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"
43 #define GET_REGINFO_MC_DESC
44 #define GET_REGINFO_TARGET_DESC
45 #include "X86GenRegisterInfo.inc"
50 ForceStackAlign("force-align-stack",
51 cl::desc("Force align the stack to the minimum alignment"
52 " needed for the function."),
53 cl::init(false), cl::Hidden);
55 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
56 const TargetInstrInfo &tii)
57 : X86GenRegisterInfo(), TM(tm), TII(tii) {
58 // Cache some information.
59 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
60 Is64Bit = Subtarget->is64Bit();
61 IsWin64 = Subtarget->isTargetWin64();
74 static unsigned getFlavour(const X86Subtarget *Subtarget, bool isEH) {
75 if (!Subtarget->is64Bit()) {
76 if (Subtarget->isTargetDarwin()) {
78 return DWARFFlavour::X86_32_DarwinEH;
80 return DWARFFlavour::X86_32_Generic;
81 } else if (Subtarget->isTargetCygMing()) {
82 // Unsupported by now, just quick fallback
83 return DWARFFlavour::X86_32_Generic;
85 return DWARFFlavour::X86_32_Generic;
88 return DWARFFlavour::X86_64;
91 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
92 /// specific numbering, used in debug info and exception tables.
93 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
94 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
95 unsigned Flavour = getFlavour(Subtarget, isEH);
97 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
100 /// getLLVMRegNum - This function maps DWARF register numbers to LLVM register.
101 int X86RegisterInfo::getLLVMRegNum(unsigned DwarfRegNo, bool isEH) const {
102 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
103 unsigned Flavour = getFlavour(Subtarget, isEH);
105 return X86GenRegisterInfo::getLLVMRegNumFull(DwarfRegNo, Flavour);
109 X86RegisterInfo::getSEHRegNum(unsigned i) const {
110 int reg = getX86RegNum(i);
112 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
113 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
114 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
115 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
116 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
117 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
118 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
119 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
120 case X86::XMM8: case X86::XMM9: case X86::XMM10: case X86::XMM11:
121 case X86::XMM12: case X86::XMM13: case X86::XMM14: case X86::XMM15:
122 case X86::YMM8: case X86::YMM9: case X86::YMM10: case X86::YMM11:
123 case X86::YMM12: case X86::YMM13: case X86::YMM14: case X86::YMM15:
129 /// getX86RegNum - This function maps LLVM register identifiers to their X86
130 /// specific numbering, which is used in various places encoding instructions.
131 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
133 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
134 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
135 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
136 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
137 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
139 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
141 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
143 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
146 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
148 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
150 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
152 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
154 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
156 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
158 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
160 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
163 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
164 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
165 return RegNo-X86::ST0;
167 case X86::XMM0: case X86::XMM8:
168 case X86::YMM0: case X86::YMM8: case X86::MM0:
170 case X86::XMM1: case X86::XMM9:
171 case X86::YMM1: case X86::YMM9: case X86::MM1:
173 case X86::XMM2: case X86::XMM10:
174 case X86::YMM2: case X86::YMM10: case X86::MM2:
176 case X86::XMM3: case X86::XMM11:
177 case X86::YMM3: case X86::YMM11: case X86::MM3:
179 case X86::XMM4: case X86::XMM12:
180 case X86::YMM4: case X86::YMM12: case X86::MM4:
182 case X86::XMM5: case X86::XMM13:
183 case X86::YMM5: case X86::YMM13: case X86::MM5:
185 case X86::XMM6: case X86::XMM14:
186 case X86::YMM6: case X86::YMM14: case X86::MM6:
188 case X86::XMM7: case X86::XMM15:
189 case X86::YMM7: case X86::YMM15: case X86::MM7:
192 case X86::ES: return 0;
193 case X86::CS: return 1;
194 case X86::SS: return 2;
195 case X86::DS: return 3;
196 case X86::FS: return 4;
197 case X86::GS: return 5;
199 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
200 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
201 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
202 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
203 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
204 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
205 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
206 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
208 // Pseudo index registers are equivalent to a "none"
209 // scaled index (See Intel Manual 2A, table 2-3)
215 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
216 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
221 const TargetRegisterClass *
222 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
223 const TargetRegisterClass *B,
224 unsigned SubIdx) const {
228 if (B == &X86::GR8RegClass) {
229 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
231 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
232 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
233 A == &X86::GR64_NOREXRegClass ||
234 A == &X86::GR64_NOSPRegClass ||
235 A == &X86::GR64_NOREX_NOSPRegClass)
236 return &X86::GR64_ABCDRegClass;
237 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
238 A == &X86::GR32_NOREXRegClass ||
239 A == &X86::GR32_NOSPRegClass)
240 return &X86::GR32_ABCDRegClass;
241 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
242 A == &X86::GR16_NOREXRegClass)
243 return &X86::GR16_ABCDRegClass;
244 } else if (B == &X86::GR8_NOREXRegClass) {
245 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
246 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
247 return &X86::GR64_NOREXRegClass;
248 else if (A == &X86::GR64_ABCDRegClass)
249 return &X86::GR64_ABCDRegClass;
250 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
251 A == &X86::GR32_NOSPRegClass)
252 return &X86::GR32_NOREXRegClass;
253 else if (A == &X86::GR32_ABCDRegClass)
254 return &X86::GR32_ABCDRegClass;
255 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
256 return &X86::GR16_NOREXRegClass;
257 else if (A == &X86::GR16_ABCDRegClass)
258 return &X86::GR16_ABCDRegClass;
261 case X86::sub_8bit_hi:
262 if (B->hasSubClassEq(&X86::GR8_ABCD_HRegClass))
263 switch (A->getSize()) {
264 case 2: return getCommonSubClass(A, &X86::GR16_ABCDRegClass);
265 case 4: return getCommonSubClass(A, &X86::GR32_ABCDRegClass);
266 case 8: return getCommonSubClass(A, &X86::GR64_ABCDRegClass);
271 if (B == &X86::GR16RegClass) {
272 if (A->getSize() == 4 || A->getSize() == 8)
274 } else if (B == &X86::GR16_ABCDRegClass) {
275 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
276 A == &X86::GR64_NOREXRegClass ||
277 A == &X86::GR64_NOSPRegClass ||
278 A == &X86::GR64_NOREX_NOSPRegClass)
279 return &X86::GR64_ABCDRegClass;
280 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
281 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
282 return &X86::GR32_ABCDRegClass;
283 } else if (B == &X86::GR16_NOREXRegClass) {
284 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
285 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
286 return &X86::GR64_NOREXRegClass;
287 else if (A == &X86::GR64_ABCDRegClass)
288 return &X86::GR64_ABCDRegClass;
289 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
290 A == &X86::GR32_NOSPRegClass)
291 return &X86::GR32_NOREXRegClass;
292 else if (A == &X86::GR32_ABCDRegClass)
293 return &X86::GR64_ABCDRegClass;
297 if (B == &X86::GR32RegClass) {
298 if (A->getSize() == 8)
300 } else if (B == &X86::GR32_NOSPRegClass) {
301 if (A == &X86::GR64RegClass || A == &X86::GR64_NOSPRegClass)
302 return &X86::GR64_NOSPRegClass;
303 if (A->getSize() == 8)
304 return getCommonSubClass(A, &X86::GR64_NOSPRegClass);
305 } else if (B == &X86::GR32_ABCDRegClass) {
306 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
307 A == &X86::GR64_NOREXRegClass ||
308 A == &X86::GR64_NOSPRegClass ||
309 A == &X86::GR64_NOREX_NOSPRegClass)
310 return &X86::GR64_ABCDRegClass;
311 } else if (B == &X86::GR32_NOREXRegClass) {
312 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass)
313 return &X86::GR64_NOREXRegClass;
314 else if (A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
315 return &X86::GR64_NOREX_NOSPRegClass;
316 else if (A == &X86::GR64_ABCDRegClass)
317 return &X86::GR64_ABCDRegClass;
318 } else if (B == &X86::GR32_NOREX_NOSPRegClass) {
319 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
320 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
321 return &X86::GR64_NOREX_NOSPRegClass;
322 else if (A == &X86::GR64_ABCDRegClass)
323 return &X86::GR64_ABCDRegClass;
327 if (B == &X86::FR32RegClass)
331 if (B == &X86::FR64RegClass)
335 if (B == &X86::VR128RegClass)
342 const TargetRegisterClass*
343 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
344 const TargetRegisterClass *Super = RC;
345 TargetRegisterClass::sc_iterator I = RC->superclasses_begin();
347 switch (Super->getID()) {
348 case X86::GR8RegClassID:
349 case X86::GR16RegClassID:
350 case X86::GR32RegClassID:
351 case X86::GR64RegClassID:
352 case X86::FR32RegClassID:
353 case X86::FR64RegClassID:
354 case X86::RFP32RegClassID:
355 case X86::RFP64RegClassID:
356 case X86::RFP80RegClassID:
357 case X86::VR128RegClassID:
358 case X86::VR256RegClassID:
359 // Don't return a super-class that would shrink the spill size.
360 // That can happen with the vector and float classes.
361 if (Super->getSize() == RC->getSize())
369 const TargetRegisterClass *
370 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
372 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
373 case 0: // Normal GPRs.
374 if (TM.getSubtarget<X86Subtarget>().is64Bit())
375 return &X86::GR64RegClass;
376 return &X86::GR32RegClass;
377 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
378 if (TM.getSubtarget<X86Subtarget>().is64Bit())
379 return &X86::GR64_NOSPRegClass;
380 return &X86::GR32_NOSPRegClass;
381 case 2: // Available for tailcall (not callee-saved GPRs).
382 if (TM.getSubtarget<X86Subtarget>().isTargetWin64())
383 return &X86::GR64_TCW64RegClass;
384 if (TM.getSubtarget<X86Subtarget>().is64Bit())
385 return &X86::GR64_TCRegClass;
386 return &X86::GR32_TCRegClass;
390 const TargetRegisterClass *
391 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
392 if (RC == &X86::CCRRegClass) {
394 return &X86::GR64RegClass;
396 return &X86::GR32RegClass;
402 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
403 MachineFunction &MF) const {
404 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
406 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
407 switch (RC->getID()) {
410 case X86::GR32RegClassID:
412 case X86::GR64RegClassID:
414 case X86::VR128RegClassID:
415 return TM.getSubtarget<X86Subtarget>().is64Bit() ? 10 : 4;
416 case X86::VR64RegClassID:
422 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
423 bool callsEHReturn = false;
424 bool ghcCall = false;
427 callsEHReturn = MF->getMMI().callsEHReturn();
428 const Function *F = MF->getFunction();
429 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
432 static const unsigned GhcCalleeSavedRegs[] = {
436 static const unsigned CalleeSavedRegs32Bit[] = {
437 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
440 static const unsigned CalleeSavedRegs32EHRet[] = {
441 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
444 static const unsigned CalleeSavedRegs64Bit[] = {
445 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
448 static const unsigned CalleeSavedRegs64EHRet[] = {
449 X86::RAX, X86::RDX, X86::RBX, X86::R12,
450 X86::R13, X86::R14, X86::R15, X86::RBP, 0
453 static const unsigned CalleeSavedRegsWin64[] = {
454 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
455 X86::R12, X86::R13, X86::R14, X86::R15,
456 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
457 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
458 X86::XMM14, X86::XMM15, 0
462 return GhcCalleeSavedRegs;
463 } else if (Is64Bit) {
465 return CalleeSavedRegsWin64;
467 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
469 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
473 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
474 BitVector Reserved(getNumRegs());
475 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
477 // Set the stack-pointer register and its aliases as reserved.
478 Reserved.set(X86::RSP);
479 Reserved.set(X86::ESP);
480 Reserved.set(X86::SP);
481 Reserved.set(X86::SPL);
483 // Set the instruction pointer register and its aliases as reserved.
484 Reserved.set(X86::RIP);
485 Reserved.set(X86::EIP);
486 Reserved.set(X86::IP);
488 // Set the frame-pointer register and its aliases as reserved if needed.
489 if (TFI->hasFP(MF)) {
490 Reserved.set(X86::RBP);
491 Reserved.set(X86::EBP);
492 Reserved.set(X86::BP);
493 Reserved.set(X86::BPL);
496 // Mark the segment registers as reserved.
497 Reserved.set(X86::CS);
498 Reserved.set(X86::SS);
499 Reserved.set(X86::DS);
500 Reserved.set(X86::ES);
501 Reserved.set(X86::FS);
502 Reserved.set(X86::GS);
504 // Reserve the registers that only exist in 64-bit mode.
506 // These 8-bit registers are part of the x86-64 extension even though their
507 // super-registers are old 32-bits.
508 Reserved.set(X86::SIL);
509 Reserved.set(X86::DIL);
510 Reserved.set(X86::BPL);
511 Reserved.set(X86::SPL);
513 for (unsigned n = 0; n != 8; ++n) {
515 const unsigned GPR64[] = {
516 X86::R8, X86::R9, X86::R10, X86::R11,
517 X86::R12, X86::R13, X86::R14, X86::R15
519 for (const unsigned *AI = getOverlaps(GPR64[n]); unsigned Reg = *AI; ++AI)
523 assert(X86::XMM15 == X86::XMM8+7);
524 for (const unsigned *AI = getOverlaps(X86::XMM8 + n); unsigned Reg = *AI;
533 //===----------------------------------------------------------------------===//
534 // Stack Frame Processing methods
535 //===----------------------------------------------------------------------===//
537 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
538 const MachineFrameInfo *MFI = MF.getFrameInfo();
539 return (RealignStack &&
540 !MFI->hasVarSizedObjects());
543 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
544 const MachineFrameInfo *MFI = MF.getFrameInfo();
545 const Function *F = MF.getFunction();
546 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
547 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
548 F->hasFnAttr(Attribute::StackAlignment));
550 // FIXME: Currently we don't support stack realignment for functions with
551 // variable-sized allocas.
552 // FIXME: It's more complicated than this...
553 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
555 "Stack realignment in presence of dynamic allocas is not supported");
557 // If we've requested that we force align the stack do so now.
559 return canRealignStack(MF);
561 return requiresRealignment && canRealignStack(MF);
564 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
565 unsigned Reg, int &FrameIdx) const {
566 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
568 if (Reg == FramePtr && TFI->hasFP(MF)) {
569 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
575 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
578 return X86::SUB64ri8;
579 return X86::SUB64ri32;
582 return X86::SUB32ri8;
587 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
590 return X86::ADD64ri8;
591 return X86::ADD64ri32;
594 return X86::ADD32ri8;
599 void X86RegisterInfo::
600 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
601 MachineBasicBlock::iterator I) const {
602 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
603 bool reseveCallFrame = TFI->hasReservedCallFrame(MF);
604 int Opcode = I->getOpcode();
605 bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
606 DebugLoc DL = I->getDebugLoc();
607 uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
608 uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
611 if (!reseveCallFrame) {
612 // If the stack pointer can be changed after prologue, turn the
613 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
614 // adjcallstackdown instruction into 'add ESP, <amt>'
615 // TODO: consider using push / pop instead of sub + store / add
619 // We need to keep the stack aligned properly. To do this, we round the
620 // amount of space needed for the outgoing arguments up to the next
621 // alignment boundary.
622 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
623 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
625 MachineInstr *New = 0;
626 if (Opcode == TII.getCallFrameSetupOpcode()) {
627 New = BuildMI(MF, DL, TII.get(getSUBriOpcode(Is64Bit, Amount)),
632 assert(Opcode == TII.getCallFrameDestroyOpcode());
634 // Factor out the amount the callee already popped.
638 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
639 New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
640 .addReg(StackPtr).addImm(Amount);
645 // The EFLAGS implicit def is dead.
646 New->getOperand(3).setIsDead();
648 // Replace the pseudo instruction with a new instruction.
655 if (Opcode == TII.getCallFrameDestroyOpcode() && CalleeAmt) {
656 // If we are performing frame pointer elimination and if the callee pops
657 // something off the stack pointer, add it back. We do this until we have
658 // more advanced stack pointer tracking ability.
659 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
660 MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
661 .addReg(StackPtr).addImm(CalleeAmt);
663 // The EFLAGS implicit def is dead.
664 New->getOperand(3).setIsDead();
670 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
671 int SPAdj, RegScavenger *RS) const{
672 assert(SPAdj == 0 && "Unexpected");
675 MachineInstr &MI = *II;
676 MachineFunction &MF = *MI.getParent()->getParent();
677 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
679 while (!MI.getOperand(i).isFI()) {
681 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
684 int FrameIndex = MI.getOperand(i).getIndex();
687 unsigned Opc = MI.getOpcode();
688 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
689 if (needsStackRealignment(MF))
690 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
694 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
696 // This must be part of a four operand memory reference. Replace the
697 // FrameIndex with base register with EBP. Add an offset to the offset.
698 MI.getOperand(i).ChangeToRegister(BasePtr, false);
700 // Now add the frame object offset to the offset from EBP.
703 // Tail call jmp happens after FP is popped.
704 const MachineFrameInfo *MFI = MF.getFrameInfo();
705 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
707 FIOffset = TFI->getFrameIndexOffset(MF, FrameIndex);
709 if (MI.getOperand(i+3).isImm()) {
710 // Offset is a 32-bit integer.
711 int Offset = FIOffset + (int)(MI.getOperand(i + 3).getImm());
712 MI.getOperand(i + 3).ChangeToImmediate(Offset);
714 // Offset is symbolic. This is extremely rare.
715 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
716 MI.getOperand(i+3).setOffset(Offset);
720 unsigned X86RegisterInfo::getRARegister() const {
721 return Is64Bit ? X86::RIP // Should have dwarf #16.
722 : X86::EIP; // Should have dwarf #8.
725 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
726 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
727 return TFI->hasFP(MF) ? FramePtr : StackPtr;
730 unsigned X86RegisterInfo::getEHExceptionRegister() const {
731 llvm_unreachable("What is the exception register");
735 unsigned X86RegisterInfo::getEHHandlerRegister() const {
736 llvm_unreachable("What is the exception handler register");
741 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
742 switch (VT.getSimpleVT().SimpleTy) {
748 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
750 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
752 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
754 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
760 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
762 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
764 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
766 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
768 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
770 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
772 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
774 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
776 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
778 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
780 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
782 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
784 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
786 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
788 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
790 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
797 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
799 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
801 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
803 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
805 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
807 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
809 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
811 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
813 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
815 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
817 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
819 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
821 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
823 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
825 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
827 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
833 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
835 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
837 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
839 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
841 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
843 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
845 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
847 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
849 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
851 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
853 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
855 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
857 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
859 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
861 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
863 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
869 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
871 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
873 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
875 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
877 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
879 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
881 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
883 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
885 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
887 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
889 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
891 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
893 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
895 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
897 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
899 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
909 struct MSAH : public MachineFunctionPass {
911 MSAH() : MachineFunctionPass(ID) {}
913 virtual bool runOnMachineFunction(MachineFunction &MF) {
914 const X86TargetMachine *TM =
915 static_cast<const X86TargetMachine *>(&MF.getTarget());
916 const TargetFrameLowering *TFI = TM->getFrameLowering();
917 MachineRegisterInfo &RI = MF.getRegInfo();
918 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
919 unsigned StackAlignment = TFI->getStackAlignment();
921 // Be over-conservative: scan over all vreg defs and find whether vector
922 // registers are used. If yes, there is a possibility that vector register
923 // will be spilled and thus require dynamic stack realignment.
924 for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
925 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
926 if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
927 FuncInfo->setReserveFP(true);
935 virtual const char *getPassName() const {
936 return "X86 Maximal Stack Alignment Check";
939 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
940 AU.setPreservesCFG();
941 MachineFunctionPass::getAnalysisUsage(AU);
949 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }