1 //===-- X86FastISel.cpp - X86 FastISel 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 X86-specific support for the FastISel class. Much
10 // of the target-specific code is generated by tablegen in the file
11 // X86GenFastISel.inc, which is #included here.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "X86.h"
16 #include "X86CallingConv.h"
17 #include "X86InstrBuilder.h"
18 #include "X86InstrInfo.h"
19 #include "X86MachineFunctionInfo.h"
20 #include "X86RegisterInfo.h"
21 #include "X86Subtarget.h"
22 #include "X86TargetMachine.h"
23 #include "llvm/Analysis/BranchProbabilityInfo.h"
24 #include "llvm/CodeGen/FastISel.h"
25 #include "llvm/CodeGen/FunctionLoweringInfo.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineRegisterInfo.h"
29 #include "llvm/IR/CallingConv.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/DerivedTypes.h"
32 #include "llvm/IR/GetElementPtrTypeIterator.h"
33 #include "llvm/IR/GlobalAlias.h"
34 #include "llvm/IR/GlobalVariable.h"
35 #include "llvm/IR/Instructions.h"
36 #include "llvm/IR/IntrinsicInst.h"
37 #include "llvm/IR/IntrinsicsX86.h"
38 #include "llvm/IR/Operator.h"
39 #include "llvm/MC/MCAsmInfo.h"
40 #include "llvm/MC/MCSymbol.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Target/TargetOptions.h"
43 using namespace llvm;
44 
45 namespace {
46 
47 class X86FastISel final : public FastISel {
48   /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
49   /// make the right decision when generating code for different targets.
50   const X86Subtarget *Subtarget;
51 
52   /// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87
53   /// floating point ops.
54   /// When SSE is available, use it for f32 operations.
55   /// When SSE2 is available, use it for f64 operations.
56   bool X86ScalarSSEf64;
57   bool X86ScalarSSEf32;
58 
59 public:
X86FastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo)60   explicit X86FastISel(FunctionLoweringInfo &funcInfo,
61                        const TargetLibraryInfo *libInfo)
62       : FastISel(funcInfo, libInfo) {
63     Subtarget = &funcInfo.MF->getSubtarget<X86Subtarget>();
64     X86ScalarSSEf64 = Subtarget->hasSSE2();
65     X86ScalarSSEf32 = Subtarget->hasSSE1();
66   }
67 
68   bool fastSelectInstruction(const Instruction *I) override;
69 
70   /// The specified machine instr operand is a vreg, and that
71   /// vreg is being provided by the specified load instruction.  If possible,
72   /// try to fold the load as an operand to the instruction, returning true if
73   /// possible.
74   bool tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
75                            const LoadInst *LI) override;
76 
77   bool fastLowerArguments() override;
78   bool fastLowerCall(CallLoweringInfo &CLI) override;
79   bool fastLowerIntrinsicCall(const IntrinsicInst *II) override;
80 
81 #include "X86GenFastISel.inc"
82 
83 private:
84   bool X86FastEmitCompare(const Value *LHS, const Value *RHS, EVT VT,
85                           const DebugLoc &DL);
86 
87   bool X86FastEmitLoad(MVT VT, X86AddressMode &AM, MachineMemOperand *MMO,
88                        unsigned &ResultReg, unsigned Alignment = 1);
89 
90   bool X86FastEmitStore(EVT VT, const Value *Val, X86AddressMode &AM,
91                         MachineMemOperand *MMO = nullptr, bool Aligned = false);
92   bool X86FastEmitStore(EVT VT, unsigned ValReg, bool ValIsKill,
93                         X86AddressMode &AM,
94                         MachineMemOperand *MMO = nullptr, bool Aligned = false);
95 
96   bool X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT,
97                          unsigned &ResultReg);
98 
99   bool X86SelectAddress(const Value *V, X86AddressMode &AM);
100   bool X86SelectCallAddress(const Value *V, X86AddressMode &AM);
101 
102   bool X86SelectLoad(const Instruction *I);
103 
104   bool X86SelectStore(const Instruction *I);
105 
106   bool X86SelectRet(const Instruction *I);
107 
108   bool X86SelectCmp(const Instruction *I);
109 
110   bool X86SelectZExt(const Instruction *I);
111 
112   bool X86SelectSExt(const Instruction *I);
113 
114   bool X86SelectBranch(const Instruction *I);
115 
116   bool X86SelectShift(const Instruction *I);
117 
118   bool X86SelectDivRem(const Instruction *I);
119 
120   bool X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I);
121 
122   bool X86FastEmitSSESelect(MVT RetVT, const Instruction *I);
123 
124   bool X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I);
125 
126   bool X86SelectSelect(const Instruction *I);
127 
128   bool X86SelectTrunc(const Instruction *I);
129 
130   bool X86SelectFPExtOrFPTrunc(const Instruction *I, unsigned Opc,
131                                const TargetRegisterClass *RC);
132 
133   bool X86SelectFPExt(const Instruction *I);
134   bool X86SelectFPTrunc(const Instruction *I);
135   bool X86SelectSIToFP(const Instruction *I);
136   bool X86SelectUIToFP(const Instruction *I);
137   bool X86SelectIntToFP(const Instruction *I, bool IsSigned);
138 
getInstrInfo() const139   const X86InstrInfo *getInstrInfo() const {
140     return Subtarget->getInstrInfo();
141   }
getTargetMachine() const142   const X86TargetMachine *getTargetMachine() const {
143     return static_cast<const X86TargetMachine *>(&TM);
144   }
145 
146   bool handleConstantAddresses(const Value *V, X86AddressMode &AM);
147 
148   unsigned X86MaterializeInt(const ConstantInt *CI, MVT VT);
149   unsigned X86MaterializeFP(const ConstantFP *CFP, MVT VT);
150   unsigned X86MaterializeGV(const GlobalValue *GV, MVT VT);
151   unsigned fastMaterializeConstant(const Constant *C) override;
152 
153   unsigned fastMaterializeAlloca(const AllocaInst *C) override;
154 
155   unsigned fastMaterializeFloatZero(const ConstantFP *CF) override;
156 
157   /// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
158   /// computed in an SSE register, not on the X87 floating point stack.
isScalarFPTypeInSSEReg(EVT VT) const159   bool isScalarFPTypeInSSEReg(EVT VT) const {
160     return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
161       (VT == MVT::f32 && X86ScalarSSEf32);   // f32 is when SSE1
162   }
163 
164   bool isTypeLegal(Type *Ty, MVT &VT, bool AllowI1 = false);
165 
166   bool IsMemcpySmall(uint64_t Len);
167 
168   bool TryEmitSmallMemcpy(X86AddressMode DestAM,
169                           X86AddressMode SrcAM, uint64_t Len);
170 
171   bool foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I,
172                             const Value *Cond);
173 
174   const MachineInstrBuilder &addFullAddress(const MachineInstrBuilder &MIB,
175                                             X86AddressMode &AM);
176 
177   unsigned fastEmitInst_rrrr(unsigned MachineInstOpcode,
178                              const TargetRegisterClass *RC, unsigned Op0,
179                              bool Op0IsKill, unsigned Op1, bool Op1IsKill,
180                              unsigned Op2, bool Op2IsKill, unsigned Op3,
181                              bool Op3IsKill);
182 };
183 
184 } // end anonymous namespace.
185 
186 static std::pair<unsigned, bool>
getX86SSEConditionCode(CmpInst::Predicate Predicate)187 getX86SSEConditionCode(CmpInst::Predicate Predicate) {
188   unsigned CC;
189   bool NeedSwap = false;
190 
191   // SSE Condition code mapping:
192   //  0 - EQ
193   //  1 - LT
194   //  2 - LE
195   //  3 - UNORD
196   //  4 - NEQ
197   //  5 - NLT
198   //  6 - NLE
199   //  7 - ORD
200   switch (Predicate) {
201   default: llvm_unreachable("Unexpected predicate");
202   case CmpInst::FCMP_OEQ: CC = 0;          break;
203   case CmpInst::FCMP_OGT: NeedSwap = true; LLVM_FALLTHROUGH;
204   case CmpInst::FCMP_OLT: CC = 1;          break;
205   case CmpInst::FCMP_OGE: NeedSwap = true; LLVM_FALLTHROUGH;
206   case CmpInst::FCMP_OLE: CC = 2;          break;
207   case CmpInst::FCMP_UNO: CC = 3;          break;
208   case CmpInst::FCMP_UNE: CC = 4;          break;
209   case CmpInst::FCMP_ULE: NeedSwap = true; LLVM_FALLTHROUGH;
210   case CmpInst::FCMP_UGE: CC = 5;          break;
211   case CmpInst::FCMP_ULT: NeedSwap = true; LLVM_FALLTHROUGH;
212   case CmpInst::FCMP_UGT: CC = 6;          break;
213   case CmpInst::FCMP_ORD: CC = 7;          break;
214   case CmpInst::FCMP_UEQ: CC = 8;          break;
215   case CmpInst::FCMP_ONE: CC = 12;         break;
216   }
217 
218   return std::make_pair(CC, NeedSwap);
219 }
220 
221 /// Adds a complex addressing mode to the given machine instr builder.
222 /// Note, this will constrain the index register.  If its not possible to
223 /// constrain the given index register, then a new one will be created.  The
224 /// IndexReg field of the addressing mode will be updated to match in this case.
225 const MachineInstrBuilder &
addFullAddress(const MachineInstrBuilder & MIB,X86AddressMode & AM)226 X86FastISel::addFullAddress(const MachineInstrBuilder &MIB,
227                             X86AddressMode &AM) {
228   // First constrain the index register.  It needs to be a GR64_NOSP.
229   AM.IndexReg = constrainOperandRegClass(MIB->getDesc(), AM.IndexReg,
230                                          MIB->getNumOperands() +
231                                          X86::AddrIndexReg);
232   return ::addFullAddress(MIB, AM);
233 }
234 
235 /// Check if it is possible to fold the condition from the XALU intrinsic
236 /// into the user. The condition code will only be updated on success.
foldX86XALUIntrinsic(X86::CondCode & CC,const Instruction * I,const Value * Cond)237 bool X86FastISel::foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I,
238                                        const Value *Cond) {
239   if (!isa<ExtractValueInst>(Cond))
240     return false;
241 
242   const auto *EV = cast<ExtractValueInst>(Cond);
243   if (!isa<IntrinsicInst>(EV->getAggregateOperand()))
244     return false;
245 
246   const auto *II = cast<IntrinsicInst>(EV->getAggregateOperand());
247   MVT RetVT;
248   const Function *Callee = II->getCalledFunction();
249   Type *RetTy =
250     cast<StructType>(Callee->getReturnType())->getTypeAtIndex(0U);
251   if (!isTypeLegal(RetTy, RetVT))
252     return false;
253 
254   if (RetVT != MVT::i32 && RetVT != MVT::i64)
255     return false;
256 
257   X86::CondCode TmpCC;
258   switch (II->getIntrinsicID()) {
259   default: return false;
260   case Intrinsic::sadd_with_overflow:
261   case Intrinsic::ssub_with_overflow:
262   case Intrinsic::smul_with_overflow:
263   case Intrinsic::umul_with_overflow: TmpCC = X86::COND_O; break;
264   case Intrinsic::uadd_with_overflow:
265   case Intrinsic::usub_with_overflow: TmpCC = X86::COND_B; break;
266   }
267 
268   // Check if both instructions are in the same basic block.
269   if (II->getParent() != I->getParent())
270     return false;
271 
272   // Make sure nothing is in the way
273   BasicBlock::const_iterator Start(I);
274   BasicBlock::const_iterator End(II);
275   for (auto Itr = std::prev(Start); Itr != End; --Itr) {
276     // We only expect extractvalue instructions between the intrinsic and the
277     // instruction to be selected.
278     if (!isa<ExtractValueInst>(Itr))
279       return false;
280 
281     // Check that the extractvalue operand comes from the intrinsic.
282     const auto *EVI = cast<ExtractValueInst>(Itr);
283     if (EVI->getAggregateOperand() != II)
284       return false;
285   }
286 
287   CC = TmpCC;
288   return true;
289 }
290 
isTypeLegal(Type * Ty,MVT & VT,bool AllowI1)291 bool X86FastISel::isTypeLegal(Type *Ty, MVT &VT, bool AllowI1) {
292   EVT evt = TLI.getValueType(DL, Ty, /*AllowUnknown=*/true);
293   if (evt == MVT::Other || !evt.isSimple())
294     // Unhandled type. Halt "fast" selection and bail.
295     return false;
296 
297   VT = evt.getSimpleVT();
298   // For now, require SSE/SSE2 for performing floating-point operations,
299   // since x87 requires additional work.
300   if (VT == MVT::f64 && !X86ScalarSSEf64)
301     return false;
302   if (VT == MVT::f32 && !X86ScalarSSEf32)
303     return false;
304   // Similarly, no f80 support yet.
305   if (VT == MVT::f80)
306     return false;
307   // We only handle legal types. For example, on x86-32 the instruction
308   // selector contains all of the 64-bit instructions from x86-64,
309   // under the assumption that i64 won't be used if the target doesn't
310   // support it.
311   return (AllowI1 && VT == MVT::i1) || TLI.isTypeLegal(VT);
312 }
313 
314 /// X86FastEmitLoad - Emit a machine instruction to load a value of type VT.
315 /// The address is either pre-computed, i.e. Ptr, or a GlobalAddress, i.e. GV.
316 /// Return true and the result register by reference if it is possible.
X86FastEmitLoad(MVT VT,X86AddressMode & AM,MachineMemOperand * MMO,unsigned & ResultReg,unsigned Alignment)317 bool X86FastISel::X86FastEmitLoad(MVT VT, X86AddressMode &AM,
318                                   MachineMemOperand *MMO, unsigned &ResultReg,
319                                   unsigned Alignment) {
320   bool HasSSE41 = Subtarget->hasSSE41();
321   bool HasAVX = Subtarget->hasAVX();
322   bool HasAVX2 = Subtarget->hasAVX2();
323   bool HasAVX512 = Subtarget->hasAVX512();
324   bool HasVLX = Subtarget->hasVLX();
325   bool IsNonTemporal = MMO && MMO->isNonTemporal();
326 
327   // Treat i1 loads the same as i8 loads. Masking will be done when storing.
328   if (VT == MVT::i1)
329     VT = MVT::i8;
330 
331   // Get opcode and regclass of the output for the given load instruction.
332   unsigned Opc = 0;
333   switch (VT.SimpleTy) {
334   default: return false;
335   case MVT::i8:
336     Opc = X86::MOV8rm;
337     break;
338   case MVT::i16:
339     Opc = X86::MOV16rm;
340     break;
341   case MVT::i32:
342     Opc = X86::MOV32rm;
343     break;
344   case MVT::i64:
345     // Must be in x86-64 mode.
346     Opc = X86::MOV64rm;
347     break;
348   case MVT::f32:
349     if (X86ScalarSSEf32)
350       Opc = HasAVX512 ? X86::VMOVSSZrm_alt :
351             HasAVX    ? X86::VMOVSSrm_alt :
352                         X86::MOVSSrm_alt;
353     else
354       Opc = X86::LD_Fp32m;
355     break;
356   case MVT::f64:
357     if (X86ScalarSSEf64)
358       Opc = HasAVX512 ? X86::VMOVSDZrm_alt :
359             HasAVX    ? X86::VMOVSDrm_alt :
360                         X86::MOVSDrm_alt;
361     else
362       Opc = X86::LD_Fp64m;
363     break;
364   case MVT::f80:
365     // No f80 support yet.
366     return false;
367   case MVT::v4f32:
368     if (IsNonTemporal && Alignment >= 16 && HasSSE41)
369       Opc = HasVLX ? X86::VMOVNTDQAZ128rm :
370             HasAVX ? X86::VMOVNTDQArm : X86::MOVNTDQArm;
371     else if (Alignment >= 16)
372       Opc = HasVLX ? X86::VMOVAPSZ128rm :
373             HasAVX ? X86::VMOVAPSrm : X86::MOVAPSrm;
374     else
375       Opc = HasVLX ? X86::VMOVUPSZ128rm :
376             HasAVX ? X86::VMOVUPSrm : X86::MOVUPSrm;
377     break;
378   case MVT::v2f64:
379     if (IsNonTemporal && Alignment >= 16 && HasSSE41)
380       Opc = HasVLX ? X86::VMOVNTDQAZ128rm :
381             HasAVX ? X86::VMOVNTDQArm : X86::MOVNTDQArm;
382     else if (Alignment >= 16)
383       Opc = HasVLX ? X86::VMOVAPDZ128rm :
384             HasAVX ? X86::VMOVAPDrm : X86::MOVAPDrm;
385     else
386       Opc = HasVLX ? X86::VMOVUPDZ128rm :
387             HasAVX ? X86::VMOVUPDrm : X86::MOVUPDrm;
388     break;
389   case MVT::v4i32:
390   case MVT::v2i64:
391   case MVT::v8i16:
392   case MVT::v16i8:
393     if (IsNonTemporal && Alignment >= 16 && HasSSE41)
394       Opc = HasVLX ? X86::VMOVNTDQAZ128rm :
395             HasAVX ? X86::VMOVNTDQArm : X86::MOVNTDQArm;
396     else if (Alignment >= 16)
397       Opc = HasVLX ? X86::VMOVDQA64Z128rm :
398             HasAVX ? X86::VMOVDQArm : X86::MOVDQArm;
399     else
400       Opc = HasVLX ? X86::VMOVDQU64Z128rm :
401             HasAVX ? X86::VMOVDQUrm : X86::MOVDQUrm;
402     break;
403   case MVT::v8f32:
404     assert(HasAVX);
405     if (IsNonTemporal && Alignment >= 32 && HasAVX2)
406       Opc = HasVLX ? X86::VMOVNTDQAZ256rm : X86::VMOVNTDQAYrm;
407     else if (IsNonTemporal && Alignment >= 16)
408       return false; // Force split for X86::VMOVNTDQArm
409     else if (Alignment >= 32)
410       Opc = HasVLX ? X86::VMOVAPSZ256rm : X86::VMOVAPSYrm;
411     else
412       Opc = HasVLX ? X86::VMOVUPSZ256rm : X86::VMOVUPSYrm;
413     break;
414   case MVT::v4f64:
415     assert(HasAVX);
416     if (IsNonTemporal && Alignment >= 32 && HasAVX2)
417       Opc = HasVLX ? X86::VMOVNTDQAZ256rm : X86::VMOVNTDQAYrm;
418     else if (IsNonTemporal && Alignment >= 16)
419       return false; // Force split for X86::VMOVNTDQArm
420     else if (Alignment >= 32)
421       Opc = HasVLX ? X86::VMOVAPDZ256rm : X86::VMOVAPDYrm;
422     else
423       Opc = HasVLX ? X86::VMOVUPDZ256rm : X86::VMOVUPDYrm;
424     break;
425   case MVT::v8i32:
426   case MVT::v4i64:
427   case MVT::v16i16:
428   case MVT::v32i8:
429     assert(HasAVX);
430     if (IsNonTemporal && Alignment >= 32 && HasAVX2)
431       Opc = HasVLX ? X86::VMOVNTDQAZ256rm : X86::VMOVNTDQAYrm;
432     else if (IsNonTemporal && Alignment >= 16)
433       return false; // Force split for X86::VMOVNTDQArm
434     else if (Alignment >= 32)
435       Opc = HasVLX ? X86::VMOVDQA64Z256rm : X86::VMOVDQAYrm;
436     else
437       Opc = HasVLX ? X86::VMOVDQU64Z256rm : X86::VMOVDQUYrm;
438     break;
439   case MVT::v16f32:
440     assert(HasAVX512);
441     if (IsNonTemporal && Alignment >= 64)
442       Opc = X86::VMOVNTDQAZrm;
443     else
444       Opc = (Alignment >= 64) ? X86::VMOVAPSZrm : X86::VMOVUPSZrm;
445     break;
446   case MVT::v8f64:
447     assert(HasAVX512);
448     if (IsNonTemporal && Alignment >= 64)
449       Opc = X86::VMOVNTDQAZrm;
450     else
451       Opc = (Alignment >= 64) ? X86::VMOVAPDZrm : X86::VMOVUPDZrm;
452     break;
453   case MVT::v8i64:
454   case MVT::v16i32:
455   case MVT::v32i16:
456   case MVT::v64i8:
457     assert(HasAVX512);
458     // Note: There are a lot more choices based on type with AVX-512, but
459     // there's really no advantage when the load isn't masked.
460     if (IsNonTemporal && Alignment >= 64)
461       Opc = X86::VMOVNTDQAZrm;
462     else
463       Opc = (Alignment >= 64) ? X86::VMOVDQA64Zrm : X86::VMOVDQU64Zrm;
464     break;
465   }
466 
467   const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
468 
469   ResultReg = createResultReg(RC);
470   MachineInstrBuilder MIB =
471     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg);
472   addFullAddress(MIB, AM);
473   if (MMO)
474     MIB->addMemOperand(*FuncInfo.MF, MMO);
475   return true;
476 }
477 
478 /// X86FastEmitStore - Emit a machine instruction to store a value Val of
479 /// type VT. The address is either pre-computed, consisted of a base ptr, Ptr
480 /// and a displacement offset, or a GlobalAddress,
481 /// i.e. V. Return true if it is possible.
X86FastEmitStore(EVT VT,unsigned ValReg,bool ValIsKill,X86AddressMode & AM,MachineMemOperand * MMO,bool Aligned)482 bool X86FastISel::X86FastEmitStore(EVT VT, unsigned ValReg, bool ValIsKill,
483                                    X86AddressMode &AM,
484                                    MachineMemOperand *MMO, bool Aligned) {
485   bool HasSSE1 = Subtarget->hasSSE1();
486   bool HasSSE2 = Subtarget->hasSSE2();
487   bool HasSSE4A = Subtarget->hasSSE4A();
488   bool HasAVX = Subtarget->hasAVX();
489   bool HasAVX512 = Subtarget->hasAVX512();
490   bool HasVLX = Subtarget->hasVLX();
491   bool IsNonTemporal = MMO && MMO->isNonTemporal();
492 
493   // Get opcode and regclass of the output for the given store instruction.
