1 //===- X86RegisterInfo.cpp - X86 Register Information -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the X86 implementation of the TargetRegisterInfo class.
11 // This file is responsible for the frame pointer elimination optimization
14 //===----------------------------------------------------------------------===//
17 #include "X86RegisterInfo.h"
18 #include "X86InstrBuilder.h"
19 #include "X86MachineFunctionInfo.h"
20 #include "X86Subtarget.h"
21 #include "X86TargetMachine.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Function.h"
24 #include "llvm/Type.h"
25 #include "llvm/CodeGen/ValueTypes.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineFrameInfo.h"
30 #include "llvm/CodeGen/MachineLocation.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/CodeGen/MachineRegisterInfo.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/Target/TargetFrameLowering.h"
35 #include "llvm/Target/TargetInstrInfo.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/ADT/BitVector.h"
39 #include "llvm/ADT/STLExtras.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/CommandLine.h"
45 ForceStackAlign("force-align-stack",
46 cl::desc("Force align the stack to the minimum alignment"
47 " needed for the function."),
48 cl::init(false), cl::Hidden);
50 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
51 const TargetInstrInfo &tii)
52 : X86GenRegisterInfo(tm.getSubtarget<X86Subtarget>().is64Bit() ?
53 X86::ADJCALLSTACKDOWN64 :
54 X86::ADJCALLSTACKDOWN32,
55 tm.getSubtarget<X86Subtarget>().is64Bit() ?
56 X86::ADJCALLSTACKUP64 :
57 X86::ADJCALLSTACKUP32),
59 // Cache some information.
60 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
61 Is64Bit = Subtarget->is64Bit();
62 IsWin64 = Subtarget->isTargetWin64();
63 StackAlign = TM.getFrameLowering()->getStackAlignment();
76 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
77 /// specific numbering, used in debug info and exception tables.
78 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
79 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
80 unsigned Flavour = DWARFFlavour::X86_64;
82 if (!Subtarget->is64Bit()) {
83 if (Subtarget->isTargetDarwin()) {
85 Flavour = DWARFFlavour::X86_32_DarwinEH;
87 Flavour = DWARFFlavour::X86_32_Generic;
88 } else if (Subtarget->isTargetCygMing()) {
89 // Unsupported by now, just quick fallback
90 Flavour = DWARFFlavour::X86_32_Generic;
92 Flavour = DWARFFlavour::X86_32_Generic;
96 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
99 /// getX86RegNum - This function maps LLVM register identifiers to their X86
100 /// specific numbering, which is used in various places encoding instructions.
101 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
103 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
104 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
105 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
106 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
107 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
109 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
111 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
113 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
116 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
118 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
120 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
122 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
124 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
126 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
128 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
130 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
133 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
134 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
135 return RegNo-X86::ST0;
137 case X86::XMM0: case X86::XMM8:
138 case X86::YMM0: case X86::YMM8: case X86::MM0:
140 case X86::XMM1: case X86::XMM9:
141 case X86::YMM1: case X86::YMM9: case X86::MM1:
143 case X86::XMM2: case X86::XMM10:
144 case X86::YMM2: case X86::YMM10: case X86::MM2:
146 case X86::XMM3: case X86::XMM11:
147 case X86::YMM3: case X86::YMM11: case X86::MM3:
149 case X86::XMM4: case X86::XMM12:
150 case X86::YMM4: case X86::YMM12: case X86::MM4:
152 case X86::XMM5: case X86::XMM13:
153 case X86::YMM5: case X86::YMM13: case X86::MM5:
155 case X86::XMM6: case X86::XMM14:
156 case X86::YMM6: case X86::YMM14: case X86::MM6:
158 case X86::XMM7: case X86::XMM15:
159 case X86::YMM7: case X86::YMM15: case X86::MM7:
162 case X86::ES: return 0;
163 case X86::CS: return 1;
164 case X86::SS: return 2;
165 case X86::DS: return 3;
166 case X86::FS: return 4;
167 case X86::GS: return 5;
169 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
170 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
171 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
172 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
173 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
174 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
175 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
176 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
178 // Pseudo index registers are equivalent to a "none"
179 // scaled index (See Intel Manual 2A, table 2-3)
185 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
186 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
191 const TargetRegisterClass *
192 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
193 const TargetRegisterClass *B,
194 unsigned SubIdx) const {
198 if (B == &X86::GR8RegClass) {
199 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
201 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
202 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
203 A == &X86::GR64_NOREXRegClass ||
204 A == &X86::GR64_NOSPRegClass ||
205 A == &X86::GR64_NOREX_NOSPRegClass)
206 return &X86::GR64_ABCDRegClass;
207 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
208 A == &X86::GR32_NOREXRegClass ||
209 A == &X86::GR32_NOSPRegClass)
210 return &X86::GR32_ABCDRegClass;
211 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
212 A == &X86::GR16_NOREXRegClass)
213 return &X86::GR16_ABCDRegClass;
214 } else if (B == &X86::GR8_NOREXRegClass) {
215 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
216 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
217 return &X86::GR64_NOREXRegClass;
218 else if (A == &X86::GR64_ABCDRegClass)
219 return &X86::GR64_ABCDRegClass;
220 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
221 A == &X86::GR32_NOSPRegClass)
222 return &X86::GR32_NOREXRegClass;
223 else if (A == &X86::GR32_ABCDRegClass)
224 return &X86::GR32_ABCDRegClass;
225 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
226 return &X86::GR16_NOREXRegClass;
227 else if (A == &X86::GR16_ABCDRegClass)
228 return &X86::GR16_ABCDRegClass;
231 case X86::sub_8bit_hi:
232 if (B == &X86::GR8_ABCD_HRegClass ||
233 B->hasSubClass(&X86::GR8_ABCD_HRegClass))
234 switch (A->getSize()) {
235 case 2: return getCommonSubClass(A, &X86::GR16_ABCDRegClass);
236 case 4: return getCommonSubClass(A, &X86::GR32_ABCDRegClass);
237 case 8: return getCommonSubClass(A, &X86::GR64_ABCDRegClass);
242 if (B == &X86::GR16RegClass) {
243 if (A->getSize() == 4 || A->getSize() == 8)
245 } else if (B == &X86::GR16_ABCDRegClass) {
246 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
247 A == &X86::GR64_NOREXRegClass ||
248 A == &X86::GR64_NOSPRegClass ||
249 A == &X86::GR64_NOREX_NOSPRegClass)
250 return &X86::GR64_ABCDRegClass;
251 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
252 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
253 return &X86::GR32_ABCDRegClass;
254 } else if (B == &X86::GR16_NOREXRegClass) {
255 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
256 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
257 return &X86::GR64_NOREXRegClass;
258 else if (A == &X86::GR64_ABCDRegClass)
259 return &X86::GR64_ABCDRegClass;
260 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
261 A == &X86::GR32_NOSPRegClass)
262 return &X86::GR32_NOREXRegClass;
263 else if (A == &X86::GR32_ABCDRegClass)
264 return &X86::GR64_ABCDRegClass;
268 if (B == &X86::GR32RegClass) {
269 if (A->getSize() == 8)
271 } else if (B == &X86::GR32_NOSPRegClass) {
272 if (A == &X86::GR64RegClass || A == &X86::GR64_NOSPRegClass)
273 return &X86::GR64_NOSPRegClass;
274 if (A->getSize() == 8)
275 return getCommonSubClass(A, &X86::GR64_NOSPRegClass);
276 } else if (B == &X86::GR32_ABCDRegClass) {
277 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
278 A == &X86::GR64_NOREXRegClass ||
279 A == &X86::GR64_NOSPRegClass ||
280 A == &X86::GR64_NOREX_NOSPRegClass)
281 return &X86::GR64_ABCDRegClass;
282 } else if (B == &X86::GR32_NOREXRegClass) {
283 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
284 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
285 return &X86::GR64_NOREXRegClass;
286 else if (A == &X86::GR64_ABCDRegClass)
287 return &X86::GR64_ABCDRegClass;
291 if (B == &X86::FR32RegClass)
295 if (B == &X86::FR64RegClass)
299 if (B == &X86::VR128RegClass)
306 const TargetRegisterClass*
307 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
308 const TargetRegisterClass *Super = RC;
309 TargetRegisterClass::sc_iterator I = RC->superclasses_begin();
311 switch (Super->getID()) {
312 case X86::GR8RegClassID:
313 case X86::GR16RegClassID:
314 case X86::GR32RegClassID:
315 case X86::GR64RegClassID:
316 case X86::FR32RegClassID:
317 case X86::FR64RegClassID:
318 case X86::RFP32RegClassID:
319 case X86::RFP64RegClassID:
320 case X86::RFP80RegClassID:
321 case X86::VR128RegClassID:
322 case X86::VR256RegClassID:
323 // Don't return a super-class that would shrink the spill size.
324 // That can happen with the vector and float classes.
325 if (Super->getSize() == RC->getSize())
333 const TargetRegisterClass *
334 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
336 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
337 case 0: // Normal GPRs.
338 if (TM.getSubtarget<X86Subtarget>().is64Bit())
339 return &X86::GR64RegClass;
340 return &X86::GR32RegClass;
341 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
342 if (TM.getSubtarget<X86Subtarget>().is64Bit())
343 return &X86::GR64_NOSPRegClass;
344 return &X86::GR32_NOSPRegClass;
345 case 2: // Available for tailcall (not callee-saved GPRs).
346 if (TM.getSubtarget<X86Subtarget>().isTargetWin64())
347 return &X86::GR64_TCW64RegClass;
348 if (TM.getSubtarget<X86Subtarget>().is64Bit())
349 return &X86::GR64_TCRegClass;
350 return &X86::GR32_TCRegClass;
354 const TargetRegisterClass *
355 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
356 if (RC == &X86::CCRRegClass) {
358 return &X86::GR64RegClass;
360 return &X86::GR32RegClass;
366 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
367 MachineFunction &MF) const {
368 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
370 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
371 switch (RC->getID()) {
374 case X86::GR32RegClassID:
376 case X86::GR64RegClassID:
378 case X86::VR128RegClassID:
379 return TM.getSubtarget<X86Subtarget>().is64Bit() ? 10 : 4;
380 case X86::VR64RegClassID:
386 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
387 bool callsEHReturn = false;
388 bool ghcCall = false;
391 callsEHReturn = MF->getMMI().callsEHReturn();
392 const Function *F = MF->getFunction();
393 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
396 static const unsigned GhcCalleeSavedRegs[] = {
400 static const unsigned CalleeSavedRegs32Bit[] = {
401 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
404 static const unsigned CalleeSavedRegs32EHRet[] = {
405 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
408 static const unsigned CalleeSavedRegs64Bit[] = {
409 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
412 static const unsigned CalleeSavedRegs64EHRet[] = {
413 X86::RAX, X86::RDX, X86::RBX, X86::R12,
414 X86::R13, X86::R14, X86::R15, X86::RBP, 0
417 static const unsigned CalleeSavedRegsWin64[] = {
418 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
419 X86::R12, X86::R13, X86::R14, X86::R15,
420 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
421 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
422 X86::XMM14, X86::XMM15, 0
426 return GhcCalleeSavedRegs;
427 } else if (Is64Bit) {
429 return CalleeSavedRegsWin64;
431 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
433 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
437 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
438 BitVector Reserved(getNumRegs());
439 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
441 // Set the stack-pointer register and its aliases as reserved.
442 Reserved.set(X86::RSP);
443 Reserved.set(X86::ESP);
444 Reserved.set(X86::SP);
445 Reserved.set(X86::SPL);
447 // Set the instruction pointer register and its aliases as reserved.
448 Reserved.set(X86::RIP);
449 Reserved.set(X86::EIP);
450 Reserved.set(X86::IP);
452 // Set the frame-pointer register and its aliases as reserved if needed.
453 if (TFI->hasFP(MF)) {
454 Reserved.set(X86::RBP);
455 Reserved.set(X86::EBP);
456 Reserved.set(X86::BP);
457 Reserved.set(X86::BPL);
460 // Mark the x87 stack registers as reserved, since they don't behave normally
461 // with respect to liveness. We don't fully model the effects of x87 stack
462 // pushes and pops after stackification.
463 Reserved.set(X86::ST0);
464 Reserved.set(X86::ST1);
465 Reserved.set(X86::ST2);
466 Reserved.set(X86::ST3);
467 Reserved.set(X86::ST4);
468 Reserved.set(X86::ST5);
469 Reserved.set(X86::ST6);
470 Reserved.set(X86::ST7);
474 //===----------------------------------------------------------------------===//
475 // Stack Frame Processing methods
476 //===----------------------------------------------------------------------===//
478 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
479 const MachineFrameInfo *MFI = MF.getFrameInfo();
480 return (RealignStack &&
481 !MFI->hasVarSizedObjects());
484 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
485 const MachineFrameInfo *MFI = MF.getFrameInfo();
486 const Function *F = MF.getFunction();
487 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
488 F->hasFnAttr(Attribute::StackAlignment));
490 // FIXME: Currently we don't support stack realignment for functions with
491 // variable-sized allocas.
492 // FIXME: It's more complicated than this...
493 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
495 "Stack realignment in presence of dynamic allocas is not supported");
497 // If we've requested that we force align the stack do so now.
499 return canRealignStack(MF);
501 return requiresRealignment && canRealignStack(MF);
504 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
505 unsigned Reg, int &FrameIdx) const {
506 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
508 if (Reg == FramePtr && TFI->hasFP(MF)) {
509 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
515 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
518 return X86::SUB64ri8;
519 return X86::SUB64ri32;
522 return X86::SUB32ri8;
527 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
530 return X86::ADD64ri8;
531 return X86::ADD64ri32;
534 return X86::ADD32ri8;
539 void X86RegisterInfo::
540 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
541 MachineBasicBlock::iterator I) const {
542 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
543 bool reseveCallFrame = TFI->hasReservedCallFrame(MF);
544 int Opcode = I->getOpcode();
545 bool isDestroy = Opcode == getCallFrameDestroyOpcode();
546 DebugLoc DL = I->getDebugLoc();
547 uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
548 uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
551 if (!reseveCallFrame) {
552 // If the stack pointer can be changed after prologue, turn the
553 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
554 // adjcallstackdown instruction into 'add ESP, <amt>'
555 // TODO: consider using push / pop instead of sub + store / add
559 // We need to keep the stack aligned properly. To do this, we round the
560 // amount of space needed for the outgoing arguments up to the next
561 // alignment boundary.
562 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
564 MachineInstr *New = 0;
565 if (Opcode == getCallFrameSetupOpcode()) {
566 New = BuildMI(MF, DL, TII.get(getSUBriOpcode(Is64Bit, Amount)),
571 assert(Opcode == getCallFrameDestroyOpcode());
573 // Factor out the amount the callee already popped.
577 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
578 New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
579 .addReg(StackPtr).addImm(Amount);
584 // The EFLAGS implicit def is dead.
585 New->getOperand(3).setIsDead();
587 // Replace the pseudo instruction with a new instruction.
594 if (Opcode == getCallFrameDestroyOpcode() && CalleeAmt) {
595 // If we are performing frame pointer elimination and if the callee pops
596 // something off the stack pointer, add it back. We do this until we have
597 // more advanced stack pointer tracking ability.
598 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
599 MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
600 .addReg(StackPtr).addImm(CalleeAmt);
602 // The EFLAGS implicit def is dead.
603 New->getOperand(3).setIsDead();
609 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
610 int SPAdj, RegScavenger *RS) const{
611 assert(SPAdj == 0 && "Unexpected");
614 MachineInstr &MI = *II;
615 MachineFunction &MF = *MI.getParent()->getParent();
616 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
618 while (!MI.getOperand(i).isFI()) {
620 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
623 int FrameIndex = MI.getOperand(i).getIndex();
626 unsigned Opc = MI.getOpcode();
627 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
628 if (needsStackRealignment(MF))
629 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
633 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
635 // This must be part of a four operand memory reference. Replace the
636 // FrameIndex with base register with EBP. Add an offset to the offset.
637 MI.getOperand(i).ChangeToRegister(BasePtr, false);
639 // Now add the frame object offset to the offset from EBP.
642 // Tail call jmp happens after FP is popped.
643 const MachineFrameInfo *MFI = MF.getFrameInfo();
644 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
646 FIOffset = TFI->getFrameIndexOffset(MF, FrameIndex);
648 if (MI.getOperand(i+3).isImm()) {
649 // Offset is a 32-bit integer.
650 int Offset = FIOffset + (int)(MI.getOperand(i + 3).getImm());
651 MI.getOperand(i + 3).ChangeToImmediate(Offset);
653 // Offset is symbolic. This is extremely rare.
654 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
655 MI.getOperand(i+3).setOffset(Offset);
659 unsigned X86RegisterInfo::getRARegister() const {
660 return Is64Bit ? X86::RIP // Should have dwarf #16.
661 : X86::EIP; // Should have dwarf #8.
664 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
665 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
666 return TFI->hasFP(MF) ? FramePtr : StackPtr;
669 unsigned X86RegisterInfo::getEHExceptionRegister() const {
670 llvm_unreachable("What is the exception register");
674 unsigned X86RegisterInfo::getEHHandlerRegister() const {
675 llvm_unreachable("What is the exception handler register");
680 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
681 switch (VT.getSimpleVT().SimpleTy) {
687 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
689 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
691 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
693 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
699 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
701 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
703 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
705 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
707 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
709 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
711 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
713 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
715 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
717 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
719 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
721 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
723 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
725 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
727 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
729 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
736 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
738 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
740 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
742 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
744 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
746 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
748 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
750 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
752 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
754 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
756 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
758 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
760 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
762 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
764 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
766 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
772 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
774 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
776 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
778 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
780 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
782 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
784 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
786 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
788 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
790 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
792 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
794 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
796 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
798 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
800 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
802 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
808 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
810 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
812 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
814 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
816 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
818 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
820 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
822 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
824 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
826 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
828 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
830 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
832 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
834 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
836 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
838 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
847 #include "X86GenRegisterInfo.inc"
850 struct MSAH : public MachineFunctionPass {
852 MSAH() : MachineFunctionPass(ID) {}
854 virtual bool runOnMachineFunction(MachineFunction &MF) {
855 const X86TargetMachine *TM =
856 static_cast<const X86TargetMachine *>(&MF.getTarget());
857 const X86RegisterInfo *X86RI = TM->getRegisterInfo();
858 MachineRegisterInfo &RI = MF.getRegInfo();
859 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
860 unsigned StackAlignment = X86RI->getStackAlignment();
862 // Be over-conservative: scan over all vreg defs and find whether vector
863 // registers are used. If yes, there is a possibility that vector register
864 // will be spilled and thus require dynamic stack realignment.
865 for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
866 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
867 if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
868 FuncInfo->setReserveFP(true);
876 virtual const char *getPassName() const {
877 return "X86 Maximal Stack Alignment Check";
880 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
881 AU.setPreservesCFG();
882 MachineFunctionPass::getAnalysisUsage(AU);
890 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }