xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision d56accc7c3dcc897489b6a07834763a03b9f3d68)
1 //===- MipsISelLowering.cpp - Mips DAG Lowering Implementation ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that Mips uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MipsISelLowering.h"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "MCTargetDesc/MipsInstPrinter.h"
17 #include "MCTargetDesc/MipsMCTargetDesc.h"
18 #include "MipsCCState.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsMachineFunction.h"
21 #include "MipsRegisterInfo.h"
22 #include "MipsSubtarget.h"
23 #include "MipsTargetMachine.h"
24 #include "MipsTargetObjectFile.h"
25 #include "llvm/ADT/APFloat.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/StringSwitch.h"
31 #include "llvm/CodeGen/CallingConvLower.h"
32 #include "llvm/CodeGen/FunctionLoweringInfo.h"
33 #include "llvm/CodeGen/ISDOpcodes.h"
34 #include "llvm/CodeGen/MachineBasicBlock.h"
35 #include "llvm/CodeGen/MachineFrameInfo.h"
36 #include "llvm/CodeGen/MachineFunction.h"
37 #include "llvm/CodeGen/MachineInstr.h"
38 #include "llvm/CodeGen/MachineInstrBuilder.h"
39 #include "llvm/CodeGen/MachineJumpTableInfo.h"
40 #include "llvm/CodeGen/MachineMemOperand.h"
41 #include "llvm/CodeGen/MachineOperand.h"
42 #include "llvm/CodeGen/MachineRegisterInfo.h"
43 #include "llvm/CodeGen/RuntimeLibcalls.h"
44 #include "llvm/CodeGen/SelectionDAG.h"
45 #include "llvm/CodeGen/SelectionDAGNodes.h"
46 #include "llvm/CodeGen/TargetFrameLowering.h"
47 #include "llvm/CodeGen/TargetInstrInfo.h"
48 #include "llvm/CodeGen/TargetRegisterInfo.h"
49 #include "llvm/CodeGen/ValueTypes.h"
50 #include "llvm/IR/CallingConv.h"
51 #include "llvm/IR/Constants.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/DebugLoc.h"
54 #include "llvm/IR/DerivedTypes.h"
55 #include "llvm/IR/Function.h"
56 #include "llvm/IR/GlobalValue.h"
57 #include "llvm/IR/Type.h"
58 #include "llvm/IR/Value.h"
59 #include "llvm/MC/MCContext.h"
60 #include "llvm/MC/MCRegisterInfo.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CodeGen.h"
63 #include "llvm/Support/CommandLine.h"
64 #include "llvm/Support/Compiler.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/MachineValueType.h"
67 #include "llvm/Support/MathExtras.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include "llvm/Target/TargetOptions.h"
70 #include <algorithm>
71 #include <cassert>
72 #include <cctype>
73 #include <cstdint>
74 #include <deque>
75 #include <iterator>
76 #include <utility>
77 #include <vector>
78 
79 using namespace llvm;
80 
81 #define DEBUG_TYPE "mips-lower"
82 
83 STATISTIC(NumTailCalls, "Number of tail calls");
84 
85 static cl::opt<bool>
86 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
87                cl::desc("MIPS: Don't trap on integer division by zero."),
88                cl::init(false));
89 
90 extern cl::opt<bool> EmitJalrReloc;
91 
92 static const MCPhysReg Mips64DPRegs[8] = {
93   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
94   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
95 };
96 
97 // If I is a shifted mask, set the size (Size) and the first bit of the
98 // mask (Pos), and return true.
99 // For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
100 static bool isShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
101   if (!isShiftedMask_64(I))
102     return false;
103 
104   Size = countPopulation(I);
105   Pos = countTrailingZeros(I);
106   return true;
107 }
108 
109 // The MIPS MSA ABI passes vector arguments in the integer register set.
110 // The number of integer registers used is dependant on the ABI used.
111 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
112                                                       CallingConv::ID CC,
113                                                       EVT VT) const {
114   if (!VT.isVector())
115     return getRegisterType(Context, VT);
116 
117   return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
118                                                            : MVT::i64;
119 }
120 
121 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
122                                                            CallingConv::ID CC,
123                                                            EVT VT) const {
124   if (VT.isVector())
125     return divideCeil(VT.getSizeInBits(), Subtarget.isABI_O32() ? 32 : 64);
126   return MipsTargetLowering::getNumRegisters(Context, VT);
127 }
128 
129 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
130     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
131     unsigned &NumIntermediates, MVT &RegisterVT) const {
132   // Break down vector types to either 2 i64s or 4 i32s.
133   RegisterVT = getRegisterTypeForCallingConv(Context, CC, VT);
134   IntermediateVT = RegisterVT;
135   NumIntermediates =
136       VT.getFixedSizeInBits() < RegisterVT.getFixedSizeInBits()
137           ? VT.getVectorNumElements()
138           : divideCeil(VT.getSizeInBits(), RegisterVT.getSizeInBits());
139   return NumIntermediates;
140 }
141 
142 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
143   MachineFunction &MF = DAG.getMachineFunction();
144   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
145   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
146 }
147 
148 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
149                                           SelectionDAG &DAG,
150                                           unsigned Flag) const {
151   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
152 }
153 
154 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
155                                           SelectionDAG &DAG,
156                                           unsigned Flag) const {
157   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
158 }
159 
160 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
161                                           SelectionDAG &DAG,
162                                           unsigned Flag) const {
163   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
164 }
165 
166 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
167                                           SelectionDAG &DAG,
168                                           unsigned Flag) const {
169   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
170 }
171 
172 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
173                                           SelectionDAG &DAG,
174                                           unsigned Flag) const {
175   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
176                                    N->getOffset(), Flag);
177 }
178 
179 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
180   switch ((MipsISD::NodeType)Opcode) {
181   case MipsISD::FIRST_NUMBER:      break;
182   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
183   case MipsISD::TailCall:          return "MipsISD::TailCall";
184   case MipsISD::Highest:           return "MipsISD::Highest";
185   case MipsISD::Higher:            return "MipsISD::Higher";
186   case MipsISD::Hi:                return "MipsISD::Hi";
187   case MipsISD::Lo:                return "MipsISD::Lo";
188   case MipsISD::GotHi:             return "MipsISD::GotHi";
189   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
190   case MipsISD::GPRel:             return "MipsISD::GPRel";
191   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
192   case MipsISD::Ret:               return "MipsISD::Ret";
193   case MipsISD::ERet:              return "MipsISD::ERet";
194   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
195   case MipsISD::FMS:               return "MipsISD::FMS";
196   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
197   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
198   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
199   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
200   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
201   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
202   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
203   case MipsISD::MFHI:              return "MipsISD::MFHI";
204   case MipsISD::MFLO:              return "MipsISD::MFLO";
205   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
206   case MipsISD::Mult:              return "MipsISD::Mult";
207   case MipsISD::Multu:             return "MipsISD::Multu";
208   case MipsISD::MAdd:              return "MipsISD::MAdd";
209   case MipsISD::MAddu:             return "MipsISD::MAddu";
210   case MipsISD::MSub:              return "MipsISD::MSub";
211   case MipsISD::MSubu:             return "MipsISD::MSubu";
212   case MipsISD::DivRem:            return "MipsISD::DivRem";
213   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
214   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
215   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
216   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
217   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
218   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
219   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
220   case MipsISD::Sync:              return "MipsISD::Sync";
221   case MipsISD::Ext:               return "MipsISD::Ext";
222   case MipsISD::Ins:               return "MipsISD::Ins";
223   case MipsISD::CIns:              return "MipsISD::CIns";
224   case MipsISD::LWL:               return "MipsISD::LWL";
225   case MipsISD::LWR:               return "MipsISD::LWR";
226   case MipsISD::SWL:               return "MipsISD::SWL";
227   case MipsISD::SWR:               return "MipsISD::SWR";
228   case MipsISD::LDL:               return "MipsISD::LDL";
229   case MipsISD::LDR:               return "MipsISD::LDR";
230   case MipsISD::SDL:               return "MipsISD::SDL";
231   case MipsISD::SDR:               return "MipsISD::SDR";
232   case MipsISD::EXTP:              return "MipsISD::EXTP";
233   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
234   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
235   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
236   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
237   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
238   case MipsISD::SHILO:             return "MipsISD::SHILO";
239   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
240   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
241   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
242   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
243   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
244   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
245   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
246   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
247   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
248   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
249   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
250   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
251   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
252   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
253   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
254   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
255   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
256   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
257   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
258   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
259   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
260   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
261   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
262   case MipsISD::MULT:              return "MipsISD::MULT";
263   case MipsISD::MULTU:             return "MipsISD::MULTU";
264   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
265   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
266   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
267   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
268   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
269   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
270   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
271   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
272   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
273   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
274   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
275   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
276   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
277   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
278   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
279   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
280   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
281   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
282   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
283   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
284   case MipsISD::VNOR:              return "MipsISD::VNOR";
285   case MipsISD::VSHF:              return "MipsISD::VSHF";
286   case MipsISD::SHF:               return "MipsISD::SHF";
287   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
288   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
289   case MipsISD::ILVL:              return "MipsISD::ILVL";
290   case MipsISD::ILVR:              return "MipsISD::ILVR";
291   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
292   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
293   case MipsISD::INSVE:             return "MipsISD::INSVE";
294   }
295   return nullptr;
296 }
297 
298 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
299                                        const MipsSubtarget &STI)
300     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
301   // Mips does not have i1 type, so use i32 for
302   // setcc operations results (slt, sgt, ...).
303   setBooleanContents(ZeroOrOneBooleanContent);
304   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
305   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
306   // does. Integer booleans still use 0 and 1.
307   if (Subtarget.hasMips32r6())
308     setBooleanContents(ZeroOrOneBooleanContent,
309                        ZeroOrNegativeOneBooleanContent);
310 
311   // Load extented operations for i1 types must be promoted
312   for (MVT VT : MVT::integer_valuetypes()) {
313     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
314     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
315     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
316   }
317 
318   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
319   // for f32, f16
320   for (MVT VT : MVT::fp_valuetypes()) {
321     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
322     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
323   }
324 
325   // Set LoadExtAction for f16 vectors to Expand
326   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
327     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
328     if (F16VT.isValid())
329       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
330   }
331 
332   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
333   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
334 
335   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
336 
337   // Used by legalize types to correctly generate the setcc result.
338   // Without this, every float setcc comes with a AND/OR with the result,
339   // we don't want this, since the fpcmp result goes to a flag register,
340   // which is used implicitly by brcond and select operations.
341   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
342 
343   // Mips Custom Operations
344   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
345   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
346   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
347   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
348   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
349   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
350   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
351   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
352   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
353   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
354   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
355   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
356   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
357   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
358   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
359 
360   if (!(TM.Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())) {
361     setOperationAction(ISD::FABS, MVT::f32, Custom);
362     setOperationAction(ISD::FABS, MVT::f64, Custom);
363   }
364 
365   if (Subtarget.isGP64bit()) {
366     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
367     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
368     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
369     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
370     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
371     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
372     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
373     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
374     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
375     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
376     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
377     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
378   }
379 
380   if (!Subtarget.isGP64bit()) {
381     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
382     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
383     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
384   }
385 
386   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
387   if (Subtarget.isGP64bit())
388     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
389 
390   setOperationAction(ISD::SDIV, MVT::i32, Expand);
391   setOperationAction(ISD::SREM, MVT::i32, Expand);
392   setOperationAction(ISD::UDIV, MVT::i32, Expand);
393   setOperationAction(ISD::UREM, MVT::i32, Expand);
394   setOperationAction(ISD::SDIV, MVT::i64, Expand);
395   setOperationAction(ISD::SREM, MVT::i64, Expand);
396   setOperationAction(ISD::UDIV, MVT::i64, Expand);
397   setOperationAction(ISD::UREM, MVT::i64, Expand);
398 
399   // Operations not directly supported by Mips.
400   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
401   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
402   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
403   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
404   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
405   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
406   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
407   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
408   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
409   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
410   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
411   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
412   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
413   if (Subtarget.hasCnMips()) {
414     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
415     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
416   } else {
417     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
418     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
419   }
420   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
421   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
422   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
423   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
424   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
425   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
426 
427   if (!Subtarget.hasMips32r2())
428     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
429 
430   if (!Subtarget.hasMips64r2())
431     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
432 
433   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
434   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
435   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
436   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
437   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
438   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
439   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
440   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
441   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
442   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
443   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
444   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
445   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
446   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
447   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
448   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
449 
450   // Lower f16 conversion operations into library calls
451   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
452   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
453   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
454   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
455 
456   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
457 
458   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
459   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
460   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
461   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
462 
463   // Use the default for now
464   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
465   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
466 
467   if (!Subtarget.isGP64bit()) {
468     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
469     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
470   }
471 
472   if (!Subtarget.hasMips32r2()) {
473     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
474     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
475   }
476 
477   // MIPS16 lacks MIPS32's clz and clo instructions.
478   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
479     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
480   if (!Subtarget.hasMips64())
481     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
482 
483   if (!Subtarget.hasMips32r2())
484     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
485   if (!Subtarget.hasMips64r2())
486     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
487 
488   if (Subtarget.isGP64bit()) {
489     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
490     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
491     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
492     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
493   }
494 
495   setOperationAction(ISD::TRAP, MVT::Other, Legal);
496 
497   setTargetDAGCombine(ISD::SDIVREM);
498   setTargetDAGCombine(ISD::UDIVREM);
499   setTargetDAGCombine(ISD::SELECT);
500   setTargetDAGCombine(ISD::AND);
501   setTargetDAGCombine(ISD::OR);
502   setTargetDAGCombine(ISD::ADD);
503   setTargetDAGCombine(ISD::SUB);
504   setTargetDAGCombine(ISD::AssertZext);
505   setTargetDAGCombine(ISD::SHL);
506 
507   if (ABI.IsO32()) {
508     // These libcalls are not available in 32-bit.
509     setLibcallName(RTLIB::SHL_I128, nullptr);
510     setLibcallName(RTLIB::SRL_I128, nullptr);
511     setLibcallName(RTLIB::SRA_I128, nullptr);
512     setLibcallName(RTLIB::MUL_I128, nullptr);
513     setLibcallName(RTLIB::MULO_I64, nullptr);
514     setLibcallName(RTLIB::MULO_I128, nullptr);
515   }
516 
517   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
518 
519   // The arguments on the stack are defined in terms of 4-byte slots on O32
520   // and 8-byte slots on N32/N64.
521   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
522                                                             : Align(4));
523 
524   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
525 
526   MaxStoresPerMemcpy = 16;
527 
528   isMicroMips = Subtarget.inMicroMipsMode();
529 }
530 
531 const MipsTargetLowering *
532 MipsTargetLowering::create(const MipsTargetMachine &TM,
533                            const MipsSubtarget &STI) {
534   if (STI.inMips16Mode())
535     return createMips16TargetLowering(TM, STI);
536 
537   return createMipsSETargetLowering(TM, STI);
538 }
539 
540 // Create a fast isel object.
541 FastISel *
542 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
543                                   const TargetLibraryInfo *libInfo) const {
544   const MipsTargetMachine &TM =
545       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
546 
547   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
548   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
549                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
550                      !Subtarget.inMicroMipsMode();
551 
552   // Disable if either of the following is true:
553   // We do not generate PIC, the ABI is not O32, XGOT is being used.
554   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
555       Subtarget.useXGOT())
556     UseFastISel = false;
557 
558   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
559 }
560 
561 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
562                                            EVT VT) const {
563   if (!VT.isVector())
564     return MVT::i32;
565   return VT.changeVectorElementTypeToInteger();
566 }
567 
568 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
569                                     TargetLowering::DAGCombinerInfo &DCI,
570                                     const MipsSubtarget &Subtarget) {
571   if (DCI.isBeforeLegalizeOps())
572     return SDValue();
573 
574   EVT Ty = N->getValueType(0);
575   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
576   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
577   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
578                                                   MipsISD::DivRemU16;
579   SDLoc DL(N);
580 
581   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
582                                N->getOperand(0), N->getOperand(1));
583   SDValue InChain = DAG.getEntryNode();
584   SDValue InGlue = DivRem;
585 
586   // insert MFLO
587   if (N->hasAnyUseOfValue(0)) {
588     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
589                                             InGlue);
590     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
591     InChain = CopyFromLo.getValue(1);
592     InGlue = CopyFromLo.getValue(2);
593   }
594 
595   // insert MFHI
596   if (N->hasAnyUseOfValue(1)) {
597     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
598                                             HI, Ty, InGlue);
599     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
600   }
601 
602   return SDValue();
603 }
604 
605 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
606   switch (CC) {
607   default: llvm_unreachable("Unknown fp condition code!");
608   case ISD::SETEQ:
609   case ISD::SETOEQ: return Mips::FCOND_OEQ;
610   case ISD::SETUNE: return Mips::FCOND_UNE;
611   case ISD::SETLT:
612   case ISD::SETOLT: return Mips::FCOND_OLT;
613   case ISD::SETGT:
614   case ISD::SETOGT: return Mips::FCOND_OGT;
615   case ISD::SETLE:
616   case ISD::SETOLE: return Mips::FCOND_OLE;
617   case ISD::SETGE:
618   case ISD::SETOGE: return Mips::FCOND_OGE;
619   case ISD::SETULT: return Mips::FCOND_ULT;
620   case ISD::SETULE: return Mips::FCOND_ULE;
621   case ISD::SETUGT: return Mips::FCOND_UGT;
622   case ISD::SETUGE: return Mips::FCOND_UGE;
623   case ISD::SETUO:  return Mips::FCOND_UN;
624   case ISD::SETO:   return Mips::FCOND_OR;
625   case ISD::SETNE:
626   case ISD::SETONE: return Mips::FCOND_ONE;
627   case ISD::SETUEQ: return Mips::FCOND_UEQ;
628   }
629 }
630 
631 /// This function returns true if the floating point conditional branches and
632 /// conditional moves which use condition code CC should be inverted.
633 static bool invertFPCondCodeUser(Mips::CondCode CC) {
634   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
635     return false;
636 
637   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
638          "Illegal Condition Code");
639 
640   return true;
641 }
642 
643 // Creates and returns an FPCmp node from a setcc node.
644 // Returns Op if setcc is not a floating point comparison.
645 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
646   // must be a SETCC node
647   if (Op.getOpcode() != ISD::SETCC)
648     return Op;
649 
650   SDValue LHS = Op.getOperand(0);
651 
652   if (!LHS.getValueType().isFloatingPoint())
653     return Op;
654 
655   SDValue RHS = Op.getOperand(1);
656   SDLoc DL(Op);
657 
658   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
659   // node if necessary.
660   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
661 
662   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
663                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
664 }
665 
666 // Creates and returns a CMovFPT/F node.
667 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
668                             SDValue False, const SDLoc &DL) {
669   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
670   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
671   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
672 
673   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
674                      True.getValueType(), True, FCC0, False, Cond);
675 }
676 
677 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
678                                     TargetLowering::DAGCombinerInfo &DCI,
679                                     const MipsSubtarget &Subtarget) {
680   if (DCI.isBeforeLegalizeOps())
681     return SDValue();
682 
683   SDValue SetCC = N->getOperand(0);
684 
685   if ((SetCC.getOpcode() != ISD::SETCC) ||
686       !SetCC.getOperand(0).getValueType().isInteger())
687     return SDValue();
688 
689   SDValue False = N->getOperand(2);
690   EVT FalseTy = False.getValueType();
691 
692   if (!FalseTy.isInteger())
693     return SDValue();
694 
695   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
696 
697   // If the RHS (False) is 0, we swap the order of the operands
698   // of ISD::SELECT (obviously also inverting the condition) so that we can
699   // take advantage of conditional moves using the $0 register.
700   // Example:
701   //   return (a != 0) ? x : 0;
702   //     load $reg, x
703   //     movz $reg, $0, a
704   if (!FalseC)
705     return SDValue();
706 
707   const SDLoc DL(N);
708 
709   if (!FalseC->getZExtValue()) {
710     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
711     SDValue True = N->getOperand(1);
712 
713     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
714                          SetCC.getOperand(1),
715                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
716 
717     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
718   }
719 
720   // If both operands are integer constants there's a possibility that we
721   // can do some interesting optimizations.
722   SDValue True = N->getOperand(1);
723   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
724 
725   if (!TrueC || !True.getValueType().isInteger())
726     return SDValue();
727 
728   // We'll also ignore MVT::i64 operands as this optimizations proves
729   // to be ineffective because of the required sign extensions as the result
730   // of a SETCC operator is always MVT::i32 for non-vector types.
731   if (True.getValueType() == MVT::i64)
732     return SDValue();
733 
734   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
735 
736   // 1)  (a < x) ? y : y-1
737   //  slti $reg1, a, x
738   //  addiu $reg2, $reg1, y-1
739   if (Diff == 1)
740     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
741 
742   // 2)  (a < x) ? y-1 : y
743   //  slti $reg1, a, x
744   //  xor $reg1, $reg1, 1
745   //  addiu $reg2, $reg1, y-1
746   if (Diff == -1) {
747     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
748     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
749                          SetCC.getOperand(1),
750                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
751     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
752   }
753 
754   // Could not optimize.
755   return SDValue();
756 }
757 
758 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
759                                     TargetLowering::DAGCombinerInfo &DCI,
760                                     const MipsSubtarget &Subtarget) {
761   if (DCI.isBeforeLegalizeOps())
762     return SDValue();
763 
764   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
765 
766   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
767   if (!FalseC || FalseC->getZExtValue())
768     return SDValue();
769 
770   // Since RHS (False) is 0, we swap the order of the True/False operands
771   // (obviously also inverting the condition) so that we can
772   // take advantage of conditional moves using the $0 register.
773   // Example:
774   //   return (a != 0) ? x : 0;
775   //     load $reg, x
776   //     movz $reg, $0, a
777   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
778                                                          MipsISD::CMovFP_T;
779 
780   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
781   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
782                      ValueIfFalse, FCC, ValueIfTrue, Glue);
783 }
784 
785 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
786                                  TargetLowering::DAGCombinerInfo &DCI,
787                                  const MipsSubtarget &Subtarget) {
788   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
789     return SDValue();
790 
791   SDValue FirstOperand = N->getOperand(0);
792   unsigned FirstOperandOpc = FirstOperand.getOpcode();
793   SDValue Mask = N->getOperand(1);
794   EVT ValTy = N->getValueType(0);
795   SDLoc DL(N);
796 
797   uint64_t Pos = 0, SMPos, SMSize;
798   ConstantSDNode *CN;
799   SDValue NewOperand;
800   unsigned Opc;
801 
802   // Op's second operand must be a shifted mask.
803   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
804       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
805     return SDValue();
806 
807   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
808     // Pattern match EXT.
809     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
810     //  => ext $dst, $src, pos, size
811 
812     // The second operand of the shift must be an immediate.
813     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
814       return SDValue();
815 
816     Pos = CN->getZExtValue();
817 
818     // Return if the shifted mask does not start at bit 0 or the sum of its size
819     // and Pos exceeds the word's size.
820     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
821       return SDValue();
822 
823     Opc = MipsISD::Ext;
824     NewOperand = FirstOperand.getOperand(0);
825   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
826     // Pattern match CINS.
827     //  $dst = and (shl $src , pos), mask
828     //  => cins $dst, $src, pos, size
829     // mask is a shifted mask with consecutive 1's, pos = shift amount,
830     // size = population count.
831 
832     // The second operand of the shift must be an immediate.
833     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
834       return SDValue();
835 
836     Pos = CN->getZExtValue();
837 
838     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
839         Pos + SMSize > ValTy.getSizeInBits())
840       return SDValue();
841 
842     NewOperand = FirstOperand.getOperand(0);
843     // SMSize is 'location' (position) in this case, not size.
844     SMSize--;
845     Opc = MipsISD::CIns;
846   } else {
847     // Pattern match EXT.
848     //  $dst = and $src, (2**size - 1) , if size > 16
849     //  => ext $dst, $src, pos, size , pos = 0
850 
851     // If the mask is <= 0xffff, andi can be used instead.
852     if (CN->getZExtValue() <= 0xffff)
853       return SDValue();
854 
855     // Return if the mask doesn't start at position 0.
856     if (SMPos)
857       return SDValue();
858 
859     Opc = MipsISD::Ext;
860     NewOperand = FirstOperand;
861   }
862   return DAG.getNode(Opc, DL, ValTy, NewOperand,
863                      DAG.getConstant(Pos, DL, MVT::i32),
864                      DAG.getConstant(SMSize, DL, MVT::i32));
865 }
866 
867 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
868                                 TargetLowering::DAGCombinerInfo &DCI,
869                                 const MipsSubtarget &Subtarget) {
870   // Pattern match INS.
871   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
872   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
873   //  => ins $dst, $src, size, pos, $src1
874   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
875     return SDValue();
876 
877   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
878   uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
879   ConstantSDNode *CN, *CN1;
880 
881   // See if Op's first operand matches (and $src1 , mask0).
882   if (And0.getOpcode() != ISD::AND)
883     return SDValue();
884 
885   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
886       !isShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
887     return SDValue();
888 
889   // See if Op's second operand matches (and (shl $src, pos), mask1).
890   if (And1.getOpcode() == ISD::AND &&
891       And1.getOperand(0).getOpcode() == ISD::SHL) {
892 
893     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
894         !isShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
895       return SDValue();
896 
897     // The shift masks must have the same position and size.
898     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
899       return SDValue();
900 
901     SDValue Shl = And1.getOperand(0);
902 
903     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
904       return SDValue();
905 
906     unsigned Shamt = CN->getZExtValue();
907 
908     // Return if the shift amount and the first bit position of mask are not the
909     // same.
910     EVT ValTy = N->getValueType(0);
911     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
912       return SDValue();
913 
914     SDLoc DL(N);
915     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
916                        DAG.getConstant(SMPos0, DL, MVT::i32),
917                        DAG.getConstant(SMSize0, DL, MVT::i32),
918                        And0.getOperand(0));
919   } else {
920     // Pattern match DINS.
921     //  $dst = or (and $src, mask0), mask1
922     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
923     //  => dins $dst, $src, pos, size
924     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
925         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
926          (SMSize0 + SMPos0 <= 32))) {
927       // Check if AND instruction has constant as argument
928       bool isConstCase = And1.getOpcode() != ISD::AND;
929       if (And1.getOpcode() == ISD::AND) {
930         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
931           return SDValue();
932       } else {
933         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
934           return SDValue();
935       }
936       // Don't generate INS if constant OR operand doesn't fit into bits
937       // cleared by constant AND operand.
938       if (CN->getSExtValue() & CN1->getSExtValue())
939         return SDValue();
940 
941       SDLoc DL(N);
942       EVT ValTy = N->getOperand(0)->getValueType(0);
943       SDValue Const1;
944       SDValue SrlX;
945       if (!isConstCase) {
946         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
947         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
948       }
949       return DAG.getNode(
950           MipsISD::Ins, DL, N->getValueType(0),
951           isConstCase
952               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
953               : SrlX,
954           DAG.getConstant(SMPos0, DL, MVT::i32),
955           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
956                                                         : SMSize0,
957                           DL, MVT::i32),
958           And0->getOperand(0));
959 
960     }
961     return SDValue();
962   }
963 }
964 
965 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
966                                        const MipsSubtarget &Subtarget) {
967   // ROOTNode must have a multiplication as an operand for the match to be
968   // successful.
969   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
970       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
971     return SDValue();
972 
973   // We don't handle vector types here.
974   if (ROOTNode->getValueType(0).isVector())
975     return SDValue();
976 
977   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
978   // arithmetic. E.g.
979   // (add (mul a b) c) =>
980   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
981   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
982   //   or
983   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
984   //
985   // The overhead of setting up the Hi/Lo registers and reassembling the
986   // result makes this a dubious optimzation for MIPS64. The core of the
987   // problem is that Hi/Lo contain the upper and lower 32 bits of the
988   // operand and result.
989   //
990   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
991   // density than doing it naively, 5 for MIPS64. Additionally, using
992   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
993   // extended operands, not true 64 bit values.
994   //
995   // FIXME: For the moment, disable this completely for MIPS64.
996   if (Subtarget.hasMips64())
997     return SDValue();
998 
999   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1000                      ? ROOTNode->getOperand(0)
1001                      : ROOTNode->getOperand(1);
1002 
1003   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1004                      ? ROOTNode->getOperand(1)
1005                      : ROOTNode->getOperand(0);
1006 
1007   // Transform this to a MADD only if the user of this node is the add.
1008   // If there are other users of the mul, this function returns here.
1009   if (!Mult.hasOneUse())
1010     return SDValue();
1011 
1012   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1013   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1014   // of the multiply must have 32 or more sign bits, otherwise we cannot
1015   // perform this optimization. We have to check this here as we're performing
1016   // this optimization pre-legalization.
1017   SDValue MultLHS = Mult->getOperand(0);
1018   SDValue MultRHS = Mult->getOperand(1);
1019 
1020   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1021                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1022   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1023                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1024 
1025   if (!IsSigned && !IsUnsigned)
1026     return SDValue();
1027 
1028   // Initialize accumulator.
1029   SDLoc DL(ROOTNode);
1030   SDValue TopHalf;
1031   SDValue BottomHalf;
1032   BottomHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1033                               CurDAG.getIntPtrConstant(0, DL));
1034 
1035   TopHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1036                            CurDAG.getIntPtrConstant(1, DL));
1037   SDValue ACCIn = CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped,
1038                                   BottomHalf,
1039                                   TopHalf);
1040 
1041   // Create MipsMAdd(u) / MipsMSub(u) node.
1042   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1043   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1044                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1045   SDValue MAddOps[3] = {
1046       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1047       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1048   EVT VTs[2] = {MVT::i32, MVT::i32};
1049   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1050 
1051   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1052   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1053   SDValue Combined =
1054       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1055   return Combined;
1056 }
1057 
1058 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1059                                  TargetLowering::DAGCombinerInfo &DCI,
1060                                  const MipsSubtarget &Subtarget) {
1061   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1062   if (DCI.isBeforeLegalizeOps()) {
1063     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1064         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1065       return performMADD_MSUBCombine(N, DAG, Subtarget);
1066 
1067     return SDValue();
1068   }
1069 
1070   return SDValue();
1071 }
1072 
1073 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1074                                  TargetLowering::DAGCombinerInfo &DCI,
1075                                  const MipsSubtarget &Subtarget) {
1076   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1077   if (DCI.isBeforeLegalizeOps()) {
1078     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1079         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1080       return performMADD_MSUBCombine(N, DAG, Subtarget);
1081 
1082     return SDValue();
1083   }
1084 
1085   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1086   SDValue Add = N->getOperand(1);
1087 
1088   if (Add.getOpcode() != ISD::ADD)
1089     return SDValue();
1090 
1091   SDValue Lo = Add.getOperand(1);
1092 
1093   if ((Lo.getOpcode() != MipsISD::Lo) ||
1094       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1095     return SDValue();
1096 
1097   EVT ValTy = N->getValueType(0);
1098   SDLoc DL(N);
1099 
1100   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1101                              Add.getOperand(0));
1102   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1103 }
1104 
1105 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1106                                  TargetLowering::DAGCombinerInfo &DCI,
1107                                  const MipsSubtarget &Subtarget) {
1108   // Pattern match CINS.
1109   //  $dst = shl (and $src , imm), pos
1110   //  => cins $dst, $src, pos, size
1111 
1112   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1113     return SDValue();
1114 
1115   SDValue FirstOperand = N->getOperand(0);
1116   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1117   SDValue SecondOperand = N->getOperand(1);
1118   EVT ValTy = N->getValueType(0);
1119   SDLoc DL(N);
1120 
1121   uint64_t Pos = 0, SMPos, SMSize;
1122   ConstantSDNode *CN;
1123   SDValue NewOperand;
1124 
1125   // The second operand of the shift must be an immediate.
1126   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1127     return SDValue();
1128 
1129   Pos = CN->getZExtValue();
1130 
1131   if (Pos >= ValTy.getSizeInBits())
1132     return SDValue();
1133 
1134   if (FirstOperandOpc != ISD::AND)
1135     return SDValue();
1136 
1137   // AND's second operand must be a shifted mask.
1138   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1139       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
1140     return SDValue();
1141 
1142   // Return if the shifted mask does not start at bit 0 or the sum of its size
1143   // and Pos exceeds the word's size.
1144   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1145     return SDValue();
1146 
1147   NewOperand = FirstOperand.getOperand(0);
1148   // SMSize is 'location' (position) in this case, not size.
1149   SMSize--;
1150 
1151   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1152                      DAG.getConstant(Pos, DL, MVT::i32),
1153                      DAG.getConstant(SMSize, DL, MVT::i32));
1154 }
1155 
1156 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1157   const {
1158   SelectionDAG &DAG = DCI.DAG;
1159   unsigned Opc = N->getOpcode();
1160 
1161   switch (Opc) {
1162   default: break;
1163   case ISD::SDIVREM:
1164   case ISD::UDIVREM:
1165     return performDivRemCombine(N, DAG, DCI, Subtarget);
1166   case ISD::SELECT:
1167     return performSELECTCombine(N, DAG, DCI, Subtarget);
1168   case MipsISD::CMovFP_F:
1169   case MipsISD::CMovFP_T:
1170     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1171   case ISD::AND:
1172     return performANDCombine(N, DAG, DCI, Subtarget);
1173   case ISD::OR:
1174     return performORCombine(N, DAG, DCI, Subtarget);
1175   case ISD::ADD:
1176     return performADDCombine(N, DAG, DCI, Subtarget);
1177   case ISD::SHL:
1178     return performSHLCombine(N, DAG, DCI, Subtarget);
1179   case ISD::SUB:
1180     return performSUBCombine(N, DAG, DCI, Subtarget);
1181   }
1182 
1183   return SDValue();
1184 }
1185 
1186 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
1187   return Subtarget.hasMips32();
1188 }
1189 
1190 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
1191   return Subtarget.hasMips32();
1192 }
1193 
1194 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1195     const SDNode *N, CombineLevel Level) const {
1196   if (N->getOperand(0).getValueType().isVector())
1197     return false;
1198   return true;
1199 }
1200 
1201 void
1202 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1203                                        SmallVectorImpl<SDValue> &Results,
1204                                        SelectionDAG &DAG) const {
1205   return LowerOperationWrapper(N, Results, DAG);
1206 }
1207 
1208 SDValue MipsTargetLowering::
1209 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1210 {
1211   switch (Op.getOpcode())
1212   {
1213   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1214   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1215   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1216   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1217   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1218   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1219   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1220   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1221   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1222   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1223   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1224   case ISD::FABS:               return lowerFABS(Op, DAG);
1225   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1226   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1227   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1228   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1229   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1230   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1231   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1232   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1233   case ISD::STORE:              return lowerSTORE(Op, DAG);
1234   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1235   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1236   }
1237   return SDValue();
1238 }
1239 
1240 //===----------------------------------------------------------------------===//
1241 //  Lower helper functions
1242 //===----------------------------------------------------------------------===//
1243 
1244 // addLiveIn - This helper function adds the specified physical register to the
1245 // MachineFunction as a live in value.  It also creates a corresponding
1246 // virtual register for it.
1247 static unsigned
1248 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1249 {
1250   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1251   MF.getRegInfo().addLiveIn(PReg, VReg);
1252   return VReg;
1253 }
1254 
1255 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1256                                               MachineBasicBlock &MBB,
1257                                               const TargetInstrInfo &TII,
1258                                               bool Is64Bit, bool IsMicroMips) {
1259   if (NoZeroDivCheck)
1260     return &MBB;
1261 
1262   // Insert instruction "teq $divisor_reg, $zero, 7".
1263   MachineBasicBlock::iterator I(MI);
1264   MachineInstrBuilder MIB;
1265   MachineOperand &Divisor = MI.getOperand(2);
1266   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1267                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1268             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1269             .addReg(Mips::ZERO)
1270             .addImm(7);
1271 
1272   // Use the 32-bit sub-register if this is a 64-bit division.
1273   if (Is64Bit)
1274     MIB->getOperand(0).setSubReg(Mips::sub_32);
1275 
1276   // Clear Divisor's kill flag.
1277   Divisor.setIsKill(false);
1278 
1279   // We would normally delete the original instruction here but in this case
1280   // we only needed to inject an additional instruction rather than replace it.
1281 
1282   return &MBB;
1283 }
1284 
1285 MachineBasicBlock *
1286 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1287                                                 MachineBasicBlock *BB) const {
1288   switch (MI.getOpcode()) {
1289   default:
1290     llvm_unreachable("Unexpected instr type to insert");
1291   case Mips::ATOMIC_LOAD_ADD_I8:
1292     return emitAtomicBinaryPartword(MI, BB, 1);
1293   case Mips::ATOMIC_LOAD_ADD_I16:
1294     return emitAtomicBinaryPartword(MI, BB, 2);
1295   case Mips::ATOMIC_LOAD_ADD_I32:
1296     return emitAtomicBinary(MI, BB);
1297   case Mips::ATOMIC_LOAD_ADD_I64:
1298     return emitAtomicBinary(MI, BB);
1299 
1300   case Mips::ATOMIC_LOAD_AND_I8:
1301     return emitAtomicBinaryPartword(MI, BB, 1);
1302   case Mips::ATOMIC_LOAD_AND_I16:
1303     return emitAtomicBinaryPartword(MI, BB, 2);
1304   case Mips::ATOMIC_LOAD_AND_I32:
1305     return emitAtomicBinary(MI, BB);
1306   case Mips::ATOMIC_LOAD_AND_I64:
1307     return emitAtomicBinary(MI, BB);
1308 
1309   case Mips::ATOMIC_LOAD_OR_I8:
1310     return emitAtomicBinaryPartword(MI, BB, 1);
1311   case Mips::ATOMIC_LOAD_OR_I16:
1312     return emitAtomicBinaryPartword(MI, BB, 2);
1313   case Mips::ATOMIC_LOAD_OR_I32:
1314     return emitAtomicBinary(MI, BB);
1315   case Mips::ATOMIC_LOAD_OR_I64:
1316     return emitAtomicBinary(MI, BB);
1317 
1318   case Mips::ATOMIC_LOAD_XOR_I8:
1319     return emitAtomicBinaryPartword(MI, BB, 1);
1320   case Mips::ATOMIC_LOAD_XOR_I16:
1321     return emitAtomicBinaryPartword(MI, BB, 2);
1322   case Mips::ATOMIC_LOAD_XOR_I32:
1323     return emitAtomicBinary(MI, BB);
1324   case Mips::ATOMIC_LOAD_XOR_I64:
1325     return emitAtomicBinary(MI, BB);
1326 
1327   case Mips::ATOMIC_LOAD_NAND_I8:
1328     return emitAtomicBinaryPartword(MI, BB, 1);
1329   case Mips::ATOMIC_LOAD_NAND_I16:
1330     return emitAtomicBinaryPartword(MI, BB, 2);
1331   case Mips::ATOMIC_LOAD_NAND_I32:
1332     return emitAtomicBinary(MI, BB);
1333   case Mips::ATOMIC_LOAD_NAND_I64:
1334     return emitAtomicBinary(MI, BB);
1335 
1336   case Mips::ATOMIC_LOAD_SUB_I8:
1337     return emitAtomicBinaryPartword(MI, BB, 1);
1338   case Mips::ATOMIC_LOAD_SUB_I16:
1339     return emitAtomicBinaryPartword(MI, BB, 2);
1340   case Mips::ATOMIC_LOAD_SUB_I32:
1341     return emitAtomicBinary(MI, BB);
1342   case Mips::ATOMIC_LOAD_SUB_I64:
1343     return emitAtomicBinary(MI, BB);
1344 
1345   case Mips::ATOMIC_SWAP_I8:
1346     return emitAtomicBinaryPartword(MI, BB, 1);
1347   case Mips::ATOMIC_SWAP_I16:
1348     return emitAtomicBinaryPartword(MI, BB, 2);
1349   case Mips::ATOMIC_SWAP_I32:
1350     return emitAtomicBinary(MI, BB);
1351   case Mips::ATOMIC_SWAP_I64:
1352     return emitAtomicBinary(MI, BB);
1353 
1354   case Mips::ATOMIC_CMP_SWAP_I8:
1355     return emitAtomicCmpSwapPartword(MI, BB, 1);
1356   case Mips::ATOMIC_CMP_SWAP_I16:
1357     return emitAtomicCmpSwapPartword(MI, BB, 2);
1358   case Mips::ATOMIC_CMP_SWAP_I32:
1359     return emitAtomicCmpSwap(MI, BB);
1360   case Mips::ATOMIC_CMP_SWAP_I64:
1361     return emitAtomicCmpSwap(MI, BB);
1362 
1363   case Mips::ATOMIC_LOAD_MIN_I8:
1364     return emitAtomicBinaryPartword(MI, BB, 1);
1365   case Mips::ATOMIC_LOAD_MIN_I16:
1366     return emitAtomicBinaryPartword(MI, BB, 2);
1367   case Mips::ATOMIC_LOAD_MIN_I32:
1368     return emitAtomicBinary(MI, BB);
1369   case Mips::ATOMIC_LOAD_MIN_I64:
1370     return emitAtomicBinary(MI, BB);
1371 
1372   case Mips::ATOMIC_LOAD_MAX_I8:
1373     return emitAtomicBinaryPartword(MI, BB, 1);
1374   case Mips::ATOMIC_LOAD_MAX_I16:
1375     return emitAtomicBinaryPartword(MI, BB, 2);
1376   case Mips::ATOMIC_LOAD_MAX_I32:
1377     return emitAtomicBinary(MI, BB);
1378   case Mips::ATOMIC_LOAD_MAX_I64:
1379     return emitAtomicBinary(MI, BB);
1380 
1381   case Mips::ATOMIC_LOAD_UMIN_I8:
1382     return emitAtomicBinaryPartword(MI, BB, 1);
1383   case Mips::ATOMIC_LOAD_UMIN_I16:
1384     return emitAtomicBinaryPartword(MI, BB, 2);
1385   case Mips::ATOMIC_LOAD_UMIN_I32:
1386     return emitAtomicBinary(MI, BB);
1387   case Mips::ATOMIC_LOAD_UMIN_I64:
1388     return emitAtomicBinary(MI, BB);
1389 
1390   case Mips::ATOMIC_LOAD_UMAX_I8:
1391     return emitAtomicBinaryPartword(MI, BB, 1);
1392   case Mips::ATOMIC_LOAD_UMAX_I16:
1393     return emitAtomicBinaryPartword(MI, BB, 2);
1394   case Mips::ATOMIC_LOAD_UMAX_I32:
1395     return emitAtomicBinary(MI, BB);
1396   case Mips::ATOMIC_LOAD_UMAX_I64:
1397     return emitAtomicBinary(MI, BB);
1398 
1399   case Mips::PseudoSDIV:
1400   case Mips::PseudoUDIV:
1401   case Mips::DIV:
1402   case Mips::DIVU:
1403   case Mips::MOD:
1404   case Mips::MODU:
1405     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1406                                false);
1407   case Mips::SDIV_MM_Pseudo:
1408   case Mips::UDIV_MM_Pseudo:
1409   case Mips::SDIV_MM:
1410   case Mips::UDIV_MM:
1411   case Mips::DIV_MMR6:
1412   case Mips::DIVU_MMR6:
1413   case Mips::MOD_MMR6:
1414   case Mips::MODU_MMR6:
1415     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1416   case Mips::PseudoDSDIV:
1417   case Mips::PseudoDUDIV:
1418   case Mips::DDIV:
1419   case Mips::DDIVU:
1420   case Mips::DMOD:
1421   case Mips::DMODU:
1422     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1423 
1424   case Mips::PseudoSELECT_I:
1425   case Mips::PseudoSELECT_I64:
1426   case Mips::PseudoSELECT_S:
1427   case Mips::PseudoSELECT_D32:
1428   case Mips::PseudoSELECT_D64:
1429     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1430   case Mips::PseudoSELECTFP_F_I:
1431   case Mips::PseudoSELECTFP_F_I64:
1432   case Mips::PseudoSELECTFP_F_S:
1433   case Mips::PseudoSELECTFP_F_D32:
1434   case Mips::PseudoSELECTFP_F_D64:
1435     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1436   case Mips::PseudoSELECTFP_T_I:
1437   case Mips::PseudoSELECTFP_T_I64:
1438   case Mips::PseudoSELECTFP_T_S:
1439   case Mips::PseudoSELECTFP_T_D32:
1440   case Mips::PseudoSELECTFP_T_D64:
1441     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1442   case Mips::PseudoD_SELECT_I:
1443   case Mips::PseudoD_SELECT_I64:
1444     return emitPseudoD_SELECT(MI, BB);
1445   case Mips::LDR_W:
1446     return emitLDR_W(MI, BB);
1447   case Mips::LDR_D:
1448     return emitLDR_D(MI, BB);
1449   case Mips::STR_W:
1450     return emitSTR_W(MI, BB);
1451   case Mips::STR_D:
1452     return emitSTR_D(MI, BB);
1453   }
1454 }
1455 
1456 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1457 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1458 MachineBasicBlock *
1459 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1460                                      MachineBasicBlock *BB) const {
1461 
1462   MachineFunction *MF = BB->getParent();
1463   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1464   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1465   DebugLoc DL = MI.getDebugLoc();
1466 
1467   unsigned AtomicOp;
1468   bool NeedsAdditionalReg = false;
1469   switch (MI.getOpcode()) {
1470   case Mips::ATOMIC_LOAD_ADD_I32:
1471     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1472     break;
1473   case Mips::ATOMIC_LOAD_SUB_I32:
1474     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1475     break;
1476   case Mips::ATOMIC_LOAD_AND_I32:
1477     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1478     break;
1479   case Mips::ATOMIC_LOAD_OR_I32:
1480     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1481     break;
1482   case Mips::ATOMIC_LOAD_XOR_I32:
1483     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1484     break;
1485   case Mips::ATOMIC_LOAD_NAND_I32:
1486     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1487     break;
1488   case Mips::ATOMIC_SWAP_I32:
1489     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1490     break;
1491   case Mips::ATOMIC_LOAD_ADD_I64:
1492     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1493     break;
1494   case Mips::ATOMIC_LOAD_SUB_I64:
1495     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1496     break;
1497   case Mips::ATOMIC_LOAD_AND_I64:
1498     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1499     break;
1500   case Mips::ATOMIC_LOAD_OR_I64:
1501     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1502     break;
1503   case Mips::ATOMIC_LOAD_XOR_I64:
1504     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1505     break;
1506   case Mips::ATOMIC_LOAD_NAND_I64:
1507     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1508     break;
1509   case Mips::ATOMIC_SWAP_I64:
1510     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1511     break;
1512   case Mips::ATOMIC_LOAD_MIN_I32:
1513     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1514     NeedsAdditionalReg = true;
1515     break;
1516   case Mips::ATOMIC_LOAD_MAX_I32:
1517     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1518     NeedsAdditionalReg = true;
1519     break;
1520   case Mips::ATOMIC_LOAD_UMIN_I32:
1521     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1522     NeedsAdditionalReg = true;
1523     break;
1524   case Mips::ATOMIC_LOAD_UMAX_I32:
1525     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1526     NeedsAdditionalReg = true;
1527     break;
1528   case Mips::ATOMIC_LOAD_MIN_I64:
1529     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1530     NeedsAdditionalReg = true;
1531     break;
1532   case Mips::ATOMIC_LOAD_MAX_I64:
1533     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1534     NeedsAdditionalReg = true;
1535     break;
1536   case Mips::ATOMIC_LOAD_UMIN_I64:
1537     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1538     NeedsAdditionalReg = true;
1539     break;
1540   case Mips::ATOMIC_LOAD_UMAX_I64:
1541     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1542     NeedsAdditionalReg = true;
1543     break;
1544   default:
1545     llvm_unreachable("Unknown pseudo atomic for replacement!");
1546   }
1547 
1548   Register OldVal = MI.getOperand(0).getReg();
1549   Register Ptr = MI.getOperand(1).getReg();
1550   Register Incr = MI.getOperand(2).getReg();
1551   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1552 
1553   MachineBasicBlock::iterator II(MI);
1554 
1555   // The scratch registers here with the EarlyClobber | Define | Implicit
1556   // flags is used to persuade the register allocator and the machine
1557   // verifier to accept the usage of this register. This has to be a real
1558   // register which has an UNDEF value but is dead after the instruction which
1559   // is unique among the registers chosen for the instruction.
1560 
1561   // The EarlyClobber flag has the semantic properties that the operand it is
1562   // attached to is clobbered before the rest of the inputs are read. Hence it
1563   // must be unique among the operands to the instruction.
1564   // The Define flag is needed to coerce the machine verifier that an Undef
1565   // value isn't a problem.
1566   // The Dead flag is needed as the value in scratch isn't used by any other
1567   // instruction. Kill isn't used as Dead is more precise.
1568   // The implicit flag is here due to the interaction between the other flags
1569   // and the machine verifier.
1570 
1571   // For correctness purpose, a new pseudo is introduced here. We need this
1572   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1573   // that is spread over >1 basic blocks. A register allocator which
1574   // introduces (or any codegen infact) a store, can violate the expectations
1575   // of the hardware.
1576   //
1577   // An atomic read-modify-write sequence starts with a linked load
1578   // instruction and ends with a store conditional instruction. The atomic
1579   // read-modify-write sequence fails if any of the following conditions
1580   // occur between the execution of ll and sc:
1581   //   * A coherent store is completed by another process or coherent I/O
1582   //     module into the block of synchronizable physical memory containing
1583   //     the word. The size and alignment of the block is
1584   //     implementation-dependent.
1585   //   * A coherent store is executed between an LL and SC sequence on the
1586   //     same processor to the block of synchornizable physical memory
1587   //     containing the word.
1588   //
1589 
1590   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1591   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1592 
1593   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1594   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1595 
1596   MachineInstrBuilder MIB =
1597       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1598           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1599           .addReg(PtrCopy)
1600           .addReg(IncrCopy)
1601           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1602                                RegState::Implicit | RegState::Dead);
1603   if (NeedsAdditionalReg) {
1604     Register Scratch2 =
1605         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1606     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1607                              RegState::Implicit | RegState::Dead);
1608   }
1609 
1610   MI.eraseFromParent();
1611 
1612   return BB;
1613 }
1614 
1615 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1616     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1617     unsigned SrcReg) const {
1618   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1619   const DebugLoc &DL = MI.getDebugLoc();
1620 
1621   if (Subtarget.hasMips32r2() && Size == 1) {
1622     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1623     return BB;
1624   }
1625 
1626   if (Subtarget.hasMips32r2() && Size == 2) {
1627     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1628     return BB;
1629   }
1630 
1631   MachineFunction *MF = BB->getParent();
1632   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1633   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1634   Register ScrReg = RegInfo.createVirtualRegister(RC);
1635 
1636   assert(Size < 32);
1637   int64_t ShiftImm = 32 - (Size * 8);
1638 
1639   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1640   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1641 
1642   return BB;
1643 }
1644 
1645 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1646     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1647   assert((Size == 1 || Size == 2) &&
1648          "Unsupported size for EmitAtomicBinaryPartial.");
1649 
1650   MachineFunction *MF = BB->getParent();
1651   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1652   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1653   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1654   const TargetRegisterClass *RCp =
1655     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1656   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1657   DebugLoc DL = MI.getDebugLoc();
1658 
1659   Register Dest = MI.getOperand(0).getReg();
1660   Register Ptr = MI.getOperand(1).getReg();
1661   Register Incr = MI.getOperand(2).getReg();
1662 
1663   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1664   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1665   Register Mask = RegInfo.createVirtualRegister(RC);
1666   Register Mask2 = RegInfo.createVirtualRegister(RC);
1667   Register Incr2 = RegInfo.createVirtualRegister(RC);
1668   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1669   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1670   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1671   Register Scratch = RegInfo.createVirtualRegister(RC);
1672   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1673   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1674 
1675   unsigned AtomicOp = 0;
1676   bool NeedsAdditionalReg = false;
1677   switch (MI.getOpcode()) {
1678   case Mips::ATOMIC_LOAD_NAND_I8:
1679     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1680     break;
1681   case Mips::ATOMIC_LOAD_NAND_I16:
1682     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1683     break;
1684   case Mips::ATOMIC_SWAP_I8:
1685     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1686     break;
1687   case Mips::ATOMIC_SWAP_I16:
1688     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1689     break;
1690   case Mips::ATOMIC_LOAD_ADD_I8:
1691     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1692     break;
1693   case Mips::ATOMIC_LOAD_ADD_I16:
1694     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1695     break;
1696   case Mips::ATOMIC_LOAD_SUB_I8:
1697     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1698     break;
1699   case Mips::ATOMIC_LOAD_SUB_I16:
1700     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1701     break;
1702   case Mips::ATOMIC_LOAD_AND_I8:
1703     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1704     break;
1705   case Mips::ATOMIC_LOAD_AND_I16:
1706     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1707     break;
1708   case Mips::ATOMIC_LOAD_OR_I8:
1709     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1710     break;
1711   case Mips::ATOMIC_LOAD_OR_I16:
1712     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1713     break;
1714   case Mips::ATOMIC_LOAD_XOR_I8:
1715     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1716     break;
1717   case Mips::ATOMIC_LOAD_XOR_I16:
1718     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1719     break;
1720   case Mips::ATOMIC_LOAD_MIN_I8:
1721     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1722     NeedsAdditionalReg = true;
1723     break;
1724   case Mips::ATOMIC_LOAD_MIN_I16:
1725     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1726     NeedsAdditionalReg = true;
1727     break;
1728   case Mips::ATOMIC_LOAD_MAX_I8:
1729     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1730     NeedsAdditionalReg = true;
1731     break;
1732   case Mips::ATOMIC_LOAD_MAX_I16:
1733     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1734     NeedsAdditionalReg = true;
1735     break;
1736   case Mips::ATOMIC_LOAD_UMIN_I8:
1737     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1738     NeedsAdditionalReg = true;
1739     break;
1740   case Mips::ATOMIC_LOAD_UMIN_I16:
1741     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1742     NeedsAdditionalReg = true;
1743     break;
1744   case Mips::ATOMIC_LOAD_UMAX_I8:
1745     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1746     NeedsAdditionalReg = true;
1747     break;
1748   case Mips::ATOMIC_LOAD_UMAX_I16:
1749     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1750     NeedsAdditionalReg = true;
1751     break;
1752   default:
1753     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1754   }
1755 
1756   // insert new blocks after the current block
1757   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1758   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1759   MachineFunction::iterator It = ++BB->getIterator();
1760   MF->insert(It, exitMBB);
1761 
1762   // Transfer the remainder of BB and its successor edges to exitMBB.
1763   exitMBB->splice(exitMBB->begin(), BB,
1764                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1765   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1766 
1767   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1768 
1769   //  thisMBB:
1770   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1771   //    and     alignedaddr,ptr,masklsb2
1772   //    andi    ptrlsb2,ptr,3
1773   //    sll     shiftamt,ptrlsb2,3
1774   //    ori     maskupper,$0,255               # 0xff
1775   //    sll     mask,maskupper,shiftamt
1776   //    nor     mask2,$0,mask
1777   //    sll     incr2,incr,shiftamt
1778 
1779   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1780   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1781     .addReg(ABI.GetNullPtr()).addImm(-4);
1782   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1783     .addReg(Ptr).addReg(MaskLSB2);
1784   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1785       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1786   if (Subtarget.isLittle()) {
1787     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1788   } else {
1789     Register Off = RegInfo.createVirtualRegister(RC);
1790     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1791       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1792     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1793   }
1794   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1795     .addReg(Mips::ZERO).addImm(MaskImm);
1796   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1797     .addReg(MaskUpper).addReg(ShiftAmt);
1798   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1799   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1800 
1801 
1802   // The purposes of the flags on the scratch registers is explained in
1803   // emitAtomicBinary. In summary, we need a scratch register which is going to
1804   // be undef, that is unique among registers chosen for the instruction.
1805 
1806   MachineInstrBuilder MIB =
1807       BuildMI(BB, DL, TII->get(AtomicOp))
1808           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1809           .addReg(AlignedAddr)
1810           .addReg(Incr2)
1811           .addReg(Mask)
1812           .addReg(Mask2)
1813           .addReg(ShiftAmt)
1814           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1815                                RegState::Dead | RegState::Implicit)
1816           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1817                                 RegState::Dead | RegState::Implicit)
1818           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1819                                 RegState::Dead | RegState::Implicit);
1820   if (NeedsAdditionalReg) {
1821     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1822     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1823                              RegState::Dead | RegState::Implicit);
1824   }
1825 
1826   MI.eraseFromParent(); // The instruction is gone now.
1827 
1828   return exitMBB;
1829 }
1830 
1831 // Lower atomic compare and swap to a pseudo instruction, taking care to
1832 // define a scratch register for the pseudo instruction's expansion. The
1833 // instruction is expanded after the register allocator as to prevent
1834 // the insertion of stores between the linked load and the store conditional.