494   unsigned Opc = 0;
495   switch (VT.getSimpleVT().SimpleTy) {
496   case MVT::f80: // No f80 support yet.
497   default: return false;
498   case MVT::i1: {
499     // Mask out all but lowest bit.
500     Register AndResult = createResultReg(&X86::GR8RegClass);
501     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
502             TII.get(X86::AND8ri), AndResult)
503       .addReg(ValReg, getKillRegState(ValIsKill)).addImm(1);
504     ValReg = AndResult;
505     LLVM_FALLTHROUGH; // handle i1 as i8.
506   }
507   case MVT::i8:  Opc = X86::MOV8mr;  break;
508   case MVT::i16: Opc = X86::MOV16mr; break;
509   case MVT::i32:
510     Opc = (IsNonTemporal && HasSSE2) ? X86::MOVNTImr : X86::MOV32mr;
511     break;
512   case MVT::i64:
513     // Must be in x86-64 mode.
514     Opc = (IsNonTemporal && HasSSE2) ? X86::MOVNTI_64mr : X86::MOV64mr;
515     break;
516   case MVT::f32:
517     if (X86ScalarSSEf32) {
518       if (IsNonTemporal && HasSSE4A)
519         Opc = X86::MOVNTSS;
520       else
521         Opc = HasAVX512 ? X86::VMOVSSZmr :
522               HasAVX ? X86::VMOVSSmr : X86::MOVSSmr;
523     } else
524       Opc = X86::ST_Fp32m;
525     break;
526   case MVT::f64:
527     if (X86ScalarSSEf32) {
528       if (IsNonTemporal && HasSSE4A)
529         Opc = X86::MOVNTSD;
530       else
531         Opc = HasAVX512 ? X86::VMOVSDZmr :
532               HasAVX ? X86::VMOVSDmr : X86::MOVSDmr;
533     } else
534       Opc = X86::ST_Fp64m;
535     break;
536   case MVT::x86mmx:
537     Opc = (IsNonTemporal && HasSSE1) ? X86::MMX_MOVNTQmr : X86::MMX_MOVQ64mr;
538     break;
539   case MVT::v4f32:
540     if (Aligned) {
541       if (IsNonTemporal)
542         Opc = HasVLX ? X86::VMOVNTPSZ128mr :
543               HasAVX ? X86::VMOVNTPSmr : X86::MOVNTPSmr;
544       else
545         Opc = HasVLX ? X86::VMOVAPSZ128mr :
546               HasAVX ? X86::VMOVAPSmr : X86::MOVAPSmr;
547     } else
548       Opc = HasVLX ? X86::VMOVUPSZ128mr :
549             HasAVX ? X86::VMOVUPSmr : X86::MOVUPSmr;
550     break;
551   case MVT::v2f64:
552     if (Aligned) {
553       if (IsNonTemporal)
554         Opc = HasVLX ? X86::VMOVNTPDZ128mr :
555               HasAVX ? X86::VMOVNTPDmr : X86::MOVNTPDmr;
556       else
557         Opc = HasVLX ? X86::VMOVAPDZ128mr :
558               HasAVX ? X86::VMOVAPDmr : X86::MOVAPDmr;
559     } else
560       Opc = HasVLX ? X86::VMOVUPDZ128mr :
561             HasAVX ? X86::VMOVUPDmr : X86::MOVUPDmr;
562     break;
563   case MVT::v4i32:
564   case MVT::v2i64:
565   case MVT::v8i16:
566   case MVT::v16i8:
567     if (Aligned) {
568       if (IsNonTemporal)
569         Opc = HasVLX ? X86::VMOVNTDQZ128mr :
570               HasAVX ? X86::VMOVNTDQmr : X86::MOVNTDQmr;
571       else
572         Opc = HasVLX ? X86::VMOVDQA64Z128mr :
573               HasAVX ? X86::VMOVDQAmr : X86::MOVDQAmr;
574     } else
575       Opc = HasVLX ? X86::VMOVDQU64Z128mr :
576             HasAVX ? X86::VMOVDQUmr : X86::MOVDQUmr;
577     break;
578   case MVT::v8f32:
579     assert(HasAVX);
580     if (Aligned) {
581       if (IsNonTemporal)
582         Opc = HasVLX ? X86::VMOVNTPSZ256mr : X86::VMOVNTPSYmr;
583       else
584         Opc = HasVLX ? X86::VMOVAPSZ256mr : X86::VMOVAPSYmr;
585     } else
586       Opc = HasVLX ? X86::VMOVUPSZ256mr : X86::VMOVUPSYmr;
587     break;
588   case MVT::v4f64:
589     assert(HasAVX);
590     if (Aligned) {
591       if (IsNonTemporal)
592         Opc = HasVLX ? X86::VMOVNTPDZ256mr : X86::VMOVNTPDYmr;
593       else
594         Opc = HasVLX ? X86::VMOVAPDZ256mr : X86::VMOVAPDYmr;
595     } else
596       Opc = HasVLX ? X86::VMOVUPDZ256mr : X86::VMOVUPDYmr;
597     break;
598   case MVT::v8i32:
599   case MVT::v4i64:
600   case MVT::v16i16:
601   case MVT::v32i8:
602     assert(HasAVX);
603     if (Aligned) {
604       if (IsNonTemporal)
605         Opc = HasVLX ? X86::VMOVNTDQZ256mr : X86::VMOVNTDQYmr;
606       else
607         Opc = HasVLX ? X86::VMOVDQA64Z256mr : X86::VMOVDQAYmr;
608     } else
609       Opc = HasVLX ? X86::VMOVDQU64Z256mr : X86::VMOVDQUYmr;
610     break;
611   case MVT::v16f32:
612     assert(HasAVX512);
613     if (Aligned)
614       Opc = IsNonTemporal ? X86::VMOVNTPSZmr : X86::VMOVAPSZmr;
615     else
616       Opc = X86::VMOVUPSZmr;
617     break;
618   case MVT::v8f64:
619     assert(HasAVX512);
620     if (Aligned) {
621       Opc = IsNonTemporal ? X86::VMOVNTPDZmr : X86::VMOVAPDZmr;
622     } else
623       Opc = X86::VMOVUPDZmr;
624     break;
625   case MVT::v8i64:
626   case MVT::v16i32:
627   case MVT::v32i16:
628   case MVT::v64i8:
629     assert(HasAVX512);
630     // Note: There are a lot more choices based on type with AVX-512, but
631     // there's really no advantage when the store isn't masked.
632     if (Aligned)
633       Opc = IsNonTemporal ? X86::VMOVNTDQZmr : X86::VMOVDQA64Zmr;
634     else
635       Opc = X86::VMOVDQU64Zmr;
636     break;
637   }
638 
639   const MCInstrDesc &Desc = TII.get(Opc);
640   // Some of the instructions in the previous switch use FR128 instead
641   // of FR32 for ValReg. Make sure the register we feed the instruction
642   // matches its register class constraints.
643   // Note: This is fine to do a copy from FR32 to FR128, this is the
644   // same registers behind the scene and actually why it did not trigger
645   // any bugs before.
646   ValReg = constrainOperandRegClass(Desc, ValReg, Desc.getNumOperands() - 1);
647   MachineInstrBuilder MIB =
648       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, Desc);
649   addFullAddress(MIB, AM).addReg(ValReg, getKillRegState(ValIsKill));
650   if (MMO)
651     MIB->addMemOperand(*FuncInfo.MF, MMO);
652 
653   return true;
654 }
655 
X86FastEmitStore(EVT VT,const Value * Val,X86AddressMode & AM,MachineMemOperand * MMO,bool Aligned)656 bool X86FastISel::X86FastEmitStore(EVT VT, const Value *Val,
657                                    X86AddressMode &AM,
658                                    MachineMemOperand *MMO, bool Aligned) {
659   // Handle 'null' like i32/i64 0.
660   if (isa<ConstantPointerNull>(Val))
661     Val = Constant::getNullValue(DL.getIntPtrType(Val->getContext()));
662 
663   // If this is a store of a simple constant, fold the constant into the store.
664   if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
665     unsigned Opc = 0;
666     bool Signed = true;
667     switch (VT.getSimpleVT().SimpleTy) {
668     default: break;
669     case MVT::i1:
670       Signed = false;
671       LLVM_FALLTHROUGH; // Handle as i8.
672     case MVT::i8:  Opc = X86::MOV8mi;  break;
673     case MVT::i16: Opc = X86::MOV16mi; break;
674     case MVT::i32: Opc = X86::MOV32mi; break;
675     case MVT::i64:
676       // Must be a 32-bit sign extended value.
677       if (isInt<32>(CI->getSExtValue()))
678         Opc = X86::MOV64mi32;
679       break;
680     }
681 
682     if (Opc) {
683       MachineInstrBuilder MIB =
684         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc));
685       addFullAddress(MIB, AM).addImm(Signed ? (uint64_t) CI->getSExtValue()
686                                             : CI->getZExtValue());
687       if (MMO)
688         MIB->addMemOperand(*FuncInfo.MF, MMO);
689       return true;
690     }
691   }
692 
693   Register ValReg = getRegForValue(Val);
694   if (ValReg == 0)
695     return false;
696 
697   bool ValKill = hasTrivialKill(Val);
698   return X86FastEmitStore(VT, ValReg, ValKill, AM, MMO, Aligned);
699 }
700 
701 /// X86FastEmitExtend - Emit a machine instruction to extend a value Src of
702 /// type SrcVT to type DstVT using the specified extension opcode Opc (e.g.
703 /// ISD::SIGN_EXTEND).
X86FastEmitExtend(ISD::NodeType Opc,EVT DstVT,unsigned Src,EVT SrcVT,unsigned & ResultReg)704 bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT,
705                                     unsigned Src, EVT SrcVT,
706                                     unsigned &ResultReg) {
707   unsigned RR = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Opc,
708                            Src, /*TODO: Kill=*/false);
709   if (RR == 0)
710     return false;
711 
712   ResultReg = RR;
713   return true;
714 }
715 
handleConstantAddresses(const Value * V,X86AddressMode & AM)716 bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) {
717   // Handle constant address.
718   if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
719     // Can't handle alternate code models yet.
720     if (TM.getCodeModel() != CodeModel::Small)
721       return false;
722 
723     // Can't handle TLS yet.
724     if (GV->isThreadLocal())
725       return false;
726 
727     // Can't handle !absolute_symbol references yet.
728     if (GV->isAbsoluteSymbolRef())
729       return false;
730 
731     // RIP-relative addresses can't have additional register operands, so if
732     // we've already folded stuff into the addressing mode, just force the
733     // global value into its own register, which we can use as the basereg.
734     if (!Subtarget->isPICStyleRIPRel() ||
735         (AM.Base.Reg == 0 && AM.IndexReg == 0)) {
736       // Okay, we've committed to selecting this global. Set up the address.
737       AM.GV = GV;
738 
739       // Allow the subtarget to classify the global.
740       unsigned char GVFlags = Subtarget->classifyGlobalReference(GV);
741 
742       // If this reference is relative to the pic base, set it now.
743       if (isGlobalRelativeToPICBase(GVFlags)) {
744         // FIXME: How do we know Base.Reg is free??
745         AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
746       }
747 
748       // Unless the ABI requires an extra load, return a direct reference to
749       // the global.
750       if (!isGlobalStubReference(GVFlags)) {
751         if (Subtarget->isPICStyleRIPRel()) {
752           // Use rip-relative addressing if we can.  Above we verified that the
753           // base and index registers are unused.
754           assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
755           AM.Base.Reg = X86::RIP;
756         }
757         AM.GVOpFlags = GVFlags;
758         return true;
759       }
760 
761       // Ok, we need to do a load from a stub.  If we've already loaded from
762       // this stub, reuse the loaded pointer, otherwise emit the load now.
763       DenseMap<const Value *, Register>::iterator I = LocalValueMap.find(V);
764       Register LoadReg;
765       if (I != LocalValueMap.end() && I->second) {
766         LoadReg = I->second;
767       } else {
768         // Issue load from stub.
769         unsigned Opc = 0;
770         const TargetRegisterClass *RC = nullptr;
771         X86AddressMode StubAM;
772         StubAM.Base.Reg = AM.Base.Reg;
773         StubAM.GV = GV;
774         StubAM.GVOpFlags = GVFlags;
775 
776         // Prepare for inserting code in the local-value area.
777         SavePoint SaveInsertPt = enterLocalValueArea();
778 
779         if (TLI.getPointerTy(DL) == MVT::i64) {
780           Opc = X86::MOV64rm;
781           RC  = &X86::GR64RegClass;
782 
783           if (Subtarget->isPICStyleRIPRel())
784             StubAM.Base.Reg = X86::RIP;
785         } else {
786           Opc = X86::MOV32rm;
787           RC  = &X86::GR32RegClass;
788         }
789 
790         LoadReg = createResultReg(RC);
791         MachineInstrBuilder LoadMI =
792           BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), LoadReg);
793         addFullAddress(LoadMI, StubAM);
794 
795         // Ok, back to normal mode.
796         leaveLocalValueArea(SaveInsertPt);
797 
798         // Prevent loading GV stub multiple times in same MBB.
799         LocalValueMap[V] = LoadReg;
800       }
801 
802       // Now construct the final address. Note that the Disp, Scale,
803       // and Index values may already be set here.
804       AM.Base.Reg = LoadReg;
805       AM.GV = nullptr;
806       return true;
807     }
808   }
809 
810   // If all else fails, try to materialize the value in a register.
811   if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
812     if (AM.Base.Reg == 0) {
813       AM.Base.Reg = getRegForValue(V);
814       return AM.Base.Reg != 0;
815     }
816     if (AM.IndexReg == 0) {
817       assert(AM.Scale == 1 && "Scale with no index!");
818       AM.IndexReg = getRegForValue(V);
819       return AM.IndexReg != 0;
820     }
821   }
822 
823   return false;
824 }
825 
826 /// X86SelectAddress - Attempt to fill in an address from the given value.
827 ///
X86SelectAddress(const Value * V,X86AddressMode & AM)828 bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
829   SmallVector<const Value *, 32> GEPs;
830 redo_gep:
831   const User *U = nullptr;
832   unsigned Opcode = Instruction::UserOp1;
833   if (const Instruction *I = dyn_cast<Instruction>(V)) {
834     // Don't walk into other basic blocks; it's possible we haven't
835     // visited them yet, so the instructions may not yet be assigned
836     // virtual registers.
837     if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(V)) ||
838         FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) {
839       Opcode = I->getOpcode();
840       U = I;
841     }
842   } else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
843     Opcode = C->getOpcode();
844     U = C;
845   }
846 
847   if (PointerType *Ty = dyn_cast<PointerType>(V->getType()))
848     if (Ty->getAddressSpace() > 255)
849       // Fast instruction selection doesn't support the special
850       // address spaces.
851       return false;
852 
853   switch (Opcode) {
854   default: break;
855   case Instruction::BitCast:
856     // Look past bitcasts.
857     return X86SelectAddress(U->getOperand(0), AM);
858 
859   case Instruction::IntToPtr:
860     // Look past no-op inttoptrs.
861     if (TLI.getValueType(DL, U->getOperand(0)->getType()) ==
862         TLI.getPointerTy(DL))
863       return X86SelectAddress(U->getOperand(0), AM);
864     break;
865 
866   case Instruction::PtrToInt:
867     // Look past no-op ptrtoints.
868     if (TLI.getValueType(DL, U->getType()) == TLI.getPointerTy(DL))
869       return X86SelectAddress(U->getOperand(0), AM);
870     break;
871 
872   case Instruction::Alloca: {
873     // Do static allocas.
874     const AllocaInst *A = cast<AllocaInst>(V);
875     DenseMap<const AllocaInst *, int>::iterator SI =
876       FuncInfo.StaticAllocaMap.find(A);
877     if (SI != FuncInfo.StaticAllocaMap.end()) {
878       AM.BaseType = X86AddressMode::FrameIndexBase;
879       AM.Base.FrameIndex = SI->second;
880       return true;
881     }
882     break;
883   }
884 
885   case Instruction::Add: {
886     // Adds of constants are common and easy enough.
887     if (const ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
888       uint64_t Disp = (int32_t)AM.Disp + (uint64_t)CI->getSExtValue();
889       // They have to fit in the 32-bit signed displacement field though.
890       if (isInt<32>(Disp)) {
891         AM.Disp = (uint32_t)Disp;
892         return X86SelectAddress(U->getOperand(0), AM);
893       }
894     }
895     break;
896   }
897 
898   case Instruction::GetElementPtr: {
899     X86AddressMode SavedAM = AM;
900 
901     // Pattern-match simple GEPs.
902     uint64_t Disp = (int32_t)AM.Disp;
903     unsigned IndexReg = AM.IndexReg;
904     unsigned Scale = AM.Scale;
905     gep_type_iterator GTI = gep_type_begin(U);
906     // Iterate through the indices, folding what we can. Constants can be
907     // folded, and one dynamic index can be handled, if the scale is supported.
908     for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end();
909          i != e; ++i, ++GTI) {
910       const Value *Op = *i;
911       if (StructType *STy = GTI.getStructTypeOrNull()) {
912         const StructLayout *SL = DL.getStructLayout(STy);
913         Disp += SL->getElementOffset(cast<ConstantInt>(Op)->getZExtValue());
914         continue;
915       }
916 
917       // A array/variable index is always of the form i*S where S is the
918       // constant scale size.  See if we can push the scale into immediates.
919       uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType());
920       for (;;) {
921         if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
922           // Constant-offset addressing.
923           Disp += CI->getSExtValue() * S;
924           break;
925         }
926         if (canFoldAddIntoGEP(U, Op)) {
927           // A compatible add with a constant operand. Fold the constant.
928           ConstantInt *CI =
929             cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
930           Disp += CI->getSExtValue() * S;
931           // Iterate on the other operand.
932           Op = cast<AddOperator>(Op)->getOperand(0);
933           continue;
934         }
935         if (IndexReg == 0 &&
936             (!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
937             (S == 1 || S == 2 || S == 4 || S == 8)) {
938           // Scaled-index addressing.
939           Scale = S;
940           IndexReg = getRegForGEPIndex(Op).first;
941           if (IndexReg == 0)
942             return false;
943           break;
944         }
945         // Unsupported.
946         goto unsupported_gep;
947       }
948     }
949 
950     // Check for displacement overflow.
951     if (!isInt<32>(Disp))
952       break;
953 
954     AM.IndexReg = IndexReg;
955     AM.Scale = Scale;
956     AM.Disp = (uint32_t)Disp;
957     GEPs.push_back(V);
958 
959     if (const GetElementPtrInst *GEP =
960           dyn_cast<GetElementPtrInst>(U->getOperand(0))) {
961       // Ok, the GEP indices were covered by constant-offset and scaled-index
962       // addressing. Update the address state and move on to examining the base.
963       V = GEP;
964       goto redo_gep;
965     } else if (X86SelectAddress(U->getOperand(0), AM)) {
966       return true;
967     }
968 
969     // If we couldn't merge the gep value into this addr mode, revert back to
970     // our address and just match the value instead of completely failing.
971     AM = SavedAM;
972 
973     for (const Value *I : reverse(GEPs))
974       if (handleConstantAddresses(I, AM))
975         return true;
976 
977     return false;
978   unsupported_gep:
979     // Ok, the GEP indices weren't all covered.
980     break;
981   }
982   }
983 
984   return handleConstantAddresses(V, AM);
985 }
986 
987 /// X86SelectCallAddress - Attempt to fill in an address from the given value.
988 ///
X86SelectCallAddress(const Value * V,X86AddressMode & AM)989 bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
990   const User *U = nullptr;
991   unsigned Opcode = Instruction::UserOp1;
992   const Instruction *I = dyn_cast<Instruction>(V);
993   // Record if the value is defined in the same basic block.
994   //
995   // This information is crucial to know whether or not folding an
996   // operand is valid.
997   // Indeed, FastISel generates or reuses a virtual register for all
998   // operands of all instructions it selects. Obviously, the definition and
999   // its uses must use the same virtual register otherwise the produced
1000   // code is incorrect.
1001   // Before instruction selection, FunctionLoweringInfo::set sets the virtual
1002   // registers for values that are alive across basic blocks. This ensures
1003   // that the values are consistently set between across basic block, even
1004   // if different instruction selection mechanisms are used (e.g., a mix of
1005   // SDISel and FastISel).
1006   // For values local to a basic block, the instruction selection process
1007   // generates these virtual registers with whatever method is appropriate
1008   // for its needs. In particular, FastISel and SDISel do not share the way
1009   // local virtual registers are set.
1010   // Therefore, this is impossible (or at least unsafe) to share values
1011   // between basic blocks unless they use the same instruction selection
1012   // method, which is not guarantee for X86.
1013   // Moreover, things like hasOneUse could not be used accurately, if we
1014   // allow to reference values across basic blocks whereas they are not
1015   // alive across basic blocks initially.
1016   bool InMBB = true;
1017   if (I) {
1018     Opcode = I->getOpcode();
1019     U = I;
1020     InMBB = I->getParent() == FuncInfo.MBB->getBasicBlock();
1021   } else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
1022     Opcode = C->getOpcode();
1023     U = C;
1024   }
1025 
1026   switch (Opcode) {
1027   default: break;
1028   case Instruction::BitCast:
1029     // Look past bitcasts if its operand is in the same BB.
1030     if (InMBB)
1031       return X86SelectCallAddress(U->getOperand(0), AM);
1032     break;
1033 
1034   case Instruction::IntToPtr:
1035     // Look past no-op inttoptrs if its operand is in the same BB.
1036     if (InMBB &&
1037         TLI.getValueType(DL, U->getOperand(0)->getType()) ==
1038             TLI.getPointerTy(DL))
1039       return X86SelectCallAddress(U->getOperand(0), AM);
1040     break;
1041 
1042   case Instruction::PtrToInt:
1043     // Look past no-op ptrtoints if its operand is in the same BB.
1044     if (InMBB && TLI.getValueType(DL, U->getType()) == TLI.getPointerTy(DL))
1045       return X86SelectCallAddress(U->getOperand(0), AM);
1046     break;
1047   }
1048 
1049   // Handle constant address.
1050   if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
1051     // Can't handle alternate code models yet.
1052     if (TM.getCodeModel() != CodeModel::Small)
1053       return false;
1054 
1055     // RIP-relative addresses can't have additional register operands.
1056     if (Subtarget->isPICStyleRIPRel() &&
1057         (AM.Base.Reg != 0 || AM.IndexReg != 0))
1058       return false;
1059 
1060     // Can't handle TLS.
1061     if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
1062       if (GVar->isThreadLocal())
1063         return false;
1064 
1065     // Okay, we've committed to selecting this global. Set up the basic address.
1066     AM.GV = GV;
1067 
1068     // Return a direct reference to the global. Fastisel can handle calls to
1069     // functions that require loads, such as dllimport and nonlazybind
1070     // functions.
1071     if (Subtarget->isPICStyleRIPRel()) {
1072       // Use rip-relative addressing if we can.  Above we verified that the
1073       // base and index registers are unused.
1074       assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
1075       AM.Base.Reg = X86::RIP;
1076     } else {
1077       AM.GVOpFlags = Subtarget->classifyLocalReference(nullptr);
1078     }
1079 
1080     return true;
1081   }
1082 
1083   // If all else fails, try to materialize the value in a register.
1084   if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
1085     if (AM.Base.Reg == 0) {
1086       AM.Base.Reg = getRegForValue(V);
1087       return AM.Base.Reg != 0;
1088     }
1089     if (AM.IndexReg == 0) {
1090       assert(AM.Scale == 1 && "Scale with no index!");
1091       AM.IndexReg = getRegForValue(V);
1092       return AM.IndexReg != 0;
1093     }
1094   }
1095 
1096   return false;
1097 }
1098 
1099 
1100 /// X86SelectStore - Select and emit code to implement store instructions.
X86SelectStore(const Instruction * I)1101 bool X86FastISel::X86SelectStore(const Instruction *I) {
1102   // Atomic stores need special handling.
1103   const StoreInst *S = cast<StoreInst>(I);
1104 
1105   if (S->isAtomic())
1106     return false;
1107 
1108   const Value *PtrV = I->getOperand(1);
1109   if (TLI.supportSwiftError()) {
1110     // Swifterror values can come from either a function parameter with
1111     // swifterror attribute or an alloca with swifterror attribute.
1112     if (const Argument *Arg = dyn_cast<Argument>(PtrV)) {
1113       if (Arg->hasSwiftErrorAttr())
1114         return false;
1115     }
1116 
1117     if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(PtrV)) {
1118       if (Alloca->isSwiftError())
1119         return false;
1120     }
1121   }
1122 
1123   const Value *Val = S->getValueOperand();
1124   const Value *Ptr = S->getPointerOperand();
1125 
1126   MVT VT;
1127   if (!isTypeLegal(Val->getType(), VT, /*AllowI1=*/true))
1128     return false;
1129 
1130   Align Alignment = S->getAlign();
1131   Align ABIAlignment = DL.getABITypeAlign(Val->getType());
1132   bool Aligned = Alignment >= ABIAlignment;
1133 
1134   X86AddressMode AM;
1135   if (!X86SelectAddress(Ptr, AM))
1136     return false;
1137 
1138   return X86FastEmitStore(VT, Val, AM, createMachineMemOperandFor(I), Aligned);
1139 }
1140 
1141 /// X86SelectRet - Select and emit code to implement ret instructions.
X86SelectRet(const Instruction * I)1142 bool X86FastISel::X86SelectRet(const Instruction *I) {
1143   const ReturnInst *Ret = cast<ReturnInst>(I);
1144   const Function &F = *I->getParent()->getParent();
1145   const X86MachineFunctionInfo *X86MFInfo =
1146       FuncInfo.MF->getInfo<X86MachineFunctionInfo>();
1147 
1148   if (!FuncInfo.CanLowerReturn)
1149     return false;
1150 
1151   if (TLI.supportSwiftError() &&
1152       F.getAttributes().hasAttrSomewhere(Attribute::SwiftError))
1153     return false;
1154 
1155   if (TLI.supportSplitCSR(FuncInfo.MF))
1156     return false;
1157 
1158   CallingConv::ID CC = F.getCallingConv();
1159   if (CC != CallingConv::C &&
1160       CC != CallingConv::Fast &&
1161       CC != CallingConv::Tail &&
1162       CC != CallingConv::X86_FastCall &&
1163       CC != CallingConv::X86_StdCall &&
1164       CC != CallingConv::X86_ThisCall &&
1165       CC != CallingConv::X86_64_SysV &&
1166       CC != CallingConv::Win64)
1167     return false;
1168 
1169   // Don't handle popping bytes if they don't fit the ret's immediate.
1170   if (!isUInt<16>(X86MFInfo->getBytesToPopOnReturn()))
1171     return false;
1172 
1173   // fastcc with -tailcallopt is intended to provide a guaranteed
1174   // tail call optimization. Fastisel doesn't know how to do that.
1175   if ((CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt) ||
1176       CC == CallingConv::Tail)
1177     return false;
1178 
1179   // Let SDISel handle vararg functions.
1180   if (F.isVarArg())
1181     return false;
1182 
1183   // Build a list of return value registers.
1184   SmallVector<unsigned, 4> RetRegs;
1185 
1186   if (Ret->getNumOperands() > 0) {
1187     SmallVector<ISD::OutputArg, 4> Outs;
1188     GetReturnInfo(CC, F.getReturnType(), F.getAttributes(), Outs, TLI, DL);
1189 
1190     // Analyze operands of the call, assigning locations to each operand.
1191     SmallVector<CCValAssign, 16> ValLocs;
1192     CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, I->getContext());
1193     CCInfo.AnalyzeReturn(Outs, RetCC_X86);
1194 
1195     const Value *RV = Ret->getOperand(0);
1196     Register Reg = getRegForValue(RV);
1197     if (Reg == 0)
1198       return false;
1199 
1200     // Only handle a single return value for now.
1201     if (ValLocs.size() != 1)
1202       return false;
1203 
1204     CCValAssign &VA = ValLocs[0];
1205 
1206     // Don't bother handling odd stuff for now.
1207     if (VA.getLocInfo() != CCValAssign::Full)
1208       return false;
1209     // Only handle register returns for now.
1210     if (!VA.isRegLoc())
1211       return false;
1212 
1213     // The calling-convention tables for x87 returns don't tell
1214     // the whole story.
1215     if (VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1)
1216       return false;
1217 
1218     unsigned SrcReg = Reg + VA.getValNo();
1219     EVT SrcVT = TLI.getValueType(DL, RV->getType());
1220     EVT DstVT = VA.getValVT();
1221     // Special handling for extended integers.
1222     if (SrcVT != DstVT) {
1223       if (SrcVT != MVT::i1 && SrcVT != MVT::i8 && SrcVT != MVT::i16)
1224         return false;
1225 
1226       if (!Outs[0].Flags.isZExt() && !Outs[0].Flags.isSExt())
1227         return false;
1228 
1229       assert(DstVT == MVT::i32 && "X86 should always ext to i32");
1230 
1231       if (SrcVT == MVT::i1) {
1232         if (Outs[0].Flags.isSExt())
1233           return false;
1234         // TODO
1235         SrcReg = fastEmitZExtFromI1(MVT::i8, SrcReg, /*Op0IsKill=*/false);
1236         SrcVT = MVT::i8;
1237       }
1238       unsigned Op = Outs[0].Flags.isZExt() ? ISD::ZERO_EXTEND :
1239                                              ISD::SIGN_EXTEND;
1240       // TODO
1241       SrcReg = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Op, SrcReg,
1242                           /*Op0IsKill=*/false);
1243     }
1244 
1245     // Make the copy.
1246     Register DstReg = VA.getLocReg();
1247     const TargetRegisterClass *SrcRC = MRI.getRegClass(SrcReg);
1248     // Avoid a cross-class copy. This is very unlikely.
1249     if (!SrcRC->contains(DstReg))
1250       return false;
1251     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1252             TII.get(TargetOpcode::COPY), DstReg).addReg(SrcReg);
1253 
1254     // Add register to return instruction.
1255     RetRegs.push_back(VA.getLocReg());
1256   }
1257 
1258   // Swift calling convention does not require we copy the sret argument
1259   // into %rax/%eax for the return, and SRetReturnReg is not set for Swift.
1260 
1261   // All x86 ABIs require that for returning structs by value we copy
1262   // the sret argument into %rax/%eax (depending on ABI) for the return.
1263   // We saved the argument into a virtual register in the entry block,
1264   // so now we copy the value out and into %rax/%eax.
1265   if (F.hasStructRetAttr() && CC != CallingConv::Swift) {
1266     Register Reg = X86MFInfo->getSRetReturnReg();
1267     assert(Reg &&
1268            "SRetReturnReg should have been set in LowerFormalArguments()!");
1269     unsigned RetReg = Subtarget->isTarget64BitLP64() ? X86::RAX : X86::EAX;
1270     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1271             TII.get(TargetOpcode::COPY), RetReg).addReg(Reg);
1272     RetRegs.push_back(RetReg);
1273   }
1274 
1275   // Now emit the RET.
1276   MachineInstrBuilder MIB;
1277   if (X86MFInfo->getBytesToPopOnReturn()) {
1278     MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1279                   TII.get(Subtarget->is64Bit() ? X86::RETIQ : X86::RETIL))
1280               .addImm(X86MFInfo->getBytesToPopOnReturn());
1281   } else {
1282     MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1283                   TII.get(Subtarget->is64Bit() ? X86::RETQ : X86::RETL));
1284   }
1285   for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
1286     MIB.addReg(RetRegs[i], RegState::Implicit);
1287   return true;
1288 }
1289 
1290 /// X86SelectLoad - Select and emit code to implement load instructions.
1291 ///
X86SelectLoad(const Instruction * I)1292 bool X86FastISel::X86SelectLoad(const Instruction *I) {
1293   const LoadInst *LI = cast<LoadInst>(I);
1294 
1295   // Atomic loads need special handling.
1296   if (LI->isAtomic())
1297     return false;
1298 
1299   const Value *SV = I->getOperand(0);
1300   if (TLI.supportSwiftError()) {
1301     // Swifterror values can come from either a function parameter with
1302     // swifterror attribute or an alloca with swifterror attribute.
1303     if (const Argument *Arg = dyn_cast<Argument>(SV)) {
1304       if (Arg->hasSwiftErrorAttr())
1305         return false;
1306     }
1307 
1308     if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(SV)) {
1309       if (Alloca->isSwiftError())
1310         return false;
1311     }
1312   }
1313 
1314   MVT VT;
1315   if (!isTypeLegal(LI->getType(), VT, /*AllowI1=*/true))
1316     return false;
1317 
1318   const Value *Ptr = LI->getPointerOperand();
1319 
1320   X86AddressMode AM;
1321   if (!X86SelectAddress(Ptr, AM))
1322     return false;
1323 
1324   unsigned ResultReg = 0;
1325   if (!X86FastEmitLoad(VT, AM, createMachineMemOperandFor(LI), ResultReg,
1326                        LI->getAlign().value()))
1327     return false;
1328 
1329   updateValueMap(I, ResultReg);
1330   return true;
1331 }
1332 
X86ChooseCmpOpcode(EVT VT,const X86Subtarget * Subtarget)1333 static unsigned X86ChooseCmpOpcode(EVT VT, const X86Subtarget *Subtarget) {
1334   bool HasAVX512 = Subtarget->hasAVX512();
1335   bool HasAVX = Subtarget->hasAVX();
1336   bool X86ScalarSSEf32 = Subtarget->hasSSE1();
1337   bool X86ScalarSSEf64 = Subtarget->hasSSE2();
1338 
1339   switch (VT.getSimpleVT().SimpleTy) {
1340   default:       return 0;
1341   case MVT::i8:  return X86::CMP8rr;
1342   case MVT::i16: return X86::CMP16rr;
1343   case MVT::i32: return X86::CMP32rr;
1344   case MVT::i64: return X86::CMP64rr;
1345   case MVT::f32:
1346     return X86ScalarSSEf32
1347                ? (HasAVX512 ? X86::VUCOMISSZrr
1348                             : HasAVX ? X86::VUCOMISSrr : X86::UCOMISSrr)
1349                : 0;
1350   case MVT::f64:
1351     return X86ScalarSSEf64
1352                ? (HasAVX512 ? X86::VUCOMISDZrr
1353                             : HasAVX ? X86::VUCOMISDrr : X86::UCOMISDrr)
1354                : 0;
1355   }
1356 }
1357 
1358 /// If we have a comparison with RHS as the RHS  of the comparison, return an
1359 /// opcode that works for the compare (e.g. CMP32ri) otherwise return 0.
X86ChooseCmpImmediateOpcode(EVT VT,const ConstantInt * RHSC)1360 static unsigned X86ChooseCmpImmediateOpcode(EVT VT, const ConstantInt *RHSC) {
1361   int64_t Val = RHSC->getSExtValue();
1362   switch (VT.getSimpleVT().SimpleTy) {
1363   // Otherwise, we can't fold the immediate into this comparison.
1364   default:
1365     return 0;
1366   case MVT::i8:
1367     return X86::CMP8ri;
1368   case MVT::i16:
1369     if (isInt<8>(Val))
1370       return X86::CMP16ri8;
1371     return X86::CMP16ri;
1372   case MVT::i32:
1373     if (isInt<8>(Val))
1374       return X86::CMP32ri8;
1375     return X86::CMP32ri;
1376   case MVT::i64:
1377     if (isInt<8>(Val))
1378       return X86::CMP64ri8;
1379     // 64-bit comparisons are only valid if the immediate fits in a 32-bit sext
1380     // field.
1381     if (isInt<32>(Val))
1382       return X86::CMP64ri32;
1383     return 0;
1384   }
1385 }
1386 
X86FastEmitCompare(const Value * Op0,const Value * Op1,EVT VT,const DebugLoc & CurDbgLoc)1387 bool X86FastISel::X86FastEmitCompare(const Value *Op0, const Value *Op1, EVT VT,
1388                                      const DebugLoc &CurDbgLoc) {
1389   Register Op0Reg = getRegForValue(Op0);
1390   if (Op0Reg == 0) return false;
1391 
1392   // Handle 'null' like i32/i64 0.
1393   if (isa<ConstantPointerNull>(Op1))
1394     Op1 = Constant::getNullValue(DL.getIntPtrType(Op0->getContext()));
1395 
1396   // We have two options: compare with register or immediate.  If the RHS of
1397   // the compare is an immediate that we can fold into this compare, use
1398   // CMPri, otherwise use CMPrr.
1399   if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
1400     if (unsigned CompareImmOpc = X86ChooseCmpImmediateOpcode(VT, Op1C)) {
1401       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareImmOpc))
1402         .addReg(Op0Reg)
1403         .addImm(Op1C->getSExtValue());
1404       return true;
1405     }
1406   }
1407 
1408   unsigned CompareOpc = X86ChooseCmpOpcode(VT, Subtarget);
1409   if (CompareOpc == 0) return false;
1410 
1411   Register Op1Reg = getRegForValue(Op1);
1412   if (Op1Reg == 0) return false;
1413   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareOpc))
1414     .addReg(Op0Reg)
1415     .addReg(Op1Reg);
1416 
1417   return true;
1418 }
1419 
X86SelectCmp(const Instruction * I)1420 bool X86FastISel::X86SelectCmp(const Instruction *I) {
1421   const CmpInst *CI = cast<CmpInst>(I);
1422 
1423   MVT VT;
1424   if (!isTypeLegal(I->getOperand(0)->getType(), VT))
1425     return false;
1426 
1427   // Try to optimize or fold the cmp.
1428   CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
1429   unsigned ResultReg = 0;
1430   switch (Predicate) {
1431   default: break;
1432   case CmpInst::FCMP_FALSE: {
1433     ResultReg = createResultReg(&X86::GR32RegClass);
1434     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV32r0),
1435             ResultReg);
1436     ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultReg,
1437                                            /*Op0IsKill=*/true, X86::sub_8bit);
1438     if (!ResultReg)
1439       return false;
1440     break;
1441   }
1442   case CmpInst::FCMP_TRUE: {
1443     ResultReg = createResultReg(&X86::GR8RegClass);
1444     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri),
1445             ResultReg).addImm(1);
1446     break;
1447   }
1448   }
1449 
1450   if (ResultReg) {
1451     updateValueMap(I, ResultReg);
1452     return true;
1453   }
1454 
1455   const Value *LHS = CI->getOperand(0);
1456   const Value *RHS = CI->getOperand(1);
1457 
1458   // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0.
1459   // We don't have to materialize a zero constant for this case and can just use
1460   // %x again on the RHS.
1461   if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
1462     const auto *RHSC = dyn_cast<ConstantFP>(RHS);
1463     if (RHSC && RHSC->isNullValue())
1464       RHS = LHS;
1465   }
1466 
1467   // FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction.
1468   static const uint16_t SETFOpcTable[2][3] = {
1469     { X86::COND_E,  X86::COND_NP, X86::AND8rr },
1470     { X86::COND_NE, X86::COND_P,  X86::OR8rr  }
1471   };
1472   const uint16_t *SETFOpc = nullptr;
1473   switch (Predicate) {
1474   default: break;
1475   case CmpInst::FCMP_OEQ: SETFOpc = &SETFOpcTable[0][0]; break;
1476   case CmpInst::FCMP_UNE: SETFOpc = &SETFOpcTable[1][0]; break;
1477   }
1478 
1479   ResultReg = createResultReg(&X86::GR8RegClass);
1480   if (SETFOpc) {
1481     if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc()))
1482       return false;
1483 
1484     Register FlagReg1 = createResultReg(&X86::GR8RegClass);
1485     Register FlagReg2 = createResultReg(&X86::GR8RegClass);
1486     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
1487             FlagReg1).addImm(SETFOpc[0]);
1488     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
1489             FlagReg2).addImm(SETFOpc[1]);
1490     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[2]),
1491             ResultReg).addReg(FlagReg1).addReg(FlagReg2);
1492     updateValueMap(I, ResultReg);
1493     return true;
1494   }
1495 
1496   X86::CondCode CC;
1497   bool SwapArgs;
1498   std::tie(CC, SwapArgs) = X86::getX86ConditionCode(Predicate);
1499   assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
1500 
1501   if (SwapArgs)
1502     std::swap(LHS, RHS);
1503 
1504   // Emit a compare of LHS/RHS.
1505   if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc()))
1506     return false;
1507 
1508   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
1509           ResultReg).addImm(CC);
1510   updateValueMap(I, ResultReg);
1511   return true;
1512 }
1513 
X86SelectZExt(const Instruction * I)1514 bool X86FastISel::X86SelectZExt(const Instruction *I) {
1515   EVT DstVT = TLI.getValueType(DL, I->getType());
1516   if (!TLI.isTypeLegal(DstVT))
1517     return false;
1518 
1519   Register ResultReg = getRegForValue(I->getOperand(0));
1520   if (ResultReg == 0)
1521     return false;
1522 
1523   // Handle zero-extension from i1 to i8, which is common.
1524   MVT SrcVT = TLI.getSimpleValueType(DL, I->getOperand(0)->getType());
1525   if (SrcVT == MVT::i1) {
1526     // Set the high bits to zero.
1527     ResultReg = fastEmitZExtFromI1(MVT::i8, ResultReg, /*TODO: Kill=*/false);
1528     SrcVT = MVT::i8;
1529 
1530     if (ResultReg == 0)
1531       return false;
1532   }
1533 
1534   if (DstVT == MVT::i64) {
1535     // Handle extension to 64-bits via sub-register shenanigans.
1536     unsigned MovInst;
1537 
1538     switch (SrcVT.SimpleTy) {
1539     case MVT::i8:  MovInst = X86::MOVZX32rr8;  break;
1540     case MVT::i16: MovInst = X86::MOVZX32rr16; break;
1541     case MVT::i32: MovInst = X86::MOV32rr;     break;
1542     default: llvm_unreachable("Unexpected zext to i64 source type");
1543     }
1544 
1545     Register Result32 = createResultReg(&X86::GR32RegClass);
1546     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(MovInst), Result32)
1547       .addReg(ResultReg);
1548 
1549     ResultReg = createResultReg(&X86::GR64RegClass);
1550     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG),
1551             ResultReg)
1552       .addImm(0).addReg(Result32).addImm(X86::sub_32bit);
1553   } else if (DstVT == MVT::i16) {
1554     // i8->i16 doesn't exist in the autogenerated isel table. Need to zero
1555     // extend to 32-bits and then extract down to 16-bits.
1556     Register Result32 = createResultReg(&X86::GR32RegClass);
1557     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOVZX32rr8),
1558             Result32).addReg(ResultReg);
1559 
1560     ResultReg = fastEmitInst_extractsubreg(MVT::i16, Result32,
1561                                            /*Op0IsKill=*/true, X86::sub_16bit);
1562   } else if (DstVT != MVT::i8) {
1563     ResultReg = fastEmit_r(MVT::i8, DstVT.getSimpleVT(), ISD::ZERO_EXTEND,
1564                            ResultReg, /*Op0IsKill=*/true);
1565     if (ResultReg == 0)
1566       return false;
1567   }
1568 
1569   updateValueMap(I, ResultReg);
1570   return true;
1571 }
1572 
X86SelectSExt(const Instruction * I)1573 bool X86FastISel::X86SelectSExt(const Instruction *I) {
1574   EVT DstVT = TLI.getValueType(DL, I->getType());
1575   if (!TLI.isTypeLegal(DstVT))
1576     return false;
1577 
1578   Register ResultReg = getRegForValue(I->getOperand(0));
1579   if (ResultReg == 0)
1580     return false;
1581 
1582   // Handle sign-extension from i1 to i8.
1583   MVT SrcVT = TLI.getSimpleValueType(DL, I->getOperand(0)->getType());
1584   if (SrcVT == MVT::i1) {
1585     // Set the high bits to zero.
1586     Register ZExtReg = fastEmitZExtFromI1(MVT::i8, ResultReg,
1587                                           /*TODO: Kill=*/false);
1588     if (ZExtReg == 0)
1589       return false;
1590 
1591     // Negate the result to make an 8-bit sign extended value.
1592     ResultReg = createResultReg(&X86::GR8RegClass);
1593     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::NEG8r),
1594             ResultReg).addReg(ZExtReg);
1595 
1596     SrcVT = MVT::i8;
1597   }
1598 
1599   if (DstVT == MVT::i16) {
1600     // i8->i16 doesn't exist in the autogenerated isel table. Need to sign
1601     // extend to 32-bits and then extract down to 16-bits.
1602     Register Result32 = createResultReg(&X86::GR32RegClass);
1603     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOVSX32rr8),
1604             Result32).addReg(ResultReg);
1605 
1606     ResultReg = fastEmitInst_extractsubreg(MVT::i16, Result32,
1607                                            /*Op0IsKill=*/true, X86::sub_16bit);
1608   } else if (DstVT != MVT::i8) {
1609     ResultReg = fastEmit_r(MVT::i8, DstVT.getSimpleVT(), ISD::SIGN_EXTEND,
1610                            ResultReg, /*Op0IsKill=*/true);
1611     if (ResultReg == 0)
1612       return false;
1613   }
1614 
1615   updateValueMap(I, ResultReg);
1616   return true;
1617 }
1618 
X86SelectBranch(const Instruction * I)1619 bool X86FastISel::X86SelectBranch(const Instruction *I) {
1620   // Unconditional branches are selected by tablegen-generated code.
1621   // Handle a conditional branch.
1622   const BranchInst *BI = cast<BranchInst>(I);
1623   MachineBasicBlock *TrueMBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
1624   MachineBasicBlock *FalseMBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
1625 
1626   // Fold the common case of a conditional branch with a comparison
1627   // in the same block (values defined on other blocks may not have
1628   // initialized registers).
1629   X86::CondCode CC;
1630   if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
1631     if (CI->hasOneUse() && CI->getParent() == I->getParent()) {
1632       EVT VT = TLI.getValueType(DL, CI->getOperand(0)->getType());
1633 
1634       // Try to optimize or fold the cmp.
1635       CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
1636       switch (Predicate) {
1637       default: break;
1638       case CmpInst::FCMP_FALSE: fastEmitBranch(FalseMBB, DbgLoc); return true;
1639       case CmpInst::FCMP_TRUE:  fastEmitBranch(TrueMBB, DbgLoc); return true;
1640       }
1641 
1642       const Value *CmpLHS = CI->getOperand(0);
1643       const Value *CmpRHS = CI->getOperand(1);
1644 
1645       // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x,
1646       // 0.0.
1647       // We don't have to materialize a zero constant for this case and can just
1648       // use %x again on the RHS.
1649       if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
1650         const auto *CmpRHSC = dyn_cast<ConstantFP>(CmpRHS);
1651         if (CmpRHSC && CmpRHSC->isNullValue())
1652           CmpRHS = CmpLHS;
1653       }
1654 
1655       // Try to take advantage of fallthrough opportunities.
1656       if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
1657         std::swap(TrueMBB, FalseMBB);
1658         Predicate = CmpInst::getInversePredicate(Predicate);
1659       }
1660 
1661       // FCMP_OEQ and FCMP_UNE cannot be expressed with a single flag/condition
1662       // code check. Instead two branch instructions are required to check all
1663       // the flags. First we change the predicate to a supported condition code,
1664       // which will be the first branch. Later one we will emit the second
1665       // branch.
1666       bool NeedExtraBranch = false;
1667       switch (Predicate) {
1668       default: break;
1669       case CmpInst::FCMP_OEQ:
1670         std::swap(TrueMBB, FalseMBB);
1671         LLVM_FALLTHROUGH;
1672       case CmpInst::FCMP_UNE:
1673         NeedExtraBranch = true;
1674         Predicate = CmpInst::FCMP_ONE;
1675         break;
1676       }
1677 
1678       bool SwapArgs;
1679       std::tie(CC, SwapArgs) = X86::getX86ConditionCode(Predicate);
1680       assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
1681 
1682       if (SwapArgs)
1683         std::swap(CmpLHS, CmpRHS);
1684 
1685       // Emit a compare of the LHS and RHS, setting the flags.
1686       if (!X86FastEmitCompare(CmpLHS, CmpRHS, VT, CI->getDebugLoc()))
1687         return false;
1688 
1689       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JCC_1))
1690         .addMBB(TrueMBB).addImm(CC);
1691 
1692       // X86 requires a second branch to handle UNE (and OEQ, which is mapped
1693       // to UNE above).
1694       if (NeedExtraBranch) {
1695         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JCC_1))
1696           .addMBB(TrueMBB).addImm(X86::COND_P);
1697       }
1698 
1699       finishCondBranch(BI->getParent(), TrueMBB, FalseMBB);
1700       return true;
1701     }
1702   } else if (TruncInst *TI = dyn_cast<TruncInst>(BI->getCondition())) {
1703     // Handle things like "%cond = trunc i32 %X to i1 / br i1 %cond", which
1704     // typically happen for _Bool and C++ bools.
1705     MVT SourceVT;
1706     if (TI->hasOneUse() && TI->getParent() == I->getParent() &&
1707         isTypeLegal(TI->getOperand(0)->getType(), SourceVT)) {
1708       unsigned TestOpc = 0;
1709       switch (SourceVT.SimpleTy) {
1710       default: break;
1711       case MVT::i8:  TestOpc = X86::TEST8ri; break;
1712       case MVT::i16: TestOpc = X86::TEST16ri; break;
1713       case MVT::i32: TestOpc = X86::TEST32ri; break;
1714       case MVT::i64: TestOpc = X86::TEST64ri32; break;
1715       }
1716       if (TestOpc) {
1717         Register OpReg = getRegForValue(TI->getOperand(0));
1718         if (OpReg == 0) return false;
1719 
1720         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TestOpc))
1721           .addReg(OpReg).addImm(1);
1722 
1723         unsigned JmpCond = X86::COND_NE;
1724         if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
1725           std::swap(TrueMBB, FalseMBB);
1726           JmpCond = X86::COND_E;
1727         }
1728 
1729         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JCC_1))
1730           .addMBB(TrueMBB).addImm(JmpCond);
1731 
1732         finishCondBranch(BI->getParent(), TrueMBB, FalseMBB);
1733         return true;
1734       }
1735     }
1736   } else if (foldX86XALUIntrinsic(CC, BI, BI->getCondition())) {
1737     // Fake request the condition, otherwise the intrinsic might be completely
1738     // optimized away.
1739     Register TmpReg = getRegForValue(BI->getCondition());
1740     if (TmpReg == 0)
1741       return false;
1742 
1743     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JCC_1))
1744       .addMBB(TrueMBB).addImm(CC);
1745     finishCondBranch(BI->getParent(), TrueMBB, FalseMBB);
1746     return true;
1747   }
1748 
1749   // Otherwise do a clumsy setcc and re-test it.
1750   // Note that i1 essentially gets ANY_EXTEND'ed to i8 where it isn't used
1751   // in an explicit cast, so make sure to handle that correctly.
1752   Register OpReg = getRegForValue(BI->getCondition());
1753   if (OpReg == 0) return false;
1754 
1755   // In case OpReg is a K register, COPY to a GPR
1756   if (MRI.getRegClass(OpReg) == &X86::VK1RegClass) {
1757     unsigned KOpReg = OpReg;
1758     OpReg = createResultReg(&X86::GR32RegClass);
1759     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1760             TII.get(TargetOpcode::COPY), OpReg)
1761         .addReg(KOpReg);
1762     OpReg = fastEmitInst_extractsubreg(MVT::i8, OpReg, /*Op0IsKill=*/true,
1763                                        X86::sub_8bit);
1764   }
1765   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
1766       .addReg(OpReg)
1767       .addImm(1);
1768   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JCC_1))
1769     .addMBB(TrueMBB).addImm(X86::COND_NE);
1770   finishCondBranch(BI->getParent(), TrueMBB, FalseMBB);
1771   return true;
1772 }
1773 
X86SelectShift(const Instruction * I)1774 bool X86FastISel::X86SelectShift(const Instruction *I) {
1775   unsigned CReg = 0, OpReg = 0;
1776   const TargetRegisterClass *RC = nullptr;
1777   if (I->getType()->isIntegerTy(8)) {
1778     CReg = X86::CL;
1779     RC = &X86::GR8RegClass;
1780     switch (I->getOpcode()) {
1781     case Instruction::LShr: OpReg = X86::SHR8rCL; break;
1782     case Instruction::AShr: OpReg = X86::SAR8rCL; break;
1783     case Instruction::Shl:  OpReg = X86::SHL8rCL; break;
1784     default: return false;
1785     }
1786   } else if (I->getType()->isIntegerTy(16)) {
1787     CReg = X86::CX;
1788     RC = &X86::GR16RegClass;
1789     switch (I->getOpcode()) {
1790     default: llvm_unreachable("Unexpected shift opcode");
1791     case Instruction::LShr: OpReg = X86::SHR16rCL; break;
1792     case Instruction::AShr: OpReg = X86::SAR16rCL; break;
1793     case Instruction::Shl:  OpReg = X86::SHL16rCL; break;
1794     }
1795   } else if (I->getType()->isIntegerTy(32)) {
1796     CReg = X86::ECX;
1797     RC = &X86::GR32RegClass;
1798     switch (I->getOpcode()) {
1799     default: llvm_unreachable("Unexpected shift opcode");
1800     case Instruction::LShr: OpReg = X86::SHR32rCL; break;
1801     case Instruction::AShr: OpReg = X86::SAR32rCL; break;
1802     case Instruction::Shl:  OpReg = X86::SHL32rCL; break;
1803     }
1804   } else if (I->getType()->isIntegerTy(64)) {
1805     CReg = X86::RCX;
1806     RC = &X86::GR64RegClass;
1807     switch (I->getOpcode()) {
1808     default: llvm_unreachable("Unexpected shift opcode");
1809     case Instruction::LShr: OpReg = X86::SHR64rCL; break;
1810     case Instruction::AShr: OpReg = X86::SAR64rCL; break;
1811     case Instruction::Shl:  OpReg = X86::SHL64rCL; break;
1812     }
1813   } else {
1814     return false;
1815   }
1816 
1817   MVT VT;
1818   if (!isTypeLegal(I->getType(), VT))
1819     return false;
1820 
1821   Register Op0Reg = getRegForValue(I->getOperand(0));
1822   if (Op0Reg == 0) return false;
1823 
1824   Register Op1Reg = getRegForValue(I->getOperand(1));
1825   if (Op1Reg == 0) return false;
1826   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY),
1827           CReg).addReg(Op1Reg);
1828 
1829   // The shift instruction uses X86::CL. If we defined a super-register
1830   // of X86::CL, emit a subreg KILL to precisely describe what we're doing here.
1831   if (CReg != X86::CL)
1832     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1833             TII.get(TargetOpcode::KILL), X86::CL)
1834       .addReg(CReg, RegState::Kill);
1835 
1836   Register ResultReg = createResultReg(RC);
1837   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpReg), ResultReg)
1838     .addReg(Op0Reg);
1839   updateValueMap(I, ResultReg);
1840   return true;
1841 }
1842 
X86SelectDivRem(const Instruction * I)1843 bool X86FastISel::X86SelectDivRem(const Instruction *I) {
1844   const static unsigned NumTypes = 4; // i8, i16, i32, i64
1845   const static unsigned NumOps   = 4; // SDiv, SRem, UDiv, URem
1846   const static bool S = true;  // IsSigned
1847   const static bool U = false; // !IsSigned
1848   const static unsigned Copy = TargetOpcode::COPY;
1849   // For the X86 DIV/IDIV instruction, in most cases the dividend
1850   // (numerator) must be in a specific register pair highreg:lowreg,
1851   // producing the quotient in lowreg and the remainder in highreg.
1852   // For most data types, to set up the instruction, the dividend is
1853   // copied into lowreg, and lowreg is sign-extended or zero-extended
1854   // into highreg.  The exception is i8, where the dividend is defined
1855   // as a single register rather than a register pair, and we
1856   // therefore directly sign-extend or zero-extend the dividend into
1857   // lowreg, instead of copying, and ignore the highreg.
1858   const static struct DivRemEntry {
1859     // The following portion depends only on the data type.
1860     const TargetRegisterClass *RC;
1861     unsigned LowInReg;  // low part of the register pair
1862     unsigned HighInReg; // high part of the register pair
1863     // The following portion depends on both the data type and the operation.
1864     struct DivRemResult {
1865     unsigned OpDivRem;        // The specific DIV/IDIV opcode to use.
1866     unsigned OpSignExtend;    // Opcode for sign-extending lowreg into
1867                               // highreg, or copying a zero into highreg.
1868     unsigned OpCopy;          // Opcode for copying dividend into lowreg, or
1869                               // zero/sign-extending into lowreg for i8.
1870     unsigned DivRemResultReg; // Register containing the desired result.
1871     bool IsOpSigned;          // Whether to use signed or unsigned form.
1872     } ResultTable[NumOps];
1873   } OpTable[NumTypes] = {
1874     { &X86::GR8RegClass,  X86::AX,  0, {
1875         { X86::IDIV8r,  0,            X86::MOVSX16rr8, X86::AL,  S }, // SDiv
1876         { X86::IDIV8r,  0,            X86::MOVSX16rr8, X86::AH,  S }, // SRem
1877         { X86::DIV8r,   0,            X86::MOVZX16rr8, X86::AL,  U }, // UDiv
1878         { X86::DIV8r,   0,            X86::MOVZX16rr8, X86::AH,  U }, // URem
1879       }
1880     }, // i8
1881     { &X86::GR16RegClass, X86::AX,  X86::DX, {
1882         { X86::IDIV16r, X86::CWD,     Copy,            X86::AX,  S }, // SDiv
1883         { X86::IDIV16r, X86::CWD,     Copy,            X86::DX,  S }, // SRem
1884         { X86::DIV16r,  X86::MOV32r0, Copy,            X86::AX,  U }, // UDiv
1885         { X86::DIV16r,  X86::MOV32r0, Copy,            X86::DX,  U }, // URem
1886       }
1887     }, // i16
1888     { &X86::GR32RegClass, X86::EAX, X86::EDX, {
1889         { X86::IDIV32r, X86::CDQ,     Copy,            X86::EAX, S }, // SDiv
1890         { X86::IDIV32r, X86::CDQ,     Copy,            X86::EDX, S }, // SRem
1891         { X86::DIV32r,  X86::MOV32r0, Copy,            X86::EAX, U }, // UDiv
1892         { X86::DIV32r,  X86::MOV32r0, Copy,            X86::EDX, U }, // URem
1893       }
1894     }, // i32
1895     { &X86::GR64RegClass, X86::RAX, X86::RDX, {
1896         { X86::IDIV64r, X86::CQO,     Copy,            X86::RAX, S }, // SDiv
1897         { X86::IDIV64r, X86::CQO,     Copy,            X86::RDX, S }, // SRem
1898         { X86::DIV64r,  X86::MOV32r0, Copy,            X86::RAX, U }, // UDiv
1899         { X86::DIV64r,  X86::MOV32r0, Copy,            X86::RDX, U }, // URem
1900       }
1901     }, // i64
1902   };
1903 
1904   MVT VT;
1905   if (!isTypeLegal(I->getType(), VT))
1906     return false;
1907 
1908   unsigned TypeIndex, OpIndex;
1909   switch (VT.SimpleTy) {
1910   default: return false;
1911   case MVT::i8:  TypeIndex = 0; break;
1912   case MVT::i16: TypeIndex = 1; break;
1913   case MVT::i32: TypeIndex = 2; break;
1914   case MVT::i64: TypeIndex = 3;
1915     if (!Subtarget->is64Bit())
1916       return false;
1917     break;
1918   }
1919 
1920   switch (I->getOpcode()) {
1921   default: llvm_unreachable("Unexpected div/rem opcode");
1922   case Instruction::SDiv: OpIndex = 0; break;
1923   case Instruction::SRem: OpIndex = 1; break;
1924   case Instruction::UDiv: OpIndex = 2; break;
1925   case Instruction::URem: OpIndex = 3; break;
1926   }
1927 
1928   const DivRemEntry &TypeEntry = OpTable[TypeIndex];
1929   const DivRemEntry::DivRemResult &OpEntry = TypeEntry.ResultTable[OpIndex];
1930   Register Op0Reg = getRegForValue(I->getOperand(0));
1931   if (Op0Reg == 0)
1932     return false;
1933   Register Op1Reg = getRegForValue(I->getOperand(1));
1934   if (Op1Reg == 0)
1935     return false;
1936 
1937   // Move op0 into low-order input register.
1938   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1939           TII.get(OpEntry.OpCopy), TypeEntry.LowInReg).addReg(Op0Reg);
1940   // Zero-extend or sign-extend into high-order input register.
1941   if (OpEntry.OpSignExtend) {
1942     if (OpEntry.IsOpSigned)
1943       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1944               TII.get(OpEntry.OpSignExtend));
1945     else {
1946       Register Zero32 = createResultReg(&X86::GR32RegClass);
1947       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1948               TII.get(X86::MOV32r0), Zero32);
1949 
1950       // Copy the zero into the appropriate sub/super/identical physical
1951       // register. Unfortunately the operations needed are not uniform enough
1952       // to fit neatly into the table above.
1953       if (VT == MVT::i16) {
1954         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1955                 TII.get(Copy), TypeEntry.HighInReg)
1956           .addReg(Zero32, 0, X86::sub_16bit);
1957       } else if (VT == MVT::i32) {
1958         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1959                 TII.get(Copy), TypeEntry.HighInReg)
1960             .addReg(Zero32);
1961       } else if (VT == MVT::i64) {
1962         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1963                 TII.get(TargetOpcode::SUBREG_TO_REG), TypeEntry.HighInReg)
1964             .addImm(0).addReg(Zero32).addImm(X86::sub_32bit);
1965       }
1966     }
1967   }
1968   // Generate the DIV/IDIV instruction.
1969   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1970           TII.get(OpEntry.OpDivRem)).addReg(Op1Reg);
1971   // For i8 remainder, we can't reference ah directly, as we'll end
1972   // up with bogus copies like %r9b = COPY %ah. Reference ax
1973   // instead to prevent ah references in a rex instruction.
1974   //
1975   // The current assumption of the fast register allocator is that isel
1976   // won't generate explicit references to the GR8_NOREX registers. If
1977   // the allocator and/or the backend get enhanced to be more robust in
1978   // that regard, this can be, and should be, removed.
1979   unsigned ResultReg = 0;
1980   if ((I->getOpcode() == Instruction::SRem ||
1981        I->getOpcode() == Instruction::URem) &&
1982       OpEntry.DivRemResultReg == X86::AH && Subtarget->is64Bit()) {
1983     Register SourceSuperReg = createResultReg(&X86::GR16RegClass);
1984     Register ResultSuperReg = createResultReg(&X86::GR16RegClass);
1985     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
1986             TII.get(Copy), SourceSuperReg).addReg(X86::AX);
1987 
1988     // Shift AX right by 8 bits instead of using AH.
1989     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SHR16ri),
1990             ResultSuperReg).addReg(SourceSuperReg).addImm(8);
1991 
1992     // Now reference the 8-bit subreg of the result.
1993     ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultSuperReg,
1994                                            /*Op0IsKill=*/true, X86::sub_8bit);
1995   }
1996   // Copy the result out of the physreg if we haven't already.
1997   if (!ResultReg) {
1998     ResultReg = createResultReg(TypeEntry.RC);
1999     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), ResultReg)
2000         .addReg(OpEntry.DivRemResultReg);
2001   }
2002   updateValueMap(I, ResultReg);
2003 
2004   return true;
2005 }
2006 
2007 /// Emit a conditional move instruction (if the are supported) to lower
2008 /// the select.
X86FastEmitCMoveSelect(MVT RetVT,const Instruction * I)2009 bool X86FastISel::X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I) {
2010   // Check if the subtarget supports these instructions.
2011   if (!Subtarget->hasCMov())
2012     return false;
2013 
2014   // FIXME: Add support for i8.
2015   if (RetVT < MVT::i16 || RetVT > MVT::i64)
2016     return false;
2017 
2018   const Value *Cond = I->getOperand(0);
2019   const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
2020   bool NeedTest = true;
2021   X86::CondCode CC = X86::COND_NE;
2022 
2023   // Optimize conditions coming from a compare if both instructions are in the
2024   // same basic block (values defined in other basic blocks may not have
2025   // initialized registers).
2026   const auto *CI = dyn_cast<CmpInst>(Cond);
2027   if (CI && (CI->getParent() == I->getParent())) {
2028     CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
2029 
2030     // FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction.
2031     static const uint16_t SETFOpcTable[2][3] = {
2032       { X86::COND_NP, X86::COND_E,  X86::TEST8rr },
2033       { X86::COND_P,  X86::COND_NE, X86::OR8rr   }
2034     };
2035     const uint16_t *SETFOpc = nullptr;
2036     switch (Predicate) {
2037     default: break;
2038     case CmpInst::FCMP_OEQ:
2039       SETFOpc = &SETFOpcTable[0][0];
2040       Predicate = CmpInst::ICMP_NE;
2041       break;
2042     case CmpInst::FCMP_UNE:
2043       SETFOpc = &SETFOpcTable[1][0];
2044       Predicate = CmpInst::ICMP_NE;
2045       break;
2046     }
2047 
2048     bool NeedSwap;
2049     std::tie(CC, NeedSwap) = X86::getX86ConditionCode(Predicate);
2050     assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
2051 
2052     const Value *CmpLHS = CI->getOperand(0);
2053     const Value *CmpRHS = CI->getOperand(1);
2054     if (NeedSwap)
2055       std::swap(CmpLHS, CmpRHS);
2056 
2057     EVT CmpVT = TLI.getValueType(DL, CmpLHS->getType());
2058     // Emit a compare of the LHS and RHS, setting the flags.
