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 static unsigned getFlavour(const X86Subtarget *Subtarget, bool isEH) {
77 if (!Subtarget->is64Bit()) {
78 if (Subtarget->isTargetDarwin()) {
80 return DWARFFlavour::X86_32_DarwinEH;
82 return DWARFFlavour::X86_32_Generic;
83 } else if (Subtarget->isTargetCygMing()) {
84 // Unsupported by now, just quick fallback
85 return DWARFFlavour::X86_32_Generic;
87 return DWARFFlavour::X86_32_Generic;
90 return DWARFFlavour::X86_64;
93 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
94 /// specific numbering, used in debug info and exception tables.
95 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
96 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
97 unsigned Flavour = getFlavour(Subtarget, isEH);
99 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
102 /// getLLVMRegNum - This function maps DWARF register numbers to LLVM register.
103 int X86RegisterInfo::getLLVMRegNum(unsigned DwarfRegNo, bool isEH) const {
104 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
105 unsigned Flavour = getFlavour(Subtarget, isEH);
107 return X86GenRegisterInfo::getLLVMRegNumFull(DwarfRegNo, Flavour);
111 X86RegisterInfo::getSEHRegNum(unsigned i) const {
112 int reg = getX86RegNum(i);
114 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
115 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
116 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
117 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
118 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
119 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
120 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
121 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
122 case X86::XMM8: case X86::XMM9: case X86::XMM10: case X86::XMM11:
123 case X86::XMM12: case X86::XMM13: case X86::XMM14: case X86::XMM15:
124 case X86::YMM8: case X86::YMM9: case X86::YMM10: case X86::YMM11:
125 case X86::YMM12: case X86::YMM13: case X86::YMM14: case X86::YMM15:
131 /// getX86RegNum - This function maps LLVM register identifiers to their X86
132 /// specific numbering, which is used in various places encoding instructions.
133 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
135 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
136 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
137 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
138 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
139 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
141 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
143 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
145 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
148 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
150 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
152 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
154 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
156 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
158 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
160 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
162 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
165 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
166 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
167 return RegNo-X86::ST0;
169 case X86::XMM0: case X86::XMM8:
170 case X86::YMM0: case X86::YMM8: case X86::MM0:
172 case X86::XMM1: case X86::XMM9:
173 case X86::YMM1: case X86::YMM9: case X86::MM1:
175 case X86::XMM2: case X86::XMM10:
176 case X86::YMM2: case X86::YMM10: case X86::MM2:
178 case X86::XMM3: case X86::XMM11:
179 case X86::YMM3: case X86::YMM11: case X86::MM3:
181 case X86::XMM4: case X86::XMM12:
182 case X86::YMM4: case X86::YMM12: case X86::MM4:
184 case X86::XMM5: case X86::XMM13:
185 case X86::YMM5: case X86::YMM13: case X86::MM5:
187 case X86::XMM6: case X86::XMM14:
188 case X86::YMM6: case X86::YMM14: case X86::MM6:
190 case X86::XMM7: case X86::XMM15:
191 case X86::YMM7: case X86::YMM15: case X86::MM7:
194 case X86::ES: return 0;
195 case X86::CS: return 1;
196 case X86::SS: return 2;
197 case X86::DS: return 3;
198 case X86::FS: return 4;
199 case X86::GS: return 5;
201 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
202 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
203 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
204 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
205 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
206 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
207 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
208 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
210 // Pseudo index registers are equivalent to a "none"
211 // scaled index (See Intel Manual 2A, table 2-3)
217 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
218 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
223 const TargetRegisterClass *
224 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
225 const TargetRegisterClass *B,
226 unsigned SubIdx) const {
230 if (B == &X86::GR8RegClass) {
231 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
233 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
234 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
235 A == &X86::GR64_NOREXRegClass ||
236 A == &X86::GR64_NOSPRegClass ||
237 A == &X86::GR64_NOREX_NOSPRegClass)
238 return &X86::GR64_ABCDRegClass;
239 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
240 A == &X86::GR32_NOREXRegClass ||
241 A == &X86::GR32_NOSPRegClass)
242 return &X86::GR32_ABCDRegClass;
243 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
244 A == &X86::GR16_NOREXRegClass)
245 return &X86::GR16_ABCDRegClass;
246 } else if (B == &X86::GR8_NOREXRegClass) {
247 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
248 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
249 return &X86::GR64_NOREXRegClass;
250 else if (A == &X86::GR64_ABCDRegClass)
251 return &X86::GR64_ABCDRegClass;
252 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
253 A == &X86::GR32_NOSPRegClass)
254 return &X86::GR32_NOREXRegClass;
255 else if (A == &X86::GR32_ABCDRegClass)
256 return &X86::GR32_ABCDRegClass;
257 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
258 return &X86::GR16_NOREXRegClass;
259 else if (A == &X86::GR16_ABCDRegClass)
260 return &X86::GR16_ABCDRegClass;
263 case X86::sub_8bit_hi:
264 if (B->hasSubClassEq(&X86::GR8_ABCD_HRegClass))
265 switch (A->getSize()) {
266 case 2: return getCommonSubClass(A, &X86::GR16_ABCDRegClass);
267 case 4: return getCommonSubClass(A, &X86::GR32_ABCDRegClass);
268 case 8: return getCommonSubClass(A, &X86::GR64_ABCDRegClass);
273 if (B == &X86::GR16RegClass) {
274 if (A->getSize() == 4 || A->getSize() == 8)
276 } else if (B == &X86::GR16_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 (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
283 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
284 return &X86::GR32_ABCDRegClass;
285 } else if (B == &X86::GR16_NOREXRegClass) {
286 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
287 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
288 return &X86::GR64_NOREXRegClass;
289 else if (A == &X86::GR64_ABCDRegClass)
290 return &X86::GR64_ABCDRegClass;
291 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
292 A == &X86::GR32_NOSPRegClass)
293 return &X86::GR32_NOREXRegClass;
294 else if (A == &X86::GR32_ABCDRegClass)
295 return &X86::GR64_ABCDRegClass;
299 if (B == &X86::GR32RegClass) {
300 if (A->getSize() == 8)
302 } else if (B == &X86::GR32_NOSPRegClass) {
303 if (A == &X86::GR64RegClass || A == &X86::GR64_NOSPRegClass)
304 return &X86::GR64_NOSPRegClass;
305 if (A->getSize() == 8)
306 return getCommonSubClass(A, &X86::GR64_NOSPRegClass);
307 } else if (B == &X86::GR32_ABCDRegClass) {
308 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
309 A == &X86::GR64_NOREXRegClass ||
310 A == &X86::GR64_NOSPRegClass ||
311 A == &X86::GR64_NOREX_NOSPRegClass)
312 return &X86::GR64_ABCDRegClass;
313 } else if (B == &X86::GR32_NOREXRegClass) {
314 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass)
315 return &X86::GR64_NOREXRegClass;
316 else if (A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
317 return &X86::GR64_NOREX_NOSPRegClass;
318 else if (A == &X86::GR64_ABCDRegClass)
319 return &X86::GR64_ABCDRegClass;
320 } else if (B == &X86::GR32_NOREX_NOSPRegClass) {
321 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
322 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
323 return &X86::GR64_NOREX_NOSPRegClass;
324 else if (A == &X86::GR64_ABCDRegClass)
325 return &X86::GR64_ABCDRegClass;
329 if (B == &X86::FR32RegClass)
333 if (B == &X86::FR64RegClass)
337 if (B == &X86::VR128RegClass)
344 const TargetRegisterClass*
345 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
346 const TargetRegisterClass *Super = RC;
347 TargetRegisterClass::sc_iterator I = RC->superclasses_begin();
349 switch (Super->getID()) {
350 case X86::GR8RegClassID:
351 case X86::GR16RegClassID:
352 case X86::GR32RegClassID:
353 case X86::GR64RegClassID:
354 case X86::FR32RegClassID:
355 case X86::FR64RegClassID:
356 case X86::RFP32RegClassID:
357 case X86::RFP64RegClassID:
358 case X86::RFP80RegClassID:
359 case X86::VR128RegClassID:
360 case X86::VR256RegClassID:
361 // Don't return a super-class that would shrink the spill size.
362 // That can happen with the vector and float classes.
363 if (Super->getSize() == RC->getSize())
371 const TargetRegisterClass *
372 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
374 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
375 case 0: // Normal GPRs.
376 if (TM.getSubtarget<X86Subtarget>().is64Bit())
377 return &X86::GR64RegClass;
378 return &X86::GR32RegClass;
379 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
380 if (TM.getSubtarget<X86Subtarget>().is64Bit())
381 return &X86::GR64_NOSPRegClass;
382 return &X86::GR32_NOSPRegClass;
383 case 2: // Available for tailcall (not callee-saved GPRs).
384 if (TM.getSubtarget<X86Subtarget>().isTargetWin64())
385 return &X86::GR64_TCW64RegClass;
386 if (TM.getSubtarget<X86Subtarget>().is64Bit())
387 return &X86::GR64_TCRegClass;
388 return &X86::GR32_TCRegClass;
392 const TargetRegisterClass *
393 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
394 if (RC == &X86::CCRRegClass) {
396 return &X86::GR64RegClass;
398 return &X86::GR32RegClass;
404 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
405 MachineFunction &MF) const {
406 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
408 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
409 switch (RC->getID()) {
412 case X86::GR32RegClassID:
414 case X86::GR64RegClassID:
416 case X86::VR128RegClassID:
417 return TM.getSubtarget<X86Subtarget>().is64Bit() ? 10 : 4;
418 case X86::VR64RegClassID:
424 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
425 bool callsEHReturn = false;
426 bool ghcCall = false;
429 callsEHReturn = MF->getMMI().callsEHReturn();
430 const Function *F = MF->getFunction();
431 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
434 static const unsigned GhcCalleeSavedRegs[] = {
438 static const unsigned CalleeSavedRegs32Bit[] = {
439 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
442 static const unsigned CalleeSavedRegs32EHRet[] = {
443 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
446 static const unsigned CalleeSavedRegs64Bit[] = {
447 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
450 static const unsigned CalleeSavedRegs64EHRet[] = {
451 X86::RAX, X86::RDX, X86::RBX, X86::R12,
452 X86::R13, X86::R14, X86::R15, X86::RBP, 0
455 static const unsigned CalleeSavedRegsWin64[] = {
456 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
457 X86::R12, X86::R13, X86::R14, X86::R15,
458 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
459 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
460 X86::XMM14, X86::XMM15, 0
464 return GhcCalleeSavedRegs;
465 } else if (Is64Bit) {
467 return CalleeSavedRegsWin64;
469 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
471 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
475 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
476 BitVector Reserved(getNumRegs());
477 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
479 // Set the stack-pointer register and its aliases as reserved.
480 Reserved.set(X86::RSP);
481 Reserved.set(X86::ESP);
482 Reserved.set(X86::SP);
483 Reserved.set(X86::SPL);
485 // Set the instruction pointer register and its aliases as reserved.
486 Reserved.set(X86::RIP);
487 Reserved.set(X86::EIP);
488 Reserved.set(X86::IP);
490 // Set the frame-pointer register and its aliases as reserved if needed.
491 if (TFI->hasFP(MF)) {
492 Reserved.set(X86::RBP);
493 Reserved.set(X86::EBP);
494 Reserved.set(X86::BP);
495 Reserved.set(X86::BPL);
498 // Mark the x87 stack registers as reserved, since they don't behave normally
499 // with respect to liveness. We don't fully model the effects of x87 stack
500 // pushes and pops after stackification.
501 Reserved.set(X86::ST0);
502 Reserved.set(X86::ST1);
503 Reserved.set(X86::ST2);
504 Reserved.set(X86::ST3);
505 Reserved.set(X86::ST4);
506 Reserved.set(X86::ST5);
507 Reserved.set(X86::ST6);
508 Reserved.set(X86::ST7);
510 // Mark the segment registers as reserved.
511 Reserved.set(X86::CS);
512 Reserved.set(X86::SS);
513 Reserved.set(X86::DS);
514 Reserved.set(X86::ES);
515 Reserved.set(X86::FS);
516 Reserved.set(X86::GS);
518 // Reserve the registers that only exist in 64-bit mode.
520 for (unsigned n = 0; n != 8; ++n) {
521 const unsigned GPR64[] = {
522 X86::R8, X86::R9, X86::R10, X86::R11,
523 X86::R12, X86::R13, X86::R14, X86::R15
525 for (const unsigned *AI = getOverlaps(GPR64[n]); unsigned Reg = *AI;
530 assert(X86::XMM15 == X86::XMM8+7);
531 for (const unsigned *AI = getOverlaps(X86::XMM8 + n); unsigned Reg = *AI;
540 //===----------------------------------------------------------------------===//
541 // Stack Frame Processing methods
542 //===----------------------------------------------------------------------===//
544 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
545 const MachineFrameInfo *MFI = MF.getFrameInfo();
546 return (RealignStack &&
547 !MFI->hasVarSizedObjects());
550 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
551 const MachineFrameInfo *MFI = MF.getFrameInfo();
552 const Function *F = MF.getFunction();
553 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
554 F->hasFnAttr(Attribute::StackAlignment));
556 // FIXME: Currently we don't support stack realignment for functions with
557 // variable-sized allocas.
558 // FIXME: It's more complicated than this...
559 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
561 "Stack realignment in presence of dynamic allocas is not supported");
563 // If we've requested that we force align the stack do so now.
565 return canRealignStack(MF);
567 return requiresRealignment && canRealignStack(MF);
570 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
571 unsigned Reg, int &FrameIdx) const {
572 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
574 if (Reg == FramePtr && TFI->hasFP(MF)) {
575 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
581 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
584 return X86::SUB64ri8;
585 return X86::SUB64ri32;
588 return X86::SUB32ri8;
593 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
596 return X86::ADD64ri8;
597 return X86::ADD64ri32;
600 return X86::ADD32ri8;
605 void X86RegisterInfo::
606 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
607 MachineBasicBlock::iterator I) const {
608 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
609 bool reseveCallFrame = TFI->hasReservedCallFrame(MF);
610 int Opcode = I->getOpcode();
611 bool isDestroy = Opcode == getCallFrameDestroyOpcode();
612 DebugLoc DL = I->getDebugLoc();
613 uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
614 uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
617 if (!reseveCallFrame) {
618 // If the stack pointer can be changed after prologue, turn the
619 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
620 // adjcallstackdown instruction into 'add ESP, <amt>'
621 // TODO: consider using push / pop instead of sub + store / add
625 // We need to keep the stack aligned properly. To do this, we round the
626 // amount of space needed for the outgoing arguments up to the next
627 // alignment boundary.
628 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
630 MachineInstr *New = 0;
631 if (Opcode == getCallFrameSetupOpcode()) {
632 New = BuildMI(MF, DL, TII.get(getSUBriOpcode(Is64Bit, Amount)),
637 assert(Opcode == getCallFrameDestroyOpcode());
639 // Factor out the amount the callee already popped.
643 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
644 New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
645 .addReg(StackPtr).addImm(Amount);
650 // The EFLAGS implicit def is dead.
651 New->getOperand(3).setIsDead();
653 // Replace the pseudo instruction with a new instruction.
660 if (Opcode == getCallFrameDestroyOpcode() && CalleeAmt) {
661 // If we are performing frame pointer elimination and if the callee pops
662 // something off the stack pointer, add it back. We do this until we have
663 // more advanced stack pointer tracking ability.
664 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
665 MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
666 .addReg(StackPtr).addImm(CalleeAmt);
668 // The EFLAGS implicit def is dead.
669 New->getOperand(3).setIsDead();
675 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
676 int SPAdj, RegScavenger *RS) const{
677 assert(SPAdj == 0 && "Unexpected");
680 MachineInstr &MI = *II;
681 MachineFunction &MF = *MI.getParent()->getParent();
682 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
684 while (!MI.getOperand(i).isFI()) {
686 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
689 int FrameIndex = MI.getOperand(i).getIndex();
692 unsigned Opc = MI.getOpcode();
693 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
694 if (needsStackRealignment(MF))
695 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
699 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
701 // This must be part of a four operand memory reference. Replace the
702 // FrameIndex with base register with EBP. Add an offset to the offset.
703 MI.getOperand(i).ChangeToRegister(BasePtr, false);
705 // Now add the frame object offset to the offset from EBP.
708 // Tail call jmp happens after FP is popped.
709 const MachineFrameInfo *MFI = MF.getFrameInfo();
710 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
712 FIOffset = TFI->getFrameIndexOffset(MF, FrameIndex);
714 if (MI.getOperand(i+3).isImm()) {
715 // Offset is a 32-bit integer.
716 int Offset = FIOffset + (int)(MI.getOperand(i + 3).getImm());
717 MI.getOperand(i + 3).ChangeToImmediate(Offset);
719 // Offset is symbolic. This is extremely rare.
720 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
721 MI.getOperand(i+3).setOffset(Offset);
725 unsigned X86RegisterInfo::getRARegister() const {
726 return Is64Bit ? X86::RIP // Should have dwarf #16.
727 : X86::EIP; // Should have dwarf #8.
730 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
731 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
732 return TFI->hasFP(MF) ? FramePtr : StackPtr;
735 unsigned X86RegisterInfo::getEHExceptionRegister() const {
736 llvm_unreachable("What is the exception register");
740 unsigned X86RegisterInfo::getEHHandlerRegister() const {
741 llvm_unreachable("What is the exception handler register");
746 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
747 switch (VT.getSimpleVT().SimpleTy) {
753 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
755 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
757 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
759 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
765 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
767 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
769 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
771 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
773 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
775 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
777 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
779 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
781 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
783 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
785 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
787 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
789 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
791 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
793 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
795 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
802 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
804 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
806 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
808 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
810 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
812 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
814 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
816 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
818 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
820 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
822 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
824 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
826 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
828 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
830 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
832 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
838 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
840 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
842 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
844 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
846 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
848 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
850 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
852 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
854 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
856 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
858 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
860 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
862 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
864 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
866 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
868 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
874 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
876 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
878 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
880 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
882 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
884 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
886 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
888 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
890 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
892 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
894 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
896 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
898 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
900 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
902 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
904 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
913 #include "X86GenRegisterInfo.inc"
916 struct MSAH : public MachineFunctionPass {
918 MSAH() : MachineFunctionPass(ID) {}
920 virtual bool runOnMachineFunction(MachineFunction &MF) {
921 const X86TargetMachine *TM =
922 static_cast<const X86TargetMachine *>(&MF.getTarget());
923 const X86RegisterInfo *X86RI = TM->getRegisterInfo();
924 MachineRegisterInfo &RI = MF.getRegInfo();
925 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
926 unsigned StackAlignment = X86RI->getStackAlignment();
928 // Be over-conservative: scan over all vreg defs and find whether vector
929 // registers are used. If yes, there is a possibility that vector register
930 // will be spilled and thus require dynamic stack realignment.
931 for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
932 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
933 if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
934 FuncInfo->setReserveFP(true);
942 virtual const char *getPassName() const {
943 return "X86 Maximal Stack Alignment Check";
946 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
947 AU.setPreservesCFG();
948 MachineFunctionPass::getAnalysisUsage(AU);
956 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }