xref: /freebsd/contrib/llvm-project/llvm/lib/Target/X86/X86MCInstLower.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===-- X86MCInstLower.cpp - Convert X86 MachineInstr to an MCInst --------===//
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 contains code to lower X86 MachineInstrs to their corresponding
10 // MCInst records.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MCTargetDesc/X86ATTInstPrinter.h"
15 #include "MCTargetDesc/X86BaseInfo.h"
16 #include "MCTargetDesc/X86EncodingOptimization.h"
17 #include "MCTargetDesc/X86InstComments.h"
18 #include "MCTargetDesc/X86ShuffleDecode.h"
19 #include "MCTargetDesc/X86TargetStreamer.h"
20 #include "X86AsmPrinter.h"
21 #include "X86MachineFunctionInfo.h"
22 #include "X86RegisterInfo.h"
23 #include "X86ShuffleDecodeConstantPool.h"
24 #include "X86Subtarget.h"
25 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/ADT/SmallString.h"
27 #include "llvm/ADT/StringExtras.h"
28 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
29 #include "llvm/CodeGen/MachineConstantPool.h"
30 #include "llvm/CodeGen/MachineFunction.h"
31 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
32 #include "llvm/CodeGen/MachineOperand.h"
33 #include "llvm/CodeGen/StackMaps.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/GlobalValue.h"
36 #include "llvm/IR/Mangler.h"
37 #include "llvm/MC/MCAsmInfo.h"
38 #include "llvm/MC/MCCodeEmitter.h"
39 #include "llvm/MC/MCContext.h"
40 #include "llvm/MC/MCExpr.h"
41 #include "llvm/MC/MCFixup.h"
42 #include "llvm/MC/MCInst.h"
43 #include "llvm/MC/MCInstBuilder.h"
44 #include "llvm/MC/MCSection.h"
45 #include "llvm/MC/MCSectionELF.h"
46 #include "llvm/MC/MCStreamer.h"
47 #include "llvm/MC/MCSymbol.h"
48 #include "llvm/MC/MCSymbolELF.h"
49 #include "llvm/MC/TargetRegistry.h"
50 #include "llvm/Target/TargetLoweringObjectFile.h"
51 #include "llvm/Target/TargetMachine.h"
52 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
53 #include "llvm/Transforms/Instrumentation/AddressSanitizerCommon.h"
54 #include <string>
55 
56 using namespace llvm;
57 
58 static cl::opt<bool> EnableBranchHint("enable-branch-hint",
59                                       cl::desc("Enable branch hint."),
60                                       cl::init(false), cl::Hidden);
61 static cl::opt<unsigned> BranchHintProbabilityThreshold(
62     "branch-hint-probability-threshold",
63     cl::desc("The probability threshold of enabling branch hint."),
64     cl::init(50), cl::Hidden);
65 
66 namespace {
67 
68 /// X86MCInstLower - This class is used to lower an MachineInstr into an MCInst.
69 class X86MCInstLower {
70   MCContext &Ctx;
71   const MachineFunction &MF;
72   const TargetMachine &TM;
73   const MCAsmInfo &MAI;
74   X86AsmPrinter &AsmPrinter;
75 
76 public:
77   X86MCInstLower(const MachineFunction &MF, X86AsmPrinter &asmprinter);
78 
79   MCOperand LowerMachineOperand(const MachineInstr *MI,
80                                 const MachineOperand &MO) const;
81   void Lower(const MachineInstr *MI, MCInst &OutMI) const;
82 
83   MCSymbol *GetSymbolFromOperand(const MachineOperand &MO) const;
84   MCOperand LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const;
85 
86 private:
87   MachineModuleInfoMachO &getMachOMMI() const;
88 };
89 
90 } // end anonymous namespace
91 
92 /// A RAII helper which defines a region of instructions which can't have
93 /// padding added between them for correctness.
94 struct NoAutoPaddingScope {
95   MCStreamer &OS;
96   const bool OldAllowAutoPadding;
NoAutoPaddingScopeNoAutoPaddingScope97   NoAutoPaddingScope(MCStreamer &OS)
98       : OS(OS), OldAllowAutoPadding(OS.getAllowAutoPadding()) {
99     changeAndComment(false);
100   }
~NoAutoPaddingScopeNoAutoPaddingScope101   ~NoAutoPaddingScope() { changeAndComment(OldAllowAutoPadding); }
changeAndCommentNoAutoPaddingScope102   void changeAndComment(bool b) {
103     if (b == OS.getAllowAutoPadding())
104       return;
105     OS.setAllowAutoPadding(b);
106     if (b)
107       OS.emitRawComment("autopadding");
108     else
109       OS.emitRawComment("noautopadding");
110   }
111 };
112 
113 // Emit a minimal sequence of nops spanning NumBytes bytes.
114 static void emitX86Nops(MCStreamer &OS, unsigned NumBytes,
115                         const X86Subtarget *Subtarget);
116 
count(MCInst & Inst,const MCSubtargetInfo & STI,MCCodeEmitter * CodeEmitter)117 void X86AsmPrinter::StackMapShadowTracker::count(MCInst &Inst,
118                                                  const MCSubtargetInfo &STI,
119                                                  MCCodeEmitter *CodeEmitter) {
120   if (InShadow) {
121     SmallString<256> Code;
122     SmallVector<MCFixup, 4> Fixups;
123     CodeEmitter->encodeInstruction(Inst, Code, Fixups, STI);
124     CurrentShadowSize += Code.size();
125     if (CurrentShadowSize >= RequiredShadowSize)
126       InShadow = false; // The shadow is big enough. Stop counting.
127   }
128 }
129 
emitShadowPadding(MCStreamer & OutStreamer,const MCSubtargetInfo & STI)130 void X86AsmPrinter::StackMapShadowTracker::emitShadowPadding(
131     MCStreamer &OutStreamer, const MCSubtargetInfo &STI) {
132   if (InShadow && CurrentShadowSize < RequiredShadowSize) {
133     InShadow = false;
134     emitX86Nops(OutStreamer, RequiredShadowSize - CurrentShadowSize,
135                 &MF->getSubtarget<X86Subtarget>());
136   }
137 }
138 
EmitAndCountInstruction(MCInst & Inst)139 void X86AsmPrinter::EmitAndCountInstruction(MCInst &Inst) {
140   OutStreamer->emitInstruction(Inst, getSubtargetInfo());
141   SMShadowTracker.count(Inst, getSubtargetInfo(), CodeEmitter.get());
142 }
143 
X86MCInstLower(const MachineFunction & mf,X86AsmPrinter & asmprinter)144 X86MCInstLower::X86MCInstLower(const MachineFunction &mf,
145                                X86AsmPrinter &asmprinter)
146     : Ctx(mf.getContext()), MF(mf), TM(mf.getTarget()), MAI(*TM.getMCAsmInfo()),
147       AsmPrinter(asmprinter) {}
148 
getMachOMMI() const149 MachineModuleInfoMachO &X86MCInstLower::getMachOMMI() const {
150   return AsmPrinter.MMI->getObjFileInfo<MachineModuleInfoMachO>();
151 }
152 
153 /// GetSymbolFromOperand - Lower an MO_GlobalAddress or MO_ExternalSymbol
154 /// operand to an MCSymbol.
GetSymbolFromOperand(const MachineOperand & MO) const155 MCSymbol *X86MCInstLower::GetSymbolFromOperand(const MachineOperand &MO) const {
156   const Triple &TT = TM.getTargetTriple();
157   if (MO.isGlobal() && TT.isOSBinFormatELF())
158     return AsmPrinter.getSymbolPreferLocal(*MO.getGlobal());
159 
160   const DataLayout &DL = MF.getDataLayout();
161   assert((MO.isGlobal() || MO.isSymbol() || MO.isMBB()) &&
162          "Isn't a symbol reference");
163 
164   MCSymbol *Sym = nullptr;
165   SmallString<128> Name;
166   StringRef Suffix;
167 
168   switch (MO.getTargetFlags()) {
169   case X86II::MO_DLLIMPORT:
170     // Handle dllimport linkage.
171     Name += "__imp_";
172     break;
173   case X86II::MO_COFFSTUB:
174     Name += ".refptr.";
175     break;
176   case X86II::MO_DARWIN_NONLAZY:
177   case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
178     Suffix = "$non_lazy_ptr";
179     break;
180   }
181 
182   if (!Suffix.empty())
183     Name += DL.getPrivateGlobalPrefix();
184 
185   if (MO.isGlobal()) {
186     const GlobalValue *GV = MO.getGlobal();
187     AsmPrinter.getNameWithPrefix(Name, GV);
188   } else if (MO.isSymbol()) {
189     Mangler::getNameWithPrefix(Name, MO.getSymbolName(), DL);
190   } else if (MO.isMBB()) {
191     assert(Suffix.empty());
192     Sym = MO.getMBB()->getSymbol();
193   }
194 
195   Name += Suffix;
196   if (!Sym)
197     Sym = Ctx.getOrCreateSymbol(Name);
198 
199   // If the target flags on the operand changes the name of the symbol, do that
200   // before we return the symbol.
201   switch (MO.getTargetFlags()) {
202   default:
203     break;
204   case X86II::MO_COFFSTUB: {
205     MachineModuleInfoCOFF &MMICOFF =
206         AsmPrinter.MMI->getObjFileInfo<MachineModuleInfoCOFF>();
207     MachineModuleInfoImpl::StubValueTy &StubSym = MMICOFF.getGVStubEntry(Sym);
208     if (!StubSym.getPointer()) {
209       assert(MO.isGlobal() && "Extern symbol not handled yet");
210       StubSym = MachineModuleInfoImpl::StubValueTy(
211           AsmPrinter.getSymbol(MO.getGlobal()), true);
212     }
213     break;
214   }
215   case X86II::MO_DARWIN_NONLAZY:
216   case X86II::MO_DARWIN_NONLAZY_PIC_BASE: {
217     MachineModuleInfoImpl::StubValueTy &StubSym =
218         getMachOMMI().getGVStubEntry(Sym);
219     if (!StubSym.getPointer()) {
220       assert(MO.isGlobal() && "Extern symbol not handled yet");
221       StubSym = MachineModuleInfoImpl::StubValueTy(
222           AsmPrinter.getSymbol(MO.getGlobal()),
223           !MO.getGlobal()->hasInternalLinkage());
224     }
225     break;
226   }
227   }
228 
229   return Sym;
230 }
231 
LowerSymbolOperand(const MachineOperand & MO,MCSymbol * Sym) const232 MCOperand X86MCInstLower::LowerSymbolOperand(const MachineOperand &MO,
233                                              MCSymbol *Sym) const {
234   // FIXME: We would like an efficient form for this, so we don't have to do a
235   // lot of extra uniquing.
236   const MCExpr *Expr = nullptr;
237   MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None;
238 
239   switch (MO.getTargetFlags()) {
240   default:
241     llvm_unreachable("Unknown target flag on GV operand");
242   case X86II::MO_NO_FLAG: // No flag.
243   // These affect the name of the symbol, not any suffix.
244   case X86II::MO_DARWIN_NONLAZY:
245   case X86II::MO_DLLIMPORT:
246   case X86II::MO_COFFSTUB:
247     break;
248 
249   case X86II::MO_TLVP:
250     RefKind = MCSymbolRefExpr::VK_TLVP;
251     break;
252   case X86II::MO_TLVP_PIC_BASE:
253     Expr = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_TLVP, Ctx);
254     // Subtract the pic base.
255     Expr = MCBinaryExpr::createSub(
256         Expr, MCSymbolRefExpr::create(MF.getPICBaseSymbol(), Ctx), Ctx);
257     break;
258   case X86II::MO_SECREL:
259     RefKind = MCSymbolRefExpr::VK_SECREL;
260     break;
261   case X86II::MO_TLSGD:
262     RefKind = MCSymbolRefExpr::VK_TLSGD;
263     break;
264   case X86II::MO_TLSLD:
265     RefKind = MCSymbolRefExpr::VK_TLSLD;
266     break;
267   case X86II::MO_TLSLDM:
268     RefKind = MCSymbolRefExpr::VK_TLSLDM;
269     break;
270   case X86II::MO_GOTTPOFF:
271     RefKind = MCSymbolRefExpr::VK_GOTTPOFF;
272     break;
273   case X86II::MO_INDNTPOFF:
274     RefKind = MCSymbolRefExpr::VK_INDNTPOFF;
275     break;
276   case X86II::MO_TPOFF:
277     RefKind = MCSymbolRefExpr::VK_TPOFF;
278     break;
279   case X86II::MO_DTPOFF:
280     RefKind = MCSymbolRefExpr::VK_DTPOFF;
281     break;
282   case X86II::MO_NTPOFF:
283     RefKind = MCSymbolRefExpr::VK_NTPOFF;
284     break;
285   case X86II::MO_GOTNTPOFF:
286     RefKind = MCSymbolRefExpr::VK_GOTNTPOFF;
287     break;
288   case X86II::MO_GOTPCREL:
289     RefKind = MCSymbolRefExpr::VK_GOTPCREL;
290     break;
291   case X86II::MO_GOTPCREL_NORELAX:
292     RefKind = MCSymbolRefExpr::VK_GOTPCREL_NORELAX;
293     break;
294   case X86II::MO_GOT:
295     RefKind = MCSymbolRefExpr::VK_GOT;
296     break;
297   case X86II::MO_GOTOFF:
298     RefKind = MCSymbolRefExpr::VK_GOTOFF;
299     break;
300   case X86II::MO_PLT:
301     RefKind = MCSymbolRefExpr::VK_PLT;
302     break;
303   case X86II::MO_ABS8:
304     RefKind = MCSymbolRefExpr::VK_X86_ABS8;
305     break;
306   case X86II::MO_PIC_BASE_OFFSET:
307   case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
308     Expr = MCSymbolRefExpr::create(Sym, Ctx);
309     // Subtract the pic base.
310     Expr = MCBinaryExpr::createSub(
311         Expr, MCSymbolRefExpr::create(MF.getPICBaseSymbol(), Ctx), Ctx);
312     if (MO.isJTI()) {
313       assert(MAI.doesSetDirectiveSuppressReloc());
314       // If .set directive is supported, use it to reduce the number of
315       // relocations the assembler will generate for differences between
316       // local labels. This is only safe when the symbols are in the same
317       // section so we are restricting it to jumptable references.
318       MCSymbol *Label = Ctx.createTempSymbol();
319       AsmPrinter.OutStreamer->emitAssignment(Label, Expr);
320       Expr = MCSymbolRefExpr::create(Label, Ctx);
321     }
322     break;
323   }
324 
325   if (!Expr)
326     Expr = MCSymbolRefExpr::create(Sym, RefKind, Ctx);
327 
328   if (!MO.isJTI() && !MO.isMBB() && MO.getOffset())
329     Expr = MCBinaryExpr::createAdd(
330         Expr, MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
331   return MCOperand::createExpr(Expr);
332 }
333 
getRetOpcode(const X86Subtarget & Subtarget)334 static unsigned getRetOpcode(const X86Subtarget &Subtarget) {
335   return Subtarget.is64Bit() ? X86::RET64 : X86::RET32;
336 }
337 
LowerMachineOperand(const MachineInstr * MI,const MachineOperand & MO) const338 MCOperand X86MCInstLower::LowerMachineOperand(const MachineInstr *MI,
339                                               const MachineOperand &MO) const {
340   switch (MO.getType()) {
341   default:
342     MI->print(errs());
343     llvm_unreachable("unknown operand type");
344   case MachineOperand::MO_Register:
345     // Ignore all implicit register operands.
346     if (MO.isImplicit())
347       return MCOperand();
348     return MCOperand::createReg(MO.getReg());
349   case MachineOperand::MO_Immediate:
350     return MCOperand::createImm(MO.getImm());
351   case MachineOperand::MO_MachineBasicBlock:
352   case MachineOperand::MO_GlobalAddress:
353   case MachineOperand::MO_ExternalSymbol:
354     return LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
355   case MachineOperand::MO_MCSymbol:
356     return LowerSymbolOperand(MO, MO.getMCSymbol());
357   case MachineOperand::MO_JumpTableIndex:
358     return LowerSymbolOperand(MO, AsmPrinter.GetJTISymbol(MO.getIndex()));
359   case MachineOperand::MO_ConstantPoolIndex:
360     return LowerSymbolOperand(MO, AsmPrinter.GetCPISymbol(MO.getIndex()));
361   case MachineOperand::MO_BlockAddress:
362     return LowerSymbolOperand(
363         MO, AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress()));
364   case MachineOperand::MO_RegisterMask:
365     // Ignore call clobbers.
366     return MCOperand();
367   }
368 }
369 
370 // Replace TAILJMP opcodes with their equivalent opcodes that have encoding
371 // information.
convertTailJumpOpcode(unsigned Opcode)372 static unsigned convertTailJumpOpcode(unsigned Opcode) {
373   switch (Opcode) {
374   case X86::TAILJMPr:
375     Opcode = X86::JMP32r;
376     break;
377   case X86::TAILJMPm:
378     Opcode = X86::JMP32m;
379     break;
380   case X86::TAILJMPr64:
381     Opcode = X86::JMP64r;
382     break;
383   case X86::TAILJMPm64:
384     Opcode = X86::JMP64m;
385     break;
386   case X86::TAILJMPr64_REX:
387     Opcode = X86::JMP64r_REX;
388     break;
389   case X86::TAILJMPm64_REX:
390     Opcode = X86::JMP64m_REX;
391     break;
392   case X86::TAILJMPd:
393   case X86::TAILJMPd64:
394     Opcode = X86::JMP_1;
395     break;
396   case X86::TAILJMPd_CC:
397   case X86::TAILJMPd64_CC:
398     Opcode = X86::JCC_1;
399     break;
400   }
401 
402   return Opcode;
403 }
404 
Lower(const MachineInstr * MI,MCInst & OutMI) const405 void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
406   OutMI.setOpcode(MI->getOpcode());
407 
408   for (const MachineOperand &MO : MI->operands())
409     if (auto Op = LowerMachineOperand(MI, MO); Op.isValid())
410       OutMI.addOperand(Op);
411 
412   bool In64BitMode = AsmPrinter.getSubtarget().is64Bit();
413   if (X86::optimizeInstFromVEX3ToVEX2(OutMI, MI->getDesc()) ||
414       X86::optimizeShiftRotateWithImmediateOne(OutMI) ||
415       X86::optimizeVPCMPWithImmediateOneOrSix(OutMI) ||
416       X86::optimizeMOVSX(OutMI) || X86::optimizeINCDEC(OutMI, In64BitMode) ||
417       X86::optimizeMOV(OutMI, In64BitMode) ||
418       X86::optimizeToFixedRegisterOrShortImmediateForm(OutMI))
419     return;
420 
421   // Handle a few special cases to eliminate operand modifiers.
422   switch (OutMI.getOpcode()) {
423   case X86::LEA64_32r:
424   case X86::LEA64r:
425   case X86::LEA16r:
426   case X86::LEA32r:
427     // LEA should have a segment register, but it must be empty.
428     assert(OutMI.getNumOperands() == 1 + X86::AddrNumOperands &&
429            "Unexpected # of LEA operands");
430     assert(OutMI.getOperand(1 + X86::AddrSegmentReg).getReg() == 0 &&
431            "LEA has segment specified!");
432     break;
433   case X86::MULX32Hrr:
434   case X86::MULX32Hrm:
435   case X86::MULX64Hrr:
436   case X86::MULX64Hrm: {
437     // Turn into regular MULX by duplicating the destination.
438     unsigned NewOpc;
439     switch (OutMI.getOpcode()) {
440     default: llvm_unreachable("Invalid opcode");
441     case X86::MULX32Hrr: NewOpc = X86::MULX32rr; break;
442     case X86::MULX32Hrm: NewOpc = X86::MULX32rm; break;
443     case X86::MULX64Hrr: NewOpc = X86::MULX64rr; break;
444     case X86::MULX64Hrm: NewOpc = X86::MULX64rm; break;
445     }
446     OutMI.setOpcode(NewOpc);
447     // Duplicate the destination.
448     unsigned DestReg = OutMI.getOperand(0).getReg();
449     OutMI.insert(OutMI.begin(), MCOperand::createReg(DestReg));
450     break;
451   }
452   // CALL64r, CALL64pcrel32 - These instructions used to have
453   // register inputs modeled as normal uses instead of implicit uses.  As such,
454   // they we used to truncate off all but the first operand (the callee). This
455   // issue seems to have been fixed at some point. This assert verifies that.
456   case X86::CALL64r:
457   case X86::CALL64pcrel32:
458     assert(OutMI.getNumOperands() == 1 && "Unexpected number of operands!");
459     break;
460   case X86::EH_RETURN:
461   case X86::EH_RETURN64: {
462     OutMI = MCInst();
463     OutMI.setOpcode(getRetOpcode(AsmPrinter.getSubtarget()));
464     break;
465   }
466   case X86::CLEANUPRET: {
467     // Replace CLEANUPRET with the appropriate RET.
468     OutMI = MCInst();
469     OutMI.setOpcode(getRetOpcode(AsmPrinter.getSubtarget()));
470     break;
471   }
472   case X86::CATCHRET: {
473     // Replace CATCHRET with the appropriate RET.
474     const X86Subtarget &Subtarget = AsmPrinter.getSubtarget();
475     unsigned ReturnReg = In64BitMode ? X86::RAX : X86::EAX;
476     OutMI = MCInst();
477     OutMI.setOpcode(getRetOpcode(Subtarget));
478     OutMI.addOperand(MCOperand::createReg(ReturnReg));
479     break;
480   }
481   // TAILJMPd, TAILJMPd64, TailJMPd_cc - Lower to the correct jump
482   // instruction.
483   case X86::TAILJMPr:
484   case X86::TAILJMPr64:
485   case X86::TAILJMPr64_REX:
486   case X86::TAILJMPd:
487   case X86::TAILJMPd64:
488     assert(OutMI.getNumOperands() == 1 && "Unexpected number of operands!");
489     OutMI.setOpcode(convertTailJumpOpcode(OutMI.getOpcode()));
490     break;
491   case X86::TAILJMPd_CC:
492   case X86::TAILJMPd64_CC:
493     assert(OutMI.getNumOperands() == 2 && "Unexpected number of operands!");
494     OutMI.setOpcode(convertTailJumpOpcode(OutMI.getOpcode()));
495     break;
496   case X86::TAILJMPm:
497   case X86::TAILJMPm64:
498   case X86::TAILJMPm64_REX:
499     assert(OutMI.getNumOperands() == X86::AddrNumOperands &&
500            "Unexpected number of operands!");
501     OutMI.setOpcode(convertTailJumpOpcode(OutMI.getOpcode()));
502     break;
503   case X86::MASKMOVDQU:
504   case X86::VMASKMOVDQU:
505     if (In64BitMode)
506       OutMI.setFlags(X86::IP_HAS_AD_SIZE);
507     break;
508   case X86::BSF16rm:
509   case X86::BSF16rr:
510   case X86::BSF32rm:
511   case X86::BSF32rr:
512   case X86::BSF64rm:
513   case X86::BSF64rr: {
514     // Add an REP prefix to BSF instructions so that new processors can
515     // recognize as TZCNT, which has better performance than BSF.
516     // BSF and TZCNT have different interpretations on ZF bit. So make sure
517     // it won't be used later.
518     const MachineOperand *FlagDef =
519         MI->findRegisterDefOperand(X86::EFLAGS, /*TRI=*/nullptr);
520     if (!MF.getFunction().hasOptSize() && FlagDef && FlagDef->isDead())
521       OutMI.setFlags(X86::IP_HAS_REPEAT);
522     break;
523   }
524   default:
525     break;
526   }
527 }
528 
LowerTlsAddr(X86MCInstLower & MCInstLowering,const MachineInstr & MI)529 void X86AsmPrinter::LowerTlsAddr(X86MCInstLower &MCInstLowering,
530                                  const MachineInstr &MI) {
531   NoAutoPaddingScope NoPadScope(*OutStreamer);
532   bool Is64Bits = getSubtarget().is64Bit();
533   bool Is64BitsLP64 = getSubtarget().isTarget64BitLP64();
534   MCContext &Ctx = OutStreamer->getContext();
535 
536   MCSymbolRefExpr::VariantKind SRVK;
537   switch (MI.getOpcode()) {
538   case X86::TLS_addr32:
539   case X86::TLS_addr64:
540   case X86::TLS_addrX32:
541     SRVK = MCSymbolRefExpr::VK_TLSGD;
542     break;
543   case X86::TLS_base_addr32:
544     SRVK = MCSymbolRefExpr::VK_TLSLDM;
545     break;
546   case X86::TLS_base_addr64:
547   case X86::TLS_base_addrX32:
548     SRVK = MCSymbolRefExpr::VK_TLSLD;
549     break;
550   case X86::TLS_desc32:
551   case X86::TLS_desc64:
552     SRVK = MCSymbolRefExpr::VK_TLSDESC;
553     break;
554   default:
555     llvm_unreachable("unexpected opcode");
556   }
557 
558   const MCSymbolRefExpr *Sym = MCSymbolRefExpr::create(
559       MCInstLowering.GetSymbolFromOperand(MI.getOperand(3)), SRVK, Ctx);
560 
561   // Before binutils 2.41, ld has a bogus TLS relaxation error when the GD/LD
562   // code sequence using R_X86_64_GOTPCREL (instead of R_X86_64_GOTPCRELX) is
563   // attempted to be relaxed to IE/LE (binutils PR24784). Work around the bug by
564   // only using GOT when GOTPCRELX is enabled.
565   // TODO Delete the workaround when rustc no longer relies on the hack
566   bool UseGot = MMI->getModule()->getRtLibUseGOT() &&
567                 Ctx.getTargetOptions()->X86RelaxRelocations;
568 
569   if (SRVK == MCSymbolRefExpr::VK_TLSDESC) {
570     const MCSymbolRefExpr *Expr = MCSymbolRefExpr::create(
571         MCInstLowering.GetSymbolFromOperand(MI.getOperand(3)),
572         MCSymbolRefExpr::VK_TLSCALL, Ctx);
573     EmitAndCountInstruction(
574         MCInstBuilder(Is64BitsLP64 ? X86::LEA64r : X86::LEA32r)
575             .addReg(Is64BitsLP64 ? X86::RAX : X86::EAX)
576             .addReg(Is64Bits ? X86::RIP : X86::EBX)
577             .addImm(1)
578             .addReg(0)
579             .addExpr(Sym)
580             .addReg(0));
581     EmitAndCountInstruction(
582         MCInstBuilder(Is64Bits ? X86::CALL64m : X86::CALL32m)
583             .addReg(Is64BitsLP64 ? X86::RAX : X86::EAX)
584             .addImm(1)
585             .addReg(0)
586             .addExpr(Expr)
587             .addReg(0));
588   } else if (Is64Bits) {
589     bool NeedsPadding = SRVK == MCSymbolRefExpr::VK_TLSGD;
590     if (NeedsPadding && Is64BitsLP64)
591       EmitAndCountInstruction(MCInstBuilder(X86::DATA16_PREFIX));
592     EmitAndCountInstruction(MCInstBuilder(X86::LEA64r)
593                                 .addReg(X86::RDI)
594                                 .addReg(X86::RIP)
595                                 .addImm(1)
596                                 .addReg(0)
597                                 .addExpr(Sym)
598                                 .addReg(0));
599     const MCSymbol *TlsGetAddr = Ctx.getOrCreateSymbol("__tls_get_addr");
600     if (NeedsPadding) {
601       if (!UseGot)
602         EmitAndCountInstruction(MCInstBuilder(X86::DATA16_PREFIX));
603       EmitAndCountInstruction(MCInstBuilder(X86::DATA16_PREFIX));
604       EmitAndCountInstruction(MCInstBuilder(X86::REX64_PREFIX));
605     }
606     if (UseGot) {
607       const MCExpr *Expr = MCSymbolRefExpr::create(
608           TlsGetAddr, MCSymbolRefExpr::VK_GOTPCREL, Ctx);
609       EmitAndCountInstruction(MCInstBuilder(X86::CALL64m)
610                                   .addReg(X86::RIP)
611                                   .addImm(1)
612                                   .addReg(0)
613                                   .addExpr(Expr)
614                                   .addReg(0));
615     } else {
616       EmitAndCountInstruction(
617           MCInstBuilder(X86::CALL64pcrel32)
618               .addExpr(MCSymbolRefExpr::create(TlsGetAddr,
619                                                MCSymbolRefExpr::VK_PLT, Ctx)));
620     }
621   } else {
622     if (SRVK == MCSymbolRefExpr::VK_TLSGD && !UseGot) {
623       EmitAndCountInstruction(MCInstBuilder(X86::LEA32r)
624                                   .addReg(X86::EAX)
625                                   .addReg(0)
626                                   .addImm(1)
627                                   .addReg(X86::EBX)
628                                   .addExpr(Sym)
629                                   .addReg(0));
630     } else {
631       EmitAndCountInstruction(MCInstBuilder(X86::LEA32r)
632                                   .addReg(X86::EAX)
633                                   .addReg(X86::EBX)
634                                   .addImm(1)
635                                   .addReg(0)
636                                   .addExpr(Sym)
637                                   .addReg(0));
638     }
639 
640     const MCSymbol *TlsGetAddr = Ctx.getOrCreateSymbol("___tls_get_addr");
641     if (UseGot) {
642       const MCExpr *Expr =
643           MCSymbolRefExpr::create(TlsGetAddr, MCSymbolRefExpr::VK_GOT, Ctx);
644       EmitAndCountInstruction(MCInstBuilder(X86::CALL32m)
645                                   .addReg(X86::EBX)
646                                   .addImm(1)
647                                   .addReg(0)
648                                   .addExpr(Expr)
649                                   .addReg(0));
650     } else {
651       EmitAndCountInstruction(
652           MCInstBuilder(X86::CALLpcrel32)
653               .addExpr(MCSymbolRefExpr::create(TlsGetAddr,
654                                                MCSymbolRefExpr::VK_PLT, Ctx)));
655     }
656   }
657 }
658 
659 /// Emit the largest nop instruction smaller than or equal to \p NumBytes
660 /// bytes.  Return the size of nop emitted.
emitNop(MCStreamer & OS,unsigned NumBytes,const X86Subtarget * Subtarget)661 static unsigned emitNop(MCStreamer &OS, unsigned NumBytes,
662                         const X86Subtarget *Subtarget) {
663   // Determine the longest nop which can be efficiently decoded for the given
664   // target cpu.  15-bytes is the longest single NOP instruction, but some
665   // platforms can't decode the longest forms efficiently.
666   unsigned MaxNopLength = 1;
667   if (Subtarget->is64Bit()) {
668     // FIXME: We can use NOOPL on 32-bit targets with FeatureNOPL, but the
669     // IndexReg/BaseReg below need to be updated.
670     if (Subtarget->hasFeature(X86::TuningFast7ByteNOP))
671       MaxNopLength = 7;
672     else if (Subtarget->hasFeature(X86::TuningFast15ByteNOP))
673       MaxNopLength = 15;
674     else if (Subtarget->hasFeature(X86::TuningFast11ByteNOP))
675       MaxNopLength = 11;
676     else
677       MaxNopLength = 10;
678   } if (Subtarget->is32Bit())
679     MaxNopLength = 2;
680 
681   // Cap a single nop emission at the profitable value for the target
682   NumBytes = std::min(NumBytes, MaxNopLength);
683 
684   unsigned NopSize;
685   unsigned Opc, BaseReg, ScaleVal, IndexReg, Displacement, SegmentReg;
686   IndexReg = Displacement = SegmentReg = 0;
687   BaseReg = X86::RAX;
688   ScaleVal = 1;
689   switch (NumBytes) {
690   case 0:
691     llvm_unreachable("Zero nops?");
692     break;
693   case 1:
694     NopSize = 1;
695     Opc = X86::NOOP;
696     break;
697   case 2:
698     NopSize = 2;
699     Opc = X86::XCHG16ar;
700     break;
701   case 3:
702     NopSize = 3;
703     Opc = X86::NOOPL;
704     break;
705   case 4:
706     NopSize = 4;
707     Opc = X86::NOOPL;
708     Displacement = 8;
709     break;
710   case 5:
711     NopSize = 5;
712     Opc = X86::NOOPL;
713     Displacement = 8;
714     IndexReg = X86::RAX;
715     break;
716   case 6:
717     NopSize = 6;
718     Opc = X86::NOOPW;
719     Displacement = 8;
720     IndexReg = X86::RAX;
721     break;
722   case 7:
723     NopSize = 7;
724     Opc = X86::NOOPL;
725     Displacement = 512;
726     break;
727   case 8:
728     NopSize = 8;
729     Opc = X86::NOOPL;
730     Displacement = 512;
731     IndexReg = X86::RAX;
732     break;
733   case 9:
734     NopSize = 9;
735     Opc = X86::NOOPW;
736     Displacement = 512;
737     IndexReg = X86::RAX;
738     break;
739   default:
740     NopSize = 10;
741     Opc = X86::NOOPW;
742     Displacement = 512;
743     IndexReg = X86::RAX;
744     SegmentReg = X86::CS;
745     break;
746   }
747 
748   unsigned NumPrefixes = std::min(NumBytes - NopSize, 5U);
749   NopSize += NumPrefixes;
750   for (unsigned i = 0; i != NumPrefixes; ++i)
751     OS.emitBytes("\x66");
752 
753   switch (Opc) {
754   default: llvm_unreachable("Unexpected opcode");
755   case X86::NOOP:
756     OS.emitInstruction(MCInstBuilder(Opc), *Subtarget);
757     break;
758   case X86::XCHG16ar:
759     OS.emitInstruction(MCInstBuilder(Opc).addReg(X86::AX).addReg(X86::AX),
760                        *Subtarget);
761     break;
762   case X86::NOOPL:
763   case X86::NOOPW:
764     OS.emitInstruction(MCInstBuilder(Opc)
765                            .addReg(BaseReg)
766                            .addImm(ScaleVal)
767                            .addReg(IndexReg)
768                            .addImm(Displacement)
769                            .addReg(SegmentReg),
770                        *Subtarget);
771     break;
772   }
773   assert(NopSize <= NumBytes && "We overemitted?");
774   return NopSize;
775 }
776 
777 /// Emit the optimal amount of multi-byte nops on X86.
emitX86Nops(MCStreamer & OS,unsigned NumBytes,const X86Subtarget * Subtarget)778 static void emitX86Nops(MCStreamer &OS, unsigned NumBytes,
779                         const X86Subtarget *Subtarget) {
780   unsigned NopsToEmit = NumBytes;
781   (void)NopsToEmit;
782   while (NumBytes) {
783     NumBytes -= emitNop(OS, NumBytes, Subtarget);
784     assert(NopsToEmit >= NumBytes && "Emitted more than I asked for!");
785   }
786 }
787 
LowerSTATEPOINT(const MachineInstr & MI,X86MCInstLower & MCIL)788 void X86AsmPrinter::LowerSTATEPOINT(const MachineInstr &MI,
789                                     X86MCInstLower &MCIL) {
790   assert(Subtarget->is64Bit() && "Statepoint currently only supports X86-64");
791 
792   NoAutoPaddingScope NoPadScope(*OutStreamer);
793 
794   StatepointOpers SOpers(&MI);
795   if (unsigned PatchBytes = SOpers.getNumPatchBytes()) {
796     emitX86Nops(*OutStreamer, PatchBytes, Subtarget);
797   } else {
798     // Lower call target and choose correct opcode
799     const MachineOperand &CallTarget = SOpers.getCallTarget();
800     MCOperand CallTargetMCOp;
801     unsigned CallOpcode;
802     switch (CallTarget.getType()) {
803     case MachineOperand::MO_GlobalAddress:
804     case MachineOperand::MO_ExternalSymbol:
805       CallTargetMCOp = MCIL.LowerSymbolOperand(
806           CallTarget, MCIL.GetSymbolFromOperand(CallTarget));
807       CallOpcode = X86::CALL64pcrel32;
808       // Currently, we only support relative addressing with statepoints.
809       // Otherwise, we'll need a scratch register to hold the target
810       // address.  You'll fail asserts during load & relocation if this
811       // symbol is to far away. (TODO: support non-relative addressing)
812       break;
813     case MachineOperand::MO_Immediate:
814       CallTargetMCOp = MCOperand::createImm(CallTarget.getImm());
815       CallOpcode = X86::CALL64pcrel32;
816       // Currently, we only support relative addressing with statepoints.
817       // Otherwise, we'll need a scratch register to hold the target
818       // immediate.  You'll fail asserts during load & relocation if this
819       // address is to far away. (TODO: support non-relative addressing)
820       break;
821     case MachineOperand::MO_Register:
822       // FIXME: Add retpoline support and remove this.
823       if (Subtarget->useIndirectThunkCalls())
824         report_fatal_error("Lowering register statepoints with thunks not "
825                            "yet implemented.");
826       CallTargetMCOp = MCOperand::createReg(CallTarget.getReg());
827       CallOpcode = X86::CALL64r;
828       break;
829     default:
830       llvm_unreachable("Unsupported operand type in statepoint call target");
831       break;
832     }
833 
834     // Emit call
835     MCInst CallInst;
836     CallInst.setOpcode(CallOpcode);
837     CallInst.addOperand(CallTargetMCOp);
838     OutStreamer->emitInstruction(CallInst, getSubtargetInfo());
839   }
840 
841   // Record our statepoint node in the same section used by STACKMAP
842   // and PATCHPOINT
843   auto &Ctx = OutStreamer->getContext();
844   MCSymbol *MILabel = Ctx.createTempSymbol();
845   OutStreamer->emitLabel(MILabel);
846   SM.recordStatepoint(*MILabel, MI);
847 }
848 
LowerFAULTING_OP(const MachineInstr & FaultingMI,X86MCInstLower & MCIL)849 void X86AsmPrinter::LowerFAULTING_OP(const MachineInstr &FaultingMI,
850                                      X86MCInstLower &MCIL) {
851   // FAULTING_LOAD_OP <def>, <faltinf type>, <MBB handler>,
852   //                  <opcode>, <operands>
853 
854   NoAutoPaddingScope NoPadScope(*OutStreamer);
855 
856   Register DefRegister = FaultingMI.getOperand(0).getReg();
857   FaultMaps::FaultKind FK =
858       static_cast<FaultMaps::FaultKind>(FaultingMI.getOperand(1).getImm());
859   MCSymbol *HandlerLabel = FaultingMI.getOperand(2).getMBB()->getSymbol();
860   unsigned Opcode = FaultingMI.getOperand(3).getImm();
861   unsigned OperandsBeginIdx = 4;
862 
863   auto &Ctx = OutStreamer->getContext();
864   MCSymbol *FaultingLabel = Ctx.createTempSymbol();
865   OutStreamer->emitLabel(FaultingLabel);
866 
867   assert(FK < FaultMaps::FaultKindMax && "Invalid Faulting Kind!");
868   FM.recordFaultingOp(FK, FaultingLabel, HandlerLabel);
869 
870   MCInst MI;
871   MI.setOpcode(Opcode);
872 
873   if (DefRegister != X86::NoRegister)
874     MI.addOperand(MCOperand::createReg(DefRegister));
875 
876   for (const MachineOperand &MO :
877        llvm::drop_begin(FaultingMI.operands(), OperandsBeginIdx))
878     if (auto Op = MCIL.LowerMachineOperand(&FaultingMI, MO); Op.isValid())
879       MI.addOperand(Op);
880 
881   OutStreamer->AddComment("on-fault: " + HandlerLabel->getName());
882   OutStreamer->emitInstruction(MI, getSubtargetInfo());
883 }
884 
LowerFENTRY_CALL(const MachineInstr & MI,X86MCInstLower & MCIL)885 void X86AsmPrinter::LowerFENTRY_CALL(const MachineInstr &MI,
886                                      X86MCInstLower &MCIL) {
887   bool Is64Bits = Subtarget->is64Bit();
888   MCContext &Ctx = OutStreamer->getContext();
889   MCSymbol *fentry = Ctx.getOrCreateSymbol("__fentry__");
890   const MCSymbolRefExpr *Op =
891       MCSymbolRefExpr::create(fentry, MCSymbolRefExpr::VK_None, Ctx);
892 
893   EmitAndCountInstruction(
894       MCInstBuilder(Is64Bits ? X86::CALL64pcrel32 : X86::CALLpcrel32)
895           .addExpr(Op));
896 }
897 
LowerKCFI_CHECK(const MachineInstr & MI)898 void X86AsmPrinter::LowerKCFI_CHECK(const MachineInstr &MI) {
899   assert(std::next(MI.getIterator())->isCall() &&
900          "KCFI_CHECK not followed by a call instruction");
901 
902   // Adjust the offset for patchable-function-prefix. X86InstrInfo::getNop()
903   // returns a 1-byte X86::NOOP, which means the offset is the same in
904   // bytes.  This assumes that patchable-function-prefix is the same for all
905   // functions.
906   const MachineFunction &MF = *MI.getMF();
907   int64_t PrefixNops = 0;
908   (void)MF.getFunction()
909       .getFnAttribute("patchable-function-prefix")
910       .getValueAsString()
911       .getAsInteger(10, PrefixNops);
912 
913   // KCFI allows indirect calls to any location that's preceded by a valid
914   // type identifier. To avoid encoding the full constant into an instruction,
915   // and thus emitting potential call target gadgets at each indirect call
916   // site, load a negated constant to a register and compare that to the
917   // expected value at the call target.
918   const Register AddrReg = MI.getOperand(0).getReg();
919   const uint32_t Type = MI.getOperand(1).getImm();
920   // The check is immediately before the call. If the call target is in R10,
921   // we can clobber R11 for the check instead.
922   unsigned TempReg = AddrReg == X86::R10 ? X86::R11D : X86::R10D;
923   EmitAndCountInstruction(
924       MCInstBuilder(X86::MOV32ri).addReg(TempReg).addImm(-MaskKCFIType(Type)));
925   EmitAndCountInstruction(MCInstBuilder(X86::ADD32rm)
926                               .addReg(X86::NoRegister)
927                               .addReg(TempReg)
928                               .addReg(AddrReg)
929                               .addImm(1)
930                               .addReg(X86::NoRegister)
931                               .addImm(-(PrefixNops + 4))
932                               .addReg(X86::NoRegister));
933 
934   MCSymbol *Pass = OutContext.createTempSymbol();
935   EmitAndCountInstruction(
936       MCInstBuilder(X86::JCC_1)
937           .addExpr(MCSymbolRefExpr::create(Pass, OutContext))
938           .addImm(X86::COND_E));
939 
940   MCSymbol *Trap = OutContext.createTempSymbol();
941   OutStreamer->emitLabel(Trap);
942   EmitAndCountInstruction(MCInstBuilder(X86::TRAP));
943   emitKCFITrapEntry(MF, Trap);
944   OutStreamer->emitLabel(Pass);
945 }
946 
LowerASAN_CHECK_MEMACCESS(const MachineInstr & MI)947 void X86AsmPrinter::LowerASAN_CHECK_MEMACCESS(const MachineInstr &MI) {
948   // FIXME: Make this work on non-ELF.
949   if (!TM.getTargetTriple().isOSBinFormatELF()) {
950     report_fatal_error("llvm.asan.check.memaccess only supported on ELF");
951     return;
952   }
953 
954   const auto &Reg = MI.getOperand(0).getReg();
955   ASanAccessInfo AccessInfo(MI.getOperand(1).getImm());
956 
957   uint64_t ShadowBase;
958   int MappingScale;
959   bool OrShadowOffset;
960   getAddressSanitizerParams(Triple(TM.getTargetTriple()), 64,
961                             AccessInfo.CompileKernel, &ShadowBase,
962                             &MappingScale, &OrShadowOffset);
963 
964   StringRef Name = AccessInfo.IsWrite ? "store" : "load";
965   StringRef Op = OrShadowOffset ? "or" : "add";
966   std::string SymName = ("__asan_check_" + Name + "_" + Op + "_" +
967                          Twine(1ULL << AccessInfo.AccessSizeIndex) + "_" +
968                          TM.getMCRegisterInfo()->getName(Reg.asMCReg()))
969                             .str();
970   if (OrShadowOffset)
971     report_fatal_error(
972         "OrShadowOffset is not supported with optimized callbacks");
973 
974   EmitAndCountInstruction(
975       MCInstBuilder(X86::CALL64pcrel32)
976           .addExpr(MCSymbolRefExpr::create(
977               OutContext.getOrCreateSymbol(SymName), OutContext)));
978 }
979 
LowerPATCHABLE_OP(const MachineInstr & MI,X86MCInstLower & MCIL)980 void X86AsmPrinter::LowerPATCHABLE_OP(const MachineInstr &MI,
981                                       X86MCInstLower &MCIL) {
982   // PATCHABLE_OP minsize
983 
984   NoAutoPaddingScope NoPadScope(*OutStreamer);
985 
986   auto NextMI = std::find_if(std::next(MI.getIterator()),
987                              MI.getParent()->end().getInstrIterator(),
988                              [](auto &II) { return !II.isMetaInstruction(); });
989 
990   SmallString<256> Code;
991   unsigned MinSize = MI.getOperand(0).getImm();
992 
993   if (NextMI != MI.getParent()->end() && !NextMI->isInlineAsm()) {
994     // Lower the next MachineInstr to find its byte size.
995     // If the next instruction is inline assembly, we skip lowering it for now,
996     // and assume we should always generate NOPs.
997     MCInst MCI;
998     MCIL.Lower(&*NextMI, MCI);
999 
1000     SmallVector<MCFixup, 4> Fixups;
1001     CodeEmitter->encodeInstruction(MCI, Code, Fixups, getSubtargetInfo());
1002   }
1003 
1004   if (Code.size() < MinSize) {
1005     if (MinSize == 2 && Subtarget->is32Bit() &&
1006         Subtarget->isTargetWindowsMSVC() &&
1007         (Subtarget->getCPU().empty() || Subtarget->getCPU() == "pentium3")) {
1008       // For compatibility reasons, when targetting MSVC, it is important to
1009       // generate a 'legacy' NOP in the form of a 8B FF MOV EDI, EDI. Some tools
1010       // rely specifically on this pattern to be able to patch a function.
1011       // This is only for 32-bit targets, when using /arch:IA32 or /arch:SSE.
1012       OutStreamer->emitInstruction(
1013           MCInstBuilder(X86::MOV32rr_REV).addReg(X86::EDI).addReg(X86::EDI),
1014           *Subtarget);
1015     } else {
1016       unsigned NopSize = emitNop(*OutStreamer, MinSize, Subtarget);
1017       assert(NopSize == MinSize && "Could not implement MinSize!");
1018       (void)NopSize;
1019     }
1020   }
1021 }
1022 
1023 // Lower a stackmap of the form:
1024 // <id>, <shadowBytes>, ...
LowerSTACKMAP(const MachineInstr & MI)1025 void X86AsmPrinter::LowerSTACKMAP(const MachineInstr &MI) {
1026   SMShadowTracker.emitShadowPadding(*OutStreamer, getSubtargetInfo());
1027 
1028   auto &Ctx = OutStreamer->getContext();
1029   MCSymbol *MILabel = Ctx.createTempSymbol();
1030   OutStreamer->emitLabel(MILabel);
1031 
1032   SM.recordStackMap(*MILabel, MI);
1033   unsigned NumShadowBytes = MI.getOperand(1).getImm();
1034   SMShadowTracker.reset(NumShadowBytes);
1035 }
1036 
1037 // Lower a patchpoint of the form:
1038 // [<def>], <id>, <numBytes>, <target>, <numArgs>, <cc>, ...
LowerPATCHPOINT(const MachineInstr & MI,X86MCInstLower & MCIL)1039 void X86AsmPrinter::LowerPATCHPOINT(const MachineInstr &MI,
1040                                     X86MCInstLower &MCIL) {
1041   assert(Subtarget->is64Bit() && "Patchpoint currently only supports X86-64");
1042 
1043   SMShadowTracker.emitShadowPadding(*OutStreamer, getSubtargetInfo());
1044 
1045   NoAutoPaddingScope NoPadScope(*OutStreamer);
1046 
1047   auto &Ctx = OutStreamer->getContext();
1048   MCSymbol *MILabel = Ctx.createTempSymbol();
1049   OutStreamer->emitLabel(MILabel);
1050   SM.recordPatchPoint(*MILabel, MI);
1051 
1052   PatchPointOpers opers(&MI);
1053   unsigned ScratchIdx = opers.getNextScratchIdx();
1054   unsigned EncodedBytes = 0;
1055   const MachineOperand &CalleeMO = opers.getCallTarget();
1056 
1057   // Check for null target. If target is non-null (i.e. is non-zero or is
1058   // symbolic) then emit a call.
1059   if (!(CalleeMO.isImm() && !CalleeMO.getImm())) {
1060     MCOperand CalleeMCOp;
1061     switch (CalleeMO.getType()) {
1062     default:
1063       /// FIXME: Add a verifier check for bad callee types.
1064       llvm_unreachable("Unrecognized callee operand type.");
1065     case MachineOperand::MO_Immediate:
1066       if (CalleeMO.getImm())
1067         CalleeMCOp = MCOperand::createImm(CalleeMO.getImm());
1068       break;
1069     case MachineOperand::MO_ExternalSymbol:
1070     case MachineOperand::MO_GlobalAddress:
1071       CalleeMCOp = MCIL.LowerSymbolOperand(CalleeMO,
1072                                            MCIL.GetSymbolFromOperand(CalleeMO));
1073       break;
1074     }
1075 
1076     // Emit MOV to materialize the target address and the CALL to target.
1077     // This is encoded with 12-13 bytes, depending on which register is used.
1078     Register ScratchReg = MI.getOperand(ScratchIdx).getReg();
1079     if (X86II::isX86_64ExtendedReg(ScratchReg))
1080       EncodedBytes = 13;
1081     else
1082       EncodedBytes = 12;
1083 
1084     EmitAndCountInstruction(
1085         MCInstBuilder(X86::MOV64ri).addReg(ScratchReg).addOperand(CalleeMCOp));
1086     // FIXME: Add retpoline support and remove this.
1087     if (Subtarget->useIndirectThunkCalls())
1088       report_fatal_error(
1089           "Lowering patchpoint with thunks not yet implemented.");
1090     EmitAndCountInstruction(MCInstBuilder(X86::CALL64r).addReg(ScratchReg));
1091   }
1092 
1093   // Emit padding.
1094   unsigned NumBytes = opers.getNumPatchBytes();
1095   assert(NumBytes >= EncodedBytes &&
1096          "Patchpoint can't request size less than the length of a call.");
1097 
1098   emitX86Nops(*OutStreamer, NumBytes - EncodedBytes, Subtarget);
1099 }
1100 
LowerPATCHABLE_EVENT_CALL(const MachineInstr & MI,X86MCInstLower & MCIL)1101 void X86AsmPrinter::LowerPATCHABLE_EVENT_CALL(const MachineInstr &MI,
1102                                               X86MCInstLower &MCIL) {
1103   assert(Subtarget->is64Bit() && "XRay custom events only supports X86-64");
1104 
1105   NoAutoPaddingScope NoPadScope(*OutStreamer);
1106 
1107   // We want to emit the following pattern, which follows the x86 calling
1108   // convention to prepare for the trampoline call to be patched in.
1109   //
1110   //   .p2align 1, ...
1111   // .Lxray_event_sled_N:
1112   //   jmp +N                        // jump across the instrumentation sled
1113   //   ...                           // set up arguments in register
1114   //   callq __xray_CustomEvent@plt  // force dependency to symbol
1115   //   ...
1116   //   <jump here>
1117   //
1118   // After patching, it would look something like:
1119   //
1120   //   nopw (2-byte nop)
1121   //   ...
1122   //   callq __xrayCustomEvent  // already lowered
1123   //   ...
1124   //
1125   // ---
1126   // First we emit the label and the jump.
1127   auto CurSled = OutContext.createTempSymbol("xray_event_sled_", true);
1128   OutStreamer->AddComment("# XRay Custom Event Log");
1129   OutStreamer->emitCodeAlignment(Align(2), &getSubtargetInfo());
1130   OutStreamer->emitLabel(CurSled);
1131 
1132   // Use a two-byte `jmp`. This version of JMP takes an 8-bit relative offset as
1133   // an operand (computed as an offset from the jmp instruction).
1134   // FIXME: Find another less hacky way do force the relative jump.
1135   OutStreamer->emitBinaryData("\xeb\x0f");
1136 
1137   // The default C calling convention will place two arguments into %rcx and
1138   // %rdx -- so we only work with those.
1139   const Register DestRegs[] = {X86::RDI, X86::RSI};
1140   bool UsedMask[] = {false, false};
1141   // Filled out in loop.
1142   Register SrcRegs[] = {0, 0};
1143 
1144   // Then we put the operands in the %rdi and %rsi registers. We spill the
1145   // values in the register before we clobber them, and mark them as used in
1146   // UsedMask. In case the arguments are already in the correct register, we use
1147   // emit nops appropriately sized to keep the sled the same size in every
1148   // situation.
1149   for (unsigned I = 0; I < MI.getNumOperands(); ++I)
1150     if (auto Op = MCIL.LowerMachineOperand(&MI, MI.getOperand(I));
1151         Op.isValid()) {
1152       assert(Op.isReg() && "Only support arguments in registers");
1153       SrcRegs[I] = getX86SubSuperRegister(Op.getReg(), 64);
1154       assert(SrcRegs[I].isValid() && "Invalid operand");
1155       if (SrcRegs[I] != DestRegs[I]) {
1156         UsedMask[I] = true;
1157         EmitAndCountInstruction(
1158             MCInstBuilder(X86::PUSH64r).addReg(DestRegs[I]));
1159       } else {
1160         emitX86Nops(*OutStreamer, 4, Subtarget);
1161       }
1162     }
1163 
1164   // Now that the register values are stashed, mov arguments into place.
1165   // FIXME: This doesn't work if one of the later SrcRegs is equal to an
1166   // earlier DestReg. We will have already overwritten over the register before
1167   // we can copy from it.
1168   for (unsigned I = 0; I < MI.getNumOperands(); ++I)
1169     if (SrcRegs[I] != DestRegs[I])
1170       EmitAndCountInstruction(
1171           MCInstBuilder(X86::MOV64rr).addReg(DestRegs[I]).addReg(SrcRegs[I]));
1172 
1173   // We emit a hard dependency on the __xray_CustomEvent symbol, which is the
1174   // name of the trampoline to be implemented by the XRay runtime.
1175   auto TSym = OutContext.getOrCreateSymbol("__xray_CustomEvent");
1176   MachineOperand TOp = MachineOperand::CreateMCSymbol(TSym);
1177   if (isPositionIndependent())
1178     TOp.setTargetFlags(X86II::MO_PLT);
1179 
1180   // Emit the call instruction.
1181   EmitAndCountInstruction(MCInstBuilder(X86::CALL64pcrel32)
1182                               .addOperand(MCIL.LowerSymbolOperand(TOp, TSym)));
1183 
1184   // Restore caller-saved and used registers.
1185   for (unsigned I = sizeof UsedMask; I-- > 0;)
1186     if (UsedMask[I])
1187       EmitAndCountInstruction(MCInstBuilder(X86::POP64r).addReg(DestRegs[I]));
1188     else
1189       emitX86Nops(*OutStreamer, 1, Subtarget);
1190 
1191   OutStreamer->AddComment("xray custom event end.");
1192 
1193   // Record the sled version. Version 0 of this sled was spelled differently, so
1194   // we let the runtime handle the different offsets we're using. Version 2
1195   // changed the absolute address to a PC-relative address.
1196   recordSled(CurSled, MI, SledKind::CUSTOM_EVENT, 2);
1197 }
1198 
LowerPATCHABLE_TYPED_EVENT_CALL(const MachineInstr & MI,X86MCInstLower & MCIL)1199 void X86AsmPrinter::LowerPATCHABLE_TYPED_EVENT_CALL(const MachineInstr &MI,
1200                                                     X86MCInstLower &MCIL) {
1201   assert(Subtarget->is64Bit() && "XRay typed events only supports X86-64");
1202 
1203   NoAutoPaddingScope NoPadScope(*OutStreamer);
1204 
1205   // We want to emit the following pattern, which follows the x86 calling
1206   // convention to prepare for the trampoline call to be patched in.
1207   //
1208   //   .p2align 1, ...
1209   // .Lxray_event_sled_N:
1210   //   jmp +N                        // jump across the instrumentation sled
1211   //   ...                           // set up arguments in register
1212   //   callq __xray_TypedEvent@plt  // force dependency to symbol
1213   //   ...
1214   //   <jump here>
1215   //
1216   // After patching, it would look something like:
1217   //
1218   //   nopw (2-byte nop)
1219   //   ...
1220   //   callq __xrayTypedEvent  // already lowered
1221   //   ...
1222   //
1223   // ---
1224   // First we emit the label and the jump.
1225   auto CurSled = OutContext.createTempSymbol("xray_typed_event_sled_", true);
1226   OutStreamer->AddComment("# XRay Typed Event Log");
1227   OutStreamer->emitCodeAlignment(Align(2), &getSubtargetInfo());
1228   OutStreamer->emitLabel(CurSled);
1229 
1230   // Use a two-byte `jmp`. This version of JMP takes an 8-bit relative offset as
1231   // an operand (computed as an offset from the jmp instruction).
1232   // FIXME: Find another less hacky way do force the relative jump.
1233   OutStreamer->emitBinaryData("\xeb\x14");
1234 
1235   // An x86-64 convention may place three arguments into %rcx, %rdx, and R8,
1236   // so we'll work with those. Or we may be called via SystemV, in which case
1237   // we don't have to do any translation.
1238   const Register DestRegs[] = {X86::RDI, X86::RSI, X86::RDX};
1239   bool UsedMask[] = {false, false, false};
1240 
1241   // Will fill out src regs in the loop.
1242   Register SrcRegs[] = {0, 0, 0};
1243 
1244   // Then we put the operands in the SystemV registers. We spill the values in
1245   // the registers before we clobber them, and mark them as used in UsedMask.
1246   // In case the arguments are already in the correct register, we emit nops
1247   // appropriately sized to keep the sled the same size in every situation.
1248   for (unsigned I = 0; I < MI.getNumOperands(); ++I)
1249     if (auto Op = MCIL.LowerMachineOperand(&MI, MI.getOperand(I));
1250         Op.isValid()) {
1251       // TODO: Is register only support adequate?
1252       assert(Op.isReg() && "Only supports arguments in registers");
1253       SrcRegs[I] = getX86SubSuperRegister(Op.getReg(), 64);
1254       assert(SrcRegs[I].isValid() && "Invalid operand");
1255       if (SrcRegs[I] != DestRegs[I]) {
1256         UsedMask[I] = true;
1257         EmitAndCountInstruction(
1258             MCInstBuilder(X86::PUSH64r).addReg(DestRegs[I]));
1259       } else {
1260         emitX86Nops(*OutStreamer, 4, Subtarget);
1261       }
1262     }
1263 
1264   // In the above loop we only stash all of the destination registers or emit
1265   // nops if the arguments are already in the right place. Doing the actually
1266   // moving is postponed until after all the registers are stashed so nothing
1267   // is clobbers. We've already added nops to account for the size of mov and
1268   // push if the register is in the right place, so we only have to worry about
1269   // emitting movs.
1270   // FIXME: This doesn't work if one of the later SrcRegs is equal to an
1271   // earlier DestReg. We will have already overwritten over the register before
1272   // we can copy from it.
1273   for (unsigned I = 0; I < MI.getNumOperands(); ++I)
1274     if (UsedMask[I])
1275       EmitAndCountInstruction(
1276           MCInstBuilder(X86::MOV64rr).addReg(DestRegs[I]).addReg(SrcRegs[I]));
1277 
1278   // We emit a hard dependency on the __xray_TypedEvent symbol, which is the
1279   // name of the trampoline to be implemented by the XRay runtime.
1280   auto TSym = OutContext.getOrCreateSymbol("__xray_TypedEvent");
1281   MachineOperand TOp = MachineOperand::CreateMCSymbol(TSym);
1282   if (isPositionIndependent())
1283     TOp.setTargetFlags(X86II::MO_PLT);
1284 
1285   // Emit the call instruction.
1286   EmitAndCountInstruction(MCInstBuilder(X86::CALL64pcrel32)
1287                               .addOperand(MCIL.LowerSymbolOperand(TOp, TSym)));
1288 
1289   // Restore caller-saved and used registers.
1290   for (unsigned I = sizeof UsedMask; I-- > 0;)
1291     if (UsedMask[I])
1292       EmitAndCountInstruction(MCInstBuilder(X86::POP64r).addReg(DestRegs[I]));
1293     else
1294       emitX86Nops(*OutStreamer, 1, Subtarget);
1295 
1296   OutStreamer->AddComment("xray typed event end.");
1297 
1298   // Record the sled version.
1299   recordSled(CurSled, MI, SledKind::TYPED_EVENT, 2);
1300 }
1301 
LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr & MI,X86MCInstLower & MCIL)1302 void X86AsmPrinter::LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI,
1303                                                   X86MCInstLower &MCIL) {
1304 
1305   NoAutoPaddingScope NoPadScope(*OutStreamer);
1306 
1307   const Function &F = MF->getFunction();
1308   if (F.hasFnAttribute("patchable-function-entry")) {
1309     unsigned Num;
1310     if (F.getFnAttribute("patchable-function-entry")
1311             .getValueAsString()
1312             .getAsInteger(10, Num))
1313       return;
1314     emitX86Nops(*OutStreamer, Num, Subtarget);
1315     return;
1316   }
1317   // We want to emit the following pattern:
1318   //
1319   //   .p2align 1, ...
1320   // .Lxray_sled_N:
1321   //   jmp .tmpN
1322   //   # 9 bytes worth of noops
1323   //
1324   // We need the 9 bytes because at runtime, we'd be patching over the full 11
1325   // bytes with the following pattern:
1326   //
1327   //   mov %r10, <function id, 32-bit>   // 6 bytes
1328   //   call <relative offset, 32-bits>   // 5 bytes
1329   //
1330   auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
1331   OutStreamer->emitCodeAlignment(Align(2), &getSubtargetInfo());
1332   OutStreamer->emitLabel(CurSled);
1333 
1334   // Use a two-byte `jmp`. This version of JMP takes an 8-bit relative offset as
1335   // an operand (computed as an offset from the jmp instruction).
1336   // FIXME: Find another less hacky way do force the relative jump.
1337   OutStreamer->emitBytes("\xeb\x09");
1338   emitX86Nops(*OutStreamer, 9, Subtarget);
1339   recordSled(CurSled, MI, SledKind::FUNCTION_ENTER, 2);
1340 }
1341 
LowerPATCHABLE_RET(const MachineInstr & MI,X86MCInstLower & MCIL)1342 void X86AsmPrinter::LowerPATCHABLE_RET(const MachineInstr &MI,
1343                                        X86MCInstLower &MCIL) {
1344   NoAutoPaddingScope NoPadScope(*OutStreamer);
1345 
1346   // Since PATCHABLE_RET takes the opcode of the return statement as an
1347   // argument, we use that to emit the correct form of the RET that we want.
1348   // i.e. when we see this:
1349   //
1350   //   PATCHABLE_RET X86::RET ...
1351   //
1352   // We should emit the RET followed by sleds.
1353   //
1354   //   .p2align 1, ...
1355   // .Lxray_sled_N:
1356   //   ret  # or equivalent instruction
1357   //   # 10 bytes worth of noops
1358   //
1359   // This just makes sure that the alignment for the next instruction is 2.
1360   auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
1361   OutStreamer->emitCodeAlignment(Align(2), &getSubtargetInfo());
1362   OutStreamer->emitLabel(CurSled);
1363   unsigned OpCode = MI.getOperand(0).getImm();
1364   MCInst Ret;
1365   Ret.setOpcode(OpCode);
1366   for (auto &MO : drop_begin(MI.operands()))
1367     if (auto Op = MCIL.LowerMachineOperand(&MI, MO); Op.isValid())
1368       Ret.addOperand(Op);
1369   OutStreamer->emitInstruction(Ret, getSubtargetInfo());
1370   emitX86Nops(*OutStreamer, 10, Subtarget);
1371   recordSled(CurSled, MI, SledKind::FUNCTION_EXIT, 2);
1372 }
1373 
LowerPATCHABLE_TAIL_CALL(const MachineInstr & MI,X86MCInstLower & MCIL)1374 void X86AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI,
1375                                              X86MCInstLower &MCIL) {
1376   MCInst TC;
1377   TC.setOpcode(convertTailJumpOpcode(MI.getOperand(0).getImm()));
1378   // Drop the tail jump opcode.
1379   auto TCOperands = drop_begin(MI.operands());
1380   bool IsConditional = TC.getOpcode() == X86::JCC_1;
1381   MCSymbol *FallthroughLabel;
1382   if (IsConditional) {
1383     // Rewrite:
1384     //   je target
1385     //
1386     // To:
1387     //   jne .fallthrough
1388     //   .p2align 1, ...
1389     // .Lxray_sled_N:
1390     //   SLED_CODE
1391     //   jmp target
1392     // .fallthrough:
1393     FallthroughLabel = OutContext.createTempSymbol();
1394     EmitToStreamer(
1395         *OutStreamer,
1396         MCInstBuilder(X86::JCC_1)
1397             .addExpr(MCSymbolRefExpr::create(FallthroughLabel, OutContext))
1398             .addImm(X86::GetOppositeBranchCondition(
1399                 static_cast<X86::CondCode>(MI.getOperand(2).getImm()))));
1400     TC.setOpcode(X86::JMP_1);
1401     // Drop the condition code.
1402     TCOperands = drop_end(TCOperands);
1403   }
1404 
1405   NoAutoPaddingScope NoPadScope(*OutStreamer);
1406 
1407   // Like PATCHABLE_RET, we have the actual instruction in the operands to this
1408   // instruction so we lower that particular instruction and its operands.
1409   // Unlike PATCHABLE_RET though, we put the sled before the JMP, much like how
1410   // we do it for PATCHABLE_FUNCTION_ENTER. The sled should be very similar to
1411   // the PATCHABLE_FUNCTION_ENTER case, followed by the lowering of the actual
1412   // tail call much like how we have it in PATCHABLE_RET.
1413   auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
1414   OutStreamer->emitCodeAlignment(Align(2), &getSubtargetInfo());
1415   OutStreamer->emitLabel(CurSled);
1416   auto Target = OutContext.createTempSymbol();
1417 
1418   // Use a two-byte `jmp`. This version of JMP takes an 8-bit relative offset as
1419   // an operand (computed as an offset from the jmp instruction).
1420   // FIXME: Find another less hacky way do force the relative jump.
1421   OutStreamer->emitBytes("\xeb\x09");
1422   emitX86Nops(*OutStreamer, 9, Subtarget);
1423   OutStreamer->emitLabel(Target);
1424   recordSled(CurSled, MI, SledKind::TAIL_CALL, 2);
1425 
1426   // Before emitting the instruction, add a comment to indicate that this is
1427   // indeed a tail call.
1428   OutStreamer->AddComment("TAILCALL");
1429   for (auto &MO : TCOperands)
1430     if (auto Op = MCIL.LowerMachineOperand(&MI, MO); Op.isValid())
1431       TC.addOperand(Op);
1432   OutStreamer->emitInstruction(TC, getSubtargetInfo());
1433 
1434   if (IsConditional)
1435     OutStreamer->emitLabel(FallthroughLabel);
1436 }
1437 
1438 // Returns instruction preceding MBBI in MachineFunction.
1439 // If MBBI is the first instruction of the first basic block, returns null.
1440 static MachineBasicBlock::const_iterator
PrevCrossBBInst(MachineBasicBlock::const_iterator MBBI)1441 PrevCrossBBInst(MachineBasicBlock::const_iterator MBBI) {
1442   const MachineBasicBlock *MBB = MBBI->getParent();
1443   while (MBBI == MBB->begin()) {
1444     if (MBB == &MBB->getParent()->front())
1445       return MachineBasicBlock::const_iterator();
1446     MBB = MBB->getPrevNode();
1447     MBBI = MBB->end();
1448   }
1449   --MBBI;
1450   return MBBI;
1451 }
1452 
getSrcIdx(const MachineInstr * MI,unsigned SrcIdx)1453 static unsigned getSrcIdx(const MachineInstr* MI, unsigned SrcIdx) {
1454   if (X86II::isKMasked(MI->getDesc().TSFlags)) {
1455     // Skip mask operand.
1456     ++SrcIdx;
1457     if (X86II::isKMergeMasked(MI->getDesc().TSFlags)) {
1458       // Skip passthru operand.
1459       ++SrcIdx;
1460     }
1461   }
1462   return SrcIdx;
1463 }
1464 
printDstRegisterName(raw_ostream & CS,const MachineInstr * MI,unsigned SrcOpIdx)1465 static void printDstRegisterName(raw_ostream &CS, const MachineInstr *MI,
1466                                  unsigned SrcOpIdx) {
1467   const MachineOperand &DstOp = MI->getOperand(0);
1468   CS << X86ATTInstPrinter::getRegisterName(DstOp.getReg());
1469 
1470   // Handle AVX512 MASK/MASXZ write mask comments.
1471   // MASK: zmmX {%kY}
1472   // MASKZ: zmmX {%kY} {z}
1473   if (X86II::isKMasked(MI->getDesc().TSFlags)) {
1474     const MachineOperand &WriteMaskOp = MI->getOperand(SrcOpIdx - 1);
1475     StringRef Mask = X86ATTInstPrinter::getRegisterName(WriteMaskOp.getReg());
1476     CS << " {%" << Mask << "}";
1477     if (!X86II::isKMergeMasked(MI->getDesc().TSFlags)) {
1478       CS << " {z}";
1479     }
1480   }
1481 }
1482 
printShuffleMask(raw_ostream & CS,StringRef Src1Name,StringRef Src2Name,ArrayRef<int> Mask)1483 static void printShuffleMask(raw_ostream &CS, StringRef Src1Name,
1484                              StringRef Src2Name, ArrayRef<int> Mask) {
1485   // One source operand, fix the mask to print all elements in one span.
1486   SmallVector<int, 8> ShuffleMask(Mask);
1487   if (Src1Name == Src2Name)
1488     for (int i = 0, e = ShuffleMask.size(); i != e; ++i)
1489       if (ShuffleMask[i] >= e)
1490         ShuffleMask[i] -= e;
1491 
1492   for (int i = 0, e = ShuffleMask.size(); i != e; ++i) {
1493     if (i != 0)
1494       CS << ",";
1495     if (ShuffleMask[i] == SM_SentinelZero) {
1496       CS << "zero";
1497       continue;
1498     }
1499 
1500     // Otherwise, it must come from src1 or src2.  Print the span of elements
1501     // that comes from this src.
1502     bool isSrc1 = ShuffleMask[i] < (int)e;
1503     CS << (isSrc1 ? Src1Name : Src2Name) << '[';
1504 
1505     bool IsFirst = true;
1506     while (i != e && ShuffleMask[i] != SM_SentinelZero &&
1507            (ShuffleMask[i] < (int)e) == isSrc1) {
1508       if (!IsFirst)
1509         CS << ',';
1510       else
1511         IsFirst = false;
1512       if (ShuffleMask[i] == SM_SentinelUndef)
1513         CS << "u";
1514       else
1515         CS << ShuffleMask[i] % (int)e;
1516       ++i;
1517     }
1518     CS << ']';
1519     --i; // For loop increments element #.
1520   }
1521 }
1522 
getShuffleComment(const MachineInstr * MI,unsigned SrcOp1Idx,unsigned SrcOp2Idx,ArrayRef<int> Mask)1523 static std::string getShuffleComment(const MachineInstr *MI, unsigned SrcOp1Idx,
1524                                      unsigned SrcOp2Idx, ArrayRef<int> Mask) {
1525   std::string Comment;
1526 
1527   const MachineOperand &SrcOp1 = MI->getOperand(SrcOp1Idx);
1528   const MachineOperand &SrcOp2 = MI->getOperand(SrcOp2Idx);
1529   StringRef Src1Name = SrcOp1.isReg()
1530                            ? X86ATTInstPrinter::getRegisterName(SrcOp1.getReg())
1531                            : "mem";
1532   StringRef Src2Name = SrcOp2.isReg()
1533                            ? X86ATTInstPrinter::getRegisterName(SrcOp2.getReg())
1534                            : "mem";
1535 
1536   raw_string_ostream CS(Comment);
1537   printDstRegisterName(CS, MI, SrcOp1Idx);
1538   CS << " = ";
1539   printShuffleMask(CS, Src1Name, Src2Name, Mask);
1540   CS.flush();
1541 
1542   return Comment;
1543 }
1544 
printConstant(const APInt & Val,raw_ostream & CS,bool PrintZero=false)1545 static void printConstant(const APInt &Val, raw_ostream &CS,
1546                           bool PrintZero = false) {
1547   if (Val.getBitWidth() <= 64) {
1548     CS << (PrintZero ? 0ULL : Val.getZExtValue());
1549   } else {
1550     // print multi-word constant as (w0,w1)
1551     CS << "(";
1552     for (int i = 0, N = Val.getNumWords(); i < N; ++i) {
1553       if (i > 0)
1554         CS << ",";
1555       CS << (PrintZero ? 0ULL : Val.getRawData()[i]);
1556     }
1557     CS << ")";
1558   }
1559 }
1560 
printConstant(const APFloat & Flt,raw_ostream & CS,bool PrintZero=false)1561 static void printConstant(const APFloat &Flt, raw_ostream &CS,
1562                           bool PrintZero = false) {
1563   SmallString<32> Str;
1564   // Force scientific notation to distinguish from integers.
1565   if (PrintZero)
1566     APFloat::getZero(Flt.getSemantics()).toString(Str, 0, 0);
1567   else
1568     Flt.toString(Str, 0, 0);
1569   CS << Str;
1570 }
1571 
printConstant(const Constant * COp,unsigned BitWidth,raw_ostream & CS,bool PrintZero=false)1572 static void printConstant(const Constant *COp, unsigned BitWidth,
1573                           raw_ostream &CS, bool PrintZero = false) {
1574   if (isa<UndefValue>(COp)) {
1575     CS << "u";
1576   } else if (auto *CI = dyn_cast<ConstantInt>(COp)) {
1577     printConstant(CI->getValue(), CS, PrintZero);
1578   } else if (auto *CF = dyn_cast<ConstantFP>(COp)) {
1579     printConstant(CF->getValueAPF(), CS, PrintZero);
1580   } else if (auto *CDS = dyn_cast<ConstantDataSequential>(COp)) {
1581     Type *EltTy = CDS->getElementType();
1582     bool IsInteger = EltTy->isIntegerTy();
1583     bool IsFP = EltTy->isHalfTy() || EltTy->isFloatTy() || EltTy->isDoubleTy();
1584     unsigned EltBits = EltTy->getPrimitiveSizeInBits();
1585     unsigned E = std::min(BitWidth / EltBits, CDS->getNumElements());
1586     assert((BitWidth % EltBits) == 0 && "Element size mismatch");
1587     for (unsigned I = 0; I != E; ++I) {
1588       if (I != 0)
1589         CS << ",";
1590       if (IsInteger)
1591         printConstant(CDS->getElementAsAPInt(I), CS, PrintZero);
1592       else if (IsFP)
1593         printConstant(CDS->getElementAsAPFloat(I), CS, PrintZero);
1594       else
1595         CS << "?";
1596     }
1597   } else if (auto *CV = dyn_cast<ConstantVector>(COp)) {
1598     unsigned EltBits = CV->getType()->getScalarSizeInBits();
1599     unsigned E = std::min(BitWidth / EltBits, CV->getNumOperands());
1600     assert((BitWidth % EltBits) == 0 && "Element size mismatch");
1601     for (unsigned I = 0; I != E; ++I) {
1602       if (I != 0)
1603         CS << ",";
1604       printConstant(CV->getOperand(I), EltBits, CS, PrintZero);
1605     }
1606   } else {
1607     CS << "?";
1608   }
1609 }
1610 
printZeroUpperMove(const MachineInstr * MI,MCStreamer & OutStreamer,int SclWidth,int VecWidth,const char * ShuffleComment)1611 static void printZeroUpperMove(const MachineInstr *MI, MCStreamer &OutStreamer,
1612                                int SclWidth, int VecWidth,
1613                                const char *ShuffleComment) {
1614   unsigned SrcIdx = getSrcIdx(MI, 1);
1615 
1616   std::string Comment;
1617   raw_string_ostream CS(Comment);
1618   printDstRegisterName(CS, MI, SrcIdx);
1619   CS << " = ";
1620 
1621   if (auto *C = X86::getConstantFromPool(*MI, SrcIdx)) {
1622     CS << "[";
1623     printConstant(C, SclWidth, CS);
1624     for (int I = 1, E = VecWidth / SclWidth; I < E; ++I) {
1625       CS << ",";
1626       printConstant(C, SclWidth, CS, true);
1627     }
1628     CS << "]";
1629     OutStreamer.AddComment(CS.str());
1630     return; // early-out
1631   }
1632 
1633   // We didn't find a constant load, fallback to a shuffle mask decode.
1634   CS << ShuffleComment;
1635   OutStreamer.AddComment(CS.str());
1636 }
1637 
printBroadcast(const MachineInstr * MI,MCStreamer & OutStreamer,int Repeats,int BitWidth)1638 static void printBroadcast(const MachineInstr *MI, MCStreamer &OutStreamer,
1639                            int Repeats, int BitWidth) {
1640   unsigned SrcIdx = getSrcIdx(MI, 1);
1641   if (auto *C = X86::getConstantFromPool(*MI, SrcIdx)) {
1642     std::string Comment;
1643     raw_string_ostream CS(Comment);
1644     printDstRegisterName(CS, MI, SrcIdx);
1645     CS << " = [";
1646     for (int l = 0; l != Repeats; ++l) {
1647       if (l != 0)
1648         CS << ",";
1649       printConstant(C, BitWidth, CS);
1650     }
1651     CS << "]";
1652     OutStreamer.AddComment(CS.str());
1653   }
1654 }
1655 
printExtend(const MachineInstr * MI,MCStreamer & OutStreamer,int SrcEltBits,int DstEltBits,bool IsSext)1656 static bool printExtend(const MachineInstr *MI, MCStreamer &OutStreamer,
1657                         int SrcEltBits, int DstEltBits, bool IsSext) {
1658   unsigned SrcIdx = getSrcIdx(MI, 1);
1659   auto *C = X86::getConstantFromPool(*MI, SrcIdx);
1660   if (C && C->getType()->getScalarSizeInBits() == unsigned(SrcEltBits)) {
1661     if (auto *CDS = dyn_cast<ConstantDataSequential>(C)) {
1662       int NumElts = CDS->getNumElements();
1663       std::string Comment;
1664       raw_string_ostream CS(Comment);
1665       printDstRegisterName(CS, MI, SrcIdx);
1666       CS << " = [";
1667       for (int i = 0; i != NumElts; ++i) {
1668         if (i != 0)
1669           CS << ",";
1670         if (CDS->getElementType()->isIntegerTy()) {
1671           APInt Elt = CDS->getElementAsAPInt(i);
1672           Elt = IsSext ? Elt.sext(DstEltBits) : Elt.zext(DstEltBits);
1673           printConstant(Elt, CS);
1674         } else
1675           CS << "?";
1676       }
1677       CS << "]";
1678       OutStreamer.AddComment(CS.str());
1679       return true;
1680     }
1681   }
1682 
1683   return false;
1684 }
printSignExtend(const MachineInstr * MI,MCStreamer & OutStreamer,int SrcEltBits,int DstEltBits)1685 static void printSignExtend(const MachineInstr *MI, MCStreamer &OutStreamer,
1686                             int SrcEltBits, int DstEltBits) {
1687   printExtend(MI, OutStreamer, SrcEltBits, DstEltBits, true);
1688 }
printZeroExtend(const MachineInstr * MI,MCStreamer & OutStreamer,int SrcEltBits,int DstEltBits)1689 static void printZeroExtend(const MachineInstr *MI, MCStreamer &OutStreamer,
1690                             int SrcEltBits, int DstEltBits) {
1691   if (printExtend(MI, OutStreamer, SrcEltBits, DstEltBits, false))
1692     return;
1693 
1694   // We didn't find a constant load, fallback to a shuffle mask decode.
1695   std::string Comment;
1696   raw_string_ostream CS(Comment);
1697   printDstRegisterName(CS, MI, getSrcIdx(MI, 1));
1698   CS << " = ";
1699 
1700   SmallVector<int> Mask;
1701   unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1702   assert((Width % DstEltBits) == 0 && (DstEltBits % SrcEltBits) == 0 &&
1703          "Illegal extension ratio");
1704   DecodeZeroExtendMask(SrcEltBits, DstEltBits, Width / DstEltBits, false, Mask);
1705   printShuffleMask(CS, "mem", "", Mask);
1706 
1707   OutStreamer.AddComment(CS.str());
1708 }
1709 
EmitSEHInstruction(const MachineInstr * MI)1710 void X86AsmPrinter::EmitSEHInstruction(const MachineInstr *MI) {
1711   assert(MF->hasWinCFI() && "SEH_ instruction in function without WinCFI?");
1712   assert((getSubtarget().isOSWindows() || TM.getTargetTriple().isUEFI()) &&
1713          "SEH_ instruction Windows and UEFI only");
1714 
1715   // Use the .cv_fpo directives if we're emitting CodeView on 32-bit x86.
1716   if (EmitFPOData) {
1717     X86TargetStreamer *XTS =
1718         static_cast<X86TargetStreamer *>(OutStreamer->getTargetStreamer());
1719     switch (MI->getOpcode()) {
1720     case X86::SEH_PushReg:
1721       XTS->emitFPOPushReg(MI->getOperand(0).getImm());
1722       break;
1723     case X86::SEH_StackAlloc:
1724       XTS->emitFPOStackAlloc(MI->getOperand(0).getImm());
1725       break;
1726     case X86::SEH_StackAlign:
1727       XTS->emitFPOStackAlign(MI->getOperand(0).getImm());
1728       break;
1729     case X86::SEH_SetFrame:
1730       assert(MI->getOperand(1).getImm() == 0 &&
1731              ".cv_fpo_setframe takes no offset");
1732       XTS->emitFPOSetFrame(MI->getOperand(0).getImm());
1733       break;
1734     case X86::SEH_EndPrologue:
1735       XTS->emitFPOEndPrologue();
1736       break;
1737     case X86::SEH_SaveReg:
1738     case X86::SEH_SaveXMM:
1739     case X86::SEH_PushFrame:
1740       llvm_unreachable("SEH_ directive incompatible with FPO");
1741       break;
1742     default:
1743       llvm_unreachable("expected SEH_ instruction");
1744     }
1745     return;
1746   }
1747 
1748   // Otherwise, use the .seh_ directives for all other Windows platforms.
1749   switch (MI->getOpcode()) {
1750   case X86::SEH_PushReg:
1751     OutStreamer->emitWinCFIPushReg(MI->getOperand(0).getImm());
1752     break;
1753 
1754   case X86::SEH_SaveReg:
1755     OutStreamer->emitWinCFISaveReg(MI->getOperand(0).getImm(),
1756                                    MI->getOperand(1).getImm());
1757     break;
1758 
1759   case X86::SEH_SaveXMM:
1760     OutStreamer->emitWinCFISaveXMM(MI->getOperand(0).getImm(),
1761                                    MI->getOperand(1).getImm());
1762     break;
1763 
1764   case X86::SEH_StackAlloc:
1765     OutStreamer->emitWinCFIAllocStack(MI->getOperand(0).getImm());
1766     break;
1767 
1768   case X86::SEH_SetFrame:
1769     OutStreamer->emitWinCFISetFrame(MI->getOperand(0).getImm(),
1770                                     MI->getOperand(1).getImm());
1771     break;
1772 
1773   case X86::SEH_PushFrame:
1774     OutStreamer->emitWinCFIPushFrame(MI->getOperand(0).getImm());
1775     break;
1776 
1777   case X86::SEH_EndPrologue:
1778     OutStreamer->emitWinCFIEndProlog();
1779     break;
1780 
1781   default:
1782     llvm_unreachable("expected SEH_ instruction");
1783   }
1784 }
1785 
addConstantComments(const MachineInstr * MI,MCStreamer & OutStreamer)1786 static void addConstantComments(const MachineInstr *MI,
1787                                 MCStreamer &OutStreamer) {
1788   switch (MI->getOpcode()) {
1789   // Lower PSHUFB and VPERMILP normally but add a comment if we can find
1790   // a constant shuffle mask. We won't be able to do this at the MC layer
1791   // because the mask isn't an immediate.
1792   case X86::PSHUFBrm:
1793   case X86::VPSHUFBrm:
1794   case X86::VPSHUFBYrm:
1795   case X86::VPSHUFBZ128rm:
1796   case X86::VPSHUFBZ128rmk:
1797   case X86::VPSHUFBZ128rmkz:
1798   case X86::VPSHUFBZ256rm:
1799   case X86::VPSHUFBZ256rmk:
1800   case X86::VPSHUFBZ256rmkz:
1801   case X86::VPSHUFBZrm:
1802   case X86::VPSHUFBZrmk:
1803   case X86::VPSHUFBZrmkz: {
1804     unsigned SrcIdx = getSrcIdx(MI, 1);
1805     if (auto *C = X86::getConstantFromPool(*MI, SrcIdx + 1)) {
1806       unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1807       SmallVector<int, 64> Mask;
1808       DecodePSHUFBMask(C, Width, Mask);
1809       if (!Mask.empty())
1810         OutStreamer.AddComment(getShuffleComment(MI, SrcIdx, SrcIdx, Mask));
1811     }
1812     break;
1813   }
1814 
1815   case X86::VPERMILPSrm:
1816   case X86::VPERMILPSYrm:
1817   case X86::VPERMILPSZ128rm:
1818   case X86::VPERMILPSZ128rmk:
1819   case X86::VPERMILPSZ128rmkz:
1820   case X86::VPERMILPSZ256rm:
1821   case X86::VPERMILPSZ256rmk:
1822   case X86::VPERMILPSZ256rmkz:
1823   case X86::VPERMILPSZrm:
1824   case X86::VPERMILPSZrmk:
1825   case X86::VPERMILPSZrmkz: {
1826     unsigned SrcIdx = getSrcIdx(MI, 1);
1827     if (auto *C = X86::getConstantFromPool(*MI, SrcIdx + 1)) {
1828       unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1829       SmallVector<int, 16> Mask;
1830       DecodeVPERMILPMask(C, 32, Width, Mask);
1831       if (!Mask.empty())
1832         OutStreamer.AddComment(getShuffleComment(MI, SrcIdx, SrcIdx, Mask));
1833     }
1834     break;
1835   }
1836   case X86::VPERMILPDrm:
1837   case X86::VPERMILPDYrm:
1838   case X86::VPERMILPDZ128rm:
1839   case X86::VPERMILPDZ128rmk:
1840   case X86::VPERMILPDZ128rmkz:
1841   case X86::VPERMILPDZ256rm:
1842   case X86::VPERMILPDZ256rmk:
1843   case X86::VPERMILPDZ256rmkz:
1844   case X86::VPERMILPDZrm:
1845   case X86::VPERMILPDZrmk:
1846   case X86::VPERMILPDZrmkz: {
1847     unsigned SrcIdx = getSrcIdx(MI, 1);
1848     if (auto *C = X86::getConstantFromPool(*MI, SrcIdx + 1)) {
1849       unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1850       SmallVector<int, 16> Mask;
1851       DecodeVPERMILPMask(C, 64, Width, Mask);
1852       if (!Mask.empty())
1853         OutStreamer.AddComment(getShuffleComment(MI, SrcIdx, SrcIdx, Mask));
1854     }
1855     break;
1856   }
1857 
1858   case X86::VPERMIL2PDrm:
1859   case X86::VPERMIL2PSrm:
1860   case X86::VPERMIL2PDYrm:
1861   case X86::VPERMIL2PSYrm: {
1862     assert(MI->getNumOperands() >= (3 + X86::AddrNumOperands + 1) &&
1863            "Unexpected number of operands!");
1864 
1865     const MachineOperand &CtrlOp = MI->getOperand(MI->getNumOperands() - 1);
1866     if (!CtrlOp.isImm())
1867       break;
1868 
1869     unsigned ElSize;
1870     switch (MI->getOpcode()) {
1871     default: llvm_unreachable("Invalid opcode");
1872     case X86::VPERMIL2PSrm: case X86::VPERMIL2PSYrm: ElSize = 32; break;
1873     case X86::VPERMIL2PDrm: case X86::VPERMIL2PDYrm: ElSize = 64; break;
1874     }
1875 
1876     if (auto *C = X86::getConstantFromPool(*MI, 3)) {
1877       unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1878       SmallVector<int, 16> Mask;
1879       DecodeVPERMIL2PMask(C, (unsigned)CtrlOp.getImm(), ElSize, Width, Mask);
1880       if (!Mask.empty())
1881         OutStreamer.AddComment(getShuffleComment(MI, 1, 2, Mask));
1882     }
1883     break;
1884   }
1885 
1886   case X86::VPPERMrrm: {
1887     if (auto *C = X86::getConstantFromPool(*MI, 3)) {
1888       unsigned Width = X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1889       SmallVector<int, 16> Mask;
1890       DecodeVPPERMMask(C, Width, Mask);
1891       if (!Mask.empty())
1892         OutStreamer.AddComment(getShuffleComment(MI, 1, 2, Mask));
1893     }
1894     break;
1895   }
1896 
1897   case X86::MMX_MOVQ64rm: {
1898     if (auto *C = X86::getConstantFromPool(*MI, 1)) {
1899       std::string Comment;
1900       raw_string_ostream CS(Comment);
1901       const MachineOperand &DstOp = MI->getOperand(0);
1902       CS << X86ATTInstPrinter::getRegisterName(DstOp.getReg()) << " = ";
1903       if (auto *CF = dyn_cast<ConstantFP>(C)) {
1904         CS << "0x" << toString(CF->getValueAPF().bitcastToAPInt(), 16, false);
1905         OutStreamer.AddComment(CS.str());
1906       }
1907     }
1908     break;
1909   }
1910 
1911 #define INSTR_CASE(Prefix, Instr, Suffix, Postfix)                             \
1912   case X86::Prefix##Instr##Suffix##rm##Postfix:
1913 
1914 #define CASE_ARITH_RM(Instr)                                                   \
1915   INSTR_CASE(, Instr, , )   /* SSE */                                          \
1916   INSTR_CASE(V, Instr, , )  /* AVX-128 */                                      \
1917   INSTR_CASE(V, Instr, Y, ) /* AVX-256 */                                      \
1918   INSTR_CASE(V, Instr, Z128, )                                                 \
1919   INSTR_CASE(V, Instr, Z128, k)                                                \
1920   INSTR_CASE(V, Instr, Z128, kz)                                               \
1921   INSTR_CASE(V, Instr, Z256, )                                                 \
1922   INSTR_CASE(V, Instr, Z256, k)                                                \
1923   INSTR_CASE(V, Instr, Z256, kz)                                               \
1924   INSTR_CASE(V, Instr, Z, )                                                    \
1925   INSTR_CASE(V, Instr, Z, k)                                                   \
1926   INSTR_CASE(V, Instr, Z, kz)
1927 
1928     // TODO: Add additional instructions when useful.
