicBinaryPartword(MI, BB, 2);
1398   case Mips::ATOMIC_LOAD_UMIN_I32:
1399     return emitAtomicBinary(MI, BB);
1400   case Mips::ATOMIC_LOAD_UMIN_I64:
1401     return emitAtomicBinary(MI, BB);
1402 
1403   case Mips::ATOMIC_LOAD_UMAX_I8:
1404     return emitAtomicBinaryPartword(MI, BB, 1);
1405   case Mips::ATOMIC_LOAD_UMAX_I16:
1406     return emitAtomicBinaryPartword(MI, BB, 2);
1407   case Mips::ATOMIC_LOAD_UMAX_I32:
1408     return emitAtomicBinary(MI, BB);
1409   case Mips::ATOMIC_LOAD_UMAX_I64:
1410     return emitAtomicBinary(MI, BB);
1411 
1412   case Mips::PseudoSDIV:
1413   case Mips::PseudoUDIV:
1414   case Mips::DIV:
1415   case Mips::DIVU:
1416   case Mips::MOD:
1417   case Mips::MODU:
1418     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1419                                false);
1420   case Mips::SDIV_MM_Pseudo:
1421   case Mips::UDIV_MM_Pseudo:
1422   case Mips::SDIV_MM:
1423   case Mips::UDIV_MM:
1424   case Mips::DIV_MMR6:
1425   case Mips::DIVU_MMR6:
1426   case Mips::MOD_MMR6:
1427   case Mips::MODU_MMR6:
1428     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1429   case Mips::PseudoDSDIV:
1430   case Mips::PseudoDUDIV:
1431   case Mips::DDIV:
1432   case Mips::DDIVU:
1433   case Mips::DMOD:
1434   case Mips::DMODU:
1435     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1436 
1437   case Mips::PseudoSELECT_I:
1438   case Mips::PseudoSELECT_I64:
1439   case Mips::PseudoSELECT_S:
1440   case Mips::PseudoSELECT_D32:
1441   case Mips::PseudoSELECT_D64:
1442     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1443   case Mips::PseudoSELECTFP_F_I:
1444   case Mips::PseudoSELECTFP_F_I64:
1445   case Mips::PseudoSELECTFP_F_S:
1446   case Mips::PseudoSELECTFP_F_D32:
1447   case Mips::PseudoSELECTFP_F_D64:
1448     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1449   case Mips::PseudoSELECTFP_T_I:
1450   case Mips::PseudoSELECTFP_T_I64:
1451   case Mips::PseudoSELECTFP_T_S:
1452   case Mips::PseudoSELECTFP_T_D32:
1453   case Mips::PseudoSELECTFP_T_D64:
1454     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1455   case Mips::PseudoD_SELECT_I:
1456   case Mips::PseudoD_SELECT_I64:
1457     return emitPseudoD_SELECT(MI, BB);
1458   case Mips::LDR_W:
1459     return emitLDR_W(MI, BB);
1460   case Mips::LDR_D:
1461     return emitLDR_D(MI, BB);
1462   case Mips::STR_W:
1463     return emitSTR_W(MI, BB);
1464   case Mips::STR_D:
1465     return emitSTR_D(MI, BB);
1466   }
1467 }
1468 
1469 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1470 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1471 MachineBasicBlock *
1472 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1473                                      MachineBasicBlock *BB) const {
1474 
1475   MachineFunction *MF = BB->getParent();
1476   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1477   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1478   DebugLoc DL = MI.getDebugLoc();
1479 
1480   unsigned AtomicOp;
1481   bool NeedsAdditionalReg = false;
1482   switch (MI.getOpcode()) {
1483   case Mips::ATOMIC_LOAD_ADD_I32:
1484     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1485     break;
1486   case Mips::ATOMIC_LOAD_SUB_I32:
1487     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1488     break;
1489   case Mips::ATOMIC_LOAD_AND_I32:
1490     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1491     break;
1492   case Mips::ATOMIC_LOAD_OR_I32:
1493     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1494     break;
1495   case Mips::ATOMIC_LOAD_XOR_I32:
1496     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1497     break;
1498   case Mips::ATOMIC_LOAD_NAND_I32:
1499     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1500     break;
1501   case Mips::ATOMIC_SWAP_I32:
1502     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1503     break;
1504   case Mips::ATOMIC_LOAD_ADD_I64:
1505     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1506     break;
1507   case Mips::ATOMIC_LOAD_SUB_I64:
1508     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1509     break;
1510   case Mips::ATOMIC_LOAD_AND_I64:
1511     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1512     break;
1513   case Mips::ATOMIC_LOAD_OR_I64:
1514     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1515     break;
1516   case Mips::ATOMIC_LOAD_XOR_I64:
1517     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1518     break;
1519   case Mips::ATOMIC_LOAD_NAND_I64:
1520     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1521     break;
1522   case Mips::ATOMIC_SWAP_I64:
1523     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1524     break;
1525   case Mips::ATOMIC_LOAD_MIN_I32:
1526     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1527     NeedsAdditionalReg = true;
1528     break;
1529   case Mips::ATOMIC_LOAD_MAX_I32:
1530     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1531     NeedsAdditionalReg = true;
1532     break;
1533   case Mips::ATOMIC_LOAD_UMIN_I32:
1534     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1535     NeedsAdditionalReg = true;
1536     break;
1537   case Mips::ATOMIC_LOAD_UMAX_I32:
1538     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1539     NeedsAdditionalReg = true;
1540     break;
1541   case Mips::ATOMIC_LOAD_MIN_I64:
1542     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1543     NeedsAdditionalReg = true;
1544     break;
1545   case Mips::ATOMIC_LOAD_MAX_I64:
1546     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1547     NeedsAdditionalReg = true;
1548     break;
1549   case Mips::ATOMIC_LOAD_UMIN_I64:
1550     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1551     NeedsAdditionalReg = true;
1552     break;
1553   case Mips::ATOMIC_LOAD_UMAX_I64:
1554     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1555     NeedsAdditionalReg = true;
1556     break;
1557   default:
1558     llvm_unreachable("Unknown pseudo atomic for replacement!");
1559   }
1560 
1561   Register OldVal = MI.getOperand(0).getReg();
1562   Register Ptr = MI.getOperand(1).getReg();
1563   Register Incr = MI.getOperand(2).getReg();
1564   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1565 
1566   MachineBasicBlock::iterator II(MI);
1567 
1568   // The scratch registers here with the EarlyClobber | Define | Implicit
1569   // flags is used to persuade the register allocator and the machine
1570   // verifier to accept the usage of this register. This has to be a real
1571   // register which has an UNDEF value but is dead after the instruction which
1572   // is unique among the registers chosen for the instruction.
1573 
1574   // The EarlyClobber flag has the semantic properties that the operand it is
1575   // attached to is clobbered before the rest of the inputs are read. Hence it
1576   // must be unique among the operands to the instruction.
1577   // The Define flag is needed to coerce the machine verifier that an Undef
1578   // value isn't a problem.
1579   // The Dead flag is needed as the value in scratch isn't used by any other
1580   // instruction. Kill isn't used as Dead is more precise.
1581   // The implicit flag is here due to the interaction between the other flags
1582   // and the machine verifier.
1583 
1584   // For correctness purpose, a new pseudo is introduced here. We need this
1585   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1586   // that is spread over >1 basic blocks. A register allocator which
1587   // introduces (or any codegen infact) a store, can violate the expectations
1588   // of the hardware.
1589   //
1590   // An atomic read-modify-write sequence starts with a linked load
1591   // instruction and ends with a store conditional instruction. The atomic
1592   // read-modify-write sequence fails if any of the following conditions
1593   // occur between the execution of ll and sc:
1594   //   * A coherent store is completed by another process or coherent I/O
1595   //     module into the block of synchronizable physical memory containing
1596   //     the word. The size and alignment of the block is
1597   //     implementation-dependent.
1598   //   * A coherent store is executed between an LL and SC sequence on the
1599   //     same processor to the block of synchornizable physical memory
1600   //     containing the word.
1601   //
1602 
1603   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1604   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1605 
1606   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1607   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1608 
1609   MachineInstrBuilder MIB =
1610       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1611           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1612           .addReg(PtrCopy)
1613           .addReg(IncrCopy)
1614           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1615                                RegState::Implicit | RegState::Dead);
1616   if (NeedsAdditionalReg) {
1617     Register Scratch2 =
1618         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1619     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1620                              RegState::Implicit | RegState::Dead);
1621   }
1622 
1623   MI.eraseFromParent();
1624 
1625   return BB;
1626 }
1627 
1628 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1629     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1630     unsigned SrcReg) const {
1631   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1632   const DebugLoc &DL = MI.getDebugLoc();
1633 
1634   if (Subtarget.hasMips32r2() && Size == 1) {
1635     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1636     return BB;
1637   }
1638 
1639   if (Subtarget.hasMips32r2() && Size == 2) {
1640     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1641     return BB;
1642   }
1643 
1644   MachineFunction *MF = BB->getParent();
1645   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1646   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1647   Register ScrReg = RegInfo.createVirtualRegister(RC);
1648 
1649   assert(Size < 32);
1650   int64_t ShiftImm = 32 - (Size * 8);
1651 
1652   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1653   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1654 
1655   return BB;
1656 }
1657 
1658 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1659     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1660   assert((Size == 1 || Size == 2) &&
1661          "Unsupported size for EmitAtomicBinaryPartial.");
1662 
1663   MachineFunction *MF = BB->getParent();
1664   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1665   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1666   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1667   const TargetRegisterClass *RCp =
1668     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1669   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1670   DebugLoc DL = MI.getDebugLoc();
1671 
1672   Register Dest = MI.getOperand(0).getReg();
1673   Register Ptr = MI.getOperand(1).getReg();
1674   Register Incr = MI.getOperand(2).getReg();
1675 
1676   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1677   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1678   Register Mask = RegInfo.createVirtualRegister(RC);
1679   Register Mask2 = RegInfo.createVirtualRegister(RC);
1680   Register Incr2 = RegInfo.createVirtualRegister(RC);
1681   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1682   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1683   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1684   Register Scratch = RegInfo.createVirtualRegister(RC);
1685   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1686   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1687 
1688   unsigned AtomicOp = 0;
1689   bool NeedsAdditionalReg = false;
1690   switch (MI.getOpcode()) {
1691   case Mips::ATOMIC_LOAD_NAND_I8:
1692     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1693     break;
1694   case Mips::ATOMIC_LOAD_NAND_I16:
1695     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1696     break;
1697   case Mips::ATOMIC_SWAP_I8:
1698     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1699     break;
1700   case Mips::ATOMIC_SWAP_I16:
1701     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1702     break;
1703   case Mips::ATOMIC_LOAD_ADD_I8:
1704     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1705     break;
1706   case Mips::ATOMIC_LOAD_ADD_I16:
1707     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1708     break;
1709   case Mips::ATOMIC_LOAD_SUB_I8:
1710     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1711     break;
1712   case Mips::ATOMIC_LOAD_SUB_I16:
1713     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1714     break;
1715   case Mips::ATOMIC_LOAD_AND_I8:
1716     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1717     break;
1718   case Mips::ATOMIC_LOAD_AND_I16:
1719     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1720     break;
1721   case Mips::ATOMIC_LOAD_OR_I8:
1722     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1723     break;
1724   case Mips::ATOMIC_LOAD_OR_I16:
1725     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1726     break;
1727   case Mips::ATOMIC_LOAD_XOR_I8:
1728     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1729     break;
1730   case Mips::ATOMIC_LOAD_XOR_I16:
1731     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1732     break;
1733   case Mips::ATOMIC_LOAD_MIN_I8:
1734     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1735     NeedsAdditionalReg = true;
1736     break;
1737   case Mips::ATOMIC_LOAD_MIN_I16:
1738     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1739     NeedsAdditionalReg = true;
1740     break;
1741   case Mips::ATOMIC_LOAD_MAX_I8:
1742     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1743     NeedsAdditionalReg = true;
1744     break;
1745   case Mips::ATOMIC_LOAD_MAX_I16:
1746     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1747     NeedsAdditionalReg = true;
1748     break;
1749   case Mips::ATOMIC_LOAD_UMIN_I8:
1750     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1751     NeedsAdditionalReg = true;
1752     break;
1753   case Mips::ATOMIC_LOAD_UMIN_I16:
1754     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1755     NeedsAdditionalReg = true;
1756     break;
1757   case Mips::ATOMIC_LOAD_UMAX_I8:
1758     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1759     NeedsAdditionalReg = true;
1760     break;
1761   case Mips::ATOMIC_LOAD_UMAX_I16:
1762     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1763     NeedsAdditionalReg = true;
1764     break;
1765   default:
1766     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1767   }
1768 
1769   // insert new blocks after the current block
1770   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1771   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1772   MachineFunction::iterator It = ++BB->getIterator();
1773   MF->insert(It, exitMBB);
1774 
1775   // Transfer the remainder of BB and its successor edges to exitMBB.
1776   exitMBB->splice(exitMBB->begin(), BB,
1777                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1778   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1779 
1780   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1781 
1782   //  thisMBB:
1783   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1784   //    and     alignedaddr,ptr,masklsb2
1785   //    andi    ptrlsb2,ptr,3
1786   //    sll     shiftamt,ptrlsb2,3
1787   //    ori     maskupper,$0,255               # 0xff
1788   //    sll     mask,maskupper,shiftamt
1789   //    nor     mask2,$0,mask
1790   //    sll     incr2,incr,shiftamt
1791 
1792   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1793   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1794     .addReg(ABI.GetNullPtr()).addImm(-4);
1795   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1796     .addReg(Ptr).addReg(MaskLSB2);
1797   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1798       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1799   if (Subtarget.isLittle()) {
1800     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1801   } else {
1802     Register Off = RegInfo.createVirtualRegister(RC);
1803     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1804       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1805     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1806   }
1807   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1808     .addReg(Mips::ZERO).addImm(MaskImm);
1809   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1810     .addReg(MaskUpper).addReg(ShiftAmt);
1811   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1812   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1813 
1814 
1815   // The purposes of the flags on the scratch registers is explained in
1816   // emitAtomicBinary. In summary, we need a scratch register which is going to
1817   // be undef, that is unique among registers chosen for the instruction.
1818 
1819   MachineInstrBuilder MIB =
1820       BuildMI(BB, DL, TII->get(AtomicOp))
1821           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1822           .addReg(AlignedAddr)
1823           .addReg(Incr2)
1824           .addReg(Mask)
1825           .addReg(Mask2)
1826           .addReg(ShiftAmt)
1827           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1828                                RegState::Dead | RegState::Implicit)
1829           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1830                                 RegState::Dead | RegState::Implicit)
1831           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1832                                 RegState::Dead | RegState::Implicit);
1833   if (NeedsAdditionalReg) {
1834     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1835     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1836                              RegState::Dead | RegState::Implicit);
1837   }
1838 
1839   MI.eraseFromParent(); // The instruction is gone now.
1840 
1841   return exitMBB;
1842 }
1843 
1844 // Lower atomic compare and swap to a pseudo instruction, taking care to
1845 // define a scratch register for the pseudo instruction's expansion. The
1846 // instruction is expanded after the register allocator as to prevent
1847 // the insertion of stores between the linked load and the store conditional.
1848 
1849 MachineBasicBlock *
1850 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1851                                       MachineBasicBlock *BB) const {
1852 
1853   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1854           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1855          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1856 
1857   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1858 
1859   MachineFunction *MF = BB->getParent();
1860   MachineRegisterInfo &MRI = MF->getRegInfo();
1861   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1862   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1863   DebugLoc DL = MI.getDebugLoc();
1864 
1865   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1866                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1867                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1868   Register Dest = MI.getOperand(0).getReg();
1869   Register Ptr = MI.getOperand(1).getReg();
1870   Register OldVal = MI.getOperand(2).getReg();
1871   Register NewVal = MI.getOperand(3).getReg();
1872 
1873   Register Scratch = MRI.createVirtualRegister(RC);
1874   MachineBasicBlock::iterator II(MI);
1875 
1876   // We need to create copies of the various registers and kill them at the
1877   // atomic pseudo. If the copies are not made, when the atomic is expanded
1878   // after fast register allocation, the spills will end up outside of the
1879   // blocks that their values are defined in, causing livein errors.
1880 
1881   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1882   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1883   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1884 
1885   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1886   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1887   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1888 
1889   // The purposes of the flags on the scratch registers is explained in
1890   // emitAtomicBinary. In summary, we need a scratch register which is going to
1891   // be undef, that is unique among registers chosen for the instruction.
1892 
1893   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1894       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1895       .addReg(PtrCopy, RegState::Kill)
1896       .addReg(OldValCopy, RegState::Kill)
1897       .addReg(NewValCopy, RegState::Kill)
1898       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1899                            RegState::Dead | RegState::Implicit);
1900 
1901   MI.eraseFromParent(); // The instruction is gone now.
1902 
1903   return BB;
1904 }
1905 
1906 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1907     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1908   assert((Size == 1 || Size == 2) &&
1909       "Unsupported size for EmitAtomicCmpSwapPartial.");
1910 
1911   MachineFunction *MF = BB->getParent();
1912   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1913   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1914   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1915   const TargetRegisterClass *RCp =
1916     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1917   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1918   DebugLoc DL = MI.getDebugLoc();
1919 
1920   Register Dest = MI.getOperand(0).getReg();
1921   Register Ptr = MI.getOperand(1).getReg();
1922   Register CmpVal = MI.getOperand(2).getReg();
1923   Register NewVal = MI.getOperand(3).getReg();
1924 
1925   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1926   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1927   Register Mask = RegInfo.createVirtualRegister(RC);
1928   Register Mask2 = RegInfo.createVirtualRegister(RC);
1929   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1930   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1931   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1932   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1933   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1934   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1935   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1936   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1937                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
1938                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
1939 
1940   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
1941   // flags are used to coerce the register allocator and the machine verifier to
1942   // accept the usage of these registers.
1943   // The EarlyClobber flag has the semantic properties that the operand it is
1944   // attached to is clobbered before the rest of the inputs are read. Hence it
1945   // must be unique among the operands to the instruction.
1946   // The Define flag is needed to coerce the machine verifier that an Undef
1947   // value isn't a problem.
1948   // The Dead flag is needed as the value in scratch isn't used by any other
1949   // instruction. Kill isn't used as Dead is more precise.
1950   Register Scratch = RegInfo.createVirtualRegister(RC);
1951   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1952 
1953   // insert new blocks after the current block
1954   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1955   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1956   MachineFunction::iterator It = ++BB->getIterator();
1957   MF->insert(It, exitMBB);
1958 
1959   // Transfer the remainder of BB and its successor edges to exitMBB.
1960   exitMBB->splice(exitMBB->begin(), BB,
1961                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1962   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1963 
1964   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1965 
1966   //  thisMBB:
1967   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1968   //    and     alignedaddr,ptr,masklsb2
1969   //    andi    ptrlsb2,ptr,3
1970   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1971   //    sll     shiftamt,ptrlsb2,3
1972   //    ori     maskupper,$0,255               # 0xff
1973   //    sll     mask,maskupper,shiftamt
1974   //    nor     mask2,$0,mask
1975   //    andi    maskedcmpval,cmpval,255
1976   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1977   //    andi    maskednewval,newval,255
1978   //    sll     shiftednewval,maskednewval,shiftamt
1979   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1980   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1981     .addReg(ABI.GetNullPtr()).addImm(-4);
1982   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1983     .addReg(Ptr).addReg(MaskLSB2);
1984   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1985       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1986   if (Subtarget.isLittle()) {
1987     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1988   } else {
1989     Register Off = RegInfo.createVirtualRegister(RC);
1990     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1991       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1992     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1993   }
1994   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1995     .addReg(Mips::ZERO).addImm(MaskImm);
1996   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1997     .addReg(MaskUpper).addReg(ShiftAmt);
1998   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1999   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
2000     .addReg(CmpVal).addImm(MaskImm);
2001   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
2002     .addReg(MaskedCmpVal).addReg(ShiftAmt);
2003   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
2004     .addReg(NewVal).addImm(MaskImm);
2005   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
2006     .addReg(MaskedNewVal).addReg(ShiftAmt);
2007 
2008   // The purposes of the flags on the scratch registers are explained in
2009   // emitAtomicBinary. In summary, we need a scratch register which is going to
2010   // be undef, that is unique among the register chosen for the instruction.
2011 
2012   BuildMI(BB, DL, TII->get(AtomicOp))
2013       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2014       .addReg(AlignedAddr)
2015       .addReg(Mask)
2016       .addReg(ShiftedCmpVal)
2017       .addReg(Mask2)
2018       .addReg(ShiftedNewVal)
2019       .addReg(ShiftAmt)
2020       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2021                            RegState::Dead | RegState::Implicit)
2022       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2023                             RegState::Dead | RegState::Implicit);
2024 
2025   MI.eraseFromParent(); // The instruction is gone now.
2026 
2027   return exitMBB;
2028 }
2029 
2030 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2031   // The first operand is the chain, the second is the condition, the third is
2032   // the block to branch to if the condition is true.
2033   SDValue Chain = Op.getOperand(0);
2034   SDValue Dest = Op.getOperand(2);
2035   SDLoc DL(Op);
2036 
2037   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2038   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2039 
2040   // Return if flag is not set by a floating point comparison.
2041   if (CondRes.getOpcode() != MipsISD::FPCmp)
2042     return Op;
2043 
2044   SDValue CCNode  = CondRes.getOperand(2);
2045   Mips::CondCode CC = (Mips::CondCode)CCNode->getAsZExtVal();
2046   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2047   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2048   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2049   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2050                      FCC0, Dest, CondRes);
2051 }
2052 
2053 SDValue MipsTargetLowering::
2054 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2055 {
2056   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2057   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2058 
2059   // Return if flag is not set by a floating point comparison.
2060   if (Cond.getOpcode() != MipsISD::FPCmp)
2061     return Op;
2062 
2063   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2064                       SDLoc(Op));
2065 }
2066 
2067 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2068   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2069   SDValue Cond = createFPCmp(DAG, Op);
2070 
2071   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2072          "Floating point operand expected.");
2073 
2074   SDLoc DL(Op);
2075   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2076   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2077 
2078   return createCMovFP(DAG, Cond, True, False, DL);
2079 }
2080 
2081 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2082                                                SelectionDAG &DAG) const {
2083   EVT Ty = Op.getValueType();
2084   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2085   const GlobalValue *GV = N->getGlobal();
2086 
2087   if (!isPositionIndependent()) {
2088     const MipsTargetObjectFile *TLOF =
2089         static_cast<const MipsTargetObjectFile *>(
2090             getTargetMachine().getObjFileLowering());
2091     const GlobalObject *GO = GV->getAliaseeObject();
2092     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2093       // %gp_rel relocation
2094       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2095 
2096                                 // %hi/%lo relocation
2097     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2098                                 // %highest/%higher/%hi/%lo relocation
2099                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2100   }
2101 
2102   // Every other architecture would use shouldAssumeDSOLocal in here, but
2103   // mips is special.
2104   // * In PIC code mips requires got loads even for local statics!
2105   // * To save on got entries, for local statics the got entry contains the
2106   //   page and an additional add instruction takes care of the low bits.
2107   // * It is legal to access a hidden symbol with a non hidden undefined,
2108   //   so one cannot guarantee that all access to a hidden symbol will know
2109   //   it is hidden.
2110   // * Mips linkers don't support creating a page and a full got entry for
2111   //   the same symbol.
2112   // * Given all that, we have to use a full got entry for hidden symbols :-(
2113   if (GV->hasLocalLinkage())
2114     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2115 
2116   if (Subtarget.useXGOT())
2117     return getAddrGlobalLargeGOT(
2118         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2119         DAG.getEntryNode(),
2120         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2121 
2122   return getAddrGlobal(
2123       N, SDLoc(N), Ty, DAG,
2124       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2125       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2126 }
2127 
2128 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2129                                               SelectionDAG &DAG) const {
2130   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2131   EVT Ty = Op.getValueType();
2132 
2133   if (!isPositionIndependent())
2134     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2135                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2136 
2137   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2138 }
2139 
2140 SDValue MipsTargetLowering::
2141 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2142 {
2143   // If the relocation model is PIC, use the General Dynamic TLS Model or
2144   // Local Dynamic TLS model, otherwise use the Initial Exec or
2145   // Local Exec TLS Model.
2146 
2147   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2148   if (DAG.getTarget().useEmulatedTLS())
2149     return LowerToTLSEmulatedModel(GA, DAG);
2150 
2151   SDLoc DL(GA);
2152   const GlobalValue *GV = GA->getGlobal();
2153   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2154 
2155   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2156 
2157   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2158     // General Dynamic and Local Dynamic TLS Model.
2159     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2160                                                       : MipsII::MO_TLSGD;
2161 
2162     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2163     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2164                                    getGlobalReg(DAG, PtrVT), TGA);
2165     unsigned PtrSize = PtrVT.getSizeInBits();
2166     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2167 
2168     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2169 
2170     ArgListTy Args;
2171     ArgListEntry Entry;
2172     Entry.Node = Argument;
2173     Entry.Ty = PtrTy;
2174     Args.push_back(Entry);
2175 
2176     TargetLowering::CallLoweringInfo CLI(DAG);
2177     CLI.setDebugLoc(DL)
2178         .setChain(DAG.getEntryNode())
2179         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2180     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2181 
2182     SDValue Ret = CallResult.first;
2183 
2184     if (model != TLSModel::LocalDynamic)
2185       return Ret;
2186 
2187     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2188                                                MipsII::MO_DTPREL_HI);
2189     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2190     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2191                                                MipsII::MO_DTPREL_LO);
2192     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2193     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2194     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2195   }
2196 
2197   SDValue Offset;
2198   if (model == TLSModel::InitialExec) {
2199     // Initial Exec TLS Model
2200     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2201                                              MipsII::MO_GOTTPREL);
2202     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2203                       TGA);
2204     Offset =
2205         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2206   } else {
2207     // Local Exec TLS Model
2208     assert(model == TLSModel::LocalExec);
2209     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2210                                                MipsII::MO_TPREL_HI);
2211     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2212                                                MipsII::MO_TPREL_LO);
2213     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2214     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2215     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2216   }
2217 
2218   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2219   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2220 }
2221 
2222 SDValue MipsTargetLowering::
2223 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2224 {
2225   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2226   EVT Ty = Op.getValueType();
2227 
2228   if (!isPositionIndependent())
2229     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2230                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2231 
2232   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2233 }
2234 
2235 SDValue MipsTargetLowering::
2236 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2237 {
2238   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2239   EVT Ty = Op.getValueType();
2240 
2241   if (!isPositionIndependent()) {
2242     const MipsTargetObjectFile *TLOF =
2243         static_cast<const MipsTargetObjectFile *>(
2244             getTargetMachine().getObjFileLowering());
2245 
2246     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2247                                        getTargetMachine()))
2248       // %gp_rel relocation
2249       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2250 
2251     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2252                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2253   }
2254 
2255  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2256 }
2257 
2258 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2259   MachineFunction &MF = DAG.getMachineFunction();
2260   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2261 
2262   SDLoc DL(Op);
2263   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2264                                  getPointerTy(MF.getDataLayout()));
2265 
2266   // vastart just stores the address of the VarArgsFrameIndex slot into the
2267   // memory location argument.
2268   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2269   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2270                       MachinePointerInfo(SV));
2271 }
2272 
2273 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2274   SDNode *Node = Op.getNode();
2275   EVT VT = Node->getValueType(0);
2276   SDValue Chain = Node->getOperand(0);
2277   SDValue VAListPtr = Node->getOperand(1);
2278   const Align Align =
2279       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2280   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2281   SDLoc DL(Node);
2282   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2283 
2284   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2285                                    VAListPtr, MachinePointerInfo(SV));
2286   SDValue VAList = VAListLoad;
2287 
2288   // Re-align the pointer if necessary.
2289   // It should only ever be necessary for 64-bit types on O32 since the minimum
2290   // argument alignment is the same as the maximum type alignment for N32/N64.
2291   //
2292   // FIXME: We currently align too often. The code generator doesn't notice
2293   //        when the pointer is still aligned from the last va_arg (or pair of
2294   //        va_args for the i64 on O32 case).
2295   if (Align > getMinStackArgumentAlignment()) {
2296     VAList = DAG.getNode(
2297         ISD::ADD, DL, VAList.getValueType(), VAList,
2298         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2299 
2300     VAList = DAG.getNode(
2301         ISD::AND, DL, VAList.getValueType(), VAList,
2302         DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
2303   }
2304 
2305   // Increment the pointer, VAList, to the next vaarg.
2306   auto &TD = DAG.getDataLayout();
2307   unsigned ArgSizeInBytes =
2308       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2309   SDValue Tmp3 =
2310       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2311                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2312                                   DL, VAList.getValueType()));
2313   // Store the incremented VAList to the legalized pointer
2314   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2315                        MachinePointerInfo(SV));
2316 
2317   // In big-endian mode we must adjust the pointer when the load size is smaller
2318   // than the argument slot size. We must also reduce the known alignment to
2319   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2320   // the correct half of the slot, and reduce the alignment from 8 (slot
2321   // alignment) down to 4 (type alignment).
2322   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2323     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2324     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2325                          DAG.getIntPtrConstant(Adjustment, DL));
2326   }
2327   // Load the actual argument out of the pointer VAList
2328   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2329 }
2330 
2331 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2332                                 bool HasExtractInsert) {
2333   EVT TyX = Op.getOperand(0).getValueType();
2334   EVT TyY = Op.getOperand(1).getValueType();
2335   SDLoc DL(Op);
2336   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2337   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2338   SDValue Res;
2339 
2340   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2341   // to i32.
2342   SDValue X = (TyX == MVT::f32) ?
2343     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2344     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2345                 Const1);
2346   SDValue Y = (TyY == MVT::f32) ?
2347     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2348     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2349                 Const1);
2350 
2351   if (HasExtractInsert) {
2352     // ext  E, Y, 31, 1  ; extract bit31 of Y
2353     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2354     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2355     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2356   } else {
2357     // sll SllX, X, 1
2358     // srl SrlX, SllX, 1
2359     // srl SrlY, Y, 31
2360     // sll SllY, SrlX, 31
2361     // or  Or, SrlX, SllY
2362     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2363     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2364     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2365     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2366     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2367   }
2368 
2369   if (TyX == MVT::f32)
2370     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2371 
2372   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2373                              Op.getOperand(0),
2374                              DAG.getConstant(0, DL, MVT::i32));
2375   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2376 }
2377 
2378 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2379                                 bool HasExtractInsert) {
2380   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2381   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2382   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2383   SDLoc DL(Op);
2384   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2385 
2386   // Bitcast to integer nodes.
2387   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2388   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2389 
2390   if (HasExtractInsert) {
2391     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2392     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2393     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2394                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2395 
2396     if (WidthX > WidthY)
2397       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2398     else if (WidthY > WidthX)
2399       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2400 
2401     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2402                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2403                             X);
2404     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2405   }
2406 
2407   // (d)sll SllX, X, 1
2408   // (d)srl SrlX, SllX, 1
2409   // (d)srl SrlY, Y, width(Y)-1
2410   // (d)sll SllY, SrlX, width(Y)-1
2411   // or     Or, SrlX, SllY
2412   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2413   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2414   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2415                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2416 
2417   if (WidthX > WidthY)
2418     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2419   else if (WidthY > WidthX)
2420     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2421 
2422   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2423                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2424   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2425   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2426 }
2427 
2428 SDValue
2429 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2430   if (Subtarget.isGP64bit())
2431     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2432 
2433   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2434 }
2435 
2436 SDValue MipsTargetLowering::lowerFABS32(SDValue Op, SelectionDAG &DAG,
2437                                         bool HasExtractInsert) const {
2438   SDLoc DL(Op);
2439   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2440 
2441   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2442     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2443 
2444   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2445   // to i32.
2446   SDValue X = (Op.getValueType() == MVT::f32)
2447                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2448                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2449                                 Op.getOperand(0), Const1);
2450 
2451   // Clear MSB.
2452   if (HasExtractInsert)
2453     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2454                       DAG.getRegister(Mips::ZERO, MVT::i32),
2455                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2456   else {
2457     // TODO: Provide DAG patterns which transform (and x, cst)
2458     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2459     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2460     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2461   }
2462 
2463   if (Op.getValueType() == MVT::f32)
2464     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2465 
2466   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2467   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2468   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2469   // place.
2470   SDValue LowX =
2471       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2472                   DAG.getConstant(0, DL, MVT::i32));
2473   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2474 }
2475 
2476 SDValue MipsTargetLowering::lowerFABS64(SDValue Op, SelectionDAG &DAG,
2477                                         bool HasExtractInsert) const {
2478   SDLoc DL(Op);
2479   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2480 
2481   if (DAG.getTarget().Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())
2482     return DAG.getNode(MipsISD::FAbs, DL, Op.getValueType(), Op.getOperand(0));
2483 
2484   // Bitcast to integer node.
2485   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2486 
2487   // Clear MSB.
2488   if (HasExtractInsert)
2489     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2490                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2491                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2492   else {
2493     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2494     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2495   }
2496 
2497   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2498 }
2499 
2500 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2501   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2502     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2503 
2504   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2505 }
2506 
2507 SDValue MipsTargetLowering::
2508 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2509   // check the depth
2510   if (Op.getConstantOperandVal(0) != 0) {
2511     DAG.getContext()->emitError(
2512         "return address can be determined only for current frame");
2513     return SDValue();
2514   }
2515 
2516   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2517   MFI.setFrameAddressIsTaken(true);
2518   EVT VT = Op.getValueType();
2519   SDLoc DL(Op);
2520   SDValue FrameAddr = DAG.getCopyFromReg(
2521       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2522   return FrameAddr;
2523 }
2524 
2525 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2526                                             SelectionDAG &DAG) const {
2527   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2528     return SDValue();
2529 
2530   // check the depth
2531   if (Op.getConstantOperandVal(0) != 0) {
2532     DAG.getContext()->emitError(
2533         "return address can be determined only for current frame");
2534     return SDValue();
2535   }
2536 
2537   MachineFunction &MF = DAG.getMachineFunction();
2538   MachineFrameInfo &MFI = MF.getFrameInfo();
2539   MVT VT = Op.getSimpleValueType();
2540   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2541   MFI.setReturnAddressIsTaken(true);
2542 
2543   // Return RA, which contains the return address. Mark it an implicit live-in.
2544   Register Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2545   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2546 }
2547 
2548 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2549 // generated from __builtin_eh_return (offset, handler)
2550 // The effect of this is to adjust the stack pointer by "offset"
2551 // and then branch to "handler".
2552 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2553                                                                      const {
2554   MachineFunction &MF = DAG.getMachineFunction();
2555   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2556 
2557   MipsFI->setCallsEhReturn();
2558   SDValue Chain     = Op.getOperand(0);
2559   SDValue Offset    = Op.getOperand(1);
2560   SDValue Handler   = Op.getOperand(2);
2561   SDLoc DL(Op);
2562   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2563 
2564   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2565   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2566   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2567   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2568   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2569   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2570   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2571                      DAG.getRegister(OffsetReg, Ty),
2572                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2573                      Chain.getValue(1));
2574 }
2575 
2576 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2577                                               SelectionDAG &DAG) const {
2578   // FIXME: Need pseudo-fence for 'singlethread' fences
2579   // FIXME: Set SType for weaker fences where supported/appropriate.
2580   unsigned SType = 0;
2581   SDLoc DL(Op);
2582   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2583                      DAG.getConstant(SType, DL, MVT::i32));
2584 }
2585 
2586 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2587                                                 SelectionDAG &DAG) const {
2588   SDLoc DL(Op);
2589   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2590 
2591   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2592   SDValue Shamt = Op.getOperand(2);
2593   // if shamt < (VT.bits):
2594   //  lo = (shl lo, shamt)
2595   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), (xor shamt, (VT.bits-1))))
2596   // else:
2597   //  lo = 0
2598   //  hi = (shl lo, shamt[4:0])
2599   SDValue Not =
2600       DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2601                   DAG.getConstant(VT.getSizeInBits() - 1, DL, MVT::i32));
2602   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2603                                       DAG.getConstant(1, DL, VT));
2604   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2605   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2606   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2607   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2608   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2609                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2610   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2611                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2612   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2613 
2614   SDValue Ops[2] = {Lo, Hi};
2615   return DAG.getMergeValues(Ops, DL);
2616 }
2617 
2618 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2619                                                  bool IsSRA) const {
2620   SDLoc DL(Op);
2621   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2622   SDValue Shamt = Op.getOperand(2);
2623   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2624 
2625   // if shamt < (VT.bits):
2626   //  lo = (or (shl (shl hi, 1), (xor shamt, (VT.bits-1))) (srl lo, shamt))
2627   //  if isSRA:
2628   //    hi = (sra hi, shamt)
2629   //  else:
2630   //    hi = (srl hi, shamt)
2631   // else:
2632   //  if isSRA:
2633   //   lo = (sra hi, shamt[4:0])
2634   //   hi = (sra hi, 31)
2635   //  else:
2636   //   lo = (srl hi, shamt[4:0])
2637   //   hi = 0
2638   SDValue Not =
2639       DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2640                   DAG.getConstant(VT.getSizeInBits() - 1, DL, MVT::i32));
2641   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2642                                      DAG.getConstant(1, DL, VT));
2643   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2644   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2645   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2646   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2647                                      DL, VT, Hi, Shamt);
2648   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2649                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2650   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2651                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2652 
2653   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2654     SDVTList VTList = DAG.getVTList(VT, VT);
2655     return DAG.getNode(Subtarget.isGP64bit() ? Mips::PseudoD_SELECT_I64
2656                                              : Mips::PseudoD_SELECT_I,
2657                        DL, VTList, Cond, ShiftRightHi,
2658                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2659                        ShiftRightHi);
2660   }
2661 
2662   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2663   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2664                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2665 
2666   SDValue Ops[2] = {Lo, Hi};
2667   return DAG.getMergeValues(Ops, DL);
2668 }
2669 
2670 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2671                             SDValue Chain, SDValue Src, unsigned Offset) {
2672   SDValue Ptr = LD->getBasePtr();
2673   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2674   EVT BasePtrVT = Ptr.getValueType();
2675   SDLoc DL(LD);
2676   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2677 
2678   if (Offset)
2679     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2680                       DAG.getConstant(Offset, DL, BasePtrVT));
2681 
2682   SDValue Ops[] = { Chain, Ptr, Src };
2683   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2684                                  LD->getMemOperand());
2685 }
2686 
2687 // Expand an unaligned 32 or 64-bit integer load node.
2688 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2689   LoadSDNode *LD = cast<LoadSDNode>(Op);
2690   EVT MemVT = LD->getMemoryVT();
2691 
2692   if (Subtarget.systemSupportsUnalignedAccess())
2693     return Op;
2694 
2695   // Return if load is aligned or if MemVT is neither i32 nor i64.
2696   if ((LD->getAlign().value() >= (MemVT.getSizeInBits() / 8)) ||
2697       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2698     return SDValue();
2699 
2700   bool IsLittle = Subtarget.isLittle();
2701   EVT VT = Op.getValueType();
2702   ISD::LoadExtType ExtType = LD->getExtensionType();
2703   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2704 
2705   assert((VT == MVT::i32) || (VT == MVT::i64));
2706 
2707   // Expand
2708   //  (set dst, (i64 (load baseptr)))
2709   // to
2710   //  (set tmp, (ldl (add baseptr, 7), undef))
2711   //  (set dst, (ldr baseptr, tmp))
2712   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2713     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2714                                IsLittle ? 7 : 0);
2715     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2716                         IsLittle ? 0 : 7);
2717   }
2718 
2719   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2720                              IsLittle ? 3 : 0);
2721   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2722                              IsLittle ? 0 : 3);
2723 
2724   // Expand
2725   //  (set dst, (i32 (load baseptr))) or
2726   //  (set dst, (i64 (sextload baseptr))) or
2727   //  (set dst, (i64 (extload baseptr)))
2728   // to
2729   //  (set tmp, (lwl (add baseptr, 3), undef))
2730   //  (set dst, (lwr baseptr, tmp))
2731   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2732       (ExtType == ISD::EXTLOAD))
2733     return LWR;
2734 
2735   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2736 
2737   // Expand
2738   //  (set dst, (i64 (zextload baseptr)))
2739   // to
2740   //  (set tmp0, (lwl (add baseptr, 3), undef))
2741   //  (set tmp1, (lwr baseptr, tmp0))
2742   //  (set tmp2, (shl tmp1, 32))
2743   //  (set dst, (srl tmp2, 32))
2744   SDLoc DL(LD);
2745   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2746   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2747   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2748   SDValue Ops[] = { SRL, LWR.getValue(1) };
2749   return DAG.getMergeValues(Ops, DL);
2750 }
2751 
2752 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2753                              SDValue Chain, unsigned Offset) {
2754   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2755   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2756   SDLoc DL(SD);
2757   SDVTList VTList = DAG.getVTList(MVT::Other);
2758 
2759   if (Offset)
2760     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2761                       DAG.getConstant(Offset, DL, BasePtrVT));
2762 
2763   SDValue Ops[] = { Chain, Value, Ptr };
2764   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2765                                  SD->getMemOperand());
2766 }
2767 
2768 // Expand an unaligned 32 or 64-bit integer store node.
2769 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2770                                       bool IsLittle) {
2771   SDValue Value = SD->getValue(), Chain = SD->getChain();
2772   EVT VT = Value.getValueType();
2773 
2774   // Expand
2775   //  (store val, baseptr) or
2776   //  (truncstore val, baseptr)
2777   // to
2778   //  (swl val, (add baseptr, 3))
2779   //  (swr val, baseptr)
2780   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2781     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2782                                 IsLittle ? 3 : 0);
2783     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2784   }
2785 
2786   assert(VT == MVT::i64);
2787 
2788   // Expand
2789   //  (store val, baseptr)
2790   // to
2791   //  (sdl val, (add baseptr, 7))
2792   //  (sdr val, baseptr)
2793   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2794   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2795 }
2796 
2797 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2798 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2799                                      bool SingleFloat) {
2800   SDValue Val = SD->getValue();
2801 
2802   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2803       (Val.getValueSizeInBits() > 32 && SingleFloat))
2804     return SDValue();
2805 
2806   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2807   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2808                            Val.getOperand(0));
2809   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2810                       SD->getPointerInfo(), SD->getAlign(),
2811                       SD->getMemOperand()->getFlags());
2812 }
2813 
2814 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2815   StoreSDNode *SD = cast<StoreSDNode>(Op);
2816   EVT MemVT = SD->getMemoryVT();
2817 
2818   // Lower unaligned integer stores.
2819   if (!Subtarget.systemSupportsUnalignedAccess() &&
2820       (SD->getAlign().value() < (MemVT.getSizeInBits() / 8)) &&
2821       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2822     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2823 
2824   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2825 }
2826 
2827 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2828                                               SelectionDAG &DAG) const {
2829 
2830   // Return a fixed StackObject with offset 0 which points to the old stack
2831   // pointer.
2832   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2833   EVT ValTy = Op->getValueType(0);
2834   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2835   return DAG.getFrameIndex(FI, ValTy);
2836 }
2837 
2838 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2839                                             SelectionDAG &DAG) const {
2840   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2841     return SDValue();
2842 
2843   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2844   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2845                               Op.getOperand(0));
2846   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2847 }
2848 
2849 //===----------------------------------------------------------------------===//
2850 //                      Calling Convention Implementation
2851 //===----------------------------------------------------------------------===//
2852 
2853 //===----------------------------------------------------------------------===//
2854 // TODO: Implement a generic logic using tblgen that can support this.
2855 // Mips O32 ABI rules:
2856 // ---
2857 // i32 - Passed in A0, A1, A2, A3 and stack
2858 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2859 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2860 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2861 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2862 //       not used, it must be shadowed. If only A3 is available, shadow it and
2863 //       go to stack.
2864 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2865 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2866 //         with the remainder spilled to the stack.
2867 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2868 //         spilling the remainder to the stack.
2869 //
2870 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2871 //===----------------------------------------------------------------------===//
2872 
2873 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2874                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2875                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2876   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2877       State.getMachineFunction().getSubtarget());
2878 
2879   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2880 
2881   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2882 
2883   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2884 
2885   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2886 
2887   // Do not process byval args here.
2888   if (ArgFlags.isByVal())
2889     return true;
2890 
2891   // Promote i8 and i16
2892   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2893     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2894       LocVT = MVT::i32;
2895       if (ArgFlags.isSExt())
2896         LocInfo = CCValAssign::SExtUpper;
2897       else if (ArgFlags.isZExt())
2898         LocInfo = CCValAssign::ZExtUpper;
2899       else
2900         LocInfo = CCValAssign::AExtUpper;
2901     }
2902   }
2903 
2904   // Promote i8 and i16
2905   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2906     LocVT = MVT::i32;
2907     if (ArgFlags.isSExt())
2908       LocInfo = CCValAssign::SExt;
2909     else if (ArgFlags.isZExt())
2910       LocInfo = CCValAssign::ZExt;
2911     else
2912       LocInfo = CCValAssign::AExt;
2913   }
2914 
2915   unsigned Reg;
2916 
2917   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2918   // is true: function is vararg, argument is 3rd or higher, there is previous
2919   // argument which is not f32 or f64.
2920   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2921                                 State.getFirstUnallocated(F32Regs) != ValNo;
2922   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
2923   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
2924   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2925 
2926   // The MIPS vector ABI for floats passes them in a pair of registers
2927   if (ValVT == MVT::i32 && isVectorFloat) {
2928     // This is the start of an vector that was scalarized into an unknown number
2929     // of components. It doesn't matter how many there are. Allocate one of the
2930     // notional 8 byte aligned registers which map onto the argument stack, and
2931     // shadow the register lost to alignment requirements.
2932     if (ArgFlags.isSplit()) {
2933       Reg = State.AllocateReg(FloatVectorIntRegs);
2934       if (Reg == Mips::A2)
2935         State.AllocateReg(Mips::A1);
2936       else if (Reg == 0)
2937         State.AllocateReg(Mips::A3);
2938     } else {
2939       // If we're an intermediate component of the split, we can just attempt to
2940       // allocate a register directly.
2941       Reg = State.AllocateReg(IntRegs);
2942     }
2943   } else if (ValVT == MVT::i32 ||
2944              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2945     Reg = State.AllocateReg(IntRegs);
2946     // If this is the first part of an i64 arg,
2947     // the allocated register must be either A0 or A2.
2948     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2949       Reg = State.AllocateReg(IntRegs);
2950     LocVT = MVT::i32;
2951   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2952     // Allocate int register and shadow next int register. If first
2953     // available register is Mips::A1 or Mips::A3, shadow it too.
2954     Reg = State.AllocateReg(IntRegs);
2955     if (Reg == Mips::A1 || Reg == Mips::A3)
2956       Reg = State.AllocateReg(IntRegs);
2957 
2958     if (Reg) {
2959       LocVT = MVT::i32;
2960 
2961       State.addLoc(
2962           CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2963       MCRegister HiReg = State.AllocateReg(IntRegs);
2964       assert(HiReg);
2965       State.addLoc(
2966           CCValAssign::getCustomReg(ValNo, ValVT, HiReg, LocVT, LocInfo));
2967       return false;
2968     }
2969   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2970     // we are guaranteed to find an available float register
2971     if (ValVT == MVT::f32) {
2972       Reg = State.AllocateReg(F32Regs);
2973       // Shadow int register
2974       State.AllocateReg(IntRegs);
2975     } else {
2976       Reg = State.AllocateReg(F64Regs);
2977       // Shadow int registers
2978       unsigned Reg2 = State.AllocateReg(IntRegs);
2979       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2980         State.AllocateReg(IntRegs);
2981       State.AllocateReg(IntRegs);
2982     }
2983   } else
2984     llvm_unreachable("Cannot handle this ValVT.");
2985 
2986   if (!Reg) {
2987     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2988     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2989   } else
2990     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2991 
2992   return false;
2993 }
2994 
2995 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2996                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2997                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2998   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2999 
3000   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
3001 }
3002 
3003 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
3004                             MVT LocVT, CCValAssign::LocInfo LocInfo,
3005                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
3006   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
3007 
3008   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
3009 }
3010 
3011 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
3012                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
3013                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
3014 
3015 #include "MipsGenCallingConv.inc"
3016 
3017  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
3018    return CC_Mips_FixedArg;
3019  }
3020 
3021  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3022    return RetCC_Mips;
3023  }
3024 //===----------------------------------------------------------------------===//
3025 //                  Call Calling Convention Implementation
3026 //===----------------------------------------------------------------------===//
3027 
3028 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3029                                            SDValue Chain, SDValue Arg,
3030                                            const SDLoc &DL, bool IsTailCall,
3031                                            SelectionDAG &DAG) const {
3032   if (!IsTailCall) {
3033     SDValue PtrOff =
3034         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3035                     DAG.getIntPtrConstant(Offset, DL));
3036     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3037   }
3038 
3039   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3040   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3041   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3042   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(), MaybeAlign(),
3043                       MachineMemOperand::MOVolatile);
3044 }
3045 
3046 void MipsTargetLowering::
3047 getOpndList(SmallVectorImpl<SDValue> &Ops,
3048             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3049             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3050             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3051             SDValue Chain) const {
3052   // Insert node "GP copy globalreg" before call to function.
3053   //
3054   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3055   // in PIC mode) allow symbols to be resolved via lazy binding.
3056   // The lazy binding stub requires GP to point to the GOT.
3057   // Note that we don't need GP to point to the GOT for indirect calls
3058   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3059   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3060   // used for the function (that is, Mips linker doesn't generate lazy binding
3061   // stub for a function whose address is taken in the program).
3062   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3063     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3064     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3065     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3066   }
3067 
3068   // Build a sequence of copy-to-reg nodes chained together with token
3069   // chain and flag operands which copy the outgoing args into registers.
3070   // The InGlue in necessary since all emitted instructions must be
3071   // stuck together.
3072   SDValue InGlue;
3073 
3074   for (auto &R : RegsToPass) {
3075     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, R.first, R.second, InGlue);
3076     InGlue = Chain.getValue(1);
3077   }
3078 
3079   // Add argument registers to the end of the list so that they are
3080   // known live into the call.
3081   for (auto &R : RegsToPass)
3082     Ops.push_back(CLI.DAG.getRegister(R.first, R.second.getValueType()));
3083 
3084   // Add a register mask operand representing the call-preserved registers.
3085   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3086   const uint32_t *Mask =
3087       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3088   assert(Mask && "Missing call preserved mask for calling convention");
3089   if (Subtarget.inMips16HardFloat()) {
3090     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3091       StringRef Sym = G->getGlobal()->getName();
3092       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3093       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3094         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3095       }
3096     }
3097   }
3098   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3099 
3100   if (InGlue.getNode())
3101     Ops.push_back(InGlue);
3102 }
3103 
3104 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3105                                                        SDNode *Node) const {
3106   switch (MI.getOpcode()) {
3107     default:
3108       return;
3109     case Mips::JALR:
3110     case Mips::JALRPseudo:
3111     case Mips::JALR64:
3112     case Mips::JALR64Pseudo:
3113     case Mips::JALR16_MM:
3114     case Mips::JALRC16_MMR6:
3115     case Mips::TAILCALLREG:
3116     case Mips::TAILCALLREG64:
3117     case Mips::TAILCALLR6REG:
3118     case Mips::TAILCALL64R6REG:
3119     case Mips::TAILCALLREG_MM:
3120     case Mips::TAILCALLREG_MMR6: {
3121       if (!EmitJalrReloc ||
3122           Subtarget.inMips16Mode() ||
3123           !isPositionIndependent() ||
3124           Node->getNumOperands() < 1 ||
3125           Node->getOperand(0).getNumOperands() < 2) {
3126         return;
3127       }
3128       // We are after the callee address, set by LowerCall().
3129       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3130       // symbol.
3131       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3132       StringRef Sym;
3133       if (const GlobalAddressSDNode *G =
3134               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3135         // We must not emit the R_MIPS_JALR relocation against data symbols
3136         // since this will cause run-time crashes if the linker replaces the
3137         // call instruction with a relative branch to the data symbol.
3138         if (!isa<Function>(G->getGlobal())) {
3139           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3140                             << G->getGlobal()->getName() << "\n");
3141           return;
3142         }
3143         Sym = G->getGlobal()->getName();
3144       }
3145       else if (const ExternalSymbolSDNode *ES =
3146                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3147         Sym = ES->getSymbol();
3148       }
3149 
3150       if (Sym.empty())
3151         return;
3152 
3153       MachineFunction *MF = MI.getParent()->getParent();
3154       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3155       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3156       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3157     }
3158   }
3159 }
3160 
3161 /// LowerCall - functions arguments are copied from virtual regs to
3162 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3163 SDValue
3164 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3165                               SmallVectorImpl<SDValue> &InVals) const {
3166   SelectionDAG &DAG                     = CLI.DAG;
3167   SDLoc DL                              = CLI.DL;
3168   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3169   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3170   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3171   SDValue Chain                         = CLI.Chain;
3172   SDValue Callee                        = CLI.Callee;
3173   bool &IsTailCall                      = CLI.IsTailCall;
3174   CallingConv::ID CallConv              = CLI.CallConv;
3175   bool IsVarArg                         = CLI.IsVarArg;
3176 
3177   MachineFunction &MF = DAG.getMachineFunction();
3178   MachineFrameInfo &MFI = MF.getFrameInfo();
3179   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3180   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3181   bool IsPIC = isPositionIndependent();
3182 
3183   // Analyze operands of the call, assigning locations to each operand.
3184   SmallVector<CCValAssign, 16> ArgLocs;
3185   MipsCCState CCInfo(
3186       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3187       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3188 
3189   const ExternalSymbolSDNode *ES =
3190       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3191 
3192   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3193   // is during the lowering of a call with a byval argument which produces
3194   // a call to memcpy. For the O32 case, this causes the caller to allocate
3195   // stack space for the reserved argument area for the callee, then recursively
3196   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3197   // ABIs mandate that the callee allocates the reserved argument area. We do
3198   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3199   //
3200   // If the callee has a byval argument and memcpy is used, we are mandated
3201   // to already have produced a reserved argument area for the callee for O32.
3202   // Therefore, the reserved argument area can be reused for both calls.
3203   //
3204   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3205   // present, as we have yet to hook that node onto the chain.
3206   //
3207   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3208   // case. GCC does a similar trick, in that wherever possible, it calculates
3209   // the maximum out going argument area (including the reserved area), and
3210   // preallocates the stack space on entrance to the caller.
3211   //
3212   // FIXME: We should do the same for efficiency and space.
3213 
3214   // Note: The check on the calling convention below must match
3215   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3216   bool MemcpyInByVal = ES &&
3217                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
3218                        CallConv != CallingConv::Fast &&
3219                        Chain.getOpcode() == ISD::CALLSEQ_START;
3220 
3221   // Allocate the reserved argument area. It seems strange to do this from the
3222   // caller side but removing it breaks the frame size calculation.
3223   unsigned ReservedArgArea =
3224       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3225   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3226 
3227   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3228                              ES ? ES->getSymbol() : nullptr);
3229 
3230   // Get a count of how many bytes are to be pushed on the stack.
3231   unsigned StackSize = CCInfo.getStackSize();
3232 
3233   // Call site info for function parameters tracking.
3234   MachineFunction::CallSiteInfo CSInfo;
3235 
3236   // Check if it's really possible to do a tail call. Restrict it to functions
3237   // that are part of this compilation unit.
3238   bool InternalLinkage = false;
3239   if (IsTailCall) {
3240     IsTailCall = isEligibleForTailCallOptimization(
3241         CCInfo, StackSize, *MF.getInfo<MipsFunctionInfo>());
3242     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3243       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3244       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3245                      G->getGlobal()->hasPrivateLinkage() ||
3246                      G->getGlobal()->hasHiddenVisibility() ||
3247                      G->getGlobal()->hasProtectedVisibility());
3248      }
3249   }
3250   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3251     report_fatal_error("failed to perform tail call elimination on a call "
3252                        "site marked musttail");
3253 
3254   if (IsTailCall)
3255     ++NumTailCalls;
3256 
3257   // Chain is the output chain of the last Load/Store or CopyToReg node.
3258   // ByValChain is the output chain of the last Memcpy node created for copying
3259   // byval arguments to the stack.
3260   unsigned StackAlignment = TFL->getStackAlignment();
3261   StackSize = alignTo(StackSize, StackAlignment);
3262 
3263   if (!(IsTailCall || MemcpyInByVal))
3264     Chain = DAG.getCALLSEQ_START(Chain, StackSize, 0, DL);
3265 
3266   SDValue StackPtr =
3267       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3268                          getPointerTy(DAG.getDataLayout()));
3269 
3270   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3271   SmallVector<SDValue, 8> MemOpChains;
3272 
3273   CCInfo.rewindByValRegsInfo();
3274 
3275   // Walk the register/memloc assignments, inserting copies/loads.
3276   for (unsigned i = 0, e = ArgLocs.size(), OutIdx = 0; i != e; ++i, ++OutIdx) {
3277     SDValue Arg = OutVals[OutIdx];
3278     CCValAssign &VA = ArgLocs[i];
3279     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3280     ISD::ArgFlagsTy Flags = Outs[OutIdx].Flags;
3281     bool UseUpperBits = false;
3282 
3283     // ByVal Arg.
3284     if (Flags.isByVal()) {
3285       unsigned FirstByValReg, LastByValReg;
3286       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3287       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3288 
3289       assert(Flags.getByValSize() &&
3290              "ByVal args of size 0 should have been ignored by front-end.");
3291       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3292       assert(!IsTailCall &&
3293              "Do not tail-call optimize if there is a byval argument.");
3294       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3295                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3296                    VA);
3297       CCInfo.nextInRegsParam();
3298       continue;
3299     }
3300 
3301     // Promote the value if needed.
3302     switch (VA.getLocInfo()) {
3303     default:
3304       llvm_unreachable("Unknown loc info!");
3305     case CCValAssign::Full:
3306       if (VA.isRegLoc()) {
3307         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3308             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3309             (ValVT == MVT::i64 && LocVT == MVT::f64))
3310           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3311         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3312           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3313                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3314           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3315                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3316           if (!Subtarget.isLittle())
3317             std::swap(Lo, Hi);
3318 
3319           assert(VA.needsCustom());
3320 
3321           Register LocRegLo = VA.getLocReg();
3322           Register LocRegHigh = ArgLocs[++i].getLocReg();
3323           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3324           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3325           continue;
3326         }
3327       }
3328       break;
3329     case CCValAssign::BCvt:
3330       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3331       break;
3332     case CCValAssign::SExtUpper:
3333       UseUpperBits = true;
3334       [[fallthrough]];
3335     case CCValAssign::SExt:
3336       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3337       break;
3338     case CCValAssign::ZExtUpper:
3339       UseUpperBits = true;
3340       [[fallthrough]];
3341     case CCValAssign::ZExt:
3342       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3343       break;
3344     case CCValAssign::AExtUpper:
3345       UseUpperBits = true;
3346       [[fallthrough]];
3347     case CCValAssign::AExt:
3348       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3349       break;
3350     }
3351 
3352     if (UseUpperBits) {
3353       unsigned ValSizeInBits = Outs[OutIdx].ArgVT.getSizeInBits();
3354       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3355       Arg = DAG.getNode(
3356           ISD::SHL, DL, VA.getLocVT(), Arg,
3357           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3358     }
3359 
3360     // Arguments that can be passed on register must be kept at
3361     // RegsToPass vector
3362     if (VA.isRegLoc()) {
3363       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3364 
3365       // If the parameter is passed through reg $D, which splits into
3366       // two physical registers, avoid creating call site info.
3367       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3368         continue;
3369 
3370       // Collect CSInfo about which register passes which parameter.
3371       const TargetOptions &Options = DAG.getTarget().Options;
3372       if (Options.SupportsDebugEntryValues)
3373         CSInfo.emplace_back(VA.getLocReg(), i);
3374 
3375       continue;
3376     }
3377 
3378     // Register can't get to this point...
3379     assert(VA.isMemLoc());
3380 
3381     // emit ISD::STORE whichs stores the
3382     // parameter value to a stack Location
3383     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3384                                          Chain, Arg, DL, IsTailCall, DAG));
3385   }
3386 
3387   // Transform all store nodes into one single node because all store
3388   // nodes are independent of each other.
3389   if (!MemOpChains.empty())
3390     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3391 
3392   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3393   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3394   // node so that legalize doesn't hack it.
3395 
3396   EVT Ty = Callee.getValueType();
3397   bool GlobalOrExternal = false, IsCallReloc = false;
3398 
3399   // The long-calls feature is ignored in case of PIC.
3400   // While we do not support -mshared / -mno-shared properly,
3401   // ignore long-calls in case of -mabicalls too.
3402   if (!Subtarget.isABICalls() && !IsPIC) {
3403     // If the function should be called using "long call",
3404     // get its address into a register to prevent using
3405     // of the `jal` instruction for the direct call.
3406     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3407       if (Subtarget.useLongCalls())
3408         Callee = Subtarget.hasSym32()
3409                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3410                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3411     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3412       bool UseLongCalls = Subtarget.useLongCalls();
3413       // If the function has long-call/far/near attribute
3414       // it overrides command line switch pased to the backend.
3415       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3416         if (F->hasFnAttribute("long-call"))
3417           UseLongCalls = true;
3418         else if (F->hasFnAttribute("short-call"))
3419           UseLongCalls = false;
3420       }
3421       if (UseLongCalls)
3422         Callee = Subtarget.hasSym32()
3423                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3424                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3425     }
3426   }
3427 
3428   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3429     if (IsPIC) {
3430       const GlobalValue *Val = G->getGlobal();
3431       InternalLinkage = Val->hasInternalLinkage();
3432 
3433       if (InternalLinkage)
3434         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3435       else if (Subtarget.useXGOT()) {
3436         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3437                                        MipsII::MO_CALL_LO16, Chain,
3438                                        FuncInfo->callPtrInfo(MF, Val));
3439         IsCallReloc = true;
3440       } else {
3441         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3442                                FuncInfo->callPtrInfo(MF, Val));
3443         IsCallReloc = true;
3444       }
3445     } else
3446       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3447                                           getPointerTy(DAG.getDataLayout()), 0,
3448                                           MipsII::MO_NO_FLAG);
3449     GlobalOrExternal = true;
3450   }
3451   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3452     const char *Sym = S->getSymbol();
3453 
3454     if (!IsPIC) // static
3455       Callee = DAG.getTargetExternalSymbol(
3456           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3457     else if (Subtarget.useXGOT()) {
3458       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3459                                      MipsII::MO_CALL_LO16, Chain,
3460                                      FuncInfo->callPtrInfo(MF, Sym));
3461       IsCallReloc = true;
3462     } else { // PIC
3463       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3464                              FuncInfo->callPtrInfo(MF, Sym));
3465       IsCallReloc = true;
3466     }
3467 
3468     GlobalOrExternal = true;
3469   }
3470 
3471   SmallVector<SDValue, 8> Ops(1, Chain);
3472   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3473 
3474   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3475               IsCallReloc, CLI, Callee, Chain);
3476 
3477   if (IsTailCall) {
3478     MF.getFrameInfo().setHasTailCall();
3479     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3480     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3481     return Ret;
3482   }
3483 
3484   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3485   SDValue InGlue = Chain.getValue(1);
3486 
3487   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3488 
3489   // Create the CALLSEQ_END node in the case of where it is not a call to
3490   // memcpy.
3491   if (!(MemcpyInByVal)) {
3492     Chain = DAG.getCALLSEQ_END(Chain, StackSize, 0, InGlue, DL);
3493     InGlue = Chain.getValue(1);
3494   }
3495 
3496   // Handle result values, copying them out of physregs into vregs that we
3497   // return.
3498   return LowerCallResult(Chain, InGlue, CallConv, IsVarArg, Ins, DL, DAG,
3499                          InVals, CLI);
3500 }
3501 
3502 /// LowerCallResult - Lower the result values of a call into the
3503 /// appropriate copies out of appropriate physical registers.
3504 SDValue MipsTargetLowering::LowerCallResult(
3505     SDValue Chain, SDValue InGlue, CallingConv::ID CallConv, bool IsVarArg,
3506     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3507     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3508     TargetLowering::CallLoweringInfo &CLI) const {
3509   // Assign locations to each value returned by this call.
3510   SmallVector<CCValAssign, 16> RVLocs;
3511   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3512                      *DAG.getContext());
3513 
3514   const ExternalSymbolSDNode *ES =
3515       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3516   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3517                            ES ? ES->getSymbol() : nullptr);
3518 
3519   // Copy all of the result registers out of their specified physreg.
3520   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3521     CCValAssign &VA = RVLocs[i];
3522     assert(VA.isRegLoc() && "Can only return in registers!");
3523 
3524     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3525                                      RVLocs[i].getLocVT(), InGlue);
3526     Chain = Val.getValue(1);
3527     InGlue = Val.getValue(2);
3528 
3529     if (VA.isUpperBitsInLoc()) {
3530       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3531       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3532       unsigned Shift =
3533           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3534       Val = DAG.getNode(
3535           Shift, DL, VA.getLocVT(), Val,
3536           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3537     }
3538 
3539     switch (VA.getLocInfo()) {
3540     default:
3541       llvm_unreachable("Unknown loc info!");
3542     case CCValAssign::Full:
3543       break;
3544     case CCValAssign::BCvt:
3545       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3546       break;
3547     case CCValAssign::AExt:
3548     case CCValAssign::AExtUpper:
3549       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3550       break;
3551     case CCValAssign::ZExt:
3552     case CCValAssign::ZExtUpper:
3553       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3554                         DAG.getValueType(VA.getValVT()));
3555       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3556       break;
3557     case CCValAssign::SExt:
3558     case CCValAssign::SExtUpper:
3559       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3560                         DAG.getValueType(VA.getValVT()));
3561       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3562       break;
3563     }
3564 
3565     InVals.push_back(Val);
3566   }
3567 
3568   return Chain;
3569 }
3570 
3571 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3572                                       EVT ArgVT, const SDLoc &DL,
3573                                       SelectionDAG &DAG) {
3574   MVT LocVT = VA.getLocVT();
3575   EVT ValVT = VA.getValVT();
3576 
3577   // Shift into the upper bits if necessary.
3578   switch (VA.getLocInfo()) {
3579   default:
3580     break;
3581   case CCValAssign::AExtUpper:
3582   case CCValAssign::SExtUpper:
3583   case CCValAssign::ZExtUpper: {
3584     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3585     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3586     unsigned Opcode =
3587         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3588     Val = DAG.getNode(
3589         Opcode, DL, VA.getLocVT(), Val,
3590         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3591     break;
3592   }
3593   }
3594 
3595   // If this is an value smaller than the argument slot size (32-bit for O32,
3596   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3597   // size. Extract the value and insert any appropriate assertions regarding
3598   // sign/zero extension.
3599   switch (VA.getLocInfo()) {
3600   default:
3601     llvm_unreachable("Unknown loc info!");
3602   case CCValAssign::Full:
3603     break;
3604   case CCValAssign::AExtUpper:
3605   case CCValAssign::AExt:
3606     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3607     break;
3608   case CCValAssign::SExtUpper:
3609   case CCValAssign::SExt:
3610     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3611     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3612     break;
3613   case CCValAssign::ZExtUpper:
3614   case CCValAssign::ZExt:
3615     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3616     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3617     break;
3618   case CCValAssign::BCvt:
3619     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3620     break;
3621   }
3622 
3623   return Val;
3624 }
3625 
3626 //===----------------------------------------------------------------------===//
3627 //             Formal Arguments Calling Convention Implementation
3628 //===----------------------------------------------------------------------===//
3629 /// LowerFormalArguments - transform physical registers into virtual registers
3630 /// and generate load operations for arguments places on the stack.
3631 SDValue MipsTargetLowering::LowerFormalArguments(
3632     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3633     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3634     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3635   MachineFunction &MF = DAG.getMachineFunction();
3636   MachineFrameInfo &MFI = MF.getFrameInfo();
3637   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3638 
3639   MipsFI->setVarArgsFrameIndex(0);
3640 
3641   // Used with vargs to acumulate store chains.
3642   std::vector<SDValue> OutChains;
3643 
3644   // Assign locations to all of the incoming arguments.
3645   SmallVector<CCValAssign, 16> ArgLocs;
3646   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3647                      *DAG.getContext());
3648   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3649   const Function &Func = DAG.getMachineFunction().getFunction();
3650   Function::const_arg_iterator FuncArg = Func.arg_begin();
3651 
3652   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3653     report_fatal_error(
3654         "Functions with the interrupt attribute cannot have arguments!");
3655 
3656   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3657   MipsFI->setFormalArgInfo(CCInfo.getStackSize(),
3658                            CCInfo.getInRegsParamsCount() > 0);
3659 
3660   unsigned CurArgIdx = 0;
3661   CCInfo.rewindByValRegsInfo();
3662 
3663   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3664     CCValAssign &VA = ArgLocs[i];
3665     if (Ins[InsIdx].isOrigArg()) {
3666       std::advance(FuncArg, Ins[InsIdx].getOrigArgIndex() - CurArgIdx);
3667       CurArgIdx = Ins[InsIdx].getOrigArgIndex();
3668     }
3669     EVT ValVT = VA.getValVT();
3670     ISD::ArgFlagsTy Flags = Ins[InsIdx].Flags;
3671     bool IsRegLoc = VA.isRegLoc();
3672 
3673     if (Flags.isByVal()) {
3674       assert(Ins[InsIdx].isOrigArg() && "Byval arguments cannot be implicit");
3675       unsigned FirstByValReg, LastByValReg;
3676       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3677       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3678 
3679       assert(Flags.getByValSize() &&
3680              "ByVal args of size 0 should have been ignored by front-end.");
3681       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3682       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3683                     FirstByValReg, LastByValReg, VA, CCInfo);
3684       CCInfo.nextInRegsParam();
3685       continue;
3686     }
3687 
3688     // Arguments stored on registers
3689     if (IsRegLoc) {
3690       MVT RegVT = VA.getLocVT();
3691       Register ArgReg = VA.getLocReg();
3692       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3693 
3694       // Transform the arguments stored on
3695       // physical registers into virtual ones
3696       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3697       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3698 
3699       ArgValue =
3700           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3701 
3702       // Handle floating point arguments passed in integer registers and
3703       // long double arguments passed in floating point registers.
3704       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3705           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3706           (RegVT == MVT::f64 && ValVT == MVT::i64))
3707         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3708       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3709                ValVT == MVT::f64) {
3710         assert(VA.needsCustom() && "Expected custom argument for f64 split");
3711         CCValAssign &NextVA = ArgLocs[++i];
3712         unsigned Reg2 =
3713             addLiveIn(DAG.getMachineFunction(), NextVA.getLocReg(), RC);
3714         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3715         if (!Subtarget.isLittle())
3716           std::swap(ArgValue, ArgValue2);
3717         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3718                                ArgValue, ArgValue2);
3719       }
3720 
3721       InVals.push_back(ArgValue);
3722     } else { // VA.isRegLoc()
3723       MVT LocVT = VA.getLocVT();
3724 
3725       assert(!VA.needsCustom() && "unexpected custom memory argument");
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 Glue;
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, Glue);
3882 
3883     // Guarantee that all emitted copies are stuck together with flags.
3884     Glue = 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, Glue);
3903     Glue = 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 glue if we have it.
3910   if (Glue.getNode())
3911     RetOps.push_back(Glue);
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(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.starts_with("$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                                                       StringRef 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.size() > 1)
4201     return;
4202 
4203   char ConstraintLetter = Constraint[0];
4204   switch (ConstraintLetter) {
4205   default: break; // This will fall through to the generic implementation
4206   case 'I': // Signed 16 bit constant
4207     // If this fails, the parent routine will give an error
4208     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4209       EVT Type = Op.getValueType();
4210       int64_t Val = C->getSExtValue();
4211       if (isInt<16>(Val)) {
4212         Result = DAG.getTargetConstant(Val, DL, Type);
4213         break;
4214       }
4215     }
4216     return;
4217   case 'J': // integer zero
4218     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4219       EVT Type = Op.getValueType();
4220       int64_t Val = C->getZExtValue();
4221       if (Val == 0) {
4222         Result = DAG.getTargetConstant(0, DL, Type);
4223         break;
4224       }
4225     }
4226     return;
4227   case 'K': // unsigned 16 bit immediate
4228     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4229       EVT Type = Op.getValueType();
4230       uint64_t Val = (uint64_t)C->getZExtValue();
4231       if (isUInt<16>(Val)) {
4232         Result = DAG.getTargetConstant(Val, DL, Type);
4233         break;
4234       }
4235     }
4236     return;
4237   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4238     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4239       EVT Type = Op.getValueType();
4240       int64_t Val = C->getSExtValue();
4241       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4242         Result = DAG.getTargetConstant(Val, DL, Type);
4243         break;
4244       }
4245     }
4246     return;
4247   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4248     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4249       EVT Type = Op.getValueType();
4250       int64_t Val = C->getSExtValue();
4251       if ((Val >= -65535) && (Val <= -1)) {
4252         Result = DAG.getTargetConstant(Val, DL, Type);
4253         break;
4254       }
4255     }
4256     return;
4257   case 'O': // signed 15 bit immediate
4258     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4259       EVT Type = Op.getValueType();
4260       int64_t Val = C->getSExtValue();
4261       if ((isInt<15>(Val))) {
4262         Result = DAG.getTargetConstant(Val, DL, Type);
4263         break;
4264       }
4265     }
4266     return;
4267   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4268     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4269       EVT Type = Op.getValueType();
4270       int64_t Val = C->getSExtValue();
4271       if ((Val <= 65535) && (Val >= 1)) {
4272         Result = DAG.getTargetConstant(Val, DL, Type);
4273         break;
4274       }
4275     }
4276     return;
4277   }
4278 
4279   if (Result.getNode()) {
4280     Ops.push_back(Result);
4281     return;
4282   }
4283 
4284   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4285 }
4286 
4287 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4288                                                const AddrMode &AM, Type *Ty,
4289                                                unsigned AS,
4290                                                Instruction *I) const {
4291   // No global is ever allowed as a base.
4292   if (AM.BaseGV)
4293     return false;
4294 
4295   switch (AM.Scale) {
4296   case 0: // "r+i" or just "i", depending on HasBaseReg.
4297     break;
4298   case 1:
4299     if (!AM.HasBaseReg) // allow "r+i".
4300       break;
4301     return false; // disallow "r+r" or "r+r+i".
4302   default:
4303     return false;
4304   }
4305 
4306   return true;
4307 }
4308 
4309 bool
4310 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4311   // The Mips target isn't yet aware of offsets.
4312   return false;
4313 }
4314 
4315 EVT MipsTargetLowering::getOptimalMemOpType(
4316     const MemOp &Op, const AttributeList &FuncAttributes) const {
4317   if (Subtarget.hasMips64())
4318     return MVT::i64;
4319 
4320   return MVT::i32;
4321 }
4322 
4323 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4324                                       bool ForCodeSize) const {
4325   if (VT != MVT::f32 && VT != MVT::f64)
4326     return false;
4327   if (Imm.isNegZero())
4328     return false;
4329   return Imm.isZero();
4330 }
4331 
4332 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4333 
4334   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4335   if (ABI.IsN64() && isPositionIndependent())
4336     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4337 
4338   return TargetLowering::getJumpTableEncoding();
4339 }
4340 
4341 bool MipsTargetLowering::useSoftFloat() const {
4342   return Subtarget.useSoftFloat();
4343 }
4344 
4345 void MipsTargetLowering::copyByValRegs(
4346     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4347     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4348     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4349     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4350     MipsCCState &State) const {
4351   MachineFunction &MF = DAG.getMachineFunction();
4352   MachineFrameInfo &MFI = MF.getFrameInfo();
4353   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4354   unsigned NumRegs = LastReg - FirstReg;
4355   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4356   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4357   int FrameObjOffset;
4358   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4359 
4360   if (RegAreaSize)
4361     FrameObjOffset =
4362         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4363         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4364   else
4365     FrameObjOffset = VA.getLocMemOffset();
4366 
4367   // Create frame object.
4368   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4369   // Make the fixed object stored to mutable so that the load instructions
4370   // referencing it have their memory dependencies added.
4371   // Set the frame object as isAliased which clears the underlying objects
4372   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4373   // stores as dependencies for loads referencing this fixed object.
4374   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4375   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4376   InVals.push_back(FIN);
4377 
4378   if (!NumRegs)
4379     return;
4380 
4381   // Copy arg registers.
4382   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4383   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4384 
4385   for (unsigned I = 0; I < NumRegs; ++I) {
4386     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4387     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4388     unsigned Offset = I * GPRSizeInBytes;
4389     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4390                                    DAG.getConstant(Offset, DL, PtrTy));
4391     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4392                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4393     OutChains.push_back(Store);
4394   }
4395 }
4396 
4397 // Copy byVal arg to registers and stack.
4398 void MipsTargetLowering::passByValArg(
4399     SDValue Chain, const SDLoc &DL,
4400     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4401     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4402     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4403     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4404     const CCValAssign &VA) const {
4405   unsigned ByValSizeInBytes = Flags.getByValSize();
4406   unsigned OffsetInBytes = 0; // From beginning of struct
4407   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4408   Align Alignment =
4409       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4410   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4411       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4412   unsigned NumRegs = LastReg - FirstReg;
4413 
4414   if (NumRegs) {
4415     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4416     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4417     unsigned I = 0;
4418 
4419     // Copy words to registers.
4420     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4421       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4422                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4423       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4424                                     MachinePointerInfo(), Alignment);
4425       MemOpChains.push_back(LoadVal.getValue(1));
4426       unsigned ArgReg = ArgRegs[FirstReg + I];
4427       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4428     }
4429 
4430     // Return if the struct has been fully copied.
4431     if (ByValSizeInBytes == OffsetInBytes)
4432       return;
4433 
4434     // Copy the remainder of the byval argument with sub-word loads and shifts.
4435     if (LeftoverBytes) {
4436       SDValue Val;
4437 
4438       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4439            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4440         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4441 
4442         if (RemainingSizeInBytes < LoadSizeInBytes)
4443           continue;
4444 
4445         // Load subword.
4446         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4447                                       DAG.getConstant(OffsetInBytes, DL,
4448                                                       PtrTy));
4449         SDValue LoadVal = DAG.getExtLoad(
4450             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4451             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4452         MemOpChains.push_back(LoadVal.getValue(1));
4453 
4454         // Shift the loaded value.
4455         unsigned Shamt;
4456 
4457         if (isLittle)
4458           Shamt = TotalBytesLoaded * 8;
4459         else
4460           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4461 
4462         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4463                                     DAG.getConstant(Shamt, DL, MVT::i32));
4464 
4465         if (Val.getNode())
4466           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4467         else
4468           Val = Shift;
4469 
4470         OffsetInBytes += LoadSizeInBytes;
4471         TotalBytesLoaded += LoadSizeInBytes;
4472         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4473       }
4474 
4475       unsigned ArgReg = ArgRegs[FirstReg + I];
4476       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4477       return;
4478     }
4479   }
4480 
4481   // Copy remainder of byval arg to it with memcpy.
4482   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4483   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4484                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4485   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4486                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4487   Chain = DAG.getMemcpy(
4488       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4489       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4490       /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
4491   MemOpChains.push_back(Chain);
4492 }
4493 
4494 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4495                                          SDValue Chain, const SDLoc &DL,
4496                                          SelectionDAG &DAG,
4497                                          CCState &State) const {
4498   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4499   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4500   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4501   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4502   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4503   MachineFunction &MF = DAG.getMachineFunction();
4504   MachineFrameInfo &MFI = MF.getFrameInfo();
4505   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4506 
4507   // Offset of the first variable argument from stack pointer.
4508   int VaArgOffset;
4509 
4510   if (ArgRegs.size() == Idx)
4511     VaArgOffset = alignTo(State.getStackSize(), RegSizeInBytes);
4512   else {
4513     VaArgOffset =
4514         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4515         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4516   }
4517 
4518   // Record the frame index of the first variable argument
4519   // which is a value necessary to VASTART.
4520   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4521   MipsFI->setVarArgsFrameIndex(FI);
4522 
4523   // Copy the integer registers that have not been used for argument passing
4524   // to the argument register save area. For O32, the save area is allocated
4525   // in the caller's stack frame, while for N32/64, it is allocated in the
4526   // callee's stack frame.
4527   for (unsigned I = Idx; I < ArgRegs.size();
4528        ++I, VaArgOffset += RegSizeInBytes) {
4529     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4530     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4531     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4532     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4533     SDValue Store =
4534         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4535     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4536         (Value *)nullptr);
4537     OutChains.push_back(Store);
4538   }
4539 }
4540 
4541 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4542                                      Align Alignment) const {
4543   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4544 
4545   assert(Size && "Byval argument's size shouldn't be 0.");
4546 
4547   Alignment = std::min(Alignment, TFL->getStackAlign());
4548 
4549   unsigned FirstReg = 0;
4550   unsigned NumRegs = 0;
4551 
4552   if (State->getCallingConv() != CallingConv::Fast) {
4553     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4554     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4555     // FIXME: The O32 case actually describes no shadow registers.
4556     const MCPhysReg *ShadowRegs =
4557         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4558 
4559     // We used to check the size as well but we can't do that anymore since
4560     // CCState::HandleByVal() rounds up the size after calling this function.
4561     assert(
4562         Alignment >= Align(RegSizeInBytes) &&
4563         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4564 
4565     FirstReg = State->getFirstUnallocated(IntArgRegs);
4566 
4567     // If Alignment > RegSizeInBytes, the first arg register must be even.
4568     // FIXME: This condition happens to do the right thing but it's not the
4569     //        right way to test it. We want to check that the stack frame offset
4570     //        of the register is aligned.
4571     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4572       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4573       ++FirstReg;
4574     }
4575 
4576     // Mark the registers allocated.
4577     Size = alignTo(Size, RegSizeInBytes);
4578     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4579          Size -= RegSizeInBytes, ++I, ++NumRegs)
4580       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4581   }
4582 
4583   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4584 }
4585 
4586 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4587                                                         MachineBasicBlock *BB,
4588                                                         bool isFPCmp,
4589                                                         unsigned Opc) const {
4590   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4591          "Subtarget already supports SELECT nodes with the use of"
4592          "conditional-move instructions.");
4593 
4594   const TargetInstrInfo *TII =
4595       Subtarget.getInstrInfo();
4596   DebugLoc DL = MI.getDebugLoc();
4597 
4598   // To "insert" a SELECT instruction, we actually have to insert the
4599   // diamond control-flow pattern.  The incoming instruction knows the
4600   // destination vreg to set, the condition code register to branch on, the
4601   // true/false values to select between, and a branch opcode to use.
4602   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4603   MachineFunction::iterator It = ++BB->getIterator();
4604 
4605   //  thisMBB:
4606   //  ...
4607   //   TrueVal = ...
4608   //   setcc r1, r2, r3
4609   //   bNE   r1, r0, copy1MBB
4610   //   fallthrough --> copy0MBB
4611   MachineBasicBlock *thisMBB  = BB;
4612   MachineFunction *F = BB->getParent();
4613   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4614   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4615   F->insert(It, copy0MBB);
4616   F->insert(It, sinkMBB);
4617 
4618   // Transfer the remainder of BB and its successor edges to sinkMBB.
4619   sinkMBB->splice(sinkMBB->begin(), BB,
4620                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4621   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4622 
4623   // Next, add the true and fallthrough blocks as its successors.
4624   BB->addSuccessor(copy0MBB);
4625   BB->addSuccessor(sinkMBB);
4626 
4627   if (isFPCmp) {
4628     // bc1[tf] cc, sinkMBB
4629     BuildMI(BB, DL, TII->get(Opc))
4630         .addReg(MI.getOperand(1).getReg())
4631         .addMBB(sinkMBB);
4632   } else {
4633     // bne rs, $0, sinkMBB
4634     BuildMI(BB, DL, TII->get(Opc))
4635         .addReg(MI.getOperand(1).getReg())
4636         .addReg(Mips::ZERO)
4637         .addMBB(sinkMBB);
4638   }
4639 
4640   //  copy0MBB:
4641   //   %FalseValue = ...
4642   //   # fallthrough to sinkMBB
4643   BB = copy0MBB;
4644 
4645   // Update machine-CFG edges
4646   BB->addSuccessor(sinkMBB);
4647 
4648   //  sinkMBB:
4649   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4650   //  ...
4651   BB = sinkMBB;
4652 
4653   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4654       .addReg(MI.getOperand(2).getReg())
4655       .addMBB(thisMBB)
4656       .addReg(MI.getOperand(3).getReg())
4657       .addMBB(copy0MBB);
4658 
4659   MI.eraseFromParent(); // The pseudo instruction is gone now.
4660 
4661   return BB;
4662 }
4663 
4664 MachineBasicBlock *
4665 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4666                                        MachineBasicBlock *BB) const {
4667   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4668          "Subtarget already supports SELECT nodes with the use of"
4669          "conditional-move instructions.");
4670 
4671   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4672   DebugLoc DL = MI.getDebugLoc();
4673 
4674   // D_SELECT substitutes two SELECT nodes that goes one after another and
4675   // have the same condition operand. On machines which don't have
4676   // conditional-move instruction, it reduces unnecessary branch instructions
4677   // which are result of using two diamond patterns that are result of two
4678   // SELECT pseudo instructions.
4679   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4680   MachineFunction::iterator It = ++BB->getIterator();
4681 
4682   //  thisMBB:
4683   //  ...
4684   //   TrueVal = ...
4685   //   setcc r1, r2, r3
4686   //   bNE   r1, r0, copy1MBB
4687   //   fallthrough --> copy0MBB
4688   MachineBasicBlock *thisMBB = BB;
4689   MachineFunction *F = BB->getParent();
4690   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4691   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4692   F->insert(It, copy0MBB);
4693   F->insert(It, sinkMBB);
4694 
4695   // Transfer the remainder of BB and its successor edges to sinkMBB.
4696   sinkMBB->splice(sinkMBB->begin(), BB,
4697                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4698   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4699 
4700   // Next, add the true and fallthrough blocks as its successors.
4701   BB->addSuccessor(copy0MBB);
4702   BB->addSuccessor(sinkMBB);
4703 
4704   // bne rs, $0, sinkMBB
4705   BuildMI(BB, DL, TII->get(Mips::BNE))
4706       .addReg(MI.getOperand(2).getReg())
4707       .addReg(Mips::ZERO)
4708       .addMBB(sinkMBB);
4709 
4710   //  copy0MBB:
4711   //   %FalseValue = ...
4712   //   # fallthrough to sinkMBB
4713   BB = copy0MBB;
4714 
4715   // Update machine-CFG edges
4716   BB->addSuccessor(sinkMBB);
4717 
4718   //  sinkMBB:
4719   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4720   //  ...
4721   BB = sinkMBB;
4722 
4723   // Use two PHI nodes to select two reults
4724   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4725       .addReg(MI.getOperand(3).getReg())
4726       .addMBB(thisMBB)
4727       .addReg(MI.getOperand(5).getReg())
4728       .addMBB(copy0MBB);
4729   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4730       .addReg(MI.getOperand(4).getReg())
4731       .addMBB(thisMBB)
4732       .addReg(MI.getOperand(6).getReg())
4733       .addMBB(copy0MBB);
4734 
4735   MI.eraseFromParent(); // The pseudo instruction is gone now.
4736 
4737   return BB;
4738 }
4739 
4740 // FIXME? Maybe this could be a TableGen attribute on some registers and
4741 // this table could be generated automatically from RegInfo.
4742 Register
4743 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4744                                       const MachineFunction &MF) const {
4745   // The Linux kernel uses $28 and sp.
4746   if (Subtarget.isGP64bit()) {
4747     Register Reg = StringSwitch<Register>(RegName)
4748                        .Case("$28", Mips::GP_64)
4749                        .Case("sp", Mips::SP_64)
4750                        .Default(Register());
4751     if (Reg)
4752       return Reg;
4753   } else {
4754     Register Reg = StringSwitch<Register>(RegName)
4755                        .Case("$28", Mips::GP)
4756                        .Case("sp", Mips::SP)
4757                        .Default(Register());
4758     if (Reg)
4759       return Reg;
4760   }
4761   report_fatal_error("Invalid register name global variable");
4762 }
4763 
4764 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4765                                                  MachineBasicBlock *BB) const {
4766   MachineFunction *MF = BB->getParent();
4767   MachineRegisterInfo &MRI = MF->getRegInfo();
4768   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4769   const bool IsLittle = Subtarget.isLittle();
4770   DebugLoc DL = MI.getDebugLoc();
4771 
4772   Register Dest = MI.getOperand(0).getReg();
4773   Register Address = MI.getOperand(1).getReg();
4774   unsigned Imm = MI.getOperand(2).getImm();
4775 
4776   MachineBasicBlock::iterator I(MI);
4777 
4778   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4779     // Mips release 6 can load from adress that is not naturally-aligned.
4780     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4781     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4782         .addDef(Temp)
4783         .addUse(Address)
4784         .addImm(Imm);
4785     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4786   } else {
4787     // Mips release 5 needs to use instructions that can load from an unaligned
4788     // memory address.
4789     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4790     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4791     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4792     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4793     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4794         .addDef(LoadHalf)
4795         .addUse(Address)
4796         .addImm(Imm + (IsLittle ? 0 : 3))
4797         .addUse(Undef);
4798     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4799         .addDef(LoadFull)
4800         .addUse(Address)
4801         .addImm(Imm + (IsLittle ? 3 : 0))
4802         .addUse(LoadHalf);
4803     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4804   }
4805 
4806   MI.eraseFromParent();
4807   return BB;
4808 }
4809 
4810 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4811                                                  MachineBasicBlock *BB) const {
4812   MachineFunction *MF = BB->getParent();
4813   MachineRegisterInfo &MRI = MF->getRegInfo();
4814   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4815   const bool IsLittle = Subtarget.isLittle();
4816   DebugLoc DL = MI.getDebugLoc();
4817 
4818   Register Dest = MI.getOperand(0).getReg();
4819   Register Address = MI.getOperand(1).getReg();
4820   unsigned Imm = MI.getOperand(2).getImm();
4821 
4822   MachineBasicBlock::iterator I(MI);
4823 
4824   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4825     // Mips release 6 can load from adress that is not naturally-aligned.
4826     if (Subtarget.isGP64bit()) {
4827       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4828       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4829           .addDef(Temp)
4830           .addUse(Address)
4831           .addImm(Imm);
4832       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4833     } else {
4834       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4835       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4836       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4837       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4838           .addDef(Lo)
4839           .addUse(Address)
4840           .addImm(Imm + (IsLittle ? 0 : 4));
4841       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4842           .addDef(Hi)
4843           .addUse(Address)
4844           .addImm(Imm + (IsLittle ? 4 : 0));
4845       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4846       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4847           .addUse(Wtemp)
4848           .addUse(Hi)
4849           .addImm(1);
4850     }
4851   } else {
4852     // Mips release 5 needs to use instructions that can load from an unaligned
4853     // memory address.
4854     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4855     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4856     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4857     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4858     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4859     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4860     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4861     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4862     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4863         .addDef(LoHalf)
4864         .addUse(Address)
4865         .addImm(Imm + (IsLittle ? 0 : 7))
4866         .addUse(LoUndef);
4867     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4868         .addDef(LoFull)
4869         .addUse(Address)
4870         .addImm(Imm + (IsLittle ? 3 : 4))
4871         .addUse(LoHalf);
4872     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4873     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4874         .addDef(HiHalf)
4875         .addUse(Address)
4876         .addImm(Imm + (IsLittle ? 4 : 3))
4877         .addUse(HiUndef);
4878     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4879         .addDef(HiFull)
4880         .addUse(Address)
4881         .addImm(Imm + (IsLittle ? 7 : 0))
4882         .addUse(HiHalf);
4883     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4884     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4885         .addUse(Wtemp)
4886         .addUse(HiFull)
4887         .addImm(1);
4888   }
4889 
4890   MI.eraseFromParent();
4891   return BB;
4892 }
4893 
4894 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4895                                                  MachineBasicBlock *BB) const {
4896   MachineFunction *MF = BB->getParent();
4897   MachineRegisterInfo &MRI = MF->getRegInfo();
4898   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4899   const bool IsLittle = Subtarget.isLittle();
4900   DebugLoc DL = MI.getDebugLoc();
4901 
4902   Register StoreVal = MI.getOperand(0).getReg();
4903   Register Address = MI.getOperand(1).getReg();
4904   unsigned Imm = MI.getOperand(2).getImm();
4905 
4906   MachineBasicBlock::iterator I(MI);
4907 
4908   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4909     // Mips release 6 can store to adress that is not naturally-aligned.
4910     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4911     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4912     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
4913     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4914         .addDef(Tmp)
4915         .addUse(BitcastW)
4916         .addImm(0);
4917     BuildMI(*BB, I, DL, TII->get(Mips::SW))
4918         .addUse(Tmp)
4919         .addUse(Address)
4920         .addImm(Imm);
4921   } else {
4922     // Mips release 5 needs to use instructions that can store to an unaligned
4923     // memory address.
4924     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4925     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4926         .addDef(Tmp)
4927         .addUse(StoreVal)
4928         .addImm(0);
4929     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4930         .addUse(Tmp)
4931         .addUse(Address)
4932         .addImm(Imm + (IsLittle ? 0 : 3));
4933     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
4934         .addUse(Tmp)
4935         .addUse(Address)
4936         .addImm(Imm + (IsLittle ? 3 : 0));
4937   }
4938 
4939   MI.eraseFromParent();
4940 
4941   return BB;
4942 }
4943 
4944 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
4945                                                  MachineBasicBlock *BB) const {
4946   MachineFunction *MF = BB->getParent();
4947   MachineRegisterInfo &MRI = MF->getRegInfo();
4948   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4949   const bool IsLittle = Subtarget.isLittle();
4950   DebugLoc DL = MI.getDebugLoc();
4951 
4952   Register StoreVal = MI.getOperand(0).getReg();
4953   Register Address = MI.getOperand(1).getReg();
4954   unsigned Imm = MI.getOperand(2).getImm();
4955 
4956   MachineBasicBlock::iterator I(MI);
4957 
4958   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4959     // Mips release 6 can store to adress that is not naturally-aligned.
4960     if (Subtarget.isGP64bit()) {
4961       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
4962       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4963       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4964           .addDef(BitcastD)
4965           .addUse(StoreVal);
4966       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
4967           .addDef(Lo)
4968           .addUse(BitcastD)
4969           .addImm(0);
4970       BuildMI(*BB, I, DL, TII->get(Mips::SD))
4971           .addUse(Lo)
4972           .addUse(Address)
4973           .addImm(Imm);
4974     } else {
4975       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4976       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4977       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4978       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4979           .addDef(BitcastW)
4980           .addUse(StoreVal);
4981       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4982           .addDef(Lo)
4983           .addUse(BitcastW)
4984           .addImm(0);
4985       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4986           .addDef(Hi)
4987           .addUse(BitcastW)
4988           .addImm(1);
4989       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4990           .addUse(Lo)
4991           .addUse(Address)
4992           .addImm(Imm + (IsLittle ? 0 : 4));
4993       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4994           .addUse(Hi)
4995           .addUse(Address)
4996           .addImm(Imm + (IsLittle ? 4 : 0));
4997     }
4998   } else {
4999     // Mips release 5 needs to use instructions that can store to an unaligned
5000     // memory address.
5001     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
5002     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5003     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
5004     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
5005     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5006         .addDef(Lo)
5007         .addUse(Bitcast)
5008         .addImm(0);
5009     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
5010         .addDef(Hi)
5011         .addUse(Bitcast)
5012         .addImm(1);
5013     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5014         .addUse(Lo)
5015         .addUse(Address)
5016         .addImm(Imm + (IsLittle ? 0 : 3));
5017     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5018         .addUse(Lo)
5019         .addUse(Address)
5020         .addImm(Imm + (IsLittle ? 3 : 0));
5021     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5022         .addUse(Hi)
5023         .addUse(Address)
5024         .addImm(Imm + (IsLittle ? 4 : 7));
5025     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5026         .addUse(Hi)
5027         .addUse(Address)
5028         .addImm(Imm + (IsLittle ? 7 : 4));
5029   }
5030 
5031   MI.eraseFromParent();
5032   return BB;
5033 }
5034