1835 
1836 MachineBasicBlock *
1837 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1838                                       MachineBasicBlock *BB) const {
1839 
1840   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1841           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1842          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1843 
1844   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1845 
1846   MachineFunction *MF = BB->getParent();
1847   MachineRegisterInfo &MRI = MF->getRegInfo();
1848   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1849   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1850   DebugLoc DL = MI.getDebugLoc();
1851 
1852   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1853                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1854                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1855   Register Dest = MI.getOperand(0).getReg();
1856   Register Ptr = MI.getOperand(1).getReg();
1857   Register OldVal = MI.getOperand(2).getReg();
1858   Register NewVal = MI.getOperand(3).getReg();
1859 
1860   Register Scratch = MRI.createVirtualRegister(RC);
1861   MachineBasicBlock::iterator II(MI);
1862 
1863   // We need to create copies of the various registers and kill them at the
1864   // atomic pseudo. If the copies are not made, when the atomic is expanded
1865   // after fast register allocation, the spills will end up outside of the
1866   // blocks that their values are defined in, causing livein errors.
1867 
1868   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1869   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1870   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1871 
1872   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1873   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1874   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1875 
1876   // The purposes of the flags on the scratch registers is explained in
1877   // emitAtomicBinary. In summary, we need a scratch register which is going to
1878   // be undef, that is unique among registers chosen for the instruction.
1879 
1880   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1881       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1882       .addReg(PtrCopy, RegState::Kill)
1883       .addReg(OldValCopy, RegState::Kill)
1884       .addReg(NewValCopy, RegState::Kill)
1885       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1886                            RegState::Dead | RegState::Implicit);
1887 
1888   MI.eraseFromParent(); // The instruction is gone now.
1889 
1890   return BB;
1891 }
1892 
1893 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1894     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1895   assert((Size == 1 || Size == 2) &&
1896       "Unsupported size for EmitAtomicCmpSwapPartial.");
1897 
1898   MachineFunction *MF = BB->getParent();
1899   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1900   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1901   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1902   const TargetRegisterClass *RCp =
1903     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1904   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1905   DebugLoc DL = MI.getDebugLoc();
1906 
1907   Register Dest = MI.getOperand(0).getReg();
1908   Register Ptr = MI.getOperand(1).getReg();
1909   Register CmpVal = MI.getOperand(2).getReg();
1910   Register NewVal = MI.getOperand(3).getReg();
1911 
1912   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1913   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1914   Register Mask = RegInfo.createVirtualRegister(RC);
1915   Register Mask2 = RegInfo.createVirtualRegister(RC);
1916   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1917   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1918   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1919   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1920   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1921   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1922   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1923   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1924                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
1925                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
1926 
1927   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
1928   // flags are used to coerce the register allocator and the machine verifier to
1929   // accept the usage of these registers.
1930   // The EarlyClobber flag has the semantic properties that the operand it is
1931   // attached to is clobbered before the rest of the inputs are read. Hence it
1932   // must be unique among the operands to the instruction.
1933   // The Define flag is needed to coerce the machine verifier that an Undef
1934   // value isn't a problem.
1935   // The Dead flag is needed as the value in scratch isn't used by any other
1936   // instruction. Kill isn't used as Dead is more precise.
1937   Register Scratch = RegInfo.createVirtualRegister(RC);
1938   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1939 
1940   // insert new blocks after the current block
1941   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1942   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1943   MachineFunction::iterator It = ++BB->getIterator();
1944   MF->insert(It, exitMBB);
1945 
1946   // Transfer the remainder of BB and its successor edges to exitMBB.
1947   exitMBB->splice(exitMBB->begin(), BB,
1948                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1949   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1950 
1951   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1952 
1953   //  thisMBB:
1954   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1955   //    and     alignedaddr,ptr,masklsb2
1956   //    andi    ptrlsb2,ptr,3
1957   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1958   //    sll     shiftamt,ptrlsb2,3
1959   //    ori     maskupper,$0,255               # 0xff
1960   //    sll     mask,maskupper,shiftamt
1961   //    nor     mask2,$0,mask
1962   //    andi    maskedcmpval,cmpval,255
1963   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1964   //    andi    maskednewval,newval,255
1965   //    sll     shiftednewval,maskednewval,shiftamt
1966   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1967   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1968     .addReg(ABI.GetNullPtr()).addImm(-4);
1969   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1970     .addReg(Ptr).addReg(MaskLSB2);
1971   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1972       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1973   if (Subtarget.isLittle()) {
1974     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1975   } else {
1976     Register Off = RegInfo.createVirtualRegister(RC);
1977     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1978       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1979     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1980   }
1981   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1982     .addReg(Mips::ZERO).addImm(MaskImm);
1983   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1984     .addReg(MaskUpper).addReg(ShiftAmt);
1985   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1986   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1987     .addReg(CmpVal).addImm(MaskImm);
1988   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1989     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1990   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1991     .addReg(NewVal).addImm(MaskImm);
1992   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1993     .addReg(MaskedNewVal).addReg(ShiftAmt);
1994 
1995   // The purposes of the flags on the scratch registers are explained in
1996   // emitAtomicBinary. In summary, we need a scratch register which is going to
1997   // be undef, that is unique among the register chosen for the instruction.
1998 
1999   BuildMI(BB, DL, TII->get(AtomicOp))
2000       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2001       .addReg(AlignedAddr)
2002       .addReg(Mask)
2003       .addReg(ShiftedCmpVal)
2004       .addReg(Mask2)
2005       .addReg(ShiftedNewVal)
2006       .addReg(ShiftAmt)
2007       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2008                            RegState::Dead | RegState::Implicit)
2009       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2010                             RegState::Dead | RegState::Implicit);
2011 
2012   MI.eraseFromParent(); // The instruction is gone now.
2013 
2014   return exitMBB;
2015 }
2016 
2017 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2018   // The first operand is the chain, the second is the condition, the third is
2019   // the block to branch to if the condition is true.
2020   SDValue Chain = Op.getOperand(0);
2021   SDValue Dest = Op.getOperand(2);
2022   SDLoc DL(Op);
2023 
2024   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2025   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2026 
2027   // Return if flag is not set by a floating point comparison.
2028   if (CondRes.getOpcode() != MipsISD::FPCmp)
2029     return Op;
2030 
2031   SDValue CCNode  = CondRes.getOperand(2);
2032   Mips::CondCode CC =
2033     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
2034   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2035   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2036   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2037   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2038                      FCC0, Dest, CondRes);
2039 }
2040 
2041 SDValue MipsTargetLowering::
2042 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2043 {
2044   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2045   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2046 
2047   // Return if flag is not set by a floating point comparison.
2048   if (Cond.getOpcode() != MipsISD::FPCmp)
2049     return Op;
2050 
2051   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2052                       SDLoc(Op));
2053 }
2054 
2055 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2056   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2057   SDValue Cond = createFPCmp(DAG, Op);
2058 
2059   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2060          "Floating point operand expected.");
2061 
2062   SDLoc DL(Op);
2063   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2064   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2065 
2066   return createCMovFP(DAG, Cond, True, False, DL);
2067 }
2068 
2069 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2070                                                SelectionDAG &DAG) const {
2071   EVT Ty = Op.getValueType();
2072   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2073   const GlobalValue *GV = N->getGlobal();
2074 
2075   if (!isPositionIndependent()) {
2076     const MipsTargetObjectFile *TLOF =
2077         static_cast<const MipsTargetObjectFile *>(
2078             getTargetMachine().getObjFileLowering());
2079     const GlobalObject *GO = GV->getAliaseeObject();
2080     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2081       // %gp_rel relocation
2082       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2083 
2084                                 // %hi/%lo relocation
2085     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2086                                 // %highest/%higher/%hi/%lo relocation
2087                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2088   }
2089 
2090   // Every other architecture would use shouldAssumeDSOLocal in here, but
2091   // mips is special.
2092   // * In PIC code mips requires got loads even for local statics!
2093   // * To save on got entries, for local statics the got entry contains the
2094   //   page and an additional add instruction takes care of the low bits.
2095   // * It is legal to access a hidden symbol with a non hidden undefined,
2096   //   so one cannot guarantee that all access to a hidden symbol will know
2097   //   it is hidden.
2098   // * Mips linkers don't support creating a page and a full got entry for
2099   //   the same symbol.
2100   // * Given all that, we have to use a full got entry for hidden symbols :-(
2101   if (GV->hasLocalLinkage())
2102     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2103 
2104   if (Subtarget.useXGOT())
2105     return getAddrGlobalLargeGOT(
2106         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2107         DAG.getEntryNode(),
2108         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2109 
2110   return getAddrGlobal(
2111       N, SDLoc(N), Ty, DAG,
2112       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2113       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2114 }
2115 
2116 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2117                                               SelectionDAG &DAG) const {
2118   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2119   EVT Ty = Op.getValueType();
2120 
2121   if (!isPositionIndependent())
2122     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2123                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2124 
2125   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2126 }
2127 
2128 SDValue MipsTargetLowering::
2129 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2130 {
2131   // If the relocation model is PIC, use the General Dynamic TLS Model or
2132   // Local Dynamic TLS model, otherwise use the Initial Exec or
2133   // Local Exec TLS Model.
2134 
2135   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2136   if (DAG.getTarget().useEmulatedTLS())
2137     return LowerToTLSEmulatedModel(GA, DAG);
2138 
2139   SDLoc DL(GA);
2140   const GlobalValue *GV = GA->getGlobal();
2141   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2142 
2143   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2144 
2145   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2146     // General Dynamic and Local Dynamic TLS Model.
2147     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2148                                                       : MipsII::MO_TLSGD;
2149 
2150     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2151     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2152                                    getGlobalReg(DAG, PtrVT), TGA);
2153     unsigned PtrSize = PtrVT.getSizeInBits();
2154     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2155 
2156     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2157 
2158     ArgListTy Args;
2159     ArgListEntry Entry;
2160     Entry.Node = Argument;
2161     Entry.Ty = PtrTy;
2162     Args.push_back(Entry);
2163 
2164     TargetLowering::CallLoweringInfo CLI(DAG);
2165     CLI.setDebugLoc(DL)
2166         .setChain(DAG.getEntryNode())
2167         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2168     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2169 
2170     SDValue Ret = CallResult.first;
2171 
2172     if (model != TLSModel::LocalDynamic)
2173       return Ret;
2174 
2175     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2176                                                MipsII::MO_DTPREL_HI);
2177     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2178     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2179                                                MipsII::MO_DTPREL_LO);
2180     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2181     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2182     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2183   }
2184 
2185   SDValue Offset;
2186   if (model == TLSModel::InitialExec) {
2187     // Initial Exec TLS Model
2188     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2189                                              MipsII::MO_GOTTPREL);
2190     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2191                       TGA);
2192     Offset =
2193         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2194   } else {
2195     // Local Exec TLS Model
2196     assert(model == TLSModel::LocalExec);
2197     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2198                                                MipsII::MO_TPREL_HI);
2199     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2200                                                MipsII::MO_TPREL_LO);
2201     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2202     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2203     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2204   }
2205 
2206   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2207   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2208 }
2209 
2210 SDValue MipsTargetLowering::
2211 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2212 {
2213   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2214   EVT Ty = Op.getValueType();
2215 
2216   if (!isPositionIndependent())
2217     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2218                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2219 
2220   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2221 }
2222 
2223 SDValue MipsTargetLowering::
2224 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2225 {
2226   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2227   EVT Ty = Op.getValueType();
2228 
2229   if (!isPositionIndependent()) {
2230     const MipsTargetObjectFile *TLOF =
2231         static_cast<const MipsTargetObjectFile *>(
2232             getTargetMachine().getObjFileLowering());
2233 
2234     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2235                                        getTargetMachine()))
2236       // %gp_rel relocation
2237       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2238 
2239     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2240                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2241   }
2242 
2243  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2244 }
2245 
2246 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2247   MachineFunction &MF = DAG.getMachineFunction();
2248   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2249 
2250   SDLoc DL(Op);
2251   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2252                                  getPointerTy(MF.getDataLayout()));
2253 
2254   // vastart just stores the address of the VarArgsFrameIndex slot into the
2255   // memory location argument.
2256   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2257   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2258                       MachinePointerInfo(SV));
2259 }
2260 
2261 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2262   SDNode *Node = Op.getNode();
2263   EVT VT = Node->getValueType(0);
2264   SDValue Chain = Node->getOperand(0);
2265   SDValue VAListPtr = Node->getOperand(1);
2266   const Align Align =
2267       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2268   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2269   SDLoc DL(Node);
2270   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2271 
2272   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2273                                    VAListPtr, MachinePointerInfo(SV));
2274   SDValue VAList = VAListLoad;
2275 
2276   // Re-align the pointer if necessary.
2277   // It should only ever be necessary for 64-bit types on O32 since the minimum
2278   // argument alignment is the same as the maximum type alignment for N32/N64.
2279   //
2280   // FIXME: We currently align too often. The code generator doesn't notice
2281   //        when the pointer is still aligned from the last va_arg (or pair of
2282   //        va_args for the i64 on O32 case).
2283   if (Align > getMinStackArgumentAlignment()) {
2284     VAList = DAG.getNode(
2285         ISD::ADD, DL, VAList.getValueType(), VAList,
2286         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2287 
2288     VAList = DAG.getNode(
2289         ISD::AND, DL, VAList.getValueType(), VAList,
2290         DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
2291   }
2292 
2293   // Increment the pointer, VAList, to the next vaarg.
2294   auto &TD = DAG.getDataLayout();
2295   unsigned ArgSizeInBytes =
2296       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2297   SDValue Tmp3 =
2298       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2299                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2300                                   DL, VAList.getValueType()));
2301   // Store the incremented VAList to the legalized pointer
2302   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2303                        MachinePointerInfo(SV));
2304 
2305   // In big-endian mode we must adjust the pointer when the load size is smaller
2306   // than the argument slot size. We must also reduce the known alignment to
2307   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2308   // the correct half of the slot, and reduce the alignment from 8 (slot
2309   // alignment) down to 4 (type alignment).
2310   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2311     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2312     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2313                          DAG.getIntPtrConstant(Adjustment, DL));
2314   }
2315   // Load the actual argument out of the pointer VAList
2316   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2317 }
2318 
2319 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2320                                 bool HasExtractInsert) {
2321   EVT TyX = Op.getOperand(0).getValueType();
2322   EVT TyY = Op.getOperand(1).getValueType();
2323   SDLoc DL(Op);
2324   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2325   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2326   SDValue Res;
2327 
2328   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2329   // to i32.
2330   SDValue X = (TyX == MVT::f32) ?
2331     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2332     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2333                 Const1);
2334   SDValue Y = (TyY == MVT::f32) ?
2335     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2336     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2337                 Const1);
2338 
2339   if (HasExtractInsert) {
2340     // ext  E, Y, 31, 1  ; extract bit31 of Y
2341     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2342     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2343     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2344   } else {
2345     // sll SllX, X, 1
2346     // srl SrlX, SllX, 1
2347     // srl SrlY, Y, 31
2348     // sll SllY, SrlX, 31
2349     // or  Or, SrlX, SllY
2350     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2351     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2352     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2353     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2354     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2355   }
2356 
2357   if (TyX == MVT::f32)
2358     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2359 
2360   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2361                              Op.getOperand(0),
2362                              DAG.getConstant(0, DL, MVT::i32));
2363   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2364 }
2365 
2366 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2367                                 bool HasExtractInsert) {
2368   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2369   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2370   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2371   SDLoc DL(Op);
2372   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2373 
2374   // Bitcast to integer nodes.
2375   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2376   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2377 
2378   if (HasExtractInsert) {
2379     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2380     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2381     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2382                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2383 
2384     if (WidthX > WidthY)
2385       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2386     else if (WidthY > WidthX)
2387       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2388 
2389     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2390                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2391                             X);
2392     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2393   }
2394 
2395   // (d)sll SllX, X, 1
2396   // (d)srl SrlX, SllX, 1
2397   // (d)srl SrlY, Y, width(Y)-1
2398   // (d)sll SllY, SrlX, width(Y)-1
2399   // or     Or, SrlX, SllY
2400   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2401   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2402   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2403                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2404 
2405   if (WidthX > WidthY)
2406     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2407   else if (WidthY > WidthX)
2408     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2409 
2410   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2411                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2412   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2413   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2414 }
2415 
2416 SDValue
2417 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2418   if (Subtarget.isGP64bit())
2419     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2420 
2421   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2422 }
2423 
2424 static SDValue lowerFABS32(SDValue Op, SelectionDAG &DAG,
2425                            bool HasExtractInsert) {
2426   SDLoc DL(Op);
2427   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2428 
2429   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2430   // to i32.
2431   SDValue X = (Op.getValueType() == MVT::f32)
2432                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2433                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2434                                 Op.getOperand(0), Const1);
2435 
2436   // Clear MSB.
2437   if (HasExtractInsert)
2438     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2439                       DAG.getRegister(Mips::ZERO, MVT::i32),
2440                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2441   else {
2442     // TODO: Provide DAG patterns which transform (and x, cst)
2443     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2444     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2445     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2446   }
2447 
2448   if (Op.getValueType() == MVT::f32)
2449     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2450 
2451   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2452   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2453   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2454   // place.
2455   SDValue LowX =
2456       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2457                   DAG.getConstant(0, DL, MVT::i32));
2458   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2459 }
2460 
2461 static SDValue lowerFABS64(SDValue Op, SelectionDAG &DAG,
2462                            bool HasExtractInsert) {
2463   SDLoc DL(Op);
2464   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2465 
2466   // Bitcast to integer node.
2467   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2468 
2469   // Clear MSB.
2470   if (HasExtractInsert)
2471     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2472                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2473                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2474   else {
2475     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2476     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2477   }
2478 
2479   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2480 }
2481 
2482 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2483   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2484     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2485 
2486   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2487 }
2488 
2489 SDValue MipsTargetLowering::
2490 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2491   // check the depth
2492   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2493     DAG.getContext()->emitError(
2494         "return address can be determined only for current frame");
2495     return SDValue();
2496   }
2497 
2498   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2499   MFI.setFrameAddressIsTaken(true);
2500   EVT VT = Op.getValueType();
2501   SDLoc DL(Op);
2502   SDValue FrameAddr = DAG.getCopyFromReg(
2503       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2504   return FrameAddr;
2505 }
2506 
2507 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2508                                             SelectionDAG &DAG) const {
2509   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2510     return SDValue();
2511 
2512   // check the depth
2513   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2514     DAG.getContext()->emitError(
2515         "return address can be determined only for current frame");
2516     return SDValue();
2517   }
2518 
2519   MachineFunction &MF = DAG.getMachineFunction();
2520   MachineFrameInfo &MFI = MF.getFrameInfo();
2521   MVT VT = Op.getSimpleValueType();
2522   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2523   MFI.setReturnAddressIsTaken(true);
2524 
2525   // Return RA, which contains the return address. Mark it an implicit live-in.
2526   Register Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2527   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2528 }
2529 
2530 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2531 // generated from __builtin_eh_return (offset, handler)
2532 // The effect of this is to adjust the stack pointer by "offset"
2533 // and then branch to "handler".
2534 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2535                                                                      const {
2536   MachineFunction &MF = DAG.getMachineFunction();
2537   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2538 
2539   MipsFI->setCallsEhReturn();
2540   SDValue Chain     = Op.getOperand(0);
2541   SDValue Offset    = Op.getOperand(1);
2542   SDValue Handler   = Op.getOperand(2);
2543   SDLoc DL(Op);
2544   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2545 
2546   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2547   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2548   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2549   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2550   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2551   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2552   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2553                      DAG.getRegister(OffsetReg, Ty),
2554                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2555                      Chain.getValue(1));
2556 }
2557 
2558 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2559                                               SelectionDAG &DAG) const {
2560   // FIXME: Need pseudo-fence for 'singlethread' fences
2561   // FIXME: Set SType for weaker fences where supported/appropriate.
2562   unsigned SType = 0;
2563   SDLoc DL(Op);
2564   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2565                      DAG.getConstant(SType, DL, MVT::i32));
2566 }
2567 
2568 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2569                                                 SelectionDAG &DAG) const {
2570   SDLoc DL(Op);
2571   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2572 
2573   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2574   SDValue Shamt = Op.getOperand(2);
2575   // if shamt < (VT.bits):
2576   //  lo = (shl lo, shamt)
2577   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2578   // else:
2579   //  lo = 0
2580   //  hi = (shl lo, shamt[4:0])
2581   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2582                             DAG.getConstant(-1, DL, MVT::i32));
2583   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2584                                       DAG.getConstant(1, DL, VT));
2585   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2586   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2587   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2588   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2589   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2590                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2591   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2592                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2593   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2594 
2595   SDValue Ops[2] = {Lo, Hi};
2596   return DAG.getMergeValues(Ops, DL);
2597 }
2598 
2599 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2600                                                  bool IsSRA) const {
2601   SDLoc DL(Op);
2602   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2603   SDValue Shamt = Op.getOperand(2);
2604   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2605 
2606   // if shamt < (VT.bits):
2607   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2608   //  if isSRA:
2609   //    hi = (sra hi, shamt)
2610   //  else:
2611   //    hi = (srl hi, shamt)
2612   // else:
2613   //  if isSRA:
2614   //   lo = (sra hi, shamt[4:0])
2615   //   hi = (sra hi, 31)
2616   //  else:
2617   //   lo = (srl hi, shamt[4:0])
2618   //   hi = 0
2619   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2620                             DAG.getConstant(-1, DL, MVT::i32));
2621   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2622                                      DAG.getConstant(1, DL, VT));
2623   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2624   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2625   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2626   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2627                                      DL, VT, Hi, Shamt);
2628   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2629                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2630   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2631                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2632 
2633   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2634     SDVTList VTList = DAG.getVTList(VT, VT);
2635     return DAG.getNode(Subtarget.isGP64bit() ? Mips::PseudoD_SELECT_I64
2636                                              : Mips::PseudoD_SELECT_I,
2637                        DL, VTList, Cond, ShiftRightHi,
2638                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2639                        ShiftRightHi);
2640   }
2641 
2642   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2643   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2644                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2645 
2646   SDValue Ops[2] = {Lo, Hi};
2647   return DAG.getMergeValues(Ops, DL);
2648 }
2649 
2650 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2651                             SDValue Chain, SDValue Src, unsigned Offset) {
2652   SDValue Ptr = LD->getBasePtr();
2653   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2654   EVT BasePtrVT = Ptr.getValueType();
2655   SDLoc DL(LD);
2656   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2657 
2658   if (Offset)
2659     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2660                       DAG.getConstant(Offset, DL, BasePtrVT));
2661 
2662   SDValue Ops[] = { Chain, Ptr, Src };
2663   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2664                                  LD->getMemOperand());
2665 }
2666 
2667 // Expand an unaligned 32 or 64-bit integer load node.
2668 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2669   LoadSDNode *LD = cast<LoadSDNode>(Op);
2670   EVT MemVT = LD->getMemoryVT();
2671 
2672   if (Subtarget.systemSupportsUnalignedAccess())
2673     return Op;
2674 
2675   // Return if load is aligned or if MemVT is neither i32 nor i64.
2676   if ((LD->getAlignment() >= MemVT.getSizeInBits() / 8) ||
2677       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2678     return SDValue();
2679 
2680   bool IsLittle = Subtarget.isLittle();
2681   EVT VT = Op.getValueType();
2682   ISD::LoadExtType ExtType = LD->getExtensionType();
2683   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2684 
2685   assert((VT == MVT::i32) || (VT == MVT::i64));
2686 
2687   // Expand
2688   //  (set dst, (i64 (load baseptr)))
2689   // to
2690   //  (set tmp, (ldl (add baseptr, 7), undef))
2691   //  (set dst, (ldr baseptr, tmp))
2692   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2693     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2694                                IsLittle ? 7 : 0);
2695     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2696                         IsLittle ? 0 : 7);
2697   }
2698 
2699   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2700                              IsLittle ? 3 : 0);
2701   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2702                              IsLittle ? 0 : 3);
2703 
2704   // Expand
2705   //  (set dst, (i32 (load baseptr))) or
2706   //  (set dst, (i64 (sextload baseptr))) or
2707   //  (set dst, (i64 (extload baseptr)))
2708   // to
2709   //  (set tmp, (lwl (add baseptr, 3), undef))
2710   //  (set dst, (lwr baseptr, tmp))
2711   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2712       (ExtType == ISD::EXTLOAD))
2713     return LWR;
2714 
2715   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2716 
2717   // Expand
2718   //  (set dst, (i64 (zextload baseptr)))
2719   // to
2720   //  (set tmp0, (lwl (add baseptr, 3), undef))
2721   //  (set tmp1, (lwr baseptr, tmp0))
2722   //  (set tmp2, (shl tmp1, 32))
2723   //  (set dst, (srl tmp2, 32))
2724   SDLoc DL(LD);
2725   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2726   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2727   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2728   SDValue Ops[] = { SRL, LWR.getValue(1) };
2729   return DAG.getMergeValues(Ops, DL);
2730 }
2731 
2732 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2733                              SDValue Chain, unsigned Offset) {
2734   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2735   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2736   SDLoc DL(SD);
2737   SDVTList VTList = DAG.getVTList(MVT::Other);
2738 
2739   if (Offset)
2740     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2741                       DAG.getConstant(Offset, DL, BasePtrVT));
2742 
2743   SDValue Ops[] = { Chain, Value, Ptr };
2744   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2745                                  SD->getMemOperand());
2746 }
2747 
2748 // Expand an unaligned 32 or 64-bit integer store node.
2749 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2750                                       bool IsLittle) {
2751   SDValue Value = SD->getValue(), Chain = SD->getChain();
2752   EVT VT = Value.getValueType();
2753 
2754   // Expand
2755   //  (store val, baseptr) or
2756   //  (truncstore val, baseptr)
2757   // to
2758   //  (swl val, (add baseptr, 3))
2759   //  (swr val, baseptr)
2760   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2761     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2762                                 IsLittle ? 3 : 0);
2763     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2764   }
2765 
2766   assert(VT == MVT::i64);
2767 
2768   // Expand
2769   //  (store val, baseptr)
2770   // to
2771   //  (sdl val, (add baseptr, 7))
2772   //  (sdr val, baseptr)
2773   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2774   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2775 }
2776 
2777 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2778 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2779                                      bool SingleFloat) {
2780   SDValue Val = SD->getValue();
2781 
2782   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2783       (Val.getValueSizeInBits() > 32 && SingleFloat))
2784     return SDValue();
2785 
2786   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2787   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2788                            Val.getOperand(0));
2789   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2790                       SD->getPointerInfo(), SD->getAlignment(),
2791                       SD->getMemOperand()->getFlags());
2792 }
2793 
2794 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2795   StoreSDNode *SD = cast<StoreSDNode>(Op);
2796   EVT MemVT = SD->getMemoryVT();
2797 
2798   // Lower unaligned integer stores.
2799   if (!Subtarget.systemSupportsUnalignedAccess() &&
2800       (SD->getAlignment() < MemVT.getSizeInBits() / 8) &&
2801       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2802     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2803 
2804   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2805 }
2806 
2807 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2808                                               SelectionDAG &DAG) const {
2809 
2810   // Return a fixed StackObject with offset 0 which points to the old stack
2811   // pointer.
2812   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2813   EVT ValTy = Op->getValueType(0);
2814   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2815   return DAG.getFrameIndex(FI, ValTy);
2816 }
2817 
2818 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2819                                             SelectionDAG &DAG) const {
2820   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2821     return SDValue();
2822 
2823   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2824   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2825                               Op.getOperand(0));
2826   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2827 }
2828 
2829 //===----------------------------------------------------------------------===//
2830 //                      Calling Convention Implementation
2831 //===----------------------------------------------------------------------===//
2832 
2833 //===----------------------------------------------------------------------===//
2834 // TODO: Implement a generic logic using tblgen that can support this.
2835 // Mips O32 ABI rules:
2836 // ---
2837 // i32 - Passed in A0, A1, A2, A3 and stack
2838 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2839 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2840 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2841 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2842 //       not used, it must be shadowed. If only A3 is available, shadow it and
2843 //       go to stack.
2844 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2845 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2846 //         with the remainder spilled to the stack.
2847 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2848 //         spilling the remainder to the stack.
2849 //
2850 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2851 //===----------------------------------------------------------------------===//
2852 
2853 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2854                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2855                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2856   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2857       State.getMachineFunction().getSubtarget());
2858 
2859   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2860 
2861   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2862 
2863   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2864 
2865   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2866 
2867   // Do not process byval args here.
2868   if (ArgFlags.isByVal())
2869     return true;
2870 
2871   // Promote i8 and i16
2872   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2873     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2874       LocVT = MVT::i32;
2875       if (ArgFlags.isSExt())
2876         LocInfo = CCValAssign::SExtUpper;
2877       else if (ArgFlags.isZExt())
2878         LocInfo = CCValAssign::ZExtUpper;
2879       else
2880         LocInfo = CCValAssign::AExtUpper;
2881     }
2882   }
2883 
2884   // Promote i8 and i16
2885   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2886     LocVT = MVT::i32;
2887     if (ArgFlags.isSExt())
2888       LocInfo = CCValAssign::SExt;
2889     else if (ArgFlags.isZExt())
2890       LocInfo = CCValAssign::ZExt;
2891     else
2892       LocInfo = CCValAssign::AExt;
2893   }
2894 
2895   unsigned Reg;
2896 
2897   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2898   // is true: function is vararg, argument is 3rd or higher, there is previous
2899   // argument which is not f32 or f64.
2900   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2901                                 State.getFirstUnallocated(F32Regs) != ValNo;
2902   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
2903   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
2904   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2905 
2906   // The MIPS vector ABI for floats passes them in a pair of registers
2907   if (ValVT == MVT::i32 && isVectorFloat) {
2908     // This is the start of an vector that was scalarized into an unknown number
2909     // of components. It doesn't matter how many there are. Allocate one of the
2910     // notional 8 byte aligned registers which map onto the argument stack, and
2911     // shadow the register lost to alignment requirements.
2912     if (ArgFlags.isSplit()) {
2913       Reg = State.AllocateReg(FloatVectorIntRegs);
2914       if (Reg == Mips::A2)
2915         State.AllocateReg(Mips::A1);
2916       else if (Reg == 0)
2917         State.AllocateReg(Mips::A3);
2918     } else {
2919       // If we're an intermediate component of the split, we can just attempt to
2920       // allocate a register directly.
2921       Reg = State.AllocateReg(IntRegs);
2922     }
2923   } else if (ValVT == MVT::i32 ||
2924              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2925     Reg = State.AllocateReg(IntRegs);
2926     // If this is the first part of an i64 arg,
2927     // the allocated register must be either A0 or A2.
2928     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2929       Reg = State.AllocateReg(IntRegs);
2930     LocVT = MVT::i32;
2931   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2932     LocVT = MVT::i32;
2933 
2934     // Allocate int register and shadow next int register. If first
2935     // available register is Mips::A1 or Mips::A3, shadow it too.
2936     Reg = State.AllocateReg(IntRegs);
2937     if (Reg == Mips::A1 || Reg == Mips::A3)
2938       Reg = State.AllocateReg(IntRegs);
2939 
2940     if (Reg) {
2941       State.addLoc(
2942           CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2943       MCRegister HiReg = State.AllocateReg(IntRegs);
2944       assert(HiReg);
2945       State.addLoc(
2946           CCValAssign::getCustomReg(ValNo, ValVT, HiReg, LocVT, LocInfo));
2947       return false;
2948     }
2949   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2950     // we are guaranteed to find an available float register
2951     if (ValVT == MVT::f32) {
2952       Reg = State.AllocateReg(F32Regs);
2953       // Shadow int register
2954       State.AllocateReg(IntRegs);
2955     } else {
2956       Reg = State.AllocateReg(F64Regs);
2957       // Shadow int registers
2958       unsigned Reg2 = State.AllocateReg(IntRegs);
2959       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2960         State.AllocateReg(IntRegs);
2961       State.AllocateReg(IntRegs);
2962     }
2963   } else
2964     llvm_unreachable("Cannot handle this ValVT.");
2965 
2966   if (!Reg) {
2967     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2968     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2969   } else
2970     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2971 
2972   return false;
2973 }
2974 
2975 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2976                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2977                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2978   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2979 
2980   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2981 }
2982 
2983 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2984                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2985                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2986   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2987 
2988   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2989 }
2990 
2991 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2992                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2993                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2994 
2995 #include "MipsGenCallingConv.inc"
2996 
2997  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
2998    return CC_Mips_FixedArg;
2999  }
3000 
3001  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3002    return RetCC_Mips;
3003  }
3004 //===----------------------------------------------------------------------===//
3005 //                  Call Calling Convention Implementation
3006 //===----------------------------------------------------------------------===//
3007 
3008 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3009                                            SDValue Chain, SDValue Arg,
3010                                            const SDLoc &DL, bool IsTailCall,
3011                                            SelectionDAG &DAG) const {
3012   if (!IsTailCall) {
3013     SDValue PtrOff =
3014         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3015                     DAG.getIntPtrConstant(Offset, DL));
3016     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3017   }
3018 
3019   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3020   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3021   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3022   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(), MaybeAlign(),
3023                       MachineMemOperand::MOVolatile);
3024 }
3025 
3026 void MipsTargetLowering::
3027 getOpndList(SmallVectorImpl<SDValue> &Ops,
3028             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3029             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3030             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3031             SDValue Chain) const {
3032   // Insert node "GP copy globalreg" before call to function.
3033   //
3034   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3035   // in PIC mode) allow symbols to be resolved via lazy binding.
3036   // The lazy binding stub requires GP to point to the GOT.
3037   // Note that we don't need GP to point to the GOT for indirect calls
3038   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3039   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3040   // used for the function (that is, Mips linker doesn't generate lazy binding
3041   // stub for a function whose address is taken in the program).
3042   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3043     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3044     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3045     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3046   }
3047 
3048   // Build a sequence of copy-to-reg nodes chained together with token
3049   // chain and flag operands which copy the outgoing args into registers.
3050   // The InFlag in necessary since all emitted instructions must be
3051   // stuck together.
3052   SDValue InFlag;
3053 
3054   for (auto &R : RegsToPass) {
3055     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, R.first, R.second, InFlag);
3056     InFlag = Chain.getValue(1);
3057   }
3058 
3059   // Add argument registers to the end of the list so that they are
3060   // known live into the call.
3061   for (auto &R : RegsToPass)
3062     Ops.push_back(CLI.DAG.getRegister(R.first, R.second.getValueType()));
3063 
3064   // Add a register mask operand representing the call-preserved registers.
3065   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3066   const uint32_t *Mask =
3067       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3068   assert(Mask && "Missing call preserved mask for calling convention");
3069   if (Subtarget.inMips16HardFloat()) {
3070     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3071       StringRef Sym = G->getGlobal()->getName();
3072       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3073       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3074         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3075       }
3076     }
3077   }
3078   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3079 
3080   if (InFlag.getNode())
3081     Ops.push_back(InFlag);
3082 }
3083 
3084 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3085                                                        SDNode *Node) const {
3086   switch (MI.getOpcode()) {
3087     default:
3088       return;
3089     case Mips::JALR:
3090     case Mips::JALRPseudo:
3091     case Mips::JALR64:
3092     case Mips::JALR64Pseudo:
3093     case Mips::JALR16_MM:
3094     case Mips::JALRC16_MMR6:
3095     case Mips::TAILCALLREG:
3096     case Mips::TAILCALLREG64:
3097     case Mips::TAILCALLR6REG:
3098     case Mips::TAILCALL64R6REG:
3099     case Mips::TAILCALLREG_MM:
3100     case Mips::TAILCALLREG_MMR6: {
3101       if (!EmitJalrReloc ||
3102           Subtarget.inMips16Mode() ||
3103           !isPositionIndependent() ||
3104           Node->getNumOperands() < 1 ||
3105           Node->getOperand(0).getNumOperands() < 2) {
3106         return;
3107       }
3108       // We are after the callee address, set by LowerCall().
3109       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3110       // symbol.
3111       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3112       StringRef Sym;
3113       if (const GlobalAddressSDNode *G =
3114               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3115         // We must not emit the R_MIPS_JALR relocation against data symbols
3116         // since this will cause run-time crashes if the linker replaces the
3117         // call instruction with a relative branch to the data symbol.
3118         if (!isa<Function>(G->getGlobal())) {
3119           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3120                             << G->getGlobal()->getName() << "\n");
3121           return;
3122         }
3123         Sym = G->getGlobal()->getName();
3124       }
3125       else if (const ExternalSymbolSDNode *ES =
3126                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3127         Sym = ES->getSymbol();
3128       }
3129 
3130       if (Sym.empty())
3131         return;
3132 
3133       MachineFunction *MF = MI.getParent()->getParent();
3134       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3135       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3136       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3137     }
3138   }
3139 }
3140 
3141 /// LowerCall - functions arguments are copied from virtual regs to
3142 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3143 SDValue
3144 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3145                               SmallVectorImpl<SDValue> &InVals) const {
3146   SelectionDAG &DAG                     = CLI.DAG;
3147   SDLoc DL                              = CLI.DL;
3148   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3149   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3150   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3151   SDValue Chain                         = CLI.Chain;
3152   SDValue Callee                        = CLI.Callee;
3153   bool &IsTailCall                      = CLI.IsTailCall;
3154   CallingConv::ID CallConv              = CLI.CallConv;
3155   bool IsVarArg                         = CLI.IsVarArg;
3156 
3157   MachineFunction &MF = DAG.getMachineFunction();
3158   MachineFrameInfo &MFI = MF.getFrameInfo();
3159   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3160   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3161   bool IsPIC = isPositionIndependent();
3162 
3163   // Analyze operands of the call, assigning locations to each operand.
3164   SmallVector<CCValAssign, 16> ArgLocs;
3165   MipsCCState CCInfo(
3166       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3167       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3168 
3169   const ExternalSymbolSDNode *ES =
3170       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3171 
3172   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3173   // is during the lowering of a call with a byval argument which produces
3174   // a call to memcpy. For the O32 case, this causes the caller to allocate
3175   // stack space for the reserved argument area for the callee, then recursively
3176   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3177   // ABIs mandate that the callee allocates the reserved argument area. We do
3178   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3179   //
3180   // If the callee has a byval argument and memcpy is used, we are mandated
3181   // to already have produced a reserved argument area for the callee for O32.
3182   // Therefore, the reserved argument area can be reused for both calls.
3183   //
3184   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3185   // present, as we have yet to hook that node onto the chain.
3186   //
3187   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3188   // case. GCC does a similar trick, in that wherever possible, it calculates
3189   // the maximum out going argument area (including the reserved area), and
3190   // preallocates the stack space on entrance to the caller.
3191   //
3192   // FIXME: We should do the same for efficiency and space.
3193 
3194   // Note: The check on the calling convention below must match
3195   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3196   bool MemcpyInByVal = ES &&
3197                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
3198                        CallConv != CallingConv::Fast &&
3199                        Chain.getOpcode() == ISD::CALLSEQ_START;
3200 
3201   // Allocate the reserved argument area. It seems strange to do this from the
3202   // caller side but removing it breaks the frame size calculation.
3203   unsigned ReservedArgArea =
3204       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3205   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3206 
3207   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3208                              ES ? ES->getSymbol() : nullptr);
3209 
3210   // Get a count of how many bytes are to be pushed on the stack.
3211   unsigned NextStackOffset = CCInfo.getNextStackOffset();
3212 
3213   // Call site info for function parameters tracking.
3214   MachineFunction::CallSiteInfo CSInfo;
3215 
3216   // Check if it's really possible to do a tail call. Restrict it to functions
3217   // that are part of this compilation unit.
3218   bool InternalLinkage = false;
3219   if (IsTailCall) {
3220     IsTailCall = isEligibleForTailCallOptimization(
3221         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
3222      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3223       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3224       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3225                      G->getGlobal()->hasPrivateLinkage() ||
3226                      G->getGlobal()->hasHiddenVisibility() ||
3227                      G->getGlobal()->hasProtectedVisibility());
3228      }
3229   }
3230   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3231     report_fatal_error("failed to perform tail call elimination on a call "
3232                        "site marked musttail");
3233 
3234   if (IsTailCall)
3235     ++NumTailCalls;
3236 
3237   // Chain is the output chain of the last Load/Store or CopyToReg node.
3238   // ByValChain is the output chain of the last Memcpy node created for copying
3239   // byval arguments to the stack.
3240   unsigned StackAlignment = TFL->getStackAlignment();
3241   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
3242   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
3243 
3244   if (!(IsTailCall || MemcpyInByVal))
3245     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffset, 0, DL);
3246 
3247   SDValue StackPtr =
3248       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3249                          getPointerTy(DAG.getDataLayout()));
3250 
3251   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3252   SmallVector<SDValue, 8> MemOpChains;
3253 
3254   CCInfo.rewindByValRegsInfo();
3255 
3256   // Walk the register/memloc assignments, inserting copies/loads.
3257   for (unsigned i = 0, e = ArgLocs.size(), OutIdx = 0; i != e; ++i, ++OutIdx) {
3258     SDValue Arg = OutVals[OutIdx];
3259     CCValAssign &VA = ArgLocs[i];
3260     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3261     ISD::ArgFlagsTy Flags = Outs[OutIdx].Flags;
3262     bool UseUpperBits = false;
3263 
3264     // ByVal Arg.
3265     if (Flags.isByVal()) {
3266       unsigned FirstByValReg, LastByValReg;
3267       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3268       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3269 
3270       assert(Flags.getByValSize() &&
3271              "ByVal args of size 0 should have been ignored by front-end.");
3272       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3273       assert(!IsTailCall &&
3274              "Do not tail-call optimize if there is a byval argument.");
3275       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3276                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3277                    VA);
3278       CCInfo.nextInRegsParam();
3279       continue;
3280     }
3281 
3282     // Promote the value if needed.
3283     switch (VA.getLocInfo()) {
3284     default:
3285       llvm_unreachable("Unknown loc info!");
3286     case CCValAssign::Full:
3287       if (VA.isRegLoc()) {
3288         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3289             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3290             (ValVT == MVT::i64 && LocVT == MVT::f64))
3291           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3292         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3293           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3294                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3295           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3296                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3297           if (!Subtarget.isLittle())
3298             std::swap(Lo, Hi);
3299 
3300           assert(VA.needsCustom());
3301 
3302           Register LocRegLo = VA.getLocReg();
3303           Register LocRegHigh = ArgLocs[++i].getLocReg();
3304           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3305           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3306           continue;
3307         }
3308       }
3309       break;
3310     case CCValAssign::BCvt:
3311       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3312       break;
3313     case CCValAssign::SExtUpper:
3314       UseUpperBits = true;
3315       LLVM_FALLTHROUGH;
3316     case CCValAssign::SExt:
3317       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3318       break;
3319     case CCValAssign::ZExtUpper:
3320       UseUpperBits = true;
3321       LLVM_FALLTHROUGH;
3322     case CCValAssign::ZExt:
3323       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3324       break;
3325     case CCValAssign::AExtUpper:
3326       UseUpperBits = true;
3327       LLVM_FALLTHROUGH;
3328     case CCValAssign::AExt:
3329       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3330       break;
3331     }
3332 
3333     if (UseUpperBits) {
3334       unsigned ValSizeInBits = Outs[OutIdx].ArgVT.getSizeInBits();
3335       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3336       Arg = DAG.getNode(
3337           ISD::SHL, DL, VA.getLocVT(), Arg,
3338           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3339     }
3340 
3341     // Arguments that can be passed on register must be kept at
3342     // RegsToPass vector
3343     if (VA.isRegLoc()) {
3344       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3345 
3346       // If the parameter is passed through reg $D, which splits into
3347       // two physical registers, avoid creating call site info.
3348       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3349         continue;
3350 
3351       // Collect CSInfo about which register passes which parameter.
3352       const TargetOptions &Options = DAG.getTarget().Options;
3353       if (Options.SupportsDebugEntryValues)
3354         CSInfo.emplace_back(VA.getLocReg(), i);
3355 
3356       continue;
3357     }
3358 
3359     // Register can't get to this point...
3360     assert(VA.isMemLoc());
3361 
3362     // emit ISD::STORE whichs stores the
3363     // parameter value to a stack Location
3364     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3365                                          Chain, Arg, DL, IsTailCall, DAG));
3366   }
3367 
3368   // Transform all store nodes into one single node because all store
3369   // nodes are independent of each other.
3370   if (!MemOpChains.empty())
3371     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3372 
3373   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3374   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3375   // node so that legalize doesn't hack it.
3376 
3377   EVT Ty = Callee.getValueType();
3378   bool GlobalOrExternal = false, IsCallReloc = false;
3379 
3380   // The long-calls feature is ignored in case of PIC.
3381   // While we do not support -mshared / -mno-shared properly,
3382   // ignore long-calls in case of -mabicalls too.
3383   if (!Subtarget.isABICalls() && !IsPIC) {
3384     // If the function should be called using "long call",
3385     // get its address into a register to prevent using
3386     // of the `jal` instruction for the direct call.
3387     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3388       if (Subtarget.useLongCalls())
3389         Callee = Subtarget.hasSym32()
3390                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3391                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3392     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3393       bool UseLongCalls = Subtarget.useLongCalls();
3394       // If the function has long-call/far/near attribute
3395       // it overrides command line switch pased to the backend.
3396       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3397         if (F->hasFnAttribute("long-call"))
3398           UseLongCalls = true;
3399         else if (F->hasFnAttribute("short-call"))
3400           UseLongCalls = false;
3401       }
3402       if (UseLongCalls)
3403         Callee = Subtarget.hasSym32()
3404                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3405                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3406     }
3407   }
3408 
3409   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3410     if (IsPIC) {
3411       const GlobalValue *Val = G->getGlobal();
3412       InternalLinkage = Val->hasInternalLinkage();
3413 
3414       if (InternalLinkage)
3415         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3416       else if (Subtarget.useXGOT()) {
3417         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3418                                        MipsII::MO_CALL_LO16, Chain,
3419                                        FuncInfo->callPtrInfo(MF, Val));
3420         IsCallReloc = true;
3421       } else {
3422         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3423                                FuncInfo->callPtrInfo(MF, Val));
3424         IsCallReloc = true;
3425       }
3426     } else
3427       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3428                                           getPointerTy(DAG.getDataLayout()), 0,
3429                                           MipsII::MO_NO_FLAG);
3430     GlobalOrExternal = true;
3431   }
3432   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3433     const char *Sym = S->getSymbol();
3434 
3435     if (!IsPIC) // static
3436       Callee = DAG.getTargetExternalSymbol(
3437           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3438     else if (Subtarget.useXGOT()) {
3439       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3440                                      MipsII::MO_CALL_LO16, Chain,
3441                                      FuncInfo->callPtrInfo(MF, Sym));
3442       IsCallReloc = true;
3443     } else { // PIC
3444       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3445                              FuncInfo->callPtrInfo(MF, Sym));
3446       IsCallReloc = true;
3447     }
3448 
3449     GlobalOrExternal = true;
3450   }
3451 
3452   SmallVector<SDValue, 8> Ops(1, Chain);
3453   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3454 
3455   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3456               IsCallReloc, CLI, Callee, Chain);
3457 
3458   if (IsTailCall) {
3459     MF.getFrameInfo().setHasTailCall();
3460     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3461     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3462     return Ret;
3463   }
3464 
3465   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3466   SDValue InFlag = Chain.getValue(1);
3467 
3468   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3469 
3470   // Create the CALLSEQ_END node in the case of where it is not a call to
3471   // memcpy.
3472   if (!(MemcpyInByVal)) {
3473     Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
3474                                DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
3475     InFlag = Chain.getValue(1);
3476   }
3477 
3478   // Handle result values, copying them out of physregs into vregs that we
3479   // return.
3480   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
3481                          InVals, CLI);
3482 }
3483 
3484 /// LowerCallResult - Lower the result values of a call into the
3485 /// appropriate copies out of appropriate physical registers.
3486 SDValue MipsTargetLowering::LowerCallResult(
3487     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
3488     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3489     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3490     TargetLowering::CallLoweringInfo &CLI) const {
3491   // Assign locations to each value returned by this call.
3492   SmallVector<CCValAssign, 16> RVLocs;
3493   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3494                      *DAG.getContext());
3495 
3496   const ExternalSymbolSDNode *ES =
3497       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3498   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3499                            ES ? ES->getSymbol() : nullptr);
3500 
3501   // Copy all of the result registers out of their specified physreg.
3502   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3503     CCValAssign &VA = RVLocs[i];
3504     assert(VA.isRegLoc() && "Can only return in registers!");
3505 
3506     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3507                                      RVLocs[i].getLocVT(), InFlag);
3508     Chain = Val.getValue(1);
3509     InFlag = Val.getValue(2);
3510 
3511     if (VA.isUpperBitsInLoc()) {
3512       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3513       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3514       unsigned Shift =
3515           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3516       Val = DAG.getNode(
3517           Shift, DL, VA.getLocVT(), Val,
3518           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3519     }
3520 
3521     switch (VA.getLocInfo()) {
3522     default:
3523       llvm_unreachable("Unknown loc info!");
3524     case CCValAssign::Full:
3525       break;
3526     case CCValAssign::BCvt:
3527       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3528       break;
3529     case CCValAssign::AExt:
3530     case CCValAssign::AExtUpper:
3531       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3532       break;
3533     case CCValAssign::ZExt:
3534     case CCValAssign::ZExtUpper:
3535       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3536                         DAG.getValueType(VA.getValVT()));
3537       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3538       break;
3539     case CCValAssign::SExt:
3540     case CCValAssign::SExtUpper:
3541       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3542                         DAG.getValueType(VA.getValVT()));
3543       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3544       break;
3545     }
3546 
3547     InVals.push_back(Val);
3548   }
3549 
3550   return Chain;
3551 }
3552 
3553 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3554                                       EVT ArgVT, const SDLoc &DL,
3555                                       SelectionDAG &DAG) {
3556   MVT LocVT = VA.getLocVT();
3557   EVT ValVT = VA.getValVT();
3558 
3559   // Shift into the upper bits if necessary.
3560   switch (VA.getLocInfo()) {
3561   default:
3562     break;
3563   case CCValAssign::AExtUpper:
3564   case CCValAssign::SExtUpper:
3565   case CCValAssign::ZExtUpper: {
3566     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3567     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3568     unsigned Opcode =
3569         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3570     Val = DAG.getNode(
3571         Opcode, DL, VA.getLocVT(), Val,
3572         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3573     break;
3574   }
3575   }
3576 
3577   // If this is an value smaller than the argument slot size (32-bit for O32,
3578   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3579   // size. Extract the value and insert any appropriate assertions regarding
3580   // sign/zero extension.
3581   switch (VA.getLocInfo()) {
3582   default:
3583     llvm_unreachable("Unknown loc info!");
3584   case CCValAssign::Full:
3585     break;
3586   case CCValAssign::AExtUpper:
3587   case CCValAssign::AExt:
3588     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3589     break;
3590   case CCValAssign::SExtUpper:
3591   case CCValAssign::SExt:
3592     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3593     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3594     break;
3595   case CCValAssign::ZExtUpper:
3596   case CCValAssign::ZExt:
3597     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3598     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3599     break;
3600   case CCValAssign::BCvt:
3601     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3602     break;
3603   }
3604 
3605   return Val;
3606 }
3607 
3608 //===----------------------------------------------------------------------===//
3609 //             Formal Arguments Calling Convention Implementation
3610 //===----------------------------------------------------------------------===//
3611 /// LowerFormalArguments - transform physical registers into virtual registers
3612 /// and generate load operations for arguments places on the stack.
3613 SDValue MipsTargetLowering::LowerFormalArguments(
3614     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3615     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3616     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3617   MachineFunction &MF = DAG.getMachineFunction();
3618   MachineFrameInfo &MFI = MF.getFrameInfo();
3619   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3620 
3621   MipsFI->setVarArgsFrameIndex(0);
3622 
3623   // Used with vargs to acumulate store chains.
3624   std::vector<SDValue> OutChains;
3625 
3626   // Assign locations to all of the incoming arguments.
3627   SmallVector<CCValAssign, 16> ArgLocs;
3628   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3629                      *DAG.getContext());
3630   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3631   const Function &Func = DAG.getMachineFunction().getFunction();
3632   Function::const_arg_iterator FuncArg = Func.arg_begin();
3633 
3634   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3635     report_fatal_error(
3636         "Functions with the interrupt attribute cannot have arguments!");
3637 
3638   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3639   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3640                            CCInfo.getInRegsParamsCount() > 0);
3641 
3642   unsigned CurArgIdx = 0;
3643   CCInfo.rewindByValRegsInfo();
3644 
3645   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3646     CCValAssign &VA = ArgLocs[i];
3647     if (Ins[InsIdx].isOrigArg()) {
3648       std::advance(FuncArg, Ins[InsIdx].getOrigArgIndex() - CurArgIdx);
3649       CurArgIdx = Ins[InsIdx].getOrigArgIndex();
3650     }
3651     EVT ValVT = VA.getValVT();
3652     ISD::ArgFlagsTy Flags = Ins[InsIdx].Flags;
3653     bool IsRegLoc = VA.isRegLoc();
3654 
3655     if (Flags.isByVal()) {
3656       assert(Ins[InsIdx].isOrigArg() && "Byval arguments cannot be implicit");
3657       unsigned FirstByValReg, LastByValReg;
3658       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3659       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3660 
3661       assert(Flags.getByValSize() &&
3662              "ByVal args of size 0 should have been ignored by front-end.");
3663       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3664       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3665                     FirstByValReg, LastByValReg, VA, CCInfo);
3666       CCInfo.nextInRegsParam();
3667       continue;
3668     }
3669 
3670     // Arguments stored on registers
3671     if (IsRegLoc) {
3672       MVT RegVT = VA.getLocVT();
3673       Register ArgReg = VA.getLocReg();
3674       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3675 
3676       // Transform the arguments stored on
3677       // physical registers into virtual ones
3678       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3679       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3680 
3681       ArgValue =
3682           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3683 
3684       // Handle floating point arguments passed in integer registers and
3685       // long double arguments passed in floating point registers.
3686       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3687           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3688           (RegVT == MVT::f64 && ValVT == MVT::i64))
3689         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3690       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3691                ValVT == MVT::f64) {
3692         assert(VA.needsCustom() && "Expected custom argument for f64 split");
3693         CCValAssign &NextVA = ArgLocs[++i];
3694         unsigned Reg2 =
3695             addLiveIn(DAG.getMachineFunction(), NextVA.getLocReg(), RC);
3696         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3697         if (!Subtarget.isLittle())
3698           std::swap(ArgValue, ArgValue2);
3699         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3700                                ArgValue, ArgValue2);
3701       }
3702 
3703       InVals.push_back(ArgValue);
3704     } else { // VA.isRegLoc()
3705       MVT LocVT = VA.getLocVT();
3706 
3707       assert(!VA.needsCustom() && "unexpected custom memory argument");
3708 
3709       if (ABI.IsO32()) {
3710         // We ought to be able to use LocVT directly but O32 sets it to i32
3711         // when allocating floating point values to integer registers.
3712         // This shouldn't influence how we load the value into registers unless
3713         // we are targeting softfloat.
3714         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3715           LocVT = VA.getValVT();
3716       }
3717 
3718       // Only arguments pased on the stack should make it here.
3719       assert(VA.isMemLoc());
3720 
3721       // The stack pointer offset is relative to the caller stack frame.
3722       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3723                                      VA.getLocMemOffset(), true);
3724 
3725       // Create load nodes to retrieve arguments from the stack
3726       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3727       SDValue ArgValue = DAG.getLoad(
3728           LocVT, DL, Chain, FIN,
3729           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3730       OutChains.push_back(ArgValue.getValue(1));
3731 
3732       ArgValue =
3733           UnpackFromArgumentSlot(ArgValue, VA, Ins[InsIdx].ArgVT, DL, DAG);
3734 
3735       InVals.push_back(ArgValue);
3736     }
3737   }
3738 
3739   for (unsigned i = 0, e = ArgLocs.size(), InsIdx = 0; i != e; ++i, ++InsIdx) {
3740 
3741     if (ArgLocs[i].needsCustom()) {
3742       ++i;
3743       continue;
3744     }
3745 
3746     // The mips ABIs for returning structs by value requires that we copy
3747     // the sret argument into $v0 for the return. Save the argument into
3748     // a virtual register so that we can access it from the return points.
3749     if (Ins[InsIdx].Flags.isSRet()) {
3750       unsigned Reg = MipsFI->getSRetReturnReg();
3751       if (!Reg) {
3752         Reg = MF.getRegInfo().createVirtualRegister(
3753             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3754         MipsFI->setSRetReturnReg(Reg);
3755       }
3756       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3757       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3758       break;
3759     }
3760   }
3761 
3762   if (IsVarArg)
3763     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3764 
3765   // All stores are grouped in one node to allow the matching between
3766   // the size of Ins and InVals. This only happens when on varg functions
3767   if (!OutChains.empty()) {
3768     OutChains.push_back(Chain);
3769     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3770   }
3771 
3772   return Chain;
3773 }
3774 
3775 //===----------------------------------------------------------------------===//
3776 //               Return Value Calling Convention Implementation
3777 //===----------------------------------------------------------------------===//
3778 
3779 bool
3780 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3781                                    MachineFunction &MF, bool IsVarArg,
3782                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3783                                    LLVMContext &Context) const {
3784   SmallVector<CCValAssign, 16> RVLocs;
3785   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3786   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3787 }
3788 
3789 bool MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type,
3790                                                        bool IsSigned) const {
3791   if ((ABI.IsN32() || ABI.IsN64()) && Type == MVT::i32)
3792       return true;
3793 
3794   return IsSigned;
3795 }
3796 
3797 SDValue
3798 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3799                                          const SDLoc &DL,
3800                                          SelectionDAG &DAG) const {
3801   MachineFunction &MF = DAG.getMachineFunction();
3802   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3803 
3804   MipsFI->setISR();
3805 
3806   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3807 }
3808 
3809 SDValue
3810 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3811                                 bool IsVarArg,
3812                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3813                                 const SmallVectorImpl<SDValue> &OutVals,
3814                                 const SDLoc &DL, SelectionDAG &DAG) const {
3815   // CCValAssign - represent the assignment of
3816   // the return value to a location
3817   SmallVector<CCValAssign, 16> RVLocs;
3818   MachineFunction &MF = DAG.getMachineFunction();
3819 
3820   // CCState - Info about the registers and stack slot.
3821   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3822 
3823   // Analyze return values.
3824   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3825 
3826   SDValue Flag;
3827   SmallVector<SDValue, 4> RetOps(1, Chain);
3828 
3829   // Copy the result values into the output registers.
3830   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3831     SDValue Val = OutVals[i];
3832     CCValAssign &VA = RVLocs[i];
3833     assert(VA.isRegLoc() && "Can only return in registers!");
3834     bool UseUpperBits = false;
3835 
3836     switch (VA.getLocInfo()) {
3837     default:
3838       llvm_unreachable("Unknown loc info!");
3839     case CCValAssign::Full:
3840       break;
3841     case CCValAssign::BCvt:
3842       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3843       break;
3844     case CCValAssign::AExtUpper:
3845       UseUpperBits = true;
3846       LLVM_FALLTHROUGH;
3847     case CCValAssign::AExt:
3848       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3849       break;
3850     case CCValAssign::ZExtUpper:
3851       UseUpperBits = true;
3852       LLVM_FALLTHROUGH;
3853     case CCValAssign::ZExt:
3854       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3855       break;
3856     case CCValAssign::SExtUpper:
3857       UseUpperBits = true;
3858       LLVM_FALLTHROUGH;
3859     case CCValAssign::SExt:
3860       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3861       break;
3862     }
3863 
3864     if (UseUpperBits) {
3865       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3866       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3867       Val = DAG.getNode(
3868           ISD::SHL, DL, VA.getLocVT(), Val,
3869           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3870     }
3871 
3872     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3873 
3874     // Guarantee that all emitted copies are stuck together with flags.
3875     Flag = Chain.getValue(1);
3876     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3877   }
3878 
3879   // The mips ABIs for returning structs by value requires that we copy
3880   // the sret argument into $v0 for the return. We saved the argument into
3881   // a virtual register in the entry block, so now we copy the value out
3882   // and into $v0.
3883   if (MF.getFunction().hasStructRetAttr()) {
3884     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3885     unsigned Reg = MipsFI->getSRetReturnReg();
3886 
3887     if (!Reg)
3888       llvm_unreachable("sret virtual register not created in the entry block");
3889     SDValue Val =
3890         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3891     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3892 
3893     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3894     Flag = Chain.getValue(1);
3895     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3896   }
3897 
3898   RetOps[0] = Chain;  // Update chain.
3899 
3900   // Add the flag if we have it.
3901   if (Flag.getNode())
3902     RetOps.push_back(Flag);
3903 
3904   // ISRs must use "eret".
3905   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
3906     return LowerInterruptReturn(RetOps, DL, DAG);
3907 
3908   // Standard return on Mips is a "jr $ra"
3909   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3910 }
3911 
3912 //===----------------------------------------------------------------------===//
3913 //                           Mips Inline Assembly Support
3914 //===----------------------------------------------------------------------===//
3915 
3916 /// getConstraintType - Given a constraint letter, return the type of
3917 /// constraint it is for this target.
3918 MipsTargetLowering::ConstraintType
3919 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3920   // Mips specific constraints
3921   // GCC config/mips/constraints.md
3922   //
3923   // 'd' : An address register. Equivalent to r
3924   //       unless generating MIPS16 code.
3925   // 'y' : Equivalent to r; retained for
3926   //       backwards compatibility.
3927   // 'c' : A register suitable for use in an indirect
3928   //       jump. This will always be $25 for -mabicalls.
3929   // 'l' : The lo register. 1 word storage.
3930   // 'x' : The hilo register pair. Double word storage.
3931   if (Constraint.size() == 1) {
3932     switch (Constraint[0]) {
3933       default : break;
3934       case 'd':
3935       case 'y':
3936       case 'f':
3937       case 'c':
3938       case 'l':
3939       case 'x':
3940         return C_RegisterClass;
3941       case 'R':
3942         return C_Memory;
3943     }
3944   }
3945 
3946   if (Constraint == "ZC")
3947     return C_Memory;
3948 
3949   return TargetLowering::getConstraintType(Constraint);
3950 }
3951 
3952 /// Examine constraint type and operand type and determine a weight value.
3953 /// This object must already have been set up with the operand type
3954 /// and the current alternative constraint selected.
3955 TargetLowering::ConstraintWeight
3956 MipsTargetLowering::getSingleConstraintMatchWeight(
3957     AsmOperandInfo &info, const char *constraint) const {
3958   ConstraintWeight weight = CW_Invalid;
3959   Value *CallOperandVal = info.CallOperandVal;
3960     // If we don't have a value, we can't do a match,
3961     // but allow it at the lowest weight.
3962   if (!CallOperandVal)
3963     return CW_Default;
3964   Type *type = CallOperandVal->getType();
3965   // Look at the constraint type.
3966   switch (*constraint) {
3967   default:
3968     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3969     break;
3970   case 'd':
3971   case 'y':
3972     if (type->isIntegerTy())
3973       weight = CW_Register;
3974     break;
3975   case 'f': // FPU or MSA register
3976     if (Subtarget.hasMSA() && type->isVectorTy() &&
3977         type->getPrimitiveSizeInBits().getFixedSize() == 128)
3978       weight = CW_Register;
3979     else if (type->isFloatTy())
3980       weight = CW_Register;
3981     break;
3982   case 'c': // $25 for indirect jumps
3983   case 'l': // lo register
3984   case 'x': // hilo register pair
3985     if (type->isIntegerTy())
3986       weight = CW_SpecificReg;
3987     break;
3988   case 'I': // signed 16 bit immediate
3989   case 'J': // integer zero
3990   case 'K': // unsigned 16 bit immediate
3991   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3992   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3993   case 'O': // signed 15 bit immediate (+- 16383)
3994   case 'P': // immediate in the range of 65535 to 1 (inclusive)
3995     if (isa<ConstantInt>(CallOperandVal))
3996       weight = CW_Constant;
3997     break;
3998   case 'R':
3999     weight = CW_Memory;
4000     break;
4001   }
4002   return weight;
4003 }
4004 
4005 /// This is a helper function to parse a physical register string and split it
4006 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
4007 /// that is returned indicates whether parsing was successful. The second flag
4008 /// is true if the numeric part exists.
4009 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
4010                                               unsigned long long &Reg) {
4011   if (C.front() != '{' || C.back() != '}')
4012     return std::make_pair(false, false);
4013 
4014   // Search for the first numeric character.
4015   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
4016   I = std::find_if(B, E, isdigit);
4017 
4018   Prefix = StringRef(B, I - B);
4019 
4020   // The second flag is set to false if no numeric characters were found.
4021   if (I == E)
4022     return std::make_pair(true, false);
4023 
4024   // Parse the numeric characters.
4025   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
4026                         true);
4027 }
4028 
4029 EVT MipsTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
4030                                             ISD::NodeType) const {
4031   bool Cond = !Subtarget.isABI_O32() && VT.getSizeInBits() == 32;
4032   EVT MinVT = getRegisterType(Context, Cond ? MVT::i64 : MVT::i32);
4033   return VT.bitsLT(MinVT) ? MinVT : VT;
4034 }
4035 
4036 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
4037 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
4038   const TargetRegisterInfo *TRI =
4039       Subtarget.getRegisterInfo();
4040   const TargetRegisterClass *RC;
4041   StringRef Prefix;
4042   unsigned long long Reg;
4043 
4044   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
4045 
4046   if (!R.first)
4047     return std::make_pair(0U, nullptr);
4048 
4049   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
4050     // No numeric characters follow "hi" or "lo".
4051     if (R.second)
4052       return std::make_pair(0U, nullptr);
4053 
4054     RC = TRI->getRegClass(Prefix == "hi" ?
4055                           Mips::HI32RegClassID : Mips::LO32RegClassID);
4056     return std::make_pair(*(RC->begin()), RC);
4057   } else if (Prefix.startswith("$msa")) {
4058     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
4059 
4060     // No numeric characters follow the name.
4061     if (R.second)
4062       return std::make_pair(0U, nullptr);
4063 
4064     Reg = StringSwitch<unsigned long long>(Prefix)
4065               .Case("$msair", Mips::MSAIR)
4066               .Case("$msacsr", Mips::MSACSR)
4067               .Case("$msaaccess", Mips::MSAAccess)
4068               .Case("$msasave", Mips::MSASave)
4069               .Case("$msamodify", Mips::MSAModify)
4070               .Case("$msarequest", Mips::MSARequest)
4071               .Case("$msamap", Mips::MSAMap)
4072               .Case("$msaunmap", Mips::MSAUnmap)
4073               .Default(0);
4074 
4075     if (!Reg)
4076       return std::make_pair(0U, nullptr);
4077 
4078     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
4079     return std::make_pair(Reg, RC);
4080   }
4081 
4082   if (!R.second)
4083     return std::make_pair(0U, nullptr);
4084 
4085   if (Prefix == "$f") { // Parse $f0-$f31.
4086     // If the size of FP registers is 64-bit or Reg is an even number, select
4087     // the 64-bit register class. Otherwise, select the 32-bit register class.
4088     if (VT == MVT::Other)
4089       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
4090 
4091     RC = getRegClassFor(VT);
4092 
4093     if (RC == &Mips::AFGR64RegClass) {
4094       assert(Reg % 2 == 0);
4095       Reg >>= 1;
4096     }
4097   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
4098     RC = TRI->getRegClass(Mips::FCCRegClassID);
4099   else if (Prefix == "$w") { // Parse $w0-$w31.
4100     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
4101   } else { // Parse $0-$31.
4102     assert(Prefix == "$");
4103     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
4104   }
4105 
4106   assert(Reg < RC->getNumRegs());
4107   return std::make_pair(*(RC->begin() + Reg), RC);
4108 }
4109 
4110 /// Given a register class constraint, like 'r', if this corresponds directly
4111 /// to an LLVM register class, return a register of 0 and the register class
4112 /// pointer.
4113 std::pair<unsigned, const TargetRegisterClass *>
4114 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
4115                                                  StringRef Constraint,
4116                                                  MVT VT) const {
4117   if (Constraint.size() == 1) {
4118     switch (Constraint[0]) {
4119     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
4120     case 'y': // Same as 'r'. Exists for compatibility.
4121     case 'r':
4122       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8 || VT == MVT::i1) {
4123         if (Subtarget.inMips16Mode())
4124           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
4125         return std::make_pair(0U, &Mips::GPR32RegClass);
4126       }
4127       if (VT == MVT::i64 && !Subtarget.isGP64bit())
4128         return std::make_pair(0U, &Mips::GPR32RegClass);
4129       if (VT == MVT::i64 && Subtarget.isGP64bit())
4130         return std::make_pair(0U, &Mips::GPR64RegClass);
4131       // This will generate an error message
4132       return std::make_pair(0U, nullptr);
4133     case 'f': // FPU or MSA register
4134       if (VT == MVT::v16i8)
4135         return std::make_pair(0U, &Mips::MSA128BRegClass);
4136       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
4137         return std::make_pair(0U, &Mips::MSA128HRegClass);
4138       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
4139         return std::make_pair(0U, &Mips::MSA128WRegClass);
4140       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
4141         return std::make_pair(0U, &Mips::MSA128DRegClass);
4142       else if (VT == MVT::f32)
4143         return std::make_pair(0U, &Mips::FGR32RegClass);
4144       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
4145         if (Subtarget.isFP64bit())
4146           return std::make_pair(0U, &Mips::FGR64RegClass);
4147         return std::make_pair(0U, &Mips::AFGR64RegClass);
4148       }
4149       break;
4150     case 'c': // register suitable for indirect jump
4151       if (VT == MVT::i32)
4152         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
4153       if (VT == MVT::i64)
4154         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
4155       // This will generate an error message
4156       return std::make_pair(0U, nullptr);
4157     case 'l': // use the `lo` register to store values
4158               // that are no bigger than a word
4159       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
4160         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
4161       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
4162     case 'x': // use the concatenated `hi` and `lo` registers
4163               // to store doubleword values
4164       // Fixme: Not triggering the use of both hi and low
4165       // This will generate an error message
4166       return std::make_pair(0U, nullptr);
4167     }
4168   }
4169 
4170   if (!Constraint.empty()) {
4171     std::pair<unsigned, const TargetRegisterClass *> R;
4172     R = parseRegForInlineAsmConstraint(Constraint, VT);
4173 
4174     if (R.second)
4175       return R;
4176   }
4177 
4178   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
4179 }
4180 
4181 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
4182 /// vector.  If it is invalid, don't add anything to Ops.
4183 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
4184                                                      std::string &Constraint,
4185                                                      std::vector<SDValue>&Ops,
4186                                                      SelectionDAG &DAG) const {
4187   SDLoc DL(Op);
4188   SDValue Result;
4189 
4190   // Only support length 1 constraints for now.
4191   if (Constraint.length() > 1) return;
4192 
4193   char ConstraintLetter = Constraint[0];
4194   switch (ConstraintLetter) {
4195   default: break; // This will fall through to the generic implementation
4196   case 'I': // Signed 16 bit constant
4197     // If this fails, the parent routine will give an error
4198     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4199       EVT Type = Op.getValueType();
4200       int64_t Val = C->getSExtValue();
4201       if (isInt<16>(Val)) {
4202         Result = DAG.getTargetConstant(Val, DL, Type);
4203         break;
4204       }
4205     }
4206     return;
4207   case 'J': // integer zero
4208     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4209       EVT Type = Op.getValueType();
4210       int64_t Val = C->getZExtValue();
4211       if (Val == 0) {
4212         Result = DAG.getTargetConstant(0, DL, Type);
4213         break;
4214       }
4215     }
4216     return;
4217   case 'K': // unsigned 16 bit immediate
4218     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4219       EVT Type = Op.getValueType();
4220       uint64_t Val = (uint64_t)C->getZExtValue();
4221       if (isUInt<16>(Val)) {
4222         Result = DAG.getTargetConstant(Val, DL, Type);
4223         break;
4224       }
4225     }
4226     return;
4227   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4228     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4229       EVT Type = Op.getValueType();
4230       int64_t Val = C->getSExtValue();
4231       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4232         Result = DAG.getTargetConstant(Val, DL, Type);
4233         break;
4234       }
4235     }
4236     return;
4237   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4238     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4239       EVT Type = Op.getValueType();
4240       int64_t Val = C->getSExtValue();
4241       if ((Val >= -65535) && (Val <= -1)) {
4242         Result = DAG.getTargetConstant(Val, DL, Type);
4243         break;
4244       }
4245     }
4246     return;
4247   case 'O': // signed 15 bit immediate
4248     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4249       EVT Type = Op.getValueType();
4250       int64_t Val = C->getSExtValue();
4251       if ((isInt<15>(Val))) {
4252         Result = DAG.getTargetConstant(Val, DL, Type);
4253         break;
4254       }
4255     }
4256     return;
4257   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4258     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4259       EVT Type = Op.getValueType();
4260       int64_t Val = C->getSExtValue();
4261       if ((Val <= 65535) && (Val >= 1)) {
4262         Result = DAG.getTargetConstant(Val, DL, Type);
4263         break;
4264       }
4265     }
4266     return;
4267   }
4268 
4269   if (Result.getNode()) {
4270     Ops.push_back(Result);
4271     return;
4272   }
4273 
4274   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4275 }
4276 
4277 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4278                                                const AddrMode &AM, Type *Ty,
4279                                                unsigned AS,
4280                                                Instruction *I) const {
4281   // No global is ever allowed as a base.
4282   if (AM.BaseGV)
4283     return false;
4284 
4285   switch (AM.Scale) {
4286   case 0: // "r+i" or just "i", depending on HasBaseReg.
4287     break;
4288   case 1:
4289     if (!AM.HasBaseReg) // allow "r+i".
4290       break;
4291     return false; // disallow "r+r" or "r+r+i".
4292   default:
4293     return false;
4294   }
4295 
4296   return true;
4297 }
4298 
4299 bool
4300 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4301   // The Mips target isn't yet aware of offsets.
4302   return false;
4303 }
4304 
4305 EVT MipsTargetLowering::getOptimalMemOpType(
4306     const MemOp &Op, const AttributeList &FuncAttributes) const {
4307   if (Subtarget.hasMips64())
4308     return MVT::i64;
4309 
4310   return MVT::i32;
4311 }
4312 
4313 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4314                                       bool ForCodeSize) const {
4315   if (VT != MVT::f32 && VT != MVT::f64)
4316     return false;
4317   if (Imm.isNegZero())
4318     return false;
4319   return Imm.isZero();
4320 }
4321 
4322 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4323 
4324   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4325   if (ABI.IsN64() && isPositionIndependent())
4326     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4327 
4328   return TargetLowering::getJumpTableEncoding();
4329 }
4330 
4331 bool MipsTargetLowering::useSoftFloat() const {
4332   return Subtarget.useSoftFloat();
4333 }
4334 
4335 void MipsTargetLowering::copyByValRegs(
4336     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4337     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4338     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4339     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4340     MipsCCState &State) const {
4341   MachineFunction &MF = DAG.getMachineFunction();
4342   MachineFrameInfo &MFI = MF.getFrameInfo();
4343   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4344   unsigned NumRegs = LastReg - FirstReg;
4345   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4346   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4347   int FrameObjOffset;
4348   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4349 
4350   if (RegAreaSize)
4351     FrameObjOffset =
4352         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4353         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4354   else
4355     FrameObjOffset = VA.getLocMemOffset();
4356 
4357   // Create frame object.
4358   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4359   // Make the fixed object stored to mutable so that the load instructions
4360   // referencing it have their memory dependencies added.
4361   // Set the frame object as isAliased which clears the underlying objects
4362   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4363   // stores as dependencies for loads referencing this fixed object.
4364   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4365   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4366   InVals.push_back(FIN);
4367 
4368   if (!NumRegs)
4369     return;
4370 
4371   // Copy arg registers.
4372   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4373   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4374 
4375   for (unsigned I = 0; I < NumRegs; ++I) {
4376     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4377     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4378     unsigned Offset = I * GPRSizeInBytes;
4379     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4380                                    DAG.getConstant(Offset, DL, PtrTy));
4381     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4382                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4383     OutChains.push_back(Store);
4384   }
4385 }
4386 
4387 // Copy byVal arg to registers and stack.
4388 void MipsTargetLowering::passByValArg(
4389     SDValue Chain, const SDLoc &DL,
4390     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4391     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4392     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4393     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4394     const CCValAssign &VA) const {
4395   unsigned ByValSizeInBytes = Flags.getByValSize();
4396   unsigned OffsetInBytes = 0; // From beginning of struct
4397   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4398   Align Alignment =
4399       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4400   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4401       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4402   unsigned NumRegs = LastReg - FirstReg;
4403 
4404   if (NumRegs) {
4405     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4406     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4407     unsigned I = 0;
4408 
4409     // Copy words to registers.
4410     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4411       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4412                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4413       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4414                                     MachinePointerInfo(), Alignment);
4415       MemOpChains.push_back(LoadVal.getValue(1));
4416       unsigned ArgReg = ArgRegs[FirstReg + I];
4417       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4418     }
4419 
4420     // Return if the struct has been fully copied.
4421     if (ByValSizeInBytes == OffsetInBytes)
4422       return;
4423 
4424     // Copy the remainder of the byval argument with sub-word loads and shifts.
4425     if (LeftoverBytes) {
4426       SDValue Val;
4427 
4428       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4429            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4430         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4431 
4432         if (RemainingSizeInBytes < LoadSizeInBytes)
4433           continue;
4434 
4435         // Load subword.
4436         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4437                                       DAG.getConstant(OffsetInBytes, DL,
4438                                                       PtrTy));
4439         SDValue LoadVal = DAG.getExtLoad(
4440             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4441             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4442         MemOpChains.push_back(LoadVal.getValue(1));
4443 
4444         // Shift the loaded value.
4445         unsigned Shamt;
4446 
4447         if (isLittle)
4448           Shamt = TotalBytesLoaded * 8;
4449         else
4450           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4451 
4452         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4453                                     DAG.getConstant(Shamt, DL, MVT::i32));
4454 
4455         if (Val.getNode())
4456           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4457         else
4458           Val = Shift;
4459 
4460         OffsetInBytes += LoadSizeInBytes;
4461         TotalBytesLoaded += LoadSizeInBytes;
4462         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4463       }
4464 
4465       unsigned ArgReg = ArgRegs[FirstReg + I];
4466       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4467       return;
4468     }
4469   }
4470 
4471   // Copy remainder of byval arg to it with memcpy.
4472   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4473   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4474                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4475   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4476                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4477   Chain = DAG.getMemcpy(
4478       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4479       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4480       /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
4481   MemOpChains.push_back(Chain);
4482 }
4483 
4484 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4485                                          SDValue Chain, const SDLoc &DL,
4486                                          SelectionDAG &DAG,
4487                                          CCState &State) const {
4488   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4489   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4490   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4491   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4492   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4493   MachineFunction &MF = DAG.getMachineFunction();
4494   MachineFrameInfo &MFI = MF.getFrameInfo();
4495   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4496 
4497   // Offset of the first variable argument from stack pointer.
4498   int VaArgOffset;
4499 
4500   if (ArgRegs.size() == Idx)
4501     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
4502   else {
4503     VaArgOffset =
4504         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4505         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4506   }
4507 
4508   // Record the frame index of the first variable argument
4509   // which is a value necessary to VASTART.
4510   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4511   MipsFI->setVarArgsFrameIndex(FI);
4512 
4513   // Copy the integer registers that have not been used for argument passing
4514   // to the argument register save area. For O32, the save area is allocated
4515   // in the caller's stack frame, while for N32/64, it is allocated in the
4516   // callee's stack frame.
4517   for (unsigned I = Idx; I < ArgRegs.size();
4518        ++I, VaArgOffset += RegSizeInBytes) {
4519     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4520     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4521     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4522     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4523     SDValue Store =
4524         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4525     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4526         (Value *)nullptr);
4527     OutChains.push_back(Store);
4528   }
4529 }
4530 
4531 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4532                                      Align Alignment) const {
4533   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4534 
4535   assert(Size && "Byval argument's size shouldn't be 0.");
4536 
4537   Alignment = std::min(Alignment, TFL->getStackAlign());
4538 
4539   unsigned FirstReg = 0;
4540   unsigned NumRegs = 0;
4541 
4542   if (State->getCallingConv() != CallingConv::Fast) {
4543     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4544     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4545     // FIXME: The O32 case actually describes no shadow registers.
4546     const MCPhysReg *ShadowRegs =
4547         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4548 
4549     // We used to check the size as well but we can't do that anymore since
4550     // CCState::HandleByVal() rounds up the size after calling this function.
4551     assert(
4552         Alignment >= Align(RegSizeInBytes) &&
4553         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4554 
4555     FirstReg = State->getFirstUnallocated(IntArgRegs);
4556 
4557     // If Alignment > RegSizeInBytes, the first arg register must be even.
4558     // FIXME: This condition happens to do the right thing but it's not the
4559     //        right way to test it. We want to check that the stack frame offset
4560     //        of the register is aligned.
4561     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4562       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4563       ++FirstReg;
4564     }
4565 
4566     // Mark the registers allocated.
4567     Size = alignTo(Size, RegSizeInBytes);
4568     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4569          Size -= RegSizeInBytes, ++I, ++NumRegs)
4570       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4571   }
4572 
4573   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4574 }
4575 
4576 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4577                                                         MachineBasicBlock *BB,
4578                                                         bool isFPCmp,
4579                                                         unsigned Opc) const {
4580   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4581          "Subtarget already supports SELECT nodes with the use of"
4582          "conditional-move instructions.");
4583 
4584   const TargetInstrInfo *TII =
4585       Subtarget.getInstrInfo();
4586   DebugLoc DL = MI.getDebugLoc();
4587 
4588   // To "insert" a SELECT instruction, we actually have to insert the
4589   // diamond control-flow pattern.  The incoming instruction knows the
4590   // destination vreg to set, the condition code register to branch on, the
4591   // true/false values to select between, and a branch opcode to use.
4592   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4593   MachineFunction::iterator It = ++BB->getIterator();
4594 
4595   //  thisMBB:
4596   //  ...
4597   //   TrueVal = ...
4598   //   setcc r1, r2, r3
4599   //   bNE   r1, r0, copy1MBB
4600   //   fallthrough --> copy0MBB
4601   MachineBasicBlock *thisMBB  = BB;
4602   MachineFunction *F = BB->getParent();
4603   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4604   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4605   F->insert(It, copy0MBB);
4606   F->insert(It, sinkMBB);
4607 
4608   // Transfer the remainder of BB and its successor edges to sinkMBB.
4609   sinkMBB->splice(sinkMBB->begin(), BB,
4610                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4611   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4612 
4613   // Next, add the true and fallthrough blocks as its successors.
4614   BB->addSuccessor(copy0MBB);
4615   BB->addSuccessor(sinkMBB);
4616 
4617   if (isFPCmp) {
4618     // bc1[tf] cc, sinkMBB
4619     BuildMI(BB, DL, TII->get(Opc))
4620         .addReg(MI.getOperand(1).getReg())
4621         .addMBB(sinkMBB);
4622   } else {
4623     // bne rs, $0, sinkMBB
4624     BuildMI(BB, DL, TII->get(Opc))
4625         .addReg(MI.getOperand(1).getReg())
4626         .addReg(Mips::ZERO)
4627         .addMBB(sinkMBB);
4628   }
4629 
4630   //  copy0MBB:
4631   //   %FalseValue = ...
4632   //   # fallthrough to sinkMBB
4633   BB = copy0MBB;
4634 
4635   // Update machine-CFG edges
4636   BB->addSuccessor(sinkMBB);
4637 
4638   //  sinkMBB:
4639   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4640   //  ...
4641   BB = sinkMBB;
4642 
4643   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4644       .addReg(MI.getOperand(2).getReg())
4645       .addMBB(thisMBB)
4646       .addReg(MI.getOperand(3).getReg())
4647       .addMBB(copy0MBB);
4648 
4649   MI.eraseFromParent(); // The pseudo instruction is gone now.
4650 
4651   return BB;
4652 }
4653 
4654 MachineBasicBlock *
4655 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4656                                        MachineBasicBlock *BB) const {
4657   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4658          "Subtarget already supports SELECT nodes with the use of"
4659          "conditional-move instructions.");
4660 
4661   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4662   DebugLoc DL = MI.getDebugLoc();
4663 
4664   // D_SELECT substitutes two SELECT nodes that goes one after another and
4665   // have the same condition operand. On machines which don't have
4666   // conditional-move instruction, it reduces unnecessary branch instructions
4667   // which are result of using two diamond patterns that are result of two
4668   // SELECT pseudo instructions.
4669   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4670   MachineFunction::iterator It = ++BB->getIterator();
4671 
4672   //  thisMBB:
4673   //  ...
4674   //   TrueVal = ...
4675   //   setcc r1, r2, r3
4676   //   bNE   r1, r0, copy1MBB
4677   //   fallthrough --> copy0MBB
4678   MachineBasicBlock *thisMBB = BB;
4679   MachineFunction *F = BB->getParent();
4680   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4681   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4682   F->insert(It, copy0MBB);
4683   F->insert(It, sinkMBB);
4684 
4685   // Transfer the remainder of BB and its successor edges to sinkMBB.
4686   sinkMBB->splice(sinkMBB->begin(), BB,
4687                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4688   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4689 
4690   // Next, add the true and fallthrough blocks as its successors.
4691   BB->addSuccessor(copy0MBB);
4692   BB->addSuccessor(sinkMBB);
4693 
4694   // bne rs, $0, sinkMBB
4695   BuildMI(BB, DL, TII->get(Mips::BNE))
4696       .addReg(MI.getOperand(2).getReg())
4697       .addReg(Mips::ZERO)
4698       .addMBB(sinkMBB);
4699 
4700   //  copy0MBB:
4701   //   %FalseValue = ...
4702   //   # fallthrough to sinkMBB
4703   BB = copy0MBB;
4704 
4705   // Update machine-CFG edges
4706   BB->addSuccessor(sinkMBB);
4707 
4708   //  sinkMBB:
4709   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4710   //  ...
4711   BB = sinkMBB;
4712 
4713   // Use two PHI nodes to select two reults
4714   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4715       .addReg(MI.getOperand(3).getReg())
4716       .addMBB(thisMBB)
4717       .addReg(MI.getOperand(5).getReg())
4718       .addMBB(copy0MBB);
4719   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4720       .addReg(MI.getOperand(4).getReg())
4721       .addMBB(thisMBB)
4722       .addReg(MI.getOperand(6).getReg())
4723       .addMBB(copy0MBB);
4724 
4725   MI.eraseFromParent(); // The pseudo instruction is gone now.
4726 
4727   return BB;
4728 }
4729 
4730 // FIXME? Maybe this could be a TableGen attribute on some registers and
4731 // this table could be generated automatically from RegInfo.
4732 Register
4733 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4734                                       const MachineFunction &MF) const {
4735   // Named registers is expected to be fairly rare. For now, just support $28
4736   // since the linux kernel uses it.
4737   if (Subtarget.isGP64bit()) {
4738     Register Reg = StringSwitch<Register>(RegName)
4739                          .Case("$28", Mips::GP_64)
4740                          .Default(Register());
4741     if (Reg)
4742       return Reg;
4743   } else {
4744     Register Reg = StringSwitch<Register>(RegName)
4745                          .Case("$28", Mips::GP)
4746                          .Default(Register());
4747     if (Reg)
4748       return Reg;
4749   }
4750   report_fatal_error("Invalid register name global variable");
4751 }
4752 
4753 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4754                                                  MachineBasicBlock *BB) const {
4755   MachineFunction *MF = BB->getParent();
4756   MachineRegisterInfo &MRI = MF->getRegInfo();
4757   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4758   const bool IsLittle = Subtarget.isLittle();
4759   DebugLoc DL = MI.getDebugLoc();
4760 
4761   Register Dest = MI.getOperand(0).getReg();
4762   Register Address = MI.getOperand(1).getReg();
4763   unsigned Imm = MI.getOperand(2).getImm();
4764 
4765   MachineBasicBlock::iterator I(MI);
4766 
4767   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4768     // Mips release 6 can load from adress that is not naturally-aligned.
4769     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4770     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4771         .addDef(Temp)
4772         .addUse(Address)
4773         .addImm(Imm);
4774     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4775   } else {
4776     // Mips release 5 needs to use instructions that can load from an unaligned
4777     // memory address.
4778     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4779     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4780     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4781     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4782     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4783         .addDef(LoadHalf)
4784         .addUse(Address)
4785         .addImm(Imm + (IsLittle ? 0 : 3))
4786         .addUse(Undef);
4787     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4788         .addDef(LoadFull)
4789         .addUse(Address)
4790         .addImm(Imm + (IsLittle ? 3 : 0))
4791         .addUse(LoadHalf);
4792     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4793   }
4794 
4795   MI.eraseFromParent();
4796   return BB;
4797 }
4798 
4799 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4800                                                  MachineBasicBlock *BB) const {
4801   MachineFunction *MF = BB->getParent();
4802   MachineRegisterInfo &MRI = MF->getRegInfo();
4803   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4804   const bool IsLittle = Subtarget.isLittle();
4805   DebugLoc DL = MI.getDebugLoc();
4806 
4807   Register Dest = MI.getOperand(0).getReg();
4808   Register Address = MI.getOperand(1).getReg();
4809   unsigned Imm = MI.getOperand(2).getImm();
4810 
4811   MachineBasicBlock::iterator I(MI);
4812 
4813   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4814     // Mips release 6 can load from adress that is not naturally-aligned.
4815     if (Subtarget.isGP64bit()) {
4816       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4817       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4818           .addDef(Temp)
4819           .addUse(Address)
4820           .addImm(Imm);
4821       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4822     } else {
4823       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4824       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4825       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4826       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4827           .addDef(Lo)
4828           .addUse(Address)
4829           .addImm(Imm + (IsLittle ? 0 : 4));
4830       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4831           .addDef(Hi)
4832           .addUse(Address)
4833           .addImm(Imm + (IsLittle ? 4 : 0));
4834       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4835       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4836           .addUse(Wtemp)
4837           .addUse(Hi)
4838           .addImm(1);
4839     }
4840   } else {
4841     // Mips release 5 needs to use instructions that can load from an unaligned
4842     // memory address.
4843     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4844     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4845     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4846     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4847     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4848     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4849     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4850     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4851     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4852         .addDef(LoHalf)
4853         .addUse(Address)
4854         .addImm(Imm + (IsLittle ? 0 : 7))
4855         .addUse(LoUndef);
4856     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4857         .addDef(LoFull)
4858         .addUse(Address)
4859         .addImm(Imm + (IsLittle ? 3 : 4))
4860         .addUse(LoHalf);
4861     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4862     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4863         .addDef(HiHalf)
4864         .addUse(Address)
4865         .addImm(Imm + (IsLittle ? 4 : 3))
4866         .addUse(HiUndef);
4867     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4868         .addDef(HiFull)
4869         .addUse(Address)
4870         .addImm(Imm + (IsLittle ? 7 : 0))
4871         .addUse(HiHalf);
4872     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4873     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4874         .addUse(Wtemp)
4875         .addUse(HiFull)
4876         .addImm(1);
4877   }
4878 
4879   MI.eraseFromParent();
4880   return BB;
4881 }
4882 
4883 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4884                                                  MachineBasicBlock *BB) const {
4885   MachineFunction *MF = BB->getParent();
4886   MachineRegisterInfo &MRI = MF->getRegInfo();
4887   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4888   const bool IsLittle = Subtarget.isLittle();
4889   DebugLoc DL = MI.getDebugLoc();
4890 
4891   Register StoreVal = MI.getOperand(0).getReg();
4892   Register Address = MI.getOperand(1).getReg();
4893   unsigned Imm = MI.getOperand(2).getImm();
4894 
4895   MachineBasicBlock::iterator I(MI);
4896 
4897   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4898     // Mips release 6 can store to adress that is not naturally-aligned.
4899     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4900     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4901     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
4902     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4903         .addDef(Tmp)
4904         .addUse(BitcastW)
4905         .addImm(0);
4906     BuildMI(*BB, I, DL, TII->get(Mips::SW))
4907         .addUse(Tmp)
4908         .addUse(Address)
4909         .addImm(Imm);
4910   } else {
4911     // Mips release 5 needs to use instructions that can store to an unaligned
4912     // memory address.
4913     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4914     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4915         .addDef(Tmp)
4916         .addUse(StoreVal)
4917         .addImm(0);
4918     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4919         .addUse(Tmp)
4920         .addUse(Address)
4921         .addImm(Imm + (IsLittle ? 0 : 3));
4922     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
4923         .addUse(Tmp)
4924         .addUse(Address)
4925         .addImm(Imm + (IsLittle ? 3 : 0));
4926   }
4927 
4928   MI.eraseFromParent();
4929 
4930   return BB;
4931 }
4932 
4933 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
4934                                                  MachineBasicBlock *BB) const {
4935   MachineFunction *MF = BB->getParent();
4936   MachineRegisterInfo &MRI = MF->getRegInfo();
4937   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4938   const bool IsLittle = Subtarget.isLittle();
4939   DebugLoc DL = MI.getDebugLoc();
4940 
4941   Register StoreVal = MI.getOperand(0).getReg();
4942   Register Address = MI.getOperand(1).getReg();
4943   unsigned Imm = MI.getOperand(2).getImm();
4944 
4945   MachineBasicBlock::iterator I(MI);
4946 
4947   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4948     // Mips release 6 can store to adress that is not naturally-aligned.
4949     if (Subtarget.isGP64bit()) {
4950       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
4951       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4952       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4953           .addDef(BitcastD)
4954           .addUse(StoreVal);
4955       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
4956           .addDef(Lo)
4957           .addUse(BitcastD)
4958           .addImm(0);
4959       BuildMI(*BB, I, DL, TII->get(Mips::SD))
4960           .addUse(Lo)
4961           .addUse(Address)
4962           .addImm(Imm);
4963     } else {
4964       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4965       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4966       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4967       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4968           .addDef(BitcastW)
4969           .addUse(StoreVal);
4970       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4971           .addDef(Lo)
4972           .addUse(BitcastW)
4973           .addImm(0);
4974       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4975           .addDef(Hi)
4976           .addUse(BitcastW)
4977           .addImm(1);
4978       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4979           .addUse(Lo)
4980           .addUse(Address)
4981           .addImm(Imm + (IsLittle ? 0 : 4));
4982       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4983           .addUse(Hi)
4984           .addUse(Address)
4985           .addImm(Imm + (IsLittle ? 4 : 0));
4986     }
4987   } else {
4988     // Mips release 5 needs to use instructions that can store to an unaligned
4989     // memory address.
4990     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4991     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4992     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4993     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
4994     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4995         .addDef(Lo)
4996         .addUse(Bitcast)
4997         .addImm(0);
4998     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4999         .addDef(Hi)
5000         .addUse(Bitcast)
5001         .addImm(1);
5002     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5003         .addUse(Lo)
5004         .addUse(Address)
5005         .addImm(Imm + (IsLittle ? 0 : 3));
5006     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5007         .addUse(Lo)
5008         .addUse(Address)
5009         .addImm(Imm + (IsLittle ? 3 : 0));
5010     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5011         .addUse(Hi)
5012         .addUse(Address)
5013         .addImm(Imm + (IsLittle ? 4 : 7));
5014     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5015         .addUse(Hi)
5016         .addUse(Address)
5017         .addImm(Imm + (IsLittle ? 7 : 4));
5018   }
5019 
5020   MI.eraseFromParent();
5021   return BB;
5022 }
5023