1929     CASE_ARITH_RM(PMADDUBSW) {
1930       unsigned SrcIdx = getSrcIdx(MI, 1);
1931       if (auto *C = X86::getConstantFromPool(*MI, SrcIdx + 1)) {
1932         if (C->getType()->getScalarSizeInBits() == 8) {
1933           std::string Comment;
1934           raw_string_ostream CS(Comment);
1935           unsigned VectorWidth =
1936               X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1937           CS << "[";
1938           printConstant(C, VectorWidth, CS);
1939           CS << "]";
1940           OutStreamer.AddComment(CS.str());
1941         }
1942       }
1943       break;
1944     }
1945 
1946     CASE_ARITH_RM(PMADDWD)
1947     CASE_ARITH_RM(PMULLW)
1948     CASE_ARITH_RM(PMULHW)
1949     CASE_ARITH_RM(PMULHUW)
1950     CASE_ARITH_RM(PMULHRSW) {
1951       unsigned SrcIdx = getSrcIdx(MI, 1);
1952       if (auto *C = X86::getConstantFromPool(*MI, SrcIdx + 1)) {
1953         if (C->getType()->getScalarSizeInBits() == 16) {
1954           std::string Comment;
1955           raw_string_ostream CS(Comment);
1956           unsigned VectorWidth =
1957               X86::getVectorRegisterWidth(MI->getDesc().operands()[0]);
1958           CS << "[";
1959           printConstant(C, VectorWidth, CS);
1960           CS << "]";
1961           OutStreamer.AddComment(CS.str());
1962         }
1963       }
1964       break;
1965     }
1966 
1967 #define MASK_AVX512_CASE(Instr)                                                \
1968   case Instr:                                                                  \
1969   case Instr##k:                                                               \
1970   case Instr##kz:
1971 
1972   case X86::MOVSDrm:
1973   case X86::VMOVSDrm:
1974   MASK_AVX512_CASE(X86::VMOVSDZrm)
1975   case X86::MOVSDrm_alt:
1976   case X86::VMOVSDrm_alt:
1977   case X86::VMOVSDZrm_alt:
1978   case X86::MOVQI2PQIrm:
1979   case X86::VMOVQI2PQIrm:
1980   case X86::VMOVQI2PQIZrm:
1981     printZeroUpperMove(MI, OutStreamer, 64, 128, "mem[0],zero");
1982     break;
1983 
1984   MASK_AVX512_CASE(X86::VMOVSHZrm)
1985   case X86::VMOVSHZrm_alt:
1986     printZeroUpperMove(MI, OutStreamer, 16, 128,
1987                        "mem[0],zero,zero,zero,zero,zero,zero,zero");
1988     break;
1989 
1990   case X86::MOVSSrm:
1991   case X86::VMOVSSrm:
1992   MASK_AVX512_CASE(X86::VMOVSSZrm)
1993   case X86::MOVSSrm_alt:
1994   case X86::VMOVSSrm_alt:
1995   case X86::VMOVSSZrm_alt:
1996   case X86::MOVDI2PDIrm:
1997   case X86::VMOVDI2PDIrm:
1998   case X86::VMOVDI2PDIZrm:
1999     printZeroUpperMove(MI, OutStreamer, 32, 128, "mem[0],zero,zero,zero");
2000     break;
2001 
2002 #define MOV_CASE(Prefix, Suffix)                                               \
2003   case X86::Prefix##MOVAPD##Suffix##rm:                                        \
2004   case X86::Prefix##MOVAPS##Suffix##rm:                                        \
2005   case X86::Prefix##MOVUPD##Suffix##rm:                                        \
2006   case X86::Prefix##MOVUPS##Suffix##rm:                                        \
2007   case X86::Prefix##MOVDQA##Suffix##rm:                                        \
2008   case X86::Prefix##MOVDQU##Suffix##rm:
2009 
2010 #define MOV_AVX512_CASE(Suffix, Postfix)                                       \
2011   case X86::VMOVDQA64##Suffix##rm##Postfix:                                    \
2012   case X86::VMOVDQA32##Suffix##rm##Postfix:                                    \
2013   case X86::VMOVDQU64##Suffix##rm##Postfix:                                    \
2014   case X86::VMOVDQU32##Suffix##rm##Postfix:                                    \
2015   case X86::VMOVDQU16##Suffix##rm##Postfix:                                    \
2016   case X86::VMOVDQU8##Suffix##rm##Postfix:                                     \
2017   case X86::VMOVAPS##Suffix##rm##Postfix:                                      \
2018   case X86::VMOVAPD##Suffix##rm##Postfix:                                      \
2019   case X86::VMOVUPS##Suffix##rm##Postfix:                                      \
2020   case X86::VMOVUPD##Suffix##rm##Postfix:
2021 
2022 #define CASE_128_MOV_RM()                                                      \
2023   MOV_CASE(, )   /* SSE */                                                     \
2024   MOV_CASE(V, )  /* AVX-128 */                                                 \
2025   MOV_AVX512_CASE(Z128, )                                                      \
2026   MOV_AVX512_CASE(Z128, k)                                                     \
2027   MOV_AVX512_CASE(Z128, kz)
2028 
2029 #define CASE_256_MOV_RM()                                                      \
2030   MOV_CASE(V, Y) /* AVX-256 */                                                 \
2031   MOV_AVX512_CASE(Z256, )                                                      \
2032   MOV_AVX512_CASE(Z256, k)                                                     \
2033   MOV_AVX512_CASE(Z256, kz)                                                    \
2034 
2035 #define CASE_512_MOV_RM()                                                      \
2036   MOV_AVX512_CASE(Z, )                                                         \
2037   MOV_AVX512_CASE(Z, k)                                                        \
2038   MOV_AVX512_CASE(Z, kz)                                                       \
2039 
2040     // For loads from a constant pool to a vector register, print the constant
2041     // loaded.
2042     CASE_128_MOV_RM()
2043     printBroadcast(MI, OutStreamer, 1, 128);
2044     break;
2045     CASE_256_MOV_RM()
2046     printBroadcast(MI, OutStreamer, 1, 256);
2047     break;
2048     CASE_512_MOV_RM()
2049     printBroadcast(MI, OutStreamer, 1, 512);
2050     break;
2051   case X86::VBROADCASTF128rm:
2052   case X86::VBROADCASTI128rm:
2053   MASK_AVX512_CASE(X86::VBROADCASTF32X4Z256rm)
2054   MASK_AVX512_CASE(X86::VBROADCASTF64X2Z128rm)
2055   MASK_AVX512_CASE(X86::VBROADCASTI32X4Z256rm)
2056   MASK_AVX512_CASE(X86::VBROADCASTI64X2Z128rm)
2057     printBroadcast(MI, OutStreamer, 2, 128);
2058     break;
2059   MASK_AVX512_CASE(X86::VBROADCASTF32X4rm)
2060   MASK_AVX512_CASE(X86::VBROADCASTF64X2rm)
2061   MASK_AVX512_CASE(X86::VBROADCASTI32X4rm)
2062   MASK_AVX512_CASE(X86::VBROADCASTI64X2rm)
2063     printBroadcast(MI, OutStreamer, 4, 128);
2064     break;
2065   MASK_AVX512_CASE(X86::VBROADCASTF32X8rm)
2066   MASK_AVX512_CASE(X86::VBROADCASTF64X4rm)
2067   MASK_AVX512_CASE(X86::VBROADCASTI32X8rm)
2068   MASK_AVX512_CASE(X86::VBROADCASTI64X4rm)
2069     printBroadcast(MI, OutStreamer, 2, 256);
2070     break;
2071 
2072   // For broadcast loads from a constant pool to a vector register, repeatedly
2073   // print the constant loaded.
2074   case X86::MOVDDUPrm:
2075   case X86::VMOVDDUPrm:
2076   MASK_AVX512_CASE(X86::VMOVDDUPZ128rm)
2077   case X86::VPBROADCASTQrm:
2078   MASK_AVX512_CASE(X86::VPBROADCASTQZ128rm)
2079     printBroadcast(MI, OutStreamer, 2, 64);
2080     break;
2081   case X86::VBROADCASTSDYrm:
2082   MASK_AVX512_CASE(X86::VBROADCASTSDZ256rm)
2083   case X86::VPBROADCASTQYrm:
2084   MASK_AVX512_CASE(X86::VPBROADCASTQZ256rm)
2085     printBroadcast(MI, OutStreamer, 4, 64);
2086     break;
2087   MASK_AVX512_CASE(X86::VBROADCASTSDZrm)
2088   MASK_AVX512_CASE(X86::VPBROADCASTQZrm)
2089     printBroadcast(MI, OutStreamer, 8, 64);
2090     break;
2091   case X86::VBROADCASTSSrm:
2092   MASK_AVX512_CASE(X86::VBROADCASTSSZ128rm)
2093   case X86::VPBROADCASTDrm:
2094   MASK_AVX512_CASE(X86::VPBROADCASTDZ128rm)
2095     printBroadcast(MI, OutStreamer, 4, 32);
2096     break;
2097   case X86::VBROADCASTSSYrm:
2098     MASK_AVX512_CASE(X86::VBROADCASTSSZ256rm)
2099   case X86::VPBROADCASTDYrm:
2100   MASK_AVX512_CASE(X86::VPBROADCASTDZ256rm)
2101     printBroadcast(MI, OutStreamer, 8, 32);
2102     break;
2103   MASK_AVX512_CASE(X86::VBROADCASTSSZrm)
2104   MASK_AVX512_CASE(X86::VPBROADCASTDZrm)
2105     printBroadcast(MI, OutStreamer, 16, 32);
2106     break;
2107   case X86::VPBROADCASTWrm:
2108   MASK_AVX512_CASE(X86::VPBROADCASTWZ128rm)
2109     printBroadcast(MI, OutStreamer, 8, 16);
2110     break;
2111   case X86::VPBROADCASTWYrm:
2112   MASK_AVX512_CASE(X86::VPBROADCASTWZ256rm)
2113     printBroadcast(MI, OutStreamer, 16, 16);
2114     break;
2115   MASK_AVX512_CASE(X86::VPBROADCASTWZrm)
2116     printBroadcast(MI, OutStreamer, 32, 16);
2117     break;
2118   case X86::VPBROADCASTBrm:
2119   MASK_AVX512_CASE(X86::VPBROADCASTBZ128rm)
2120     printBroadcast(MI, OutStreamer, 16, 8);
2121     break;
2122   case X86::VPBROADCASTBYrm:
2123   MASK_AVX512_CASE(X86::VPBROADCASTBZ256rm)
2124     printBroadcast(MI, OutStreamer, 32, 8);
2125     break;
2126   MASK_AVX512_CASE(X86::VPBROADCASTBZrm)
2127     printBroadcast(MI, OutStreamer, 64, 8);
2128     break;
2129 
2130 #define MOVX_CASE(Prefix, Ext, Type, Suffix, Postfix)                          \
2131   case X86::Prefix##PMOV##Ext##Type##Suffix##rm##Postfix:
2132 
2133 #define CASE_MOVX_RM(Ext, Type)                                                \
2134   MOVX_CASE(, Ext, Type, , )                                                   \
2135   MOVX_CASE(V, Ext, Type, , )                                                  \
2136   MOVX_CASE(V, Ext, Type, Y, )                                                 \
2137   MOVX_CASE(V, Ext, Type, Z128, )                                              \
2138   MOVX_CASE(V, Ext, Type, Z128, k )                                            \
2139   MOVX_CASE(V, Ext, Type, Z128, kz )                                           \
2140   MOVX_CASE(V, Ext, Type, Z256, )                                              \
2141   MOVX_CASE(V, Ext, Type, Z256, k )                                            \
2142   MOVX_CASE(V, Ext, Type, Z256, kz )                                           \
2143   MOVX_CASE(V, Ext, Type, Z, )                                                 \
2144   MOVX_CASE(V, Ext, Type, Z, k )                                               \
2145   MOVX_CASE(V, Ext, Type, Z, kz )
2146 
2147     CASE_MOVX_RM(SX, BD)
2148     printSignExtend(MI, OutStreamer, 8, 32);
2149     break;
2150     CASE_MOVX_RM(SX, BQ)
2151     printSignExtend(MI, OutStreamer, 8, 64);
2152     break;
2153     CASE_MOVX_RM(SX, BW)
2154     printSignExtend(MI, OutStreamer, 8, 16);
2155     break;
2156     CASE_MOVX_RM(SX, DQ)
2157     printSignExtend(MI, OutStreamer, 32, 64);
2158     break;
2159     CASE_MOVX_RM(SX, WD)
2160     printSignExtend(MI, OutStreamer, 16, 32);
2161     break;
2162     CASE_MOVX_RM(SX, WQ)
2163     printSignExtend(MI, OutStreamer, 16, 64);
2164     break;
2165 
2166     CASE_MOVX_RM(ZX, BD)
2167     printZeroExtend(MI, OutStreamer, 8, 32);
2168     break;
2169     CASE_MOVX_RM(ZX, BQ)
2170     printZeroExtend(MI, OutStreamer, 8, 64);
2171     break;
2172     CASE_MOVX_RM(ZX, BW)
2173     printZeroExtend(MI, OutStreamer, 8, 16);
2174     break;
2175     CASE_MOVX_RM(ZX, DQ)
2176     printZeroExtend(MI, OutStreamer, 32, 64);
2177     break;
2178     CASE_MOVX_RM(ZX, WD)
2179     printZeroExtend(MI, OutStreamer, 16, 32);
2180     break;
2181     CASE_MOVX_RM(ZX, WQ)
2182     printZeroExtend(MI, OutStreamer, 16, 64);
2183     break;
2184   }
2185 }
2186 
emitInstruction(const MachineInstr * MI)2187 void X86AsmPrinter::emitInstruction(const MachineInstr *MI) {
2188   // FIXME: Enable feature predicate checks once all the test pass.
2189   // X86_MC::verifyInstructionPredicates(MI->getOpcode(),
2190   //                                     Subtarget->getFeatureBits());
2191 
2192   X86MCInstLower MCInstLowering(*MF, *this);
2193   const X86RegisterInfo *RI =
2194       MF->getSubtarget<X86Subtarget>().getRegisterInfo();
2195 
2196   if (MI->getOpcode() == X86::OR64rm) {
2197     for (auto &Opd : MI->operands()) {
2198       if (Opd.isSymbol() && StringRef(Opd.getSymbolName()) ==
2199                                 "swift_async_extendedFramePointerFlags") {
2200         ShouldEmitWeakSwiftAsyncExtendedFramePointerFlags = true;
2201       }
2202     }
2203   }
2204 
2205   // Add comments for values loaded from constant pool.
2206   if (OutStreamer->isVerboseAsm())
2207     addConstantComments(MI, *OutStreamer);
2208 
2209   // Add a comment about EVEX compression
2210   if (TM.Options.MCOptions.ShowMCEncoding) {
2211     if (MI->getAsmPrinterFlags() & X86::AC_EVEX_2_LEGACY)
2212       OutStreamer->AddComment("EVEX TO LEGACY Compression ", false);
2213     else if (MI->getAsmPrinterFlags() & X86::AC_EVEX_2_VEX)
2214       OutStreamer->AddComment("EVEX TO VEX Compression ", false);
2215     else if (MI->getAsmPrinterFlags() & X86::AC_EVEX_2_EVEX)
2216       OutStreamer->AddComment("EVEX TO EVEX Compression ", false);
2217   }
2218 
2219   switch (MI->getOpcode()) {
2220   case TargetOpcode::DBG_VALUE:
2221     llvm_unreachable("Should be handled target independently");
2222 
2223   case X86::EH_RETURN:
2224   case X86::EH_RETURN64: {
2225     // Lower these as normal, but add some comments.
2226     Register Reg = MI->getOperand(0).getReg();
2227     OutStreamer->AddComment(StringRef("eh_return, addr: %") +
2228                             X86ATTInstPrinter::getRegisterName(Reg));
2229     break;
2230   }
2231   case X86::CLEANUPRET: {
2232     // Lower these as normal, but add some comments.
2233     OutStreamer->AddComment("CLEANUPRET");
2234     break;
2235   }
2236 
2237   case X86::CATCHRET: {
2238     // Lower these as normal, but add some comments.
2239     OutStreamer->AddComment("CATCHRET");
2240     break;
2241   }
2242 
2243   case X86::ENDBR32:
2244   case X86::ENDBR64: {
2245     // CurrentPatchableFunctionEntrySym can be CurrentFnBegin only for
2246     // -fpatchable-function-entry=N,0. The entry MBB is guaranteed to be
2247     // non-empty. If MI is the initial ENDBR, place the
2248     // __patchable_function_entries label after ENDBR.
2249     if (CurrentPatchableFunctionEntrySym &&
2250         CurrentPatchableFunctionEntrySym == CurrentFnBegin &&
2251         MI == &MF->front().front()) {
2252       MCInst Inst;
2253       MCInstLowering.Lower(MI, Inst);
2254       EmitAndCountInstruction(Inst);
2255       CurrentPatchableFunctionEntrySym = createTempSymbol("patch");
2256       OutStreamer->emitLabel(CurrentPatchableFunctionEntrySym);
2257       return;
2258     }
2259     break;
2260   }
2261 
2262   case X86::TAILJMPd64:
2263     if (IndCSPrefix && MI->hasRegisterImplicitUseOperand(X86::R11))
2264       EmitAndCountInstruction(MCInstBuilder(X86::CS_PREFIX));
2265     [[fallthrough]];
2266   case X86::TAILJMPr:
2267   case X86::TAILJMPm:
2268   case X86::TAILJMPd:
2269   case X86::TAILJMPd_CC:
2270   case X86::TAILJMPr64:
2271   case X86::TAILJMPm64:
2272   case X86::TAILJMPd64_CC:
2273   case X86::TAILJMPr64_REX:
2274   case X86::TAILJMPm64_REX:
2275     // Lower these as normal, but add some comments.
2276     OutStreamer->AddComment("TAILCALL");
2277     break;
2278 
2279   case X86::TLS_addr32:
2280   case X86::TLS_addr64:
2281   case X86::TLS_addrX32:
2282   case X86::TLS_base_addr32:
2283   case X86::TLS_base_addr64:
2284   case X86::TLS_base_addrX32:
2285   case X86::TLS_desc32:
2286   case X86::TLS_desc64:
2287     return LowerTlsAddr(MCInstLowering, *MI);
2288 
2289   case X86::MOVPC32r: {
2290     // This is a pseudo op for a two instruction sequence with a label, which
2291     // looks like:
2292     //     call "L1$pb"
2293     // "L1$pb":
2294     //     popl %esi
2295 
2296     // Emit the call.
2297     MCSymbol *PICBase = MF->getPICBaseSymbol();
2298     // FIXME: We would like an efficient form for this, so we don't have to do a
2299     // lot of extra uniquing.
2300     EmitAndCountInstruction(
2301         MCInstBuilder(X86::CALLpcrel32)
2302             .addExpr(MCSymbolRefExpr::create(PICBase, OutContext)));
2303 
2304     const X86FrameLowering *FrameLowering =
2305         MF->getSubtarget<X86Subtarget>().getFrameLowering();
2306     bool hasFP = FrameLowering->hasFP(*MF);
2307 
2308     // TODO: This is needed only if we require precise CFA.
2309     bool HasActiveDwarfFrame = OutStreamer->getNumFrameInfos() &&
2310                                !OutStreamer->getDwarfFrameInfos().back().End;
2311 
2312     int stackGrowth = -RI->getSlotSize();
2313 
2314     if (HasActiveDwarfFrame && !hasFP) {
2315       OutStreamer->emitCFIAdjustCfaOffset(-stackGrowth);
2316       MF->getInfo<X86MachineFunctionInfo>()->setHasCFIAdjustCfa(true);
2317     }
2318 
2319     // Emit the label.
2320     OutStreamer->emitLabel(PICBase);
2321 
2322     // popl $reg
2323     EmitAndCountInstruction(
2324         MCInstBuilder(X86::POP32r).addReg(MI->getOperand(0).getReg()));
2325 
2326     if (HasActiveDwarfFrame && !hasFP) {
2327       OutStreamer->emitCFIAdjustCfaOffset(stackGrowth);
2328     }
2329     return;
2330   }
2331 
2332   case X86::ADD32ri: {
2333     // Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri.
2334     if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS)
2335       break;
2336 
2337     // Okay, we have something like:
2338     //  EAX = ADD32ri EAX, MO_GOT_ABSOLUTE_ADDRESS(@MYGLOBAL)
2339 
2340     // For this, we want to print something like:
2341     //   MYGLOBAL + (. - PICBASE)
2342     // However, we can't generate a ".", so just emit a new label here and refer
2343     // to it.
2344     MCSymbol *DotSym = OutContext.createTempSymbol();
2345     OutStreamer->emitLabel(DotSym);
2346 
2347     // Now that we have emitted the label, lower the complex operand expression.
2348     MCSymbol *OpSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2));
2349 
2350     const MCExpr *DotExpr = MCSymbolRefExpr::create(DotSym, OutContext);
2351     const MCExpr *PICBase =
2352         MCSymbolRefExpr::create(MF->getPICBaseSymbol(), OutContext);
2353     DotExpr = MCBinaryExpr::createSub(DotExpr, PICBase, OutContext);
2354 
2355     DotExpr = MCBinaryExpr::createAdd(
2356         MCSymbolRefExpr::create(OpSym, OutContext), DotExpr, OutContext);
2357 
2358     EmitAndCountInstruction(MCInstBuilder(X86::ADD32ri)
2359                                 .addReg(MI->getOperand(0).getReg())
2360                                 .addReg(MI->getOperand(1).getReg())
2361                                 .addExpr(DotExpr));
2362     return;
2363   }
2364   case TargetOpcode::STATEPOINT:
2365     return LowerSTATEPOINT(*MI, MCInstLowering);
2366 
2367   case TargetOpcode::FAULTING_OP:
2368     return LowerFAULTING_OP(*MI, MCInstLowering);
2369 
2370   case TargetOpcode::FENTRY_CALL:
2371     return LowerFENTRY_CALL(*MI, MCInstLowering);
2372 
2373   case TargetOpcode::PATCHABLE_OP:
2374     return LowerPATCHABLE_OP(*MI, MCInstLowering);
2375 
2376   case TargetOpcode::STACKMAP:
2377     return LowerSTACKMAP(*MI);
2378 
2379   case TargetOpcode::PATCHPOINT:
2380     return LowerPATCHPOINT(*MI, MCInstLowering);
2381 
2382   case TargetOpcode::PATCHABLE_FUNCTION_ENTER:
2383     return LowerPATCHABLE_FUNCTION_ENTER(*MI, MCInstLowering);
2384 
2385   case TargetOpcode::PATCHABLE_RET:
2386     return LowerPATCHABLE_RET(*MI, MCInstLowering);
2387 
2388   case TargetOpcode::PATCHABLE_TAIL_CALL:
2389     return LowerPATCHABLE_TAIL_CALL(*MI, MCInstLowering);
2390 
2391   case TargetOpcode::PATCHABLE_EVENT_CALL:
2392     return LowerPATCHABLE_EVENT_CALL(*MI, MCInstLowering);
2393 
2394   case TargetOpcode::PATCHABLE_TYPED_EVENT_CALL:
2395     return LowerPATCHABLE_TYPED_EVENT_CALL(*MI, MCInstLowering);
2396 
2397   case X86::MORESTACK_RET:
2398     EmitAndCountInstruction(MCInstBuilder(getRetOpcode(*Subtarget)));
2399     return;
2400 
2401   case X86::KCFI_CHECK:
2402     return LowerKCFI_CHECK(*MI);
2403 
2404   case X86::ASAN_CHECK_MEMACCESS:
2405     return LowerASAN_CHECK_MEMACCESS(*MI);
2406 
2407   case X86::MORESTACK_RET_RESTORE_R10:
2408     // Return, then restore R10.
2409     EmitAndCountInstruction(MCInstBuilder(getRetOpcode(*Subtarget)));
2410     EmitAndCountInstruction(
2411         MCInstBuilder(X86::MOV64rr).addReg(X86::R10).addReg(X86::RAX));
2412     return;
2413 
2414   case X86::SEH_PushReg:
2415   case X86::SEH_SaveReg:
2416   case X86::SEH_SaveXMM:
2417   case X86::SEH_StackAlloc:
2418   case X86::SEH_StackAlign:
2419   case X86::SEH_SetFrame:
2420   case X86::SEH_PushFrame:
2421   case X86::SEH_EndPrologue:
2422     EmitSEHInstruction(MI);
2423     return;
2424 
2425   case X86::SEH_Epilogue: {
2426     assert(MF->hasWinCFI() && "SEH_ instruction in function without WinCFI?");
2427     MachineBasicBlock::const_iterator MBBI(MI);
2428     // Check if preceded by a call and emit nop if so.
2429     for (MBBI = PrevCrossBBInst(MBBI);
2430          MBBI != MachineBasicBlock::const_iterator();
2431          MBBI = PrevCrossBBInst(MBBI)) {
2432       // Pseudo instructions that aren't a call are assumed to not emit any
2433       // code. If they do, we worst case generate unnecessary noops after a
2434       // call.
2435       if (MBBI->isCall() || !MBBI->isPseudo()) {
2436         if (MBBI->isCall())
2437           EmitAndCountInstruction(MCInstBuilder(X86::NOOP));
2438         break;
2439       }
2440     }
2441     return;
2442   }
2443   case X86::UBSAN_UD1:
2444     EmitAndCountInstruction(MCInstBuilder(X86::UD1Lm)
2445                                 .addReg(X86::EAX)
2446                                 .addReg(X86::EAX)
2447                                 .addImm(1)
2448                                 .addReg(X86::NoRegister)
2449                                 .addImm(MI->getOperand(0).getImm())
2450                                 .addReg(X86::NoRegister));
2451     return;
2452   case X86::CALL64pcrel32:
2453     if (IndCSPrefix && MI->hasRegisterImplicitUseOperand(X86::R11))
2454       EmitAndCountInstruction(MCInstBuilder(X86::CS_PREFIX));
2455     break;
2456   case X86::JCC_1:
2457     // Two instruction prefixes (2EH for branch not-taken and 3EH for branch
2458     // taken) are used as branch hints. Here we add branch taken prefix for
2459     // jump instruction with higher probability than threshold.
2460     if (getSubtarget().hasBranchHint() && EnableBranchHint) {
2461       const MachineBranchProbabilityInfo *MBPI =
2462           &getAnalysis<MachineBranchProbabilityInfoWrapperPass>().getMBPI();
2463       MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
2464       BranchProbability EdgeProb =
2465           MBPI->getEdgeProbability(MI->getParent(), DestBB);
2466       BranchProbability Threshold(BranchHintProbabilityThreshold, 100);
2467       if (EdgeProb > Threshold)
2468         EmitAndCountInstruction(MCInstBuilder(X86::DS_PREFIX));
2469     }
2470     break;
2471   }
2472 
2473   MCInst TmpInst;
2474   MCInstLowering.Lower(MI, TmpInst);
2475 
2476   // Stackmap shadows cannot include branch targets, so we can count the bytes
2477   // in a call towards the shadow, but must ensure that the no thread returns
2478   // in to the stackmap shadow.  The only way to achieve this is if the call
2479   // is at the end of the shadow.
2480   if (MI->isCall()) {
2481     // Count then size of the call towards the shadow
2482     SMShadowTracker.count(TmpInst, getSubtargetInfo(), CodeEmitter.get());
2483     // Then flush the shadow so that we fill with nops before the call, not
2484     // after it.
2485     SMShadowTracker.emitShadowPadding(*OutStreamer, getSubtargetInfo());
2486     // Then emit the call
2487     OutStreamer->emitInstruction(TmpInst, getSubtargetInfo());
2488     return;
2489   }
2490 
2491   EmitAndCountInstruction(TmpInst);
2492 }
2493