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"
42 #include "X86GenRegisterDesc.inc"
43 #include "X86GenRegisterInfo.inc"
47 ForceStackAlign("force-align-stack",
48 cl::desc("Force align the stack to the minimum alignment"
49 " needed for the function."),
50 cl::init(false), cl::Hidden);
52 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
53 const TargetInstrInfo &tii)
54 : X86GenRegisterInfo(X86RegDesc, X86RegInfoDesc,
55 tm.getSubtarget<X86Subtarget>().is64Bit() ?
56 X86::ADJCALLSTACKDOWN64 :
57 X86::ADJCALLSTACKDOWN32,
58 tm.getSubtarget<X86Subtarget>().is64Bit() ?
59 X86::ADJCALLSTACKUP64 :
60 X86::ADJCALLSTACKUP32),
62 // Cache some information.
63 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
64 Is64Bit = Subtarget->is64Bit();
65 IsWin64 = Subtarget->isTargetWin64();
78 static unsigned getFlavour(const X86Subtarget *Subtarget, bool isEH) {
79 if (!Subtarget->is64Bit()) {
80 if (Subtarget->isTargetDarwin()) {
82 return DWARFFlavour::X86_32_DarwinEH;
84 return DWARFFlavour::X86_32_Generic;
85 } else if (Subtarget->isTargetCygMing()) {
86 // Unsupported by now, just quick fallback
87 return DWARFFlavour::X86_32_Generic;
89 return DWARFFlavour::X86_32_Generic;
92 return DWARFFlavour::X86_64;
95 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
96 /// specific numbering, used in debug info and exception tables.
97 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
98 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
99 unsigned Flavour = getFlavour(Subtarget, isEH);
101 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
104 /// getLLVMRegNum - This function maps DWARF register numbers to LLVM register.
105 int X86RegisterInfo::getLLVMRegNum(unsigned DwarfRegNo, bool isEH) const {
106 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
107 unsigned Flavour = getFlavour(Subtarget, isEH);
109 return X86GenRegisterInfo::getLLVMRegNumFull(DwarfRegNo, Flavour);
113 X86RegisterInfo::getSEHRegNum(unsigned i) const {
114 int reg = getX86RegNum(i);
116 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
117 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
118 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
119 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
120 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
121 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
122 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
123 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
124 case X86::XMM8: case X86::XMM9: case X86::XMM10: case X86::XMM11:
125 case X86::XMM12: case X86::XMM13: case X86::XMM14: case X86::XMM15:
126 case X86::YMM8: case X86::YMM9: case X86::YMM10: case X86::YMM11:
127 case X86::YMM12: case X86::YMM13: case X86::YMM14: case X86::YMM15:
133 /// getX86RegNum - This function maps LLVM register identifiers to their X86
134 /// specific numbering, which is used in various places encoding instructions.
135 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
137 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
138 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
139 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
140 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
141 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
143 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
145 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
147 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
150 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
152 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
154 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
156 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
158 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
160 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
162 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
164 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
167 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
168 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
169 return RegNo-X86::ST0;
171 case X86::XMM0: case X86::XMM8:
172 case X86::YMM0: case X86::YMM8: case X86::MM0:
174 case X86::XMM1: case X86::XMM9:
175 case X86::YMM1: case X86::YMM9: case X86::MM1:
177 case X86::XMM2: case X86::XMM10:
178 case X86::YMM2: case X86::YMM10: case X86::MM2:
180 case X86::XMM3: case X86::XMM11:
181 case X86::YMM3: case X86::YMM11: case X86::MM3:
183 case X86::XMM4: case X86::XMM12:
184 case X86::YMM4: case X86::YMM12: case X86::MM4:
186 case X86::XMM5: case X86::XMM13:
187 case X86::YMM5: case X86::YMM13: case X86::MM5:
189 case X86::XMM6: case X86::XMM14:
190 case X86::YMM6: case X86::YMM14: case X86::MM6:
192 case X86::XMM7: case X86::XMM15:
193 case X86::YMM7: case X86::YMM15: case X86::MM7:
196 case X86::ES: return 0;
197 case X86::CS: return 1;
198 case X86::SS: return 2;
199 case X86::DS: return 3;
200 case X86::FS: return 4;
201 case X86::GS: return 5;
203 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
204 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
205 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
206 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
