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