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