2059     if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc()))
2060       return false;
2061 
2062     if (SETFOpc) {
2063       Register FlagReg1 = createResultReg(&X86::GR8RegClass);
2064       Register FlagReg2 = createResultReg(&X86::GR8RegClass);
2065       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
2066               FlagReg1).addImm(SETFOpc[0]);
2067       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
2068               FlagReg2).addImm(SETFOpc[1]);
2069       auto const &II = TII.get(SETFOpc[2]);
2070       if (II.getNumDefs()) {
2071         Register TmpReg = createResultReg(&X86::GR8RegClass);
2072         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, TmpReg)
2073           .addReg(FlagReg2).addReg(FlagReg1);
2074       } else {
2075         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
2076           .addReg(FlagReg2).addReg(FlagReg1);
2077       }
2078     }
2079     NeedTest = false;
2080   } else if (foldX86XALUIntrinsic(CC, I, Cond)) {
2081     // Fake request the condition, otherwise the intrinsic might be completely
2082     // optimized away.
2083     Register TmpReg = getRegForValue(Cond);
2084     if (TmpReg == 0)
2085       return false;
2086 
2087     NeedTest = false;
2088   }
2089 
2090   if (NeedTest) {
2091     // Selects operate on i1, however, CondReg is 8 bits width and may contain
2092     // garbage. Indeed, only the less significant bit is supposed to be
2093     // accurate. If we read more than the lsb, we may see non-zero values
2094     // whereas lsb is zero. Therefore, we have to truncate Op0Reg to i1 for
2095     // the select. This is achieved by performing TEST against 1.
2096     Register CondReg = getRegForValue(Cond);
2097     if (CondReg == 0)
2098       return false;
2099     bool CondIsKill = hasTrivialKill(Cond);
2100 
2101     // In case OpReg is a K register, COPY to a GPR
2102     if (MRI.getRegClass(CondReg) == &X86::VK1RegClass) {
2103       unsigned KCondReg = CondReg;
2104       CondReg = createResultReg(&X86::GR32RegClass);
2105       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2106               TII.get(TargetOpcode::COPY), CondReg)
2107           .addReg(KCondReg, getKillRegState(CondIsKill));
2108       CondReg = fastEmitInst_extractsubreg(MVT::i8, CondReg, /*Op0IsKill=*/true,
2109                                            X86::sub_8bit);
2110     }
2111     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
2112         .addReg(CondReg, getKillRegState(CondIsKill))
2113         .addImm(1);
2114   }
2115 
2116   const Value *LHS = I->getOperand(1);
2117   const Value *RHS = I->getOperand(2);
2118 
2119   Register RHSReg = getRegForValue(RHS);
2120   bool RHSIsKill = hasTrivialKill(RHS);
2121 
2122   Register LHSReg = getRegForValue(LHS);
2123   bool LHSIsKill = hasTrivialKill(LHS);
2124 
2125   if (!LHSReg || !RHSReg)
2126     return false;
2127 
2128   const TargetRegisterInfo &TRI = *Subtarget->getRegisterInfo();
2129   unsigned Opc = X86::getCMovOpcode(TRI.getRegSizeInBits(*RC)/8);
2130   Register ResultReg = fastEmitInst_rri(Opc, RC, RHSReg, RHSIsKill,
2131                                         LHSReg, LHSIsKill, CC);
2132   updateValueMap(I, ResultReg);
2133   return true;
2134 }
2135 
2136 /// Emit SSE or AVX instructions to lower the select.
2137 ///
2138 /// Try to use SSE1/SSE2 instructions to simulate a select without branches.
2139 /// This lowers fp selects into a CMP/AND/ANDN/OR sequence when the necessary
2140 /// SSE instructions are available. If AVX is available, try to use a VBLENDV.
X86FastEmitSSESelect(MVT RetVT,const Instruction * I)2141 bool X86FastISel::X86FastEmitSSESelect(MVT RetVT, const Instruction *I) {
2142   // Optimize conditions coming from a compare if both instructions are in the
2143   // same basic block (values defined in other basic blocks may not have
2144   // initialized registers).
2145   const auto *CI = dyn_cast<FCmpInst>(I->getOperand(0));
2146   if (!CI || (CI->getParent() != I->getParent()))
2147     return false;
2148 
2149   if (I->getType() != CI->getOperand(0)->getType() ||
2150       !((Subtarget->hasSSE1() && RetVT == MVT::f32) ||
2151         (Subtarget->hasSSE2() && RetVT == MVT::f64)))
2152     return false;
2153 
2154   const Value *CmpLHS = CI->getOperand(0);
2155   const Value *CmpRHS = CI->getOperand(1);
2156   CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
2157 
2158   // The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0.
2159   // We don't have to materialize a zero constant for this case and can just use
2160   // %x again on the RHS.
2161   if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
2162     const auto *CmpRHSC = dyn_cast<ConstantFP>(CmpRHS);
2163     if (CmpRHSC && CmpRHSC->isNullValue())
2164       CmpRHS = CmpLHS;
2165   }
2166 
2167   unsigned CC;
2168   bool NeedSwap;
2169   std::tie(CC, NeedSwap) = getX86SSEConditionCode(Predicate);
2170   if (CC > 7 && !Subtarget->hasAVX())
2171     return false;
2172 
2173   if (NeedSwap)
2174     std::swap(CmpLHS, CmpRHS);
2175 
2176   const Value *LHS = I->getOperand(1);
2177   const Value *RHS = I->getOperand(2);
2178 
2179   Register LHSReg = getRegForValue(LHS);
2180   bool LHSIsKill = hasTrivialKill(LHS);
2181 
2182   Register RHSReg = getRegForValue(RHS);
2183   bool RHSIsKill = hasTrivialKill(RHS);
2184 
2185   Register CmpLHSReg = getRegForValue(CmpLHS);
2186   bool CmpLHSIsKill = hasTrivialKill(CmpLHS);
2187 
2188   Register CmpRHSReg = getRegForValue(CmpRHS);
2189   bool CmpRHSIsKill = hasTrivialKill(CmpRHS);
2190 
2191   if (!LHSReg || !RHSReg || !CmpLHSReg || !CmpRHSReg)
2192     return false;
2193 
2194   const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
2195   unsigned ResultReg;
2196 
2197   if (Subtarget->hasAVX512()) {
2198     // If we have AVX512 we can use a mask compare and masked movss/sd.
2199     const TargetRegisterClass *VR128X = &X86::VR128XRegClass;
2200     const TargetRegisterClass *VK1 = &X86::VK1RegClass;
2201 
2202     unsigned CmpOpcode =
2203       (RetVT == MVT::f32) ? X86::VCMPSSZrr : X86::VCMPSDZrr;
2204     Register CmpReg = fastEmitInst_rri(CmpOpcode, VK1, CmpLHSReg, CmpLHSIsKill,
2205                                        CmpRHSReg, CmpRHSIsKill, CC);
2206 
2207     // Need an IMPLICIT_DEF for the input that is used to generate the upper
2208     // bits of the result register since its not based on any of the inputs.
2209     Register ImplicitDefReg = createResultReg(VR128X);
2210     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2211             TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
2212 
2213     // Place RHSReg is the passthru of the masked movss/sd operation and put
2214     // LHS in the input. The mask input comes from the compare.
2215     unsigned MovOpcode =
2216       (RetVT == MVT::f32) ? X86::VMOVSSZrrk : X86::VMOVSDZrrk;
2217     unsigned MovReg = fastEmitInst_rrrr(MovOpcode, VR128X, RHSReg, RHSIsKill,
2218                                         CmpReg, true, ImplicitDefReg, true,
2219                                         LHSReg, LHSIsKill);
2220 
2221     ResultReg = createResultReg(RC);
2222     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2223             TII.get(TargetOpcode::COPY), ResultReg).addReg(MovReg);
2224 
2225   } else if (Subtarget->hasAVX()) {
2226     const TargetRegisterClass *VR128 = &X86::VR128RegClass;
2227 
2228     // If we have AVX, create 1 blendv instead of 3 logic instructions.
2229     // Blendv was introduced with SSE 4.1, but the 2 register form implicitly
2230     // uses XMM0 as the selection register. That may need just as many
2231     // instructions as the AND/ANDN/OR sequence due to register moves, so
2232     // don't bother.
2233     unsigned CmpOpcode =
2234       (RetVT == MVT::f32) ? X86::VCMPSSrr : X86::VCMPSDrr;
2235     unsigned BlendOpcode =
2236       (RetVT == MVT::f32) ? X86::VBLENDVPSrr : X86::VBLENDVPDrr;
2237 
2238     Register CmpReg = fastEmitInst_rri(CmpOpcode, RC, CmpLHSReg, CmpLHSIsKill,
2239                                        CmpRHSReg, CmpRHSIsKill, CC);
2240     Register VBlendReg = fastEmitInst_rrr(BlendOpcode, VR128, RHSReg, RHSIsKill,
2241                                           LHSReg, LHSIsKill, CmpReg, true);
2242     ResultReg = createResultReg(RC);
2243     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2244             TII.get(TargetOpcode::COPY), ResultReg).addReg(VBlendReg);
2245   } else {
2246     // Choose the SSE instruction sequence based on data type (float or double).
2247     static const uint16_t OpcTable[2][4] = {
2248       { X86::CMPSSrr,  X86::ANDPSrr,  X86::ANDNPSrr,  X86::ORPSrr  },
2249       { X86::CMPSDrr,  X86::ANDPDrr,  X86::ANDNPDrr,  X86::ORPDrr  }
2250     };
2251 
2252     const uint16_t *Opc = nullptr;
2253     switch (RetVT.SimpleTy) {
2254     default: return false;
2255     case MVT::f32: Opc = &OpcTable[0][0]; break;
2256     case MVT::f64: Opc = &OpcTable[1][0]; break;
2257     }
2258 
2259     const TargetRegisterClass *VR128 = &X86::VR128RegClass;
2260     Register CmpReg = fastEmitInst_rri(Opc[0], RC, CmpLHSReg, CmpLHSIsKill,
2261                                        CmpRHSReg, CmpRHSIsKill, CC);
2262     Register AndReg = fastEmitInst_rr(Opc[1], VR128, CmpReg,
2263                                       /*Op0IsKill=*/false, LHSReg, LHSIsKill);
2264     Register AndNReg = fastEmitInst_rr(Opc[2], VR128, CmpReg,
2265                                        /*Op0IsKill=*/true, RHSReg, RHSIsKill);
2266     Register OrReg = fastEmitInst_rr(Opc[3], VR128, AndNReg, /*Op0IsKill=*/true,
2267                                      AndReg, /*Op1IsKill=*/true);
2268     ResultReg = createResultReg(RC);
2269     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2270             TII.get(TargetOpcode::COPY), ResultReg).addReg(OrReg);
2271   }
2272   updateValueMap(I, ResultReg);
2273   return true;
2274 }
2275 
X86FastEmitPseudoSelect(MVT RetVT,const Instruction * I)2276 bool X86FastISel::X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I) {
2277   // These are pseudo CMOV instructions and will be later expanded into control-
2278   // flow.
2279   unsigned Opc;
2280   switch (RetVT.SimpleTy) {
2281   default: return false;
2282   case MVT::i8:  Opc = X86::CMOV_GR8;  break;
2283   case MVT::i16: Opc = X86::CMOV_GR16; break;
2284   case MVT::i32: Opc = X86::CMOV_GR32; break;
2285   case MVT::f32: Opc = Subtarget->hasAVX512() ? X86::CMOV_FR32X
2286                                               : X86::CMOV_FR32; break;
2287   case MVT::f64: Opc = Subtarget->hasAVX512() ? X86::CMOV_FR64X
2288                                               : X86::CMOV_FR64; break;
2289   }
2290 
2291   const Value *Cond = I->getOperand(0);
2292   X86::CondCode CC = X86::COND_NE;
2293 
2294   // Optimize conditions coming from a compare if both instructions are in the
2295   // same basic block (values defined in other basic blocks may not have
2296   // initialized registers).
2297   const auto *CI = dyn_cast<CmpInst>(Cond);
2298   if (CI && (CI->getParent() == I->getParent())) {
2299     bool NeedSwap;
2300     std::tie(CC, NeedSwap) = X86::getX86ConditionCode(CI->getPredicate());
2301     if (CC > X86::LAST_VALID_COND)
2302       return false;
2303 
2304     const Value *CmpLHS = CI->getOperand(0);
2305     const Value *CmpRHS = CI->getOperand(1);
2306 
2307     if (NeedSwap)
2308       std::swap(CmpLHS, CmpRHS);
2309 
2310     EVT CmpVT = TLI.getValueType(DL, CmpLHS->getType());
2311     if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc()))
2312       return false;
2313   } else {
2314     Register CondReg = getRegForValue(Cond);
2315     if (CondReg == 0)
2316       return false;
2317     bool CondIsKill = hasTrivialKill(Cond);
2318 
2319     // In case OpReg is a K register, COPY to a GPR
2320     if (MRI.getRegClass(CondReg) == &X86::VK1RegClass) {
2321       unsigned KCondReg = CondReg;
2322       CondReg = createResultReg(&X86::GR32RegClass);
2323       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2324               TII.get(TargetOpcode::COPY), CondReg)
2325           .addReg(KCondReg, getKillRegState(CondIsKill));
2326       CondReg = fastEmitInst_extractsubreg(MVT::i8, CondReg, /*Op0IsKill=*/true,
2327                                            X86::sub_8bit);
2328     }
2329     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
2330         .addReg(CondReg, getKillRegState(CondIsKill))
2331         .addImm(1);
2332   }
2333 
2334   const Value *LHS = I->getOperand(1);
2335   const Value *RHS = I->getOperand(2);
2336 
2337   Register LHSReg = getRegForValue(LHS);
2338   bool LHSIsKill = hasTrivialKill(LHS);
2339 
2340   Register RHSReg = getRegForValue(RHS);
2341   bool RHSIsKill = hasTrivialKill(RHS);
2342 
2343   if (!LHSReg || !RHSReg)
2344     return false;
2345 
2346   const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
2347 
2348   Register ResultReg =
2349     fastEmitInst_rri(Opc, RC, RHSReg, RHSIsKill, LHSReg, LHSIsKill, CC);
2350   updateValueMap(I, ResultReg);
2351   return true;
2352 }
2353 
X86SelectSelect(const Instruction * I)2354 bool X86FastISel::X86SelectSelect(const Instruction *I) {
2355   MVT RetVT;
2356   if (!isTypeLegal(I->getType(), RetVT))
2357     return false;
2358 
2359   // Check if we can fold the select.
2360   if (const auto *CI = dyn_cast<CmpInst>(I->getOperand(0))) {
2361     CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
2362     const Value *Opnd = nullptr;
2363     switch (Predicate) {
2364     default:                              break;
2365     case CmpInst::FCMP_FALSE: Opnd = I->getOperand(2); break;
2366     case CmpInst::FCMP_TRUE:  Opnd = I->getOperand(1); break;
2367     }
2368     // No need for a select anymore - this is an unconditional move.
2369     if (Opnd) {
2370       Register OpReg = getRegForValue(Opnd);
2371       if (OpReg == 0)
2372         return false;
2373       bool OpIsKill = hasTrivialKill(Opnd);
2374       const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
2375       Register ResultReg = createResultReg(RC);
2376       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2377               TII.get(TargetOpcode::COPY), ResultReg)
2378         .addReg(OpReg, getKillRegState(OpIsKill));
2379       updateValueMap(I, ResultReg);
2380       return true;
2381     }
2382   }
2383 
2384   // First try to use real conditional move instructions.
2385   if (X86FastEmitCMoveSelect(RetVT, I))
2386     return true;
2387 
2388   // Try to use a sequence of SSE instructions to simulate a conditional move.
2389   if (X86FastEmitSSESelect(RetVT, I))
2390     return true;
2391 
2392   // Fall-back to pseudo conditional move instructions, which will be later
2393   // converted to control-flow.
2394   if (X86FastEmitPseudoSelect(RetVT, I))
2395     return true;
2396 
2397   return false;
2398 }
2399 
2400 // Common code for X86SelectSIToFP and X86SelectUIToFP.
X86SelectIntToFP(const Instruction * I,bool IsSigned)2401 bool X86FastISel::X86SelectIntToFP(const Instruction *I, bool IsSigned) {
2402   // The target-independent selection algorithm in FastISel already knows how
2403   // to select a SINT_TO_FP if the target is SSE but not AVX.
2404   // Early exit if the subtarget doesn't have AVX.
2405   // Unsigned conversion requires avx512.
2406   bool HasAVX512 = Subtarget->hasAVX512();
2407   if (!Subtarget->hasAVX() || (!IsSigned && !HasAVX512))
2408     return false;
2409 
2410   // TODO: We could sign extend narrower types.
2411   MVT SrcVT = TLI.getSimpleValueType(DL, I->getOperand(0)->getType());
2412   if (SrcVT != MVT::i32 && SrcVT != MVT::i64)
2413     return false;
2414 
2415   // Select integer to float/double conversion.
2416   Register OpReg = getRegForValue(I->getOperand(0));
2417   if (OpReg == 0)
2418     return false;
2419 
2420   unsigned Opcode;
2421 
2422   static const uint16_t SCvtOpc[2][2][2] = {
2423     { { X86::VCVTSI2SSrr,  X86::VCVTSI642SSrr },
2424       { X86::VCVTSI2SDrr,  X86::VCVTSI642SDrr } },
2425     { { X86::VCVTSI2SSZrr, X86::VCVTSI642SSZrr },
2426       { X86::VCVTSI2SDZrr, X86::VCVTSI642SDZrr } },
2427   };
2428   static const uint16_t UCvtOpc[2][2] = {
2429     { X86::VCVTUSI2SSZrr, X86::VCVTUSI642SSZrr },
2430     { X86::VCVTUSI2SDZrr, X86::VCVTUSI642SDZrr },
2431   };
2432   bool Is64Bit = SrcVT == MVT::i64;
2433 
2434   if (I->getType()->isDoubleTy()) {
2435     // s/uitofp int -> double
2436     Opcode = IsSigned ? SCvtOpc[HasAVX512][1][Is64Bit] : UCvtOpc[1][Is64Bit];
2437   } else if (I->getType()->isFloatTy()) {
2438     // s/uitofp int -> float
2439     Opcode = IsSigned ? SCvtOpc[HasAVX512][0][Is64Bit] : UCvtOpc[0][Is64Bit];
2440   } else
2441     return false;
2442 
2443   MVT DstVT = TLI.getValueType(DL, I->getType()).getSimpleVT();
2444   const TargetRegisterClass *RC = TLI.getRegClassFor(DstVT);
2445   Register ImplicitDefReg = createResultReg(RC);
2446   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2447           TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
2448   Register ResultReg =
2449       fastEmitInst_rr(Opcode, RC, ImplicitDefReg, true, OpReg, false);
2450   updateValueMap(I, ResultReg);
2451   return true;
2452 }
2453 
X86SelectSIToFP(const Instruction * I)2454 bool X86FastISel::X86SelectSIToFP(const Instruction *I) {
2455   return X86SelectIntToFP(I, /*IsSigned*/true);
2456 }
2457 
X86SelectUIToFP(const Instruction * I)2458 bool X86FastISel::X86SelectUIToFP(const Instruction *I) {
2459   return X86SelectIntToFP(I, /*IsSigned*/false);
2460 }
2461 
2462 // Helper method used by X86SelectFPExt and X86SelectFPTrunc.
X86SelectFPExtOrFPTrunc(const Instruction * I,unsigned TargetOpc,const TargetRegisterClass * RC)2463 bool X86FastISel::X86SelectFPExtOrFPTrunc(const Instruction *I,
2464                                           unsigned TargetOpc,
2465                                           const TargetRegisterClass *RC) {
2466   assert((I->getOpcode() == Instruction::FPExt ||
2467           I->getOpcode() == Instruction::FPTrunc) &&
2468          "Instruction must be an FPExt or FPTrunc!");
2469   bool HasAVX = Subtarget->hasAVX();
2470 
2471   Register OpReg = getRegForValue(I->getOperand(0));
2472   if (OpReg == 0)
2473     return false;
2474 
2475   unsigned ImplicitDefReg;
2476   if (HasAVX) {
2477     ImplicitDefReg = createResultReg(RC);
2478     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2479             TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
2480 
2481   }
2482 
2483   Register ResultReg = createResultReg(RC);
2484   MachineInstrBuilder MIB;
2485   MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpc),
2486                 ResultReg);
2487 
2488   if (HasAVX)
2489     MIB.addReg(ImplicitDefReg);
2490 
2491   MIB.addReg(OpReg);
2492   updateValueMap(I, ResultReg);
2493   return true;
2494 }
2495 
X86SelectFPExt(const Instruction * I)2496 bool X86FastISel::X86SelectFPExt(const Instruction *I) {
2497   if (X86ScalarSSEf64 && I->getType()->isDoubleTy() &&
2498       I->getOperand(0)->getType()->isFloatTy()) {
2499     bool HasAVX512 = Subtarget->hasAVX512();
2500     // fpext from float to double.
2501     unsigned Opc =
2502         HasAVX512 ? X86::VCVTSS2SDZrr
2503                   : Subtarget->hasAVX() ? X86::VCVTSS2SDrr : X86::CVTSS2SDrr;
2504     return X86SelectFPExtOrFPTrunc(I, Opc, TLI.getRegClassFor(MVT::f64));
2505   }
2506 
2507   return false;
2508 }
2509 
X86SelectFPTrunc(const Instruction * I)2510 bool X86FastISel::X86SelectFPTrunc(const Instruction *I) {
2511   if (X86ScalarSSEf64 && I->getType()->isFloatTy() &&
2512       I->getOperand(0)->getType()->isDoubleTy()) {
2513     bool HasAVX512 = Subtarget->hasAVX512();
2514     // fptrunc from double to float.
2515     unsigned Opc =
2516         HasAVX512 ? X86::VCVTSD2SSZrr
2517                   : Subtarget->hasAVX() ? X86::VCVTSD2SSrr : X86::CVTSD2SSrr;
2518     return X86SelectFPExtOrFPTrunc(I, Opc, TLI.getRegClassFor(MVT::f32));
2519   }
2520 
2521   return false;
2522 }
2523 
X86SelectTrunc(const Instruction * I)2524 bool X86FastISel::X86SelectTrunc(const Instruction *I) {
2525   EVT SrcVT = TLI.getValueType(DL, I->getOperand(0)->getType());
2526   EVT DstVT = TLI.getValueType(DL, I->getType());
2527 
2528   // This code only handles truncation to byte.
2529   if (DstVT != MVT::i8 && DstVT != MVT::i1)
2530     return false;
2531   if (!TLI.isTypeLegal(SrcVT))
2532     return false;
2533 
2534   Register InputReg = getRegForValue(I->getOperand(0));
2535   if (!InputReg)
2536     // Unhandled operand.  Halt "fast" selection and bail.
2537     return false;
2538 
2539   if (SrcVT == MVT::i8) {
2540     // Truncate from i8 to i1; no code needed.
2541     updateValueMap(I, InputReg);
2542     return true;
2543   }
2544 
2545   // Issue an extract_subreg.
2546   Register ResultReg = fastEmitInst_extractsubreg(MVT::i8,
2547                                                   InputReg, false,
2548                                                   X86::sub_8bit);
2549   if (!ResultReg)
2550     return false;
2551 
2552   updateValueMap(I, ResultReg);
2553   return true;
2554 }
2555 
IsMemcpySmall(uint64_t Len)2556 bool X86FastISel::IsMemcpySmall(uint64_t Len) {
2557   return Len <= (Subtarget->is64Bit() ? 32 : 16);
2558 }
2559 
TryEmitSmallMemcpy(X86AddressMode DestAM,X86AddressMode SrcAM,uint64_t Len)2560 bool X86FastISel::TryEmitSmallMemcpy(X86AddressMode DestAM,
2561                                      X86AddressMode SrcAM, uint64_t Len) {
2562 
2563   // Make sure we don't bloat code by inlining very large memcpy's.
2564   if (!IsMemcpySmall(Len))
2565     return false;
2566 
2567   bool i64Legal = Subtarget->is64Bit();
2568 
2569   // We don't care about alignment here since we just emit integer accesses.
2570   while (Len) {
2571     MVT VT;
2572     if (Len >= 8 && i64Legal)
2573       VT = MVT::i64;
2574     else if (Len >= 4)
2575       VT = MVT::i32;
2576     else if (Len >= 2)
2577       VT = MVT::i16;
2578     else
2579       VT = MVT::i8;
2580 
2581     unsigned Reg;
2582     bool RV = X86FastEmitLoad(VT, SrcAM, nullptr, Reg);
2583     RV &= X86FastEmitStore(VT, Reg, /*ValIsKill=*/true, DestAM);
2584     assert(RV && "Failed to emit load or store??");
2585 
2586     unsigned Size = VT.getSizeInBits()/8;
2587     Len -= Size;
2588     DestAM.Disp += Size;
2589     SrcAM.Disp += Size;
2590   }
2591 
2592   return true;
2593 }
2594 
fastLowerIntrinsicCall(const IntrinsicInst * II)2595 bool X86FastISel::fastLowerIntrinsicCall(const IntrinsicInst *II) {
2596   // FIXME: Handle more intrinsics.
2597   switch (II->getIntrinsicID()) {
2598   default: return false;
2599   case Intrinsic::convert_from_fp16:
2600   case Intrinsic::convert_to_fp16: {
2601     if (Subtarget->useSoftFloat() || !Subtarget->hasF16C())
2602       return false;
2603 
2604     const Value *Op = II->getArgOperand(0);
2605     Register InputReg = getRegForValue(Op);
2606     if (InputReg == 0)
2607       return false;
2608 
2609     // F16C only allows converting from float to half and from half to float.
2610     bool IsFloatToHalf = II->getIntrinsicID() == Intrinsic::convert_to_fp16;
2611     if (IsFloatToHalf) {
2612       if (!Op->getType()->isFloatTy())
2613         return false;
2614     } else {
2615       if (!II->getType()->isFloatTy())
2616         return false;
2617     }
2618 
2619     unsigned ResultReg = 0;
2620     const TargetRegisterClass *RC = TLI.getRegClassFor(MVT::v8i16);
2621     if (IsFloatToHalf) {
2622       // 'InputReg' is implicitly promoted from register class FR32 to
2623       // register class VR128 by method 'constrainOperandRegClass' which is
2624       // directly called by 'fastEmitInst_ri'.
2625       // Instruction VCVTPS2PHrr takes an extra immediate operand which is
2626       // used to provide rounding control: use MXCSR.RC, encoded as 0b100.
2627       // It's consistent with the other FP instructions, which are usually
2628       // controlled by MXCSR.
2629       unsigned Opc = Subtarget->hasVLX() ? X86::VCVTPS2PHZ128rr
2630                                          : X86::VCVTPS2PHrr;
2631       InputReg = fastEmitInst_ri(Opc, RC, InputReg, false, 4);
2632 
2633       // Move the lower 32-bits of ResultReg to another register of class GR32.
2634       Opc = Subtarget->hasAVX512() ? X86::VMOVPDI2DIZrr
2635                                    : X86::VMOVPDI2DIrr;
2636       ResultReg = createResultReg(&X86::GR32RegClass);
2637       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
2638           .addReg(InputReg, RegState::Kill);
2639 
2640       // The result value is in the lower 16-bits of ResultReg.
2641       unsigned RegIdx = X86::sub_16bit;
2642       ResultReg = fastEmitInst_extractsubreg(MVT::i16, ResultReg, true, RegIdx);
2643     } else {
2644       assert(Op->getType()->isIntegerTy(16) && "Expected a 16-bit integer!");
2645       // Explicitly zero-extend the input to 32-bit.
2646       InputReg = fastEmit_r(MVT::i16, MVT::i32, ISD::ZERO_EXTEND, InputReg,
2647                             /*Op0IsKill=*/false);
2648 
2649       // The following SCALAR_TO_VECTOR will be expanded into a VMOVDI2PDIrr.
2650       InputReg = fastEmit_r(MVT::i32, MVT::v4i32, ISD::SCALAR_TO_VECTOR,
2651                             InputReg, /*Op0IsKill=*/true);
2652 
2653       unsigned Opc = Subtarget->hasVLX() ? X86::VCVTPH2PSZ128rr
2654                                          : X86::VCVTPH2PSrr;
2655       InputReg = fastEmitInst_r(Opc, RC, InputReg, /*Op0IsKill=*/true);
2656 
2657       // The result value is in the lower 32-bits of ResultReg.
2658       // Emit an explicit copy from register class VR128 to register class FR32.
2659       ResultReg = createResultReg(TLI.getRegClassFor(MVT::f32));
2660       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2661               TII.get(TargetOpcode::COPY), ResultReg)
2662           .addReg(InputReg, RegState::Kill);
2663     }
2664 
2665     updateValueMap(II, ResultReg);
2666     return true;
2667   }
2668   case Intrinsic::frameaddress: {
2669     MachineFunction *MF = FuncInfo.MF;
2670     if (MF->getTarget().getMCAsmInfo()->usesWindowsCFI())
2671       return false;
2672 
2673     Type *RetTy = II->getCalledFunction()->getReturnType();
2674 
2675     MVT VT;
2676     if (!isTypeLegal(RetTy, VT))
2677       return false;
2678 
2679     unsigned Opc;
2680     const TargetRegisterClass *RC = nullptr;
2681 
2682     switch (VT.SimpleTy) {
2683     default: llvm_unreachable("Invalid result type for frameaddress.");
2684     case MVT::i32: Opc = X86::MOV32rm; RC = &X86::GR32RegClass; break;
2685     case MVT::i64: Opc = X86::MOV64rm; RC = &X86::GR64RegClass; break;
2686     }
2687 
2688     // This needs to be set before we call getPtrSizedFrameRegister, otherwise
2689     // we get the wrong frame register.
2690     MachineFrameInfo &MFI = MF->getFrameInfo();
2691     MFI.setFrameAddressIsTaken(true);
2692 
2693     const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
2694     unsigned FrameReg = RegInfo->getPtrSizedFrameRegister(*MF);
2695     assert(((FrameReg == X86::RBP && VT == MVT::i64) ||
2696             (FrameReg == X86::EBP && VT == MVT::i32)) &&
2697            "Invalid Frame Register!");
2698 
2699     // Always make a copy of the frame register to a vreg first, so that we
2700     // never directly reference the frame register (the TwoAddressInstruction-
2701     // Pass doesn't like that).
2702     Register SrcReg = createResultReg(RC);
2703     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2704             TII.get(TargetOpcode::COPY), SrcReg).addReg(FrameReg);
2705 
2706     // Now recursively load from the frame address.
2707     // movq (%rbp), %rax
2708     // movq (%rax), %rax
2709     // movq (%rax), %rax
2710     // ...
2711     unsigned Depth = cast<ConstantInt>(II->getOperand(0))->getZExtValue();
2712     while (Depth--) {
2713       Register DestReg = createResultReg(RC);
2714       addDirectMem(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2715                            TII.get(Opc), DestReg), SrcReg);
2716       SrcReg = DestReg;
2717     }
2718 
2719     updateValueMap(II, SrcReg);
2720     return true;
2721   }
2722   case Intrinsic::memcpy: {
2723     const MemCpyInst *MCI = cast<MemCpyInst>(II);
2724     // Don't handle volatile or variable length memcpys.
2725     if (MCI->isVolatile())
2726       return false;
2727 
2728     if (isa<ConstantInt>(MCI->getLength())) {
2729       // Small memcpy's are common enough that we want to do them
2730       // without a call if possible.
2731       uint64_t Len = cast<ConstantInt>(MCI->getLength())->getZExtValue();
2732       if (IsMemcpySmall(Len)) {
2733         X86AddressMode DestAM, SrcAM;
2734         if (!X86SelectAddress(MCI->getRawDest(), DestAM) ||
2735             !X86SelectAddress(MCI->getRawSource(), SrcAM))
2736           return false;
2737         TryEmitSmallMemcpy(DestAM, SrcAM, Len);
2738         return true;
2739       }
2740     }
2741 
2742     unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
2743     if (!MCI->getLength()->getType()->isIntegerTy(SizeWidth))
2744       return false;
2745 
2746     if (MCI->getSourceAddressSpace() > 255 || MCI->getDestAddressSpace() > 255)
2747       return false;
2748 
2749     return lowerCallTo(II, "memcpy", II->getNumArgOperands() - 1);
2750   }
2751   case Intrinsic::memset: {
2752     const MemSetInst *MSI = cast<MemSetInst>(II);
2753 
2754     if (MSI->isVolatile())
2755       return false;
2756 
2757     unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
2758     if (!MSI->getLength()->getType()->isIntegerTy(SizeWidth))
2759       return false;
2760 
2761     if (MSI->getDestAddressSpace() > 255)
2762       return false;
2763 
2764     return lowerCallTo(II, "memset", II->getNumArgOperands() - 1);
2765   }
2766   case Intrinsic::stackprotector: {
2767     // Emit code to store the stack guard onto the stack.
2768     EVT PtrTy = TLI.getPointerTy(DL);
2769 
2770     const Value *Op1 = II->getArgOperand(0); // The guard's value.
2771     const AllocaInst *Slot = cast<AllocaInst>(II->getArgOperand(1));
2772 
2773     MFI.setStackProtectorIndex(FuncInfo.StaticAllocaMap[Slot]);
2774 
2775     // Grab the frame index.
2776     X86AddressMode AM;
2777     if (!X86SelectAddress(Slot, AM)) return false;
2778     if (!X86FastEmitStore(PtrTy, Op1, AM)) return false;
2779     return true;
2780   }
2781   case Intrinsic::dbg_declare: {
2782     const DbgDeclareInst *DI = cast<DbgDeclareInst>(II);
2783     X86AddressMode AM;
2784     assert(DI->getAddress() && "Null address should be checked earlier!");
2785     if (!X86SelectAddress(DI->getAddress(), AM))
2786       return false;
2787     const MCInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE);
2788     // FIXME may need to add RegState::Debug to any registers produced,
2789     // although ESP/EBP should be the only ones at the moment.
2790     assert(DI->getVariable()->isValidLocationForIntrinsic(DbgLoc) &&
2791            "Expected inlined-at fields to agree");
2792     addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II), AM)
2793         .addImm(0)
2794         .addMetadata(DI->getVariable())
2795         .addMetadata(DI->getExpression());
2796     return true;
2797   }
2798   case Intrinsic::trap: {
2799     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TRAP));
2800     return true;
2801   }
2802   case Intrinsic::sqrt: {
2803     if (!Subtarget->hasSSE1())
2804       return false;
2805 
2806     Type *RetTy = II->getCalledFunction()->getReturnType();
2807 
2808     MVT VT;
2809     if (!isTypeLegal(RetTy, VT))
2810       return false;
2811 
2812     // Unfortunately we can't use fastEmit_r, because the AVX version of FSQRT
2813     // is not generated by FastISel yet.
2814     // FIXME: Update this code once tablegen can handle it.
2815     static const uint16_t SqrtOpc[3][2] = {
2816       { X86::SQRTSSr,   X86::SQRTSDr },
2817       { X86::VSQRTSSr,  X86::VSQRTSDr },
2818       { X86::VSQRTSSZr, X86::VSQRTSDZr },
2819     };
2820     unsigned AVXLevel = Subtarget->hasAVX512() ? 2 :
2821                         Subtarget->hasAVX()    ? 1 :
2822                                                  0;
2823     unsigned Opc;
2824     switch (VT.SimpleTy) {
2825     default: return false;
2826     case MVT::f32: Opc = SqrtOpc[AVXLevel][0]; break;
2827     case MVT::f64: Opc = SqrtOpc[AVXLevel][1]; break;
2828     }
2829 
2830     const Value *SrcVal = II->getArgOperand(0);
2831     Register SrcReg = getRegForValue(SrcVal);
2832 
2833     if (SrcReg == 0)
2834       return false;
2835 
2836     const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
2837     unsigned ImplicitDefReg = 0;
2838     if (AVXLevel > 0) {
2839       ImplicitDefReg = createResultReg(RC);
2840       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2841               TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
2842     }
2843 
2844     Register ResultReg = createResultReg(RC);
2845     MachineInstrBuilder MIB;
2846     MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
2847                   ResultReg);
2848 
2849     if (ImplicitDefReg)
2850       MIB.addReg(ImplicitDefReg);
2851 
2852     MIB.addReg(SrcReg);
2853 
2854     updateValueMap(II, ResultReg);
2855     return true;
2856   }
2857   case Intrinsic::sadd_with_overflow:
2858   case Intrinsic::uadd_with_overflow:
2859   case Intrinsic::ssub_with_overflow:
2860   case Intrinsic::usub_with_overflow:
2861   case Intrinsic::smul_with_overflow:
2862   case Intrinsic::umul_with_overflow: {
2863     // This implements the basic lowering of the xalu with overflow intrinsics
2864     // into add/sub/mul followed by either seto or setb.
2865     const Function *Callee = II->getCalledFunction();
2866     auto *Ty = cast<StructType>(Callee->getReturnType());
2867     Type *RetTy = Ty->getTypeAtIndex(0U);
2868     assert(Ty->getTypeAtIndex(1)->isIntegerTy() &&
2869            Ty->getTypeAtIndex(1)->getScalarSizeInBits() == 1 &&
2870            "Overflow value expected to be an i1");
2871 
2872     MVT VT;
2873     if (!isTypeLegal(RetTy, VT))
2874       return false;
2875 
2876     if (VT < MVT::i8 || VT > MVT::i64)
2877       return false;
2878 
2879     const Value *LHS = II->getArgOperand(0);
2880     const Value *RHS = II->getArgOperand(1);
2881 
2882     // Canonicalize immediate to the RHS.
2883     if (isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS) && II->isCommutative())
2884       std::swap(LHS, RHS);
2885 
2886     unsigned BaseOpc, CondCode;
2887     switch (II->getIntrinsicID()) {
2888     default: llvm_unreachable("Unexpected intrinsic!");
2889     case Intrinsic::sadd_with_overflow:
2890       BaseOpc = ISD::ADD; CondCode = X86::COND_O; break;
2891     case Intrinsic::uadd_with_overflow:
2892       BaseOpc = ISD::ADD; CondCode = X86::COND_B; break;
2893     case Intrinsic::ssub_with_overflow:
2894       BaseOpc = ISD::SUB; CondCode = X86::COND_O; break;
2895     case Intrinsic::usub_with_overflow:
2896       BaseOpc = ISD::SUB; CondCode = X86::COND_B; break;
2897     case Intrinsic::smul_with_overflow:
2898       BaseOpc = X86ISD::SMUL; CondCode = X86::COND_O; break;
2899     case Intrinsic::umul_with_overflow:
2900       BaseOpc = X86ISD::UMUL; CondCode = X86::COND_O; break;
2901     }
2902 
2903     Register LHSReg = getRegForValue(LHS);
2904     if (LHSReg == 0)
2905       return false;
2906     bool LHSIsKill = hasTrivialKill(LHS);
2907 
2908     unsigned ResultReg = 0;
2909     // Check if we have an immediate version.
2910     if (const auto *CI = dyn_cast<ConstantInt>(RHS)) {
2911       static const uint16_t Opc[2][4] = {
2912         { X86::INC8r, X86::INC16r, X86::INC32r, X86::INC64r },
2913         { X86::DEC8r, X86::DEC16r, X86::DEC32r, X86::DEC64r }
2914       };
2915 
2916       if (CI->isOne() && (BaseOpc == ISD::ADD || BaseOpc == ISD::SUB) &&
2917           CondCode == X86::COND_O) {
2918         // We can use INC/DEC.
2919         ResultReg = createResultReg(TLI.getRegClassFor(VT));
2920         bool IsDec = BaseOpc == ISD::SUB;
2921         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2922                 TII.get(Opc[IsDec][VT.SimpleTy-MVT::i8]), ResultReg)
2923           .addReg(LHSReg, getKillRegState(LHSIsKill));
2924       } else
2925         ResultReg = fastEmit_ri(VT, VT, BaseOpc, LHSReg, LHSIsKill,
2926                                 CI->getZExtValue());
2927     }
2928 
2929     unsigned RHSReg;
2930     bool RHSIsKill;
2931     if (!ResultReg) {
2932       RHSReg = getRegForValue(RHS);
2933       if (RHSReg == 0)
2934         return false;
2935       RHSIsKill = hasTrivialKill(RHS);
2936       ResultReg = fastEmit_rr(VT, VT, BaseOpc, LHSReg, LHSIsKill, RHSReg,
2937                               RHSIsKill);
2938     }
2939 
2940     // FastISel doesn't have a pattern for all X86::MUL*r and X86::IMUL*r. Emit
2941     // it manually.
2942     if (BaseOpc == X86ISD::UMUL && !ResultReg) {
2943       static const uint16_t MULOpc[] =
2944         { X86::MUL8r, X86::MUL16r, X86::MUL32r, X86::MUL64r };
2945       static const MCPhysReg Reg[] = { X86::AL, X86::AX, X86::EAX, X86::RAX };
2946       // First copy the first operand into RAX, which is an implicit input to
2947       // the X86::MUL*r instruction.
2948       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2949               TII.get(TargetOpcode::COPY), Reg[VT.SimpleTy-MVT::i8])
2950         .addReg(LHSReg, getKillRegState(LHSIsKill));
2951       ResultReg = fastEmitInst_r(MULOpc[VT.SimpleTy-MVT::i8],
2952                                  TLI.getRegClassFor(VT), RHSReg, RHSIsKill);
2953     } else if (BaseOpc == X86ISD::SMUL && !ResultReg) {
2954       static const uint16_t MULOpc[] =
2955         { X86::IMUL8r, X86::IMUL16rr, X86::IMUL32rr, X86::IMUL64rr };
2956       if (VT == MVT::i8) {
2957         // Copy the first operand into AL, which is an implicit input to the
2958         // X86::IMUL8r instruction.
2959         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
2960                TII.get(TargetOpcode::COPY), X86::AL)
2961           .addReg(LHSReg, getKillRegState(LHSIsKill));
2962         ResultReg = fastEmitInst_r(MULOpc[0], TLI.getRegClassFor(VT), RHSReg,
2963                                    RHSIsKill);
2964       } else
2965         ResultReg = fastEmitInst_rr(MULOpc[VT.SimpleTy-MVT::i8],
2966                                     TLI.getRegClassFor(VT), LHSReg, LHSIsKill,
2967                                     RHSReg, RHSIsKill);
2968     }
2969 
2970     if (!ResultReg)
2971       return false;
2972 
2973     // Assign to a GPR since the overflow return value is lowered to a SETcc.
2974     Register ResultReg2 = createResultReg(&X86::GR8RegClass);
2975     assert((ResultReg+1) == ResultReg2 && "Nonconsecutive result registers.");
2976     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SETCCr),
2977             ResultReg2).addImm(CondCode);
2978 
2979     updateValueMap(II, ResultReg, 2);
2980     return true;
2981   }
2982   case Intrinsic::x86_sse_cvttss2si:
2983   case Intrinsic::x86_sse_cvttss2si64:
2984   case Intrinsic::x86_sse2_cvttsd2si:
2985   case Intrinsic::x86_sse2_cvttsd2si64: {
2986     bool IsInputDouble;
2987     switch (II->getIntrinsicID()) {
2988     default: llvm_unreachable("Unexpected intrinsic.");
2989     case Intrinsic::x86_sse_cvttss2si:
2990     case Intrinsic::x86_sse_cvttss2si64:
2991       if (!Subtarget->hasSSE1())
2992         return false;
2993       IsInputDouble = false;
2994       break;
2995     case Intrinsic::x86_sse2_cvttsd2si:
2996     case Intrinsic::x86_sse2_cvttsd2si64:
2997       if (!Subtarget->hasSSE2())
2998         return false;
2999       IsInputDouble = true;
3000       break;
3001     }
3002 
3003     Type *RetTy = II->getCalledFunction()->getReturnType();
3004     MVT VT;
3005     if (!isTypeLegal(RetTy, VT))
3006       return false;
3007 
3008     static const uint16_t CvtOpc[3][2][2] = {
3009       { { X86::CVTTSS2SIrr,   X86::CVTTSS2SI64rr },
3010         { X86::CVTTSD2SIrr,   X86::CVTTSD2SI64rr } },
3011       { { X86::VCVTTSS2SIrr,  X86::VCVTTSS2SI64rr },
3012         { X86::VCVTTSD2SIrr,  X86::VCVTTSD2SI64rr } },
3013       { { X86::VCVTTSS2SIZrr, X86::VCVTTSS2SI64Zrr },
3014         { X86::VCVTTSD2SIZrr, X86::VCVTTSD2SI64Zrr } },
3015     };
3016     unsigned AVXLevel = Subtarget->hasAVX512() ? 2 :
3017                         Subtarget->hasAVX()    ? 1 :
3018                                                  0;
3019     unsigned Opc;
3020     switch (VT.SimpleTy) {
3021     default: llvm_unreachable("Unexpected result type.");
3022     case MVT::i32: Opc = CvtOpc[AVXLevel][IsInputDouble][0]; break;
3023     case MVT::i64: Opc = CvtOpc[AVXLevel][IsInputDouble][1]; break;
3024     }
3025 
3026     // Check if we can fold insertelement instructions into the convert.
3027     const Value *Op = II->getArgOperand(0);
3028     while (auto *IE = dyn_cast<InsertElementInst>(Op)) {
3029       const Value *Index = IE->getOperand(2);
3030       if (!isa<ConstantInt>(Index))
3031         break;
3032       unsigned Idx = cast<ConstantInt>(Index)->getZExtValue();
3033 
3034       if (Idx == 0) {
3035         Op = IE->getOperand(1);
3036         break;
3037       }
3038       Op = IE->getOperand(0);
3039     }
3040 
3041     Register Reg = getRegForValue(Op);
3042     if (Reg == 0)
3043       return false;
3044 
3045     Register ResultReg = createResultReg(TLI.getRegClassFor(VT));
3046     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
3047       .addReg(Reg);
3048 
3049     updateValueMap(II, ResultReg);
3050     return true;
3051   }
3052   }
3053 }
3054 
fastLowerArguments()3055 bool X86FastISel::fastLowerArguments() {
3056   if (!FuncInfo.CanLowerReturn)
3057     return false;
3058 
3059   const Function *F = FuncInfo.Fn;
3060   if (F->isVarArg())
3061     return false;
3062 
3063   CallingConv::ID CC = F->getCallingConv();
3064   if (CC != CallingConv::C)
3065     return false;
3066 
3067   if (Subtarget->isCallingConvWin64(CC))
3068     return false;
3069 
3070   if (!Subtarget->is64Bit())
3071     return false;
3072 
3073   if (Subtarget->useSoftFloat())
3074     return false;
3075 
3076   // Only handle simple cases. i.e. Up to 6 i32/i64 scalar arguments.
3077   unsigned GPRCnt = 0;
3078   unsigned FPRCnt = 0;
3079   for (auto const &Arg : F->args()) {
3080     if (Arg.hasAttribute(Attribute::ByVal) ||
3081         Arg.hasAttribute(Attribute::InReg) ||
3082         Arg.hasAttribute(Attribute::StructRet) ||
3083         Arg.hasAttribute(Attribute::SwiftSelf) ||
3084         Arg.hasAttribute(Attribute::SwiftError) ||
3085         Arg.hasAttribute(Attribute::Nest))
3086       return false;
3087 
3088     Type *ArgTy = Arg.getType();
3089     if (ArgTy->isStructTy() || ArgTy->isArrayTy() || ArgTy->isVectorTy())
3090       return false;
3091 
3092     EVT ArgVT = TLI.getValueType(DL, ArgTy);
3093     if (!ArgVT.isSimple()) return false;
3094     switch (ArgVT.getSimpleVT().SimpleTy) {
3095     default: return false;
3096     case MVT::i32:
3097     case MVT::i64:
3098       ++GPRCnt;
3099       break;
3100     case MVT::f32:
3101     case MVT::f64:
3102       if (!Subtarget->hasSSE1())
3103         return false;
3104       ++FPRCnt;
3105       break;
3106     }
3107 
3108     if (GPRCnt > 6)
3109       return false;
3110 
3111     if (FPRCnt > 8)
3112       return false;
3113   }
3114 
3115   static const MCPhysReg GPR32ArgRegs[] = {
3116     X86::EDI, X86::ESI, X86::EDX, X86::ECX, X86::R8D, X86::R9D
3117   };
3118   static const MCPhysReg GPR64ArgRegs[] = {
3119     X86::RDI, X86::RSI, X86::RDX, X86::RCX, X86::R8 , X86::R9
3120   };
3121   static const MCPhysReg XMMArgRegs[] = {
3122     X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
3123     X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
3124   };
3125 
3126   unsigned GPRIdx = 0;
3127   unsigned FPRIdx = 0;
3128   for (auto const &Arg : F->args()) {
3129     MVT VT = TLI.getSimpleValueType(DL, Arg.getType());
3130     const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
3131     unsigned SrcReg;
3132     switch (VT.SimpleTy) {
3133     default: llvm_unreachable("Unexpected value type.");
3134     case MVT::i32: SrcReg = GPR32ArgRegs[GPRIdx++]; break;
3135     case MVT::i64: SrcReg = GPR64ArgRegs[GPRIdx++]; break;
3136     case MVT::f32: LLVM_FALLTHROUGH;
3137     case MVT::f64: SrcReg = XMMArgRegs[FPRIdx++]; break;
3138     }
3139     Register DstReg = FuncInfo.MF->addLiveIn(SrcReg, RC);
3140     // FIXME: Unfortunately it's necessary to emit a copy from the livein copy.
3141     // Without this, EmitLiveInCopies may eliminate the livein if its only
3142     // use is a bitcast (which isn't turned into an instruction).
3143     Register ResultReg = createResultReg(RC);
3144     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3145             TII.get(TargetOpcode::COPY), ResultReg)
3146       .addReg(DstReg, getKillRegState(true));
3147     updateValueMap(&Arg, ResultReg);
3148   }
3149   return true;
3150 }
3151 
computeBytesPoppedByCalleeForSRet(const X86Subtarget * Subtarget,CallingConv::ID CC,const CallBase * CB)3152 static unsigned computeBytesPoppedByCalleeForSRet(const X86Subtarget *Subtarget,
3153                                                   CallingConv::ID CC,
3154                                                   const CallBase *CB) {
3155   if (Subtarget->is64Bit())
3156     return 0;
3157   if (Subtarget->getTargetTriple().isOSMSVCRT())
3158     return 0;
3159   if (CC == CallingConv::Fast || CC == CallingConv::GHC ||
3160       CC == CallingConv::HiPE || CC == CallingConv::Tail)
3161     return 0;
3162 
3163   if (CB)
3164     if (CB->arg_empty() || !CB->paramHasAttr(0, Attribute::StructRet) ||
3165         CB->paramHasAttr(0, Attribute::InReg) || Subtarget->isTargetMCU())
3166       return 0;
3167 
3168   return 4;
3169 }
3170 
fastLowerCall(CallLoweringInfo & CLI)3171 bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) {
3172   auto &OutVals       = CLI.OutVals;
3173   auto &OutFlags      = CLI.OutFlags;
3174   auto &OutRegs       = CLI.OutRegs;
3175   auto &Ins           = CLI.Ins;
3176   auto &InRegs        = CLI.InRegs;
3177   CallingConv::ID CC  = CLI.CallConv;
3178   bool &IsTailCall    = CLI.IsTailCall;
3179   bool IsVarArg       = CLI.IsVarArg;
3180   const Value *Callee = CLI.Callee;
3181   MCSymbol *Symbol = CLI.Symbol;
3182 
3183   bool Is64Bit        = Subtarget->is64Bit();
3184   bool IsWin64        = Subtarget->isCallingConvWin64(CC);
3185 
3186   const CallInst *CI = dyn_cast_or_null<CallInst>(CLI.CB);
3187   const Function *CalledFn = CI ? CI->getCalledFunction() : nullptr;
3188 
3189   // Call / invoke instructions with NoCfCheck attribute require special
3190   // handling.
3191   const auto *II = dyn_cast_or_null<InvokeInst>(CLI.CB);
3192   if ((CI && CI->doesNoCfCheck()) || (II && II->doesNoCfCheck()))
3193     return false;
3194 
3195   // Functions with no_caller_saved_registers that need special handling.
3196   if ((CI && CI->hasFnAttr("no_caller_saved_registers")) ||
3197       (CalledFn && CalledFn->hasFnAttribute("no_caller_saved_registers")))
3198     return false;
3199 
3200   // Functions using thunks for indirect calls need to use SDISel.
3201   if (Subtarget->useIndirectThunkCalls())
3202     return false;
3203 
3204   // Handle only C, fastcc, and webkit_js calling conventions for now.
3205   switch (CC) {
3206   default: return false;
3207   case CallingConv::C:
3208   case CallingConv::Fast:
3209   case CallingConv::Tail:
3210   case CallingConv::WebKit_JS:
3211   case CallingConv::Swift:
3212   case CallingConv::X86_FastCall:
3213   case CallingConv::X86_StdCall:
3214   case CallingConv::X86_ThisCall:
3215   case CallingConv::Win64:
3216   case CallingConv::X86_64_SysV:
3217   case CallingConv::CFGuard_Check:
3218     break;
3219   }
3220 
3221   // Allow SelectionDAG isel to handle tail calls.
3222   if (IsTailCall)
3223     return false;
3224 
3225   // fastcc with -tailcallopt is intended to provide a guaranteed
3226   // tail call optimization. Fastisel doesn't know how to do that.
3227   if ((CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt) ||
3228       CC == CallingConv::Tail)
3229     return false;
3230 
3231   // Don't know how to handle Win64 varargs yet.  Nothing special needed for
3232   // x86-32. Special handling for x86-64 is implemented.
3233   if (IsVarArg && IsWin64)
3234     return false;
3235 
3236   // Don't know about inalloca yet.
3237   if (CLI.CB && CLI.CB->hasInAllocaArgument())
3238     return false;
3239 
3240   for (auto Flag : CLI.OutFlags)
3241     if (Flag.isSwiftError() || Flag.isPreallocated())
3242       return false;
3243 
3244   SmallVector<MVT, 16> OutVTs;
3245   SmallVector<unsigned, 16> ArgRegs;
3246 
3247   // If this is a constant i1/i8/i16 argument, promote to i32 to avoid an extra
3248   // instruction. This is safe because it is common to all FastISel supported
3249   // calling conventions on x86.
3250   for (int i = 0, e = OutVals.size(); i != e; ++i) {
3251     Value *&Val = OutVals[i];
3252     ISD::ArgFlagsTy Flags = OutFlags[i];
3253     if (auto *CI = dyn_cast<ConstantInt>(Val)) {
3254       if (CI->getBitWidth() < 32) {
3255         if (Flags.isSExt())
3256           Val = ConstantExpr::getSExt(CI, Type::getInt32Ty(CI->getContext()));
3257         else
3258           Val = ConstantExpr::getZExt(CI, Type::getInt32Ty(CI->getContext()));
3259       }
3260     }
3261 
3262     // Passing bools around ends up doing a trunc to i1 and passing it.
3263     // Codegen this as an argument + "and 1".
3264     MVT VT;
3265     auto *TI = dyn_cast<TruncInst>(Val);
3266     unsigned ResultReg;
3267     if (TI && TI->getType()->isIntegerTy(1) && CLI.CB &&
3268         (TI->getParent() == CLI.CB->getParent()) && TI->hasOneUse()) {
3269       Value *PrevVal = TI->getOperand(0);
3270       ResultReg = getRegForValue(PrevVal);
3271 
3272       if (!ResultReg)
3273         return false;
3274 
3275       if (!isTypeLegal(PrevVal->getType(), VT))
3276         return false;
3277 
3278       ResultReg =
3279         fastEmit_ri(VT, VT, ISD::AND, ResultReg, hasTrivialKill(PrevVal), 1);
3280     } else {
3281       if (!isTypeLegal(Val->getType(), VT) ||
3282           (VT.isVector() && VT.getVectorElementType() == MVT::i1))
3283         return false;
3284       ResultReg = getRegForValue(Val);
3285     }
3286 
3287     if (!ResultReg)
3288       return false;
3289 
3290     ArgRegs.push_back(ResultReg);
3291     OutVTs.push_back(VT);
3292   }
3293 
3294   // Analyze operands of the call, assigning locations to each operand.
3295   SmallVector<CCValAssign, 16> ArgLocs;
3296   CCState CCInfo(CC, IsVarArg, *FuncInfo.MF, ArgLocs, CLI.RetTy->getContext());
3297 
3298   // Allocate shadow area for Win64
3299   if (IsWin64)
3300     CCInfo.AllocateStack(32, Align(8));
3301 
3302   CCInfo.AnalyzeCallOperands(OutVTs, OutFlags, CC_X86);
3303 
3304   // Get a count of how many bytes are to be pushed on the stack.
3305   unsigned NumBytes = CCInfo.getAlignedCallFrameSize();
3306 
3307   // Issue CALLSEQ_START
3308   unsigned AdjStackDown = TII.getCallFrameSetupOpcode();
3309   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackDown))
3310     .addImm(NumBytes).addImm(0).addImm(0);
3311 
3312   // Walk the register/memloc assignments, inserting copies/loads.
3313   const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
3314   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3315     CCValAssign const &VA = ArgLocs[i];
3316     const Value *ArgVal = OutVals[VA.getValNo()];
3317     MVT ArgVT = OutVTs[VA.getValNo()];
3318 
3319     if (ArgVT == MVT::x86mmx)
3320       return false;
3321 
3322     unsigned ArgReg = ArgRegs[VA.getValNo()];
3323 
3324     // Promote the value if needed.
3325     switch (VA.getLocInfo()) {
3326     case CCValAssign::Full: break;
3327     case CCValAssign::SExt: {
3328       assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
3329              "Unexpected extend");
3330 
3331       if (ArgVT == MVT::i1)
3332         return false;
3333 
3334       bool Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg,
3335                                        ArgVT, ArgReg);
3336       assert(Emitted && "Failed to emit a sext!"); (void)Emitted;
3337       ArgVT = VA.getLocVT();
3338       break;
3339     }
3340     case CCValAssign::ZExt: {
3341       assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
3342              "Unexpected extend");
3343 
3344       // Handle zero-extension from i1 to i8, which is common.
3345       if (ArgVT == MVT::i1) {
3346         // Set the high bits to zero.
3347         ArgReg = fastEmitZExtFromI1(MVT::i8, ArgReg, /*TODO: Kill=*/false);
3348         ArgVT = MVT::i8;
3349 
3350         if (ArgReg == 0)
3351           return false;
3352       }
3353 
3354       bool Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg,
3355                                        ArgVT, ArgReg);
3356       assert(Emitted && "Failed to emit a zext!"); (void)Emitted;
3357       ArgVT = VA.getLocVT();
3358       break;
3359     }
3360     case CCValAssign::AExt: {
3361       assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
3362              "Unexpected extend");
3363       bool Emitted = X86FastEmitExtend(ISD::ANY_EXTEND, VA.getLocVT(), ArgReg,
3364                                        ArgVT, ArgReg);
3365       if (!Emitted)
3366         Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg,
3367                                     ArgVT, ArgReg);
3368       if (!Emitted)
3369         Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg,
3370                                     ArgVT, ArgReg);
3371 
3372       assert(Emitted && "Failed to emit a aext!"); (void)Emitted;
3373       ArgVT = VA.getLocVT();
3374       break;
3375     }
3376     case CCValAssign::BCvt: {
3377       ArgReg = fastEmit_r(ArgVT, VA.getLocVT(), ISD::BITCAST, ArgReg,
3378                           /*TODO: Kill=*/false);
3379       assert(ArgReg && "Failed to emit a bitcast!");
3380       ArgVT = VA.getLocVT();
3381       break;
3382     }
3383     case CCValAssign::VExt:
3384       // VExt has not been implemented, so this should be impossible to reach
3385       // for now.  However, fallback to Selection DAG isel once implemented.
3386       return false;
3387     case CCValAssign::AExtUpper:
3388     case CCValAssign::SExtUpper:
3389     case CCValAssign::ZExtUpper:
3390     case CCValAssign::FPExt:
3391     case CCValAssign::Trunc:
3392       llvm_unreachable("Unexpected loc info!");
3393     case CCValAssign::Indirect:
3394       // FIXME: Indirect doesn't need extending, but fast-isel doesn't fully
3395       // support this.
3396       return false;
3397     }
3398 
3399     if (VA.isRegLoc()) {
3400       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3401               TII.get(TargetOpcode::COPY), VA.getLocReg()).addReg(ArgReg);
3402       OutRegs.push_back(VA.getLocReg());
3403     } else {
3404       assert(VA.isMemLoc() && "Unknown value location!");
3405 
3406       // Don't emit stores for undef values.
3407       if (isa<UndefValue>(ArgVal))
3408         continue;
3409 
3410       unsigned LocMemOffset = VA.getLocMemOffset();
3411       X86AddressMode AM;
3412       AM.Base.Reg = RegInfo->getStackRegister();
3413       AM.Disp = LocMemOffset;
3414       ISD::ArgFlagsTy Flags = OutFlags[VA.getValNo()];
3415       Align Alignment = DL.getABITypeAlign(ArgVal->getType());
3416       MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
3417           MachinePointerInfo::getStack(*FuncInfo.MF, LocMemOffset),
3418           MachineMemOperand::MOStore, ArgVT.getStoreSize(), Alignment);
3419       if (Flags.isByVal()) {
3420         X86AddressMode SrcAM;
3421         SrcAM.Base.Reg = ArgReg;
3422         if (!TryEmitSmallMemcpy(AM, SrcAM, Flags.getByValSize()))
3423           return false;
3424       } else if (isa<ConstantInt>(ArgVal) || isa<ConstantPointerNull>(ArgVal)) {
3425         // If this is a really simple value, emit this with the Value* version
3426         // of X86FastEmitStore.  If it isn't simple, we don't want to do this,
3427         // as it can cause us to reevaluate the argument.
3428         if (!X86FastEmitStore(ArgVT, ArgVal, AM, MMO))
3429           return false;
3430       } else {
3431         bool ValIsKill = hasTrivialKill(ArgVal);
3432         if (!X86FastEmitStore(ArgVT, ArgReg, ValIsKill, AM, MMO))
3433           return false;
3434       }
3435     }
3436   }
3437 
3438   // ELF / PIC requires GOT in the EBX register before function calls via PLT
3439   // GOT pointer.
3440   if (Subtarget->isPICStyleGOT()) {
3441     unsigned Base = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
3442     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3443             TII.get(TargetOpcode::COPY), X86::EBX).addReg(Base);
3444   }
3445 
3446   if (Is64Bit && IsVarArg && !IsWin64) {
3447     // From AMD64 ABI document:
3448     // For calls that may call functions that use varargs or stdargs
3449     // (prototype-less calls or calls to functions containing ellipsis (...) in
3450     // the declaration) %al is used as hidden argument to specify the number
3451     // of SSE registers used. The contents of %al do not need to match exactly
3452     // the number of registers, but must be an ubound on the number of SSE
3453     // registers used and is in the range 0 - 8 inclusive.
3454 
3455     // Count the number of XMM registers allocated.
3456     static const MCPhysReg XMMArgRegs[] = {
3457       X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
3458       X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
3459     };
3460     unsigned NumXMMRegs = CCInfo.getFirstUnallocated(XMMArgRegs);
3461     assert((Subtarget->hasSSE1() || !NumXMMRegs)
3462            && "SSE registers cannot be used when SSE is disabled");
3463     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri),
3464             X86::AL).addImm(NumXMMRegs);
3465   }
3466 
3467   // Materialize callee address in a register. FIXME: GV address can be
3468   // handled with a CALLpcrel32 instead.
3469   X86AddressMode CalleeAM;
3470   if (!X86SelectCallAddress(Callee, CalleeAM))
3471     return false;
3472 
3473   unsigned CalleeOp = 0;
3474   const GlobalValue *GV = nullptr;
3475   if (CalleeAM.GV != nullptr) {
3476     GV = CalleeAM.GV;
3477   } else if (CalleeAM.Base.Reg != 0) {
3478     CalleeOp = CalleeAM.Base.Reg;
3479   } else
3480     return false;
3481 
3482   // Issue the call.
3483   MachineInstrBuilder MIB;
3484   if (CalleeOp) {
3485     // Register-indirect call.
3486     unsigned CallOpc = Is64Bit ? X86::CALL64r : X86::CALL32r;
3487     MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc))
3488       .addReg(CalleeOp);
3489   } else {
3490     // Direct call.
3491     assert(GV && "Not a direct call");
3492     // See if we need any target-specific flags on the GV operand.
3493     unsigned char OpFlags = Subtarget->classifyGlobalFunctionReference(GV);
3494 
3495     // This will be a direct call, or an indirect call through memory for
3496     // NonLazyBind calls or dllimport calls.
3497     bool NeedLoad = OpFlags == X86II::MO_DLLIMPORT ||
3498                     OpFlags == X86II::MO_GOTPCREL ||
3499                     OpFlags == X86II::MO_COFFSTUB;
3500     unsigned CallOpc = NeedLoad
3501                            ? (Is64Bit ? X86::CALL64m : X86::CALL32m)
3502                            : (Is64Bit ? X86::CALL64pcrel32 : X86::CALLpcrel32);
3503 
3504     MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc));
3505     if (NeedLoad)
3506       MIB.addReg(Is64Bit ? X86::RIP : 0).addImm(1).addReg(0);
3507     if (Symbol)
3508       MIB.addSym(Symbol, OpFlags);
3509     else
3510       MIB.addGlobalAddress(GV, 0, OpFlags);
3511     if (NeedLoad)
3512       MIB.addReg(0);
3513   }
3514 
3515   // Add a register mask operand representing the call-preserved registers.
3516   // Proper defs for return values will be added by setPhysRegsDeadExcept().
3517   MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC));
3518 
3519   // Add an implicit use GOT pointer in EBX.
3520   if (Subtarget->isPICStyleGOT())
3521     MIB.addReg(X86::EBX, RegState::Implicit);
3522 
3523   if (Is64Bit && IsVarArg && !IsWin64)
3524     MIB.addReg(X86::AL, RegState::Implicit);
3525 
3526   // Add implicit physical register uses to the call.
3527   for (auto Reg : OutRegs)
3528     MIB.addReg(Reg, RegState::Implicit);
3529 
3530   // Issue CALLSEQ_END
3531   unsigned NumBytesForCalleeToPop =
3532       X86::isCalleePop(CC, Subtarget->is64Bit(), IsVarArg,
3533                        TM.Options.GuaranteedTailCallOpt)
3534           ? NumBytes // Callee pops everything.
3535           : computeBytesPoppedByCalleeForSRet(Subtarget, CC, CLI.CB);
3536   unsigned AdjStackUp = TII.getCallFrameDestroyOpcode();
3537   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackUp))
3538     .addImm(NumBytes).addImm(NumBytesForCalleeToPop);
3539 
3540   // Now handle call return values.
3541   SmallVector<CCValAssign, 16> RVLocs;
3542   CCState CCRetInfo(CC, IsVarArg, *FuncInfo.MF, RVLocs,
3543                     CLI.RetTy->getContext());
3544   CCRetInfo.AnalyzeCallResult(Ins, RetCC_X86);
3545 
3546   // Copy all of the result registers out of their specified physreg.
3547   Register ResultReg = FuncInfo.CreateRegs(CLI.RetTy);
3548   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3549     CCValAssign &VA = RVLocs[i];
3550     EVT CopyVT = VA.getValVT();
3551     unsigned CopyReg = ResultReg + i;
3552     Register SrcReg = VA.getLocReg();
3553 
3554     // If this is x86-64, and we disabled SSE, we can't return FP values
3555     if ((CopyVT == MVT::f32 || CopyVT == MVT::f64) &&
3556         ((Is64Bit || Ins[i].Flags.isInReg()) && !Subtarget->hasSSE1())) {
3557       report_fatal_error("SSE register return with SSE disabled");
3558     }
3559 
3560     // If we prefer to use the value in xmm registers, copy it out as f80 and
3561     // use a truncate to move it from fp stack reg to xmm reg.
3562     if ((SrcReg == X86::FP0 || SrcReg == X86::FP1) &&
3563         isScalarFPTypeInSSEReg(VA.getValVT())) {
3564       CopyVT = MVT::f80;
3565       CopyReg = createResultReg(&X86::RFP80RegClass);
3566     }
3567 
3568     // Copy out the result.
3569     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3570             TII.get(TargetOpcode::COPY), CopyReg).addReg(SrcReg);
3571     InRegs.push_back(VA.getLocReg());
3572 
3573     // Round the f80 to the right size, which also moves it to the appropriate
3574     // xmm register. This is accomplished by storing the f80 value in memory
3575     // and then loading it back.
3576     if (CopyVT != VA.getValVT()) {
3577       EVT ResVT = VA.getValVT();
3578       unsigned Opc = ResVT == MVT::f32 ? X86::ST_Fp80m32 : X86::ST_Fp80m64;
3579       unsigned MemSize = ResVT.getSizeInBits()/8;
3580       int FI = MFI.CreateStackObject(MemSize, Align(MemSize), false);
3581       addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3582                                 TII.get(Opc)), FI)
3583         .addReg(CopyReg);
3584       Opc = ResVT == MVT::f32 ? X86::MOVSSrm_alt : X86::MOVSDrm_alt;
3585       addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3586                                 TII.get(Opc), ResultReg + i), FI);
3587     }
3588   }
3589 
3590   CLI.ResultReg = ResultReg;
3591   CLI.NumResultRegs = RVLocs.size();
3592   CLI.Call = MIB;
3593 
3594   return true;
3595 }
3596 
3597 bool
fastSelectInstruction(const Instruction * I)3598 X86FastISel::fastSelectInstruction(const Instruction *I)  {
3599   switch (I->getOpcode()) {
3600   default: break;
3601   case Instruction::Load:
3602     return X86SelectLoad(I);
3603   case Instruction::Store:
3604     return X86SelectStore(I);
3605   case Instruction::Ret:
3606     return X86SelectRet(I);
3607   case Instruction::ICmp:
3608   case Instruction::FCmp:
3609     return X86SelectCmp(I);
3610   case Instruction::ZExt:
3611     return X86SelectZExt(I);
3612   case Instruction::SExt:
3613     return X86SelectSExt(I);
3614   case Instruction::Br:
3615     return X86SelectBranch(I);
3616   case Instruction::LShr:
3617   case Instruction::AShr:
3618   case Instruction::Shl:
3619     return X86SelectShift(I);
3620   case Instruction::SDiv:
3621   case Instruction::UDiv:
3622   case Instruction::SRem:
3623   case Instruction::URem:
3624     return X86SelectDivRem(I);
3625   case Instruction::Select:
3626     return X86SelectSelect(I);
3627   case Instruction::Trunc:
3628     return X86SelectTrunc(I);
3629   case Instruction::FPExt:
3630     return X86SelectFPExt(I);
3631   case Instruction::FPTrunc:
3632     return X86SelectFPTrunc(I);
3633   case Instruction::SIToFP:
3634     return X86SelectSIToFP(I);
3635   case Instruction::UIToFP:
3636     return X86SelectUIToFP(I);
3637   case Instruction::IntToPtr: // Deliberate fall-through.
3638   case Instruction::PtrToInt: {
3639     EVT SrcVT = TLI.getValueType(DL, I->getOperand(0)->getType());
3640     EVT DstVT = TLI.getValueType(DL, I->getType());
3641     if (DstVT.bitsGT(SrcVT))
3642       return X86SelectZExt(I);
3643     if (DstVT.bitsLT(SrcVT))
3644       return X86SelectTrunc(I);
3645     Register Reg = getRegForValue(I->getOperand(0));
3646     if (Reg == 0) return false;
3647     updateValueMap(I, Reg);
3648     return true;
3649   }
3650   case Instruction::BitCast: {
3651     // Select SSE2/AVX bitcasts between 128/256/512 bit vector types.
3652     if (!Subtarget->hasSSE2())
3653       return false;
3654 
3655     MVT SrcVT, DstVT;
3656     if (!isTypeLegal(I->getOperand(0)->getType(), SrcVT) ||
3657         !isTypeLegal(I->getType(), DstVT))
3658       return false;
3659 
3660     // Only allow vectors that use xmm/ymm/zmm.
3661     if (!SrcVT.isVector() || !DstVT.isVector() ||
3662         SrcVT.getVectorElementType() == MVT::i1 ||
3663         DstVT.getVectorElementType() == MVT::i1)
3664       return false;
3665 
3666     Register Reg = getRegForValue(I->getOperand(0));
3667     if (!Reg)
3668       return false;
3669 
3670     // Emit a reg-reg copy so we don't propagate cached known bits information
3671     // with the wrong VT if we fall out of fast isel after selecting this.
3672     const TargetRegisterClass *DstClass = TLI.getRegClassFor(DstVT);
3673     Register ResultReg = createResultReg(DstClass);
3674     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3675               TII.get(TargetOpcode::COPY), ResultReg).addReg(Reg);
3676 
3677     updateValueMap(I, ResultReg);
3678     return true;
3679   }
3680   }
3681 
3682   return false;
3683 }
3684 
X86MaterializeInt(const ConstantInt * CI,MVT VT)3685 unsigned X86FastISel::X86MaterializeInt(const ConstantInt *CI, MVT VT) {
3686   if (VT > MVT::i64)
3687     return 0;
3688 
3689   uint64_t Imm = CI->getZExtValue();
3690   if (Imm == 0) {
3691     Register SrcReg = fastEmitInst_(X86::MOV32r0, &X86::GR32RegClass);
3692     switch (VT.SimpleTy) {
3693     default: llvm_unreachable("Unexpected value type");
3694     case MVT::i1:
3695     case MVT::i8:
3696       return fastEmitInst_extractsubreg(MVT::i8, SrcReg, /*Op0IsKill=*/true,
3697                                         X86::sub_8bit);
3698     case MVT::i16:
3699       return fastEmitInst_extractsubreg(MVT::i16, SrcReg, /*Op0IsKill=*/true,
3700                                         X86::sub_16bit);
3701     case MVT::i32:
3702       return SrcReg;
3703     case MVT::i64: {
3704       Register ResultReg = createResultReg(&X86::GR64RegClass);
3705       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3706               TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg)
3707         .addImm(0).addReg(SrcReg).addImm(X86::sub_32bit);
3708       return ResultReg;
3709     }
3710     }
3711   }
3712 
3713   unsigned Opc = 0;
3714   switch (VT.SimpleTy) {
3715   default: llvm_unreachable("Unexpected value type");
3716   case MVT::i1:
3717     VT = MVT::i8;
3718     LLVM_FALLTHROUGH;
3719   case MVT::i8:  Opc = X86::MOV8ri;  break;
3720   case MVT::i16: Opc = X86::MOV16ri; break;
3721   case MVT::i32: Opc = X86::MOV32ri; break;
3722   case MVT::i64: {
3723     if (isUInt<32>(Imm))
3724       Opc = X86::MOV32ri64;
3725     else if (isInt<32>(Imm))
3726       Opc = X86::MOV64ri32;
3727     else
3728       Opc = X86::MOV64ri;
3729     break;
3730   }
3731   }
3732   return fastEmitInst_i(Opc, TLI.getRegClassFor(VT), Imm);
3733 }
3734 
X86MaterializeFP(const ConstantFP * CFP,MVT VT)3735 unsigned X86FastISel::X86MaterializeFP(const ConstantFP *CFP, MVT VT) {
3736   if (CFP->isNullValue())
3737     return fastMaterializeFloatZero(CFP);
3738 
3739   // Can't handle alternate code models yet.
3740   CodeModel::Model CM = TM.getCodeModel();
3741   if (CM != CodeModel::Small && CM != CodeModel::Large)
3742     return 0;
3743 
3744   // Get opcode and regclass of the output for the given load instruction.
3745   unsigned Opc = 0;
3746   bool HasAVX = Subtarget->hasAVX();
3747   bool HasAVX512 = Subtarget->hasAVX512();
3748   switch (VT.SimpleTy) {
3749   default: return 0;
3750   case MVT::f32:
3751     if (X86ScalarSSEf32)
3752       Opc = HasAVX512 ? X86::VMOVSSZrm_alt :
3753             HasAVX    ? X86::VMOVSSrm_alt :
3754                         X86::MOVSSrm_alt;
3755     else
3756       Opc = X86::LD_Fp32m;
3757     break;
3758   case MVT::f64:
3759     if (X86ScalarSSEf64)
3760       Opc = HasAVX512 ? X86::VMOVSDZrm_alt :
3761             HasAVX    ? X86::VMOVSDrm_alt :
3762                         X86::MOVSDrm_alt;
3763     else
3764       Opc = X86::LD_Fp64m;
3765     break;
3766   case MVT::f80:
3767     // No f80 support yet.
3768     return 0;
3769   }
3770 
3771   // MachineConstantPool wants an explicit alignment.
3772   Align Alignment = DL.getPrefTypeAlign(CFP->getType());
3773 
3774   // x86-32 PIC requires a PIC base register for constant pools.
3775   unsigned PICBase = 0;
3776   unsigned char OpFlag = Subtarget->classifyLocalReference(nullptr);
3777   if (OpFlag == X86II::MO_PIC_BASE_OFFSET)
3778     PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
3779   else if (OpFlag == X86II::MO_GOTOFF)
3780     PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
3781   else if (Subtarget->is64Bit() && TM.getCodeModel() == CodeModel::Small)
3782     PICBase = X86::RIP;
3783 
3784   // Create the load from the constant pool.
3785   unsigned CPI = MCP.getConstantPoolIndex(CFP, Alignment);
3786   Register ResultReg = createResultReg(TLI.getRegClassFor(VT.SimpleTy));
3787 
3788   // Large code model only applies to 64-bit mode.
3789   if (Subtarget->is64Bit() && CM == CodeModel::Large) {
3790     Register AddrReg = createResultReg(&X86::GR64RegClass);
3791     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri),
3792             AddrReg)
3793       .addConstantPoolIndex(CPI, 0, OpFlag);
3794     MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3795                                       TII.get(Opc), ResultReg);
3796     addRegReg(MIB, AddrReg, false, PICBase, false);
3797     MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
3798         MachinePointerInfo::getConstantPool(*FuncInfo.MF),
3799         MachineMemOperand::MOLoad, DL.getPointerSize(), Alignment);
3800     MIB->addMemOperand(*FuncInfo.MF, MMO);
3801     return ResultReg;
3802   }
3803 
3804   addConstantPoolReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3805                                    TII.get(Opc), ResultReg),
3806                            CPI, PICBase, OpFlag);
3807   return ResultReg;
3808 }
3809 
X86MaterializeGV(const GlobalValue * GV,MVT VT)3810 unsigned X86FastISel::X86MaterializeGV(const GlobalValue *GV, MVT VT) {
3811   // Can't handle alternate code models yet.
3812   if (TM.getCodeModel() != CodeModel::Small)
3813     return 0;
3814 
3815   // Materialize addresses with LEA/MOV instructions.
3816   X86AddressMode AM;
3817   if (X86SelectAddress(GV, AM)) {
3818     // If the expression is just a basereg, then we're done, otherwise we need
3819     // to emit an LEA.
3820     if (AM.BaseType == X86AddressMode::RegBase &&
3821         AM.IndexReg == 0 && AM.Disp == 0 && AM.GV == nullptr)
3822       return AM.Base.Reg;
3823 
3824     Register ResultReg = createResultReg(TLI.getRegClassFor(VT));
3825     if (TM.getRelocationModel() == Reloc::Static &&
3826         TLI.getPointerTy(DL) == MVT::i64) {
3827       // The displacement code could be more than 32 bits away so we need to use
3828       // an instruction with a 64 bit immediate
3829       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri),
3830               ResultReg)
3831         .addGlobalAddress(GV);
3832     } else {
3833       unsigned Opc =
3834           TLI.getPointerTy(DL) == MVT::i32
3835               ? (Subtarget->isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r)
3836               : X86::LEA64r;
3837       addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3838                              TII.get(Opc), ResultReg), AM);
3839     }
3840     return ResultReg;
3841   }
3842   return 0;
3843 }
3844 
fastMaterializeConstant(const Constant * C)3845 unsigned X86FastISel::fastMaterializeConstant(const Constant *C) {
3846   EVT CEVT = TLI.getValueType(DL, C->getType(), true);
3847 
3848   // Only handle simple types.
3849   if (!CEVT.isSimple())
3850     return 0;
3851   MVT VT = CEVT.getSimpleVT();
3852 
3853   if (const auto *CI = dyn_cast<ConstantInt>(C))
3854     return X86MaterializeInt(CI, VT);
3855   else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
3856     return X86MaterializeFP(CFP, VT);
3857   else if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
3858     return X86MaterializeGV(GV, VT);
3859 
3860   return 0;
3861 }
3862 
fastMaterializeAlloca(const AllocaInst * C)3863 unsigned X86FastISel::fastMaterializeAlloca(const AllocaInst *C) {
3864   // Fail on dynamic allocas. At this point, getRegForValue has already
3865   // checked its CSE maps, so if we're here trying to handle a dynamic
3866   // alloca, we're not going to succeed. X86SelectAddress has a
3867   // check for dynamic allocas, because it's called directly from
3868   // various places, but targetMaterializeAlloca also needs a check
3869   // in order to avoid recursion between getRegForValue,
3870   // X86SelectAddrss, and targetMaterializeAlloca.
3871   if (!FuncInfo.StaticAllocaMap.count(C))
3872     return 0;
3873   assert(C->isStaticAlloca() && "dynamic alloca in the static alloca map?");
3874 
3875   X86AddressMode AM;
3876   if (!X86SelectAddress(C, AM))
3877     return 0;
3878   unsigned Opc =
3879       TLI.getPointerTy(DL) == MVT::i32
3880           ? (Subtarget->isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r)
3881           : X86::LEA64r;
3882   const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy(DL));
3883   Register ResultReg = createResultReg(RC);
3884   addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3885                          TII.get(Opc), ResultReg), AM);
3886   return ResultReg;
3887 }
3888 
fastMaterializeFloatZero(const ConstantFP * CF)3889 unsigned X86FastISel::fastMaterializeFloatZero(const ConstantFP *CF) {
3890   MVT VT;
3891   if (!isTypeLegal(CF->getType(), VT))
3892     return 0;
3893 
3894   // Get opcode and regclass for the given zero.
3895   bool HasAVX512 = Subtarget->hasAVX512();
3896   unsigned Opc = 0;
3897   switch (VT.SimpleTy) {
3898   default: return 0;
3899   case MVT::f32:
3900     if (X86ScalarSSEf32)
3901       Opc = HasAVX512 ? X86::AVX512_FsFLD0SS : X86::FsFLD0SS;
3902     else
3903       Opc = X86::LD_Fp032;
3904     break;
3905   case MVT::f64:
3906     if (X86ScalarSSEf64)
3907       Opc = HasAVX512 ? X86::AVX512_FsFLD0SD : X86::FsFLD0SD;
3908     else
3909       Opc = X86::LD_Fp064;
3910     break;
3911   case MVT::f80:
3912     // No f80 support yet.
3913     return 0;
3914   }
3915 
3916   Register ResultReg = createResultReg(TLI.getRegClassFor(VT));
3917   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg);
3918   return ResultReg;
3919 }
3920 
3921 
tryToFoldLoadIntoMI(MachineInstr * MI,unsigned OpNo,const LoadInst * LI)3922 bool X86FastISel::tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
3923                                       const LoadInst *LI) {
3924   const Value *Ptr = LI->getPointerOperand();
3925   X86AddressMode AM;
3926   if (!X86SelectAddress(Ptr, AM))
3927     return false;
3928 
3929   const X86InstrInfo &XII = (const X86InstrInfo &)TII;
3930 
3931   unsigned Size = DL.getTypeAllocSize(LI->getType());
3932 
3933   SmallVector<MachineOperand, 8> AddrOps;
3934   AM.getFullAddress(AddrOps);
3935 
3936   MachineInstr *Result = XII.foldMemoryOperandImpl(
3937       *FuncInfo.MF, *MI, OpNo, AddrOps, FuncInfo.InsertPt, Size, LI->getAlign(),
3938       /*AllowCommute=*/true);
3939   if (!Result)
3940     return false;
3941 
3942   // The index register could be in the wrong register class.  Unfortunately,
3943   // foldMemoryOperandImpl could have commuted the instruction so its not enough
3944   // to just look at OpNo + the offset to the index reg.  We actually need to
3945   // scan the instruction to find the index reg and see if its the correct reg
3946   // class.
3947   unsigned OperandNo = 0;
3948   for (MachineInstr::mop_iterator I = Result->operands_begin(),
3949        E = Result->operands_end(); I != E; ++I, ++OperandNo) {
3950     MachineOperand &MO = *I;
3951     if (!MO.isReg() || MO.isDef() || MO.getReg() != AM.IndexReg)
3952       continue;
3953     // Found the index reg, now try to rewrite it.
3954     Register IndexReg = constrainOperandRegClass(Result->getDesc(),
3955                                                  MO.getReg(), OperandNo);
3956     if (IndexReg == MO.getReg())
3957       continue;
3958     MO.setReg(IndexReg);
3959   }
3960 
3961   Result->addMemOperand(*FuncInfo.MF, createMachineMemOperandFor(LI));
3962   Result->cloneInstrSymbols(*FuncInfo.MF, *MI);
3963   MachineBasicBlock::iterator I(MI);
3964   removeDeadCode(I, std::next(I));
3965   return true;
3966 }
3967 
fastEmitInst_rrrr(unsigned MachineInstOpcode,const TargetRegisterClass * RC,unsigned Op0,bool Op0IsKill,unsigned Op1,bool Op1IsKill,unsigned Op2,bool Op2IsKill,unsigned Op3,bool Op3IsKill)3968 unsigned X86FastISel::fastEmitInst_rrrr(unsigned MachineInstOpcode,
3969                                         const TargetRegisterClass *RC,
3970                                         unsigned Op0, bool Op0IsKill,
3971                                         unsigned Op1, bool Op1IsKill,
3972                                         unsigned Op2, bool Op2IsKill,
3973                                         unsigned Op3, bool Op3IsKill) {
3974   const MCInstrDesc &II = TII.get(MachineInstOpcode);
3975 
3976   Register ResultReg = createResultReg(RC);
3977   Op0 = constrainOperandRegClass(II, Op0, II.getNumDefs());
3978   Op1 = constrainOperandRegClass(II, Op1, II.getNumDefs() + 1);
3979   Op2 = constrainOperandRegClass(II, Op2, II.getNumDefs() + 2);
3980   Op3 = constrainOperandRegClass(II, Op3, II.getNumDefs() + 3);
3981 
3982   if (II.getNumDefs() >= 1)
3983     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, ResultReg)
3984         .addReg(Op0, getKillRegState(Op0IsKill))
3985         .addReg(Op1, getKillRegState(Op1IsKill))
3986         .addReg(Op2, getKillRegState(Op2IsKill))
3987         .addReg(Op3, getKillRegState(Op3IsKill));
3988   else {
3989     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
3990         .addReg(Op0, getKillRegState(Op0IsKill))
3991         .addReg(Op1, getKillRegState(Op1IsKill))
3992         .addReg(Op2, getKillRegState(Op2IsKill))
3993         .addReg(Op3, getKillRegState(Op3IsKill));
3994     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
3995             TII.get(TargetOpcode::COPY), ResultReg).addReg(II.ImplicitDefs[0]);
3996   }
3997   return ResultReg;
3998 }
3999 
4000 
4001 namespace llvm {
createFastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo)4002   FastISel *X86::createFastISel(FunctionLoweringInfo &funcInfo,
4003                                 const TargetLibraryInfo *libInfo) {
4004     return new X86FastISel(funcInfo, libInfo);
4005   }
4006 }
4007