207 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
208 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
209 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
210 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
212 // Pseudo index registers are equivalent to a "none"
213 // scaled index (See Intel Manual 2A, table 2-3)
219 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
220 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
225 const TargetRegisterClass *
226 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
227 const TargetRegisterClass *B,
228 unsigned SubIdx) const {
232 if (B == &X86::GR8RegClass) {
233 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
235 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
236 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
237 A == &X86::GR64_NOREXRegClass ||
238 A == &X86::GR64_NOSPRegClass ||
239 A == &X86::GR64_NOREX_NOSPRegClass)
240 return &X86::GR64_ABCDRegClass;
241 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
242 A == &X86::GR32_NOREXRegClass ||
243 A == &X86::GR32_NOSPRegClass)
244 return &X86::GR32_ABCDRegClass;
245 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
246 A == &X86::GR16_NOREXRegClass)
247 return &X86::GR16_ABCDRegClass;
248 } else if (B == &X86::GR8_NOREXRegClass) {
249 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
250 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
251 return &X86::GR64_NOREXRegClass;
252 else if (A == &X86::GR64_ABCDRegClass)
253 return &X86::GR64_ABCDRegClass;
254 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
255 A == &X86::GR32_NOSPRegClass)
256 return &X86::GR32_NOREXRegClass;
257 else if (A == &X86::GR32_ABCDRegClass)
258 return &X86::GR32_ABCDRegClass;
259 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
260 return &X86::GR16_NOREXRegClass;
261 else if (A == &X86::GR16_ABCDRegClass)
262 return &X86::GR16_ABCDRegClass;
265 case X86::sub_8bit_hi:
266 if (B->hasSubClassEq(&X86::GR8_ABCD_HRegClass))
267 switch (A->getSize()) {
268 case 2: return getCommonSubClass(A, &X86::GR16_ABCDRegClass);
269 case 4: return getCommonSubClass(A, &X86::GR32_ABCDRegClass);
270 case 8: return getCommonSubClass(A, &X86::GR64_ABCDRegClass);
275 if (B == &X86::GR16RegClass) {
276 if (A->getSize() == 4 || A->getSize() == 8)
278 } else if (B == &X86::GR16_ABCDRegClass) {
279 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
280 A == &X86::GR64_NOREXRegClass ||
281 A == &X86::GR64_NOSPRegClass ||
282 A == &X86::GR64_NOREX_NOSPRegClass)
283 return &X86::GR64_ABCDRegClass;
284 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
285 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
286 return &X86::GR32_ABCDRegClass;
287 } else if (B == &X86::GR16_NOREXRegClass) {
288 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
289 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
290 return &X86::GR64_NOREXRegClass;
291 else if (A == &X86::GR64_ABCDRegClass)
292 return &X86::GR64_ABCDRegClass;
293 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
294 A == &X86::GR32_NOSPRegClass)
295 return &X86::GR32_NOREXRegClass;
296 else if (A == &X86::GR32_ABCDRegClass)
297 return &X86::GR64_ABCDRegClass;
301 if (B == &X86::GR32RegClass) {
302 if (A->getSize() == 8)
304 } else if (B == &X86::GR32_NOSPRegClass) {
305 if (A == &X86::GR64RegClass || A == &X86::GR64_NOSPRegClass)
306 return &X86::GR64_NOSPRegClass;
307 if (A->getSize() == 8)
308 return getCommonSubClass(A, &X86::GR64_NOSPRegClass);
309 } else if (B == &X86::GR32_ABCDRegClass) {
310 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
311 A == &X86::GR64_NOREXRegClass ||
312 A == &X86::GR64_NOSPRegClass ||
313 A == &X86::GR64_NOREX_NOSPRegClass)
314 return &X86::GR64_ABCDRegClass;
315 } else if (B == &X86::GR32_NOREXRegClass) {
316 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass)
317 return &X86::GR64_NOREXRegClass;
318 else if (A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
319 return &X86::GR64_NOREX_NOSPRegClass;
320 else if (A == &X86::GR64_ABCDRegClass)
321 return &X86::GR64_ABCDRegClass;
322 } else if (B == &X86::GR32_NOREX_NOSPRegClass) {
323 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
324 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
325 return &X86::GR64_NOREX_NOSPRegClass;
326 else if (A == &X86::GR64_ABCDRegClass)
327 return &X86::GR64_ABCDRegClass;
331 if (B == &X86::FR32RegClass)
335 if (B == &X86::FR64RegClass)
339 if (B == &X86::VR128RegClass)
346 const TargetRegisterClass*
347 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
348 const TargetRegisterClass *Super = RC;
349 TargetRegisterClass::sc_iterator I = RC->superclasses_begin();
351 switch (Super->getID()) {
352 case X86::GR8RegClassID:
353 case X86::GR16RegClassID:
354 case X86::GR32RegClassID:
355 case X86::GR64RegClassID:
356 case X86::FR32RegClassID:
357 case X86::FR64RegClassID:
358 case X86::RFP32RegClassID:
359 case X86::RFP64RegClassID:
360 case X86::RFP80RegClassID:
361 case X86::VR128RegClassID:
362 case X86::VR256RegClassID:
363 // Don't return a super-class that would shrink the spill size.
364 // That can happen with the vector and float classes.
365 if (Super->getSize() == RC->getSize())
373 const TargetRegisterClass *
374 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
376 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
377 case 0: // Normal GPRs.
378 if (TM.getSubtarget<X86Subtarget>().is64Bit())
379 return &X86::GR64RegClass;
380 return &X86::GR32RegClass;
381 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
382 if (TM.getSubtarget<X86Subtarget>().is64Bit())
383 return &X86::GR64_NOSPRegClass;
384 return &X86::GR32_NOSPRegClass;
385 case 2: // Available for tailcall (not callee-saved GPRs).
386 if (TM.getSubtarget<X86Subtarget>().isTargetWin64())
387 return &X86::GR64_TCW64RegClass;
388 if (TM.getSubtarget<X86Subtarget>().is64Bit())
389 return &X86::GR64_TCRegClass;
390 return &X86::GR32_TCRegClass;
394 const TargetRegisterClass *
395 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
396 if (RC == &X86::CCRRegClass) {
398 return &X86::GR64RegClass;
400 return &X86::GR32RegClass;
406 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
407 MachineFunction &MF) const {
408 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
410 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
411 switch (RC->getID()) {
414 case X86::GR32RegClassID:
416 case X86::GR64RegClassID:
418 case X86::VR128RegClassID:
419 return TM.getSubtarget<X86Subtarget>().is64Bit() ? 10 : 4;
420 case X86::VR64RegClassID:
426 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
427 bool callsEHReturn = false;
428 bool ghcCall = false;
431 callsEHReturn = MF->getMMI().callsEHReturn();
432 const Function *F = MF->getFunction();
433 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
436 static const unsigned GhcCalleeSavedRegs[] = {
440 static const unsigned CalleeSavedRegs32Bit[] = {
441 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
444 static const unsigned CalleeSavedRegs32EHRet[] = {
445 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
448 static const unsigned CalleeSavedRegs64Bit[] = {
449 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
452 static const unsigned CalleeSavedRegs64EHRet[] = {
453 X86::RAX, X86::RDX, X86::RBX, X86::R12,
454 X86::R13, X86::R14, X86::R15, X86::RBP, 0
457 static const unsigned CalleeSavedRegsWin64[] = {
458 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
459 X86::R12, X86::R13, X86::R14, X86::R15,
460 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
461 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
462 X86::XMM14, X86::XMM15, 0
466 return GhcCalleeSavedRegs;
467 } else if (Is64Bit) {
469 return CalleeSavedRegsWin64;
471 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
473 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
477 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
478 BitVector Reserved(getNumRegs());
479 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
481 // Set the stack-pointer register and its aliases as reserved.
482 Reserved.set(X86::RSP);
483 Reserved.set(X86::ESP);
484 Reserved.set(X86::SP);
485 Reserved.set(X86::SPL);
487 // Set the instruction pointer register and its aliases as reserved.
488 Reserved.set(X86::RIP);
489 Reserved.set(X86::EIP);
490 Reserved.set(X86::IP);
492 // Set the frame-pointer register and its aliases as reserved if needed.
493 if (TFI->hasFP(MF)) {
494 Reserved.set(X86::RBP);
495 Reserved.set(X86::EBP);
496 Reserved.set(X86::BP);
497 Reserved.set(X86::BPL);
500 // Mark the x87 stack registers as reserved, since they don't behave normally
501 // with respect to liveness. We don't fully model the effects of x87 stack
502 // pushes and pops after stackification.
503 Reserved.set(X86::ST0);
504 Reserved.set(X86::ST1);
505 Reserved.set(X86::ST2);
506 Reserved.set(X86::ST3);
507 Reserved.set(X86::ST4);
508 Reserved.set(X86::ST5);
509 Reserved.set(X86::ST6);
510 Reserved.set(X86::ST7);
512 // Mark the segment registers as reserved.
513 Reserved.set(X86::CS);
514 Reserved.set(X86::SS);
515 Reserved.set(X86::DS);
516 Reserved.set(X86::ES);
517 Reserved.set(X86::FS);
518 Reserved.set(X86::GS);
520 // Reserve the registers that only exist in 64-bit mode.
522 // These 8-bit registers are part of the x86-64 extension even though their
523 // super-registers are old 32-bits.
524 Reserved.set(X86::SIL);
525 Reserved.set(X86::DIL);
526 Reserved.set(X86::BPL);
527 Reserved.set(X86::SPL);
529 for (unsigned n = 0; n != 8; ++n) {
531 const unsigned GPR64[] = {
532 X86::R8, X86::R9, X86::R10, X86::R11,
533 X86::R12, X86::R13, X86::R14, X86::R15
535 for (const unsigned *AI = getOverlaps(GPR64[n]); unsigned Reg = *AI; ++AI)
539 assert(X86::XMM15 == X86::XMM8+7);
540 for (const unsigned *AI = getOverlaps(X86::XMM8 + n); unsigned Reg = *AI;
549 //===----------------------------------------------------------------------===//
550 // Stack Frame Processing methods
551 //===----------------------------------------------------------------------===//
553 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
554 const MachineFrameInfo *MFI = MF.getFrameInfo();
555 return (RealignStack &&
556 !MFI->hasVarSizedObjects());
559 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
560 const MachineFrameInfo *MFI = MF.getFrameInfo();
561 const Function *F = MF.getFunction();
562 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
563 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
564 F->hasFnAttr(Attribute::StackAlignment));
566 // FIXME: Currently we don't support stack realignment for functions with
567 // variable-sized allocas.
568 // FIXME: It's more complicated than this...
569 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
571 "Stack realignment in presence of dynamic allocas is not supported");
573 // If we've requested that we force align the stack do so now.
575 return canRealignStack(MF);
577 return requiresRealignment && canRealignStack(MF);
580 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
581 unsigned Reg, int &FrameIdx) const {
582 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
584 if (Reg == FramePtr && TFI->hasFP(MF)) {
585 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
591 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
594 return X86::SUB64ri8;
595 return X86::SUB64ri32;
598 return X86::SUB32ri8;
603 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
606 return X86::ADD64ri8;
607 return X86::ADD64ri32;
610 return X86::ADD32ri8;
615 void X86RegisterInfo::
616 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
617 MachineBasicBlock::iterator I) const {
618 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
619 bool reseveCallFrame = TFI->hasReservedCallFrame(MF);
620 int Opcode = I->getOpcode();
621 bool isDestroy = Opcode == getCallFrameDestroyOpcode();
622 DebugLoc DL = I->getDebugLoc();
623 uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
624 uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
627 if (!reseveCallFrame) {
628 // If the stack pointer can be changed after prologue, turn the
629 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
630 // adjcallstackdown instruction into 'add ESP, <amt>'
631 // TODO: consider using push / pop instead of sub + store / add
635 // We need to keep the stack aligned properly. To do this, we round the
636 // amount of space needed for the outgoing arguments up to the next
637 // alignment boundary.
638 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
639 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
641 MachineInstr *New = 0;
642 if (Opcode == getCallFrameSetupOpcode()) {
643 New = BuildMI(MF, DL, TII.get(getSUBriOpcode(Is64Bit, Amount)),
648 assert(Opcode == getCallFrameDestroyOpcode());
650 // Factor out the amount the callee already popped.
654 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
655 New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
656 .addReg(StackPtr).addImm(Amount);
661 // The EFLAGS implicit def is dead.
662 New->getOperand(3).setIsDead();
664 // Replace the pseudo instruction with a new instruction.
671 if (Opcode == getCallFrameDestroyOpcode() && CalleeAmt) {
672 // If we are performing frame pointer elimination and if the callee pops
673 // something off the stack pointer, add it back. We do this until we have
674 // more advanced stack pointer tracking ability.
675 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
676 MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
677 .addReg(StackPtr).addImm(CalleeAmt);
679 // The EFLAGS implicit def is dead.
680 New->getOperand(3).setIsDead();
686 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
687 int SPAdj, RegScavenger *RS) const{
688 assert(SPAdj == 0 && "Unexpected");
691 MachineInstr &MI = *II;
692 MachineFunction &MF = *MI.getParent()->getParent();
693 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
695 while (!MI.getOperand(i).isFI()) {
697 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
700 int FrameIndex = MI.getOperand(i).getIndex();
703 unsigned Opc = MI.getOpcode();
704 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
705 if (needsStackRealignment(MF))
706 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
710 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
712 // This must be part of a four operand memory reference. Replace the
713 // FrameIndex with base register with EBP. Add an offset to the offset.
714 MI.getOperand(i).ChangeToRegister(BasePtr, false);
716 // Now add the frame object offset to the offset from EBP.
719 // Tail call jmp happens after FP is popped.
720 const MachineFrameInfo *MFI = MF.getFrameInfo();
721 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
723 FIOffset = TFI->getFrameIndexOffset(MF, FrameIndex);
725 if (MI.getOperand(i+3).isImm()) {
726 // Offset is a 32-bit integer.
727 int Offset = FIOffset + (int)(MI.getOperand(i + 3).getImm());
728 MI.getOperand(i + 3).ChangeToImmediate(Offset);
730 // Offset is symbolic. This is extremely rare.
731 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
732 MI.getOperand(i+3).setOffset(Offset);
736 unsigned X86RegisterInfo::getRARegister() const {
737 return Is64Bit ? X86::RIP // Should have dwarf #16.
738 : X86::EIP; // Should have dwarf #8.
741 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
742 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
743 return TFI->hasFP(MF) ? FramePtr : StackPtr;
746 unsigned X86RegisterInfo::getEHExceptionRegister() const {
747 llvm_unreachable("What is the exception register");
751 unsigned X86RegisterInfo::getEHHandlerRegister() const {
752 llvm_unreachable("What is the exception handler register");
757 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
758 switch (VT.getSimpleVT().SimpleTy) {
764 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
766 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
768 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
770 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
776 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
778 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
780 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
782 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
784 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
786 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
788 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
790 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
792 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
794 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
796 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
798 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
800 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
802 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
804 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
806 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
813 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
815 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
817 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
819 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
821 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
823 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
825 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
827 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
829 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
831 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
833 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
835 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
837 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
839 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
841 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
843 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
849 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
851 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
853 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
855 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
857 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
859 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
861 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
863 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
865 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
867 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
869 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
871 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
873 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
875 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
877 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
879 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
885 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
887 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
889 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
891 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
893 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
895 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
897 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
899 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
901 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
903 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
905 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
907 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
909 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
911 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
913 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
915 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
925 struct MSAH : public MachineFunctionPass {
927 MSAH() : MachineFunctionPass(ID) {}
929 virtual bool runOnMachineFunction(MachineFunction &MF) {
930 const X86TargetMachine *TM =
931 static_cast<const X86TargetMachine *>(&MF.getTarget());
932 const TargetFrameLowering *TFI = TM->getFrameLowering();
933 MachineRegisterInfo &RI = MF.getRegInfo();
934 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
935 unsigned StackAlignment = TFI->getStackAlignment();
937 // Be over-conservative: scan over all vreg defs and find whether vector
938 // registers are used. If yes, there is a possibility that vector register
939 // will be spilled and thus require dynamic stack realignment.
940 for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
941 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
942 if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
943 FuncInfo->setReserveFP(true);
951 virtual const char *getPassName() const {
952 return "X86 Maximal Stack Alignment Check";
955 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
956 AU.setPreservesCFG();
957 MachineFunctionPass::getAnalysisUsage(AU);
965 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }