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_TARGET_DESC
44 #include "X86GenRegisterInfo.inc"
49 ForceStackAlign("force-align-stack",
50 cl::desc("Force align the stack to the minimum alignment"
51 " needed for the function."),
52 cl::init(false), cl::Hidden);
54 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
55 const TargetInstrInfo &tii)
56 : X86GenRegisterInfo(), TM(tm), TII(tii) {
57 // Cache some information.
58 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
59 Is64Bit = Subtarget->is64Bit();
60 IsWin64 = Subtarget->isTargetWin64();
73 static unsigned getFlavour(const X86Subtarget *Subtarget, bool isEH) {
74 if (!Subtarget->is64Bit()) {
75 if (Subtarget->isTargetDarwin()) {
77 return DWARFFlavour::X86_32_DarwinEH;
79 return DWARFFlavour::X86_32_Generic;
80 } else if (Subtarget->isTargetCygMing()) {
81 // Unsupported by now, just quick fallback
82 return DWARFFlavour::X86_32_Generic;
84 return DWARFFlavour::X86_32_Generic;
87 return DWARFFlavour::X86_64;
90 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
91 /// specific numbering, used in debug info and exception tables.
92 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
93 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
94 unsigned Flavour = getFlavour(Subtarget, isEH);
96 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
99 /// getLLVMRegNum - This function maps DWARF register numbers to LLVM register.
100 int X86RegisterInfo::getLLVMRegNum(unsigned DwarfRegNo, bool isEH) const {
101 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
102 unsigned Flavour = getFlavour(Subtarget, isEH);
104 return X86GenRegisterInfo::getLLVMRegNumFull(DwarfRegNo, Flavour);
107 /// getCompactUnwindRegNum - This function maps the register to the number for
108 /// compact unwind encoding. Return -1 if the register isn't valid.
109 int X86RegisterInfo::getCompactUnwindRegNum(unsigned RegNum, bool isEH) const {
110 switch (getLLVMRegNum(RegNum, isEH)) {
111 case X86::EBX: case X86::RBX: return 1;
112 case X86::ECX: case X86::R12: return 2;
113 case X86::EDX: case X86::R13: return 3;
114 case X86::EDI: case X86::R14: return 4;
115 case X86::ESI: case X86::R15: return 5;
116 case X86::EBP: case X86::RBP: return 6;
123 X86RegisterInfo::getSEHRegNum(unsigned i) const {
124 int reg = getX86RegNum(i);
126 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
127 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
128 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
129 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
130 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
131 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
132 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
133 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
134 case X86::XMM8: case X86::XMM9: case X86::XMM10: case X86::XMM11:
135 case X86::XMM12: case X86::XMM13: case X86::XMM14: case X86::XMM15:
136 case X86::YMM8: case X86::YMM9: case X86::YMM10: case X86::YMM11:
137 case X86::YMM12: case X86::YMM13: case X86::YMM14: case X86::YMM15:
143 /// getX86RegNum - This function maps LLVM register identifiers to their X86
144 /// specific numbering, which is used in various places encoding instructions.
145 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
147 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
148 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
149 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
150 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
151 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
153 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
155 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
157 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
160 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
162 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
164 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
166 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
168 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
170 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
172 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
174 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
177 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
178 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
179 return RegNo-X86::ST0;
181 case X86::XMM0: case X86::XMM8:
182 case X86::YMM0: case X86::YMM8: case X86::MM0:
184 case X86::XMM1: case X86::XMM9:
185 case X86::YMM1: case X86::YMM9: case X86::MM1:
187 case X86::XMM2: case X86::XMM10:
188 case X86::YMM2: case X86::YMM10: case X86::MM2:
190 case X86::XMM3: case X86::XMM11:
191 case X86::YMM3: case X86::YMM11: case X86::MM3:
193 case X86::XMM4: case X86::XMM12:
194 case X86::YMM4: case X86::YMM12: case X86::MM4:
196 case X86::XMM5: case X86::XMM13:
197 case X86::YMM5: case X86::YMM13: case X86::MM5:
199 case X86::XMM6: case X86::XMM14:
200 case X86::YMM6: case X86::YMM14: case X86::MM6:
202 case X86::XMM7: case X86::XMM15:
203 case X86::YMM7: case X86::YMM15: case X86::MM7:
206 case X86::ES: return 0;
207 case X86::CS: return 1;
208 case X86::SS: return 2;
209 case X86::DS: return 3;
210 case X86::FS: return 4;
211 case X86::GS: return 5;
213 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
214 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
215 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
216 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
217 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
218 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
219 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
220 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
222 // Pseudo index registers are equivalent to a "none"
223 // scaled index (See Intel Manual 2A, table 2-3)
229 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
230 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
235 const TargetRegisterClass *
236 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
237 const TargetRegisterClass *B,
238 unsigned SubIdx) const {
242 if (B == &X86::GR8RegClass) {
243 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
245 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
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 ||
253 A == &X86::GR32_NOSPRegClass)
254 return &X86::GR32_ABCDRegClass;
255 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
256 A == &X86::GR16_NOREXRegClass)
257 return &X86::GR16_ABCDRegClass;
258 } else if (B == &X86::GR8_NOREXRegClass) {
259 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
260 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
261 return &X86::GR64_NOREXRegClass;
262 else if (A == &X86::GR64_ABCDRegClass)
263 return &X86::GR64_ABCDRegClass;
264 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
265 A == &X86::GR32_NOSPRegClass)
266 return &X86::GR32_NOREXRegClass;
267 else if (A == &X86::GR32_ABCDRegClass)
268 return &X86::GR32_ABCDRegClass;
269 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
270 return &X86::GR16_NOREXRegClass;
271 else if (A == &X86::GR16_ABCDRegClass)
272 return &X86::GR16_ABCDRegClass;
275 case X86::sub_8bit_hi:
276 if (B->hasSubClassEq(&X86::GR8_ABCD_HRegClass))
277 switch (A->getSize()) {
278 case 2: return getCommonSubClass(A, &X86::GR16_ABCDRegClass);
279 case 4: return getCommonSubClass(A, &X86::GR32_ABCDRegClass);
280 case 8: return getCommonSubClass(A, &X86::GR64_ABCDRegClass);
285 if (B == &X86::GR16RegClass) {
286 if (A->getSize() == 4 || A->getSize() == 8)
288 } else if (B == &X86::GR16_ABCDRegClass) {
289 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
290 A == &X86::GR64_NOREXRegClass ||
291 A == &X86::GR64_NOSPRegClass ||
292 A == &X86::GR64_NOREX_NOSPRegClass)
293 return &X86::GR64_ABCDRegClass;
294 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
295 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
296 return &X86::GR32_ABCDRegClass;
297 } else if (B == &X86::GR16_NOREXRegClass) {
298 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
299 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
300 return &X86::GR64_NOREXRegClass;
301 else if (A == &X86::GR64_ABCDRegClass)
302 return &X86::GR64_ABCDRegClass;
303 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
304 A == &X86::GR32_NOSPRegClass)
305 return &X86::GR32_NOREXRegClass;
306 else if (A == &X86::GR32_ABCDRegClass)
307 return &X86::GR64_ABCDRegClass;
311 if (B == &X86::GR32RegClass) {
312 if (A->getSize() == 8)
314 } else if (B == &X86::GR32_NOSPRegClass) {
315 if (A == &X86::GR64RegClass || A == &X86::GR64_NOSPRegClass)
316 return &X86::GR64_NOSPRegClass;
317 if (A->getSize() == 8)
318 return getCommonSubClass(A, &X86::GR64_NOSPRegClass);
319 } else if (B == &X86::GR32_ABCDRegClass) {
320 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
321 A == &X86::GR64_NOREXRegClass ||
322 A == &X86::GR64_NOSPRegClass ||
323 A == &X86::GR64_NOREX_NOSPRegClass)
324 return &X86::GR64_ABCDRegClass;
325 } else if (B == &X86::GR32_NOREXRegClass) {
326 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass)
327 return &X86::GR64_NOREXRegClass;
328 else if (A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
329 return &X86::GR64_NOREX_NOSPRegClass;
330 else if (A == &X86::GR64_ABCDRegClass)
331 return &X86::GR64_ABCDRegClass;
332 } else if (B == &X86::GR32_NOREX_NOSPRegClass) {
333 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
334 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
335 return &X86::GR64_NOREX_NOSPRegClass;
336 else if (A == &X86::GR64_ABCDRegClass)
337 return &X86::GR64_ABCDRegClass;
341 if (B == &X86::FR32RegClass)
345 if (B == &X86::FR64RegClass)
349 if (B == &X86::VR128RegClass)
356 const TargetRegisterClass*
357 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{
358 const TargetRegisterClass *Super = RC;
359 TargetRegisterClass::sc_iterator I = RC->superclasses_begin();
361 switch (Super->getID()) {
362 case X86::GR8RegClassID:
363 case X86::GR16RegClassID:
364 case X86::GR32RegClassID:
365 case X86::GR64RegClassID:
366 case X86::FR32RegClassID:
367 case X86::FR64RegClassID:
368 case X86::RFP32RegClassID:
369 case X86::RFP64RegClassID:
370 case X86::RFP80RegClassID:
371 case X86::VR128RegClassID:
372 case X86::VR256RegClassID:
373 // Don't return a super-class that would shrink the spill size.
374 // That can happen with the vector and float classes.
375 if (Super->getSize() == RC->getSize())
383 const TargetRegisterClass *
384 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
386 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
387 case 0: // Normal GPRs.
388 if (TM.getSubtarget<X86Subtarget>().is64Bit())
389 return &X86::GR64RegClass;
390 return &X86::GR32RegClass;
391 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
392 if (TM.getSubtarget<X86Subtarget>().is64Bit())
393 return &X86::GR64_NOSPRegClass;
394 return &X86::GR32_NOSPRegClass;
395 case 2: // Available for tailcall (not callee-saved GPRs).
396 if (TM.getSubtarget<X86Subtarget>().isTargetWin64())
397 return &X86::GR64_TCW64RegClass;
398 if (TM.getSubtarget<X86Subtarget>().is64Bit())
399 return &X86::GR64_TCRegClass;
400 return &X86::GR32_TCRegClass;
404 const TargetRegisterClass *
405 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
406 if (RC == &X86::CCRRegClass) {
408 return &X86::GR64RegClass;
410 return &X86::GR32RegClass;
416 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
417 MachineFunction &MF) const {
418 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
420 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
421 switch (RC->getID()) {
424 case X86::GR32RegClassID:
426 case X86::GR64RegClassID:
428 case X86::VR128RegClassID:
429 return TM.getSubtarget<X86Subtarget>().is64Bit() ? 10 : 4;
430 case X86::VR64RegClassID:
436 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
437 bool callsEHReturn = false;
438 bool ghcCall = false;
441 callsEHReturn = MF->getMMI().callsEHReturn();
442 const Function *F = MF->getFunction();
443 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
446 static const unsigned GhcCalleeSavedRegs[] = {
450 static const unsigned CalleeSavedRegs32Bit[] = {
451 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
454 static const unsigned CalleeSavedRegs32EHRet[] = {
455 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
458 static const unsigned CalleeSavedRegs64Bit[] = {
459 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
462 static const unsigned CalleeSavedRegs64EHRet[] = {
463 X86::RAX, X86::RDX, X86::RBX, X86::R12,
464 X86::R13, X86::R14, X86::R15, X86::RBP, 0
467 static const unsigned CalleeSavedRegsWin64[] = {
468 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
469 X86::R12, X86::R13, X86::R14, X86::R15,
470 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
471 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
472 X86::XMM14, X86::XMM15, 0
476 return GhcCalleeSavedRegs;
477 } else if (Is64Bit) {
479 return CalleeSavedRegsWin64;
481 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
483 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
487 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
488 BitVector Reserved(getNumRegs());
489 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
491 // Set the stack-pointer register and its aliases as reserved.
492 Reserved.set(X86::RSP);
493 Reserved.set(X86::ESP);
494 Reserved.set(X86::SP);
495 Reserved.set(X86::SPL);
497 // Set the instruction pointer register and its aliases as reserved.
498 Reserved.set(X86::RIP);
499 Reserved.set(X86::EIP);
500 Reserved.set(X86::IP);
502 // Set the frame-pointer register and its aliases as reserved if needed.
503 if (TFI->hasFP(MF)) {
504 Reserved.set(X86::RBP);
505 Reserved.set(X86::EBP);
506 Reserved.set(X86::BP);
507 Reserved.set(X86::BPL);
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 // These 8-bit registers are part of the x86-64 extension even though their
521 // super-registers are old 32-bits.
522 Reserved.set(X86::SIL);
523 Reserved.set(X86::DIL);
524 Reserved.set(X86::BPL);
525 Reserved.set(X86::SPL);
527 for (unsigned n = 0; n != 8; ++n) {
529 const unsigned GPR64[] = {
530 X86::R8, X86::R9, X86::R10, X86::R11,
531 X86::R12, X86::R13, X86::R14, X86::R15
533 for (const unsigned *AI = getOverlaps(GPR64[n]); unsigned Reg = *AI; ++AI)
537 assert(X86::XMM15 == X86::XMM8+7);
538 for (const unsigned *AI = getOverlaps(X86::XMM8 + n); unsigned Reg = *AI;
547 //===----------------------------------------------------------------------===//
548 // Stack Frame Processing methods
549 //===----------------------------------------------------------------------===//
551 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
552 const MachineFrameInfo *MFI = MF.getFrameInfo();
553 return (RealignStack &&
554 !MFI->hasVarSizedObjects());
557 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
558 const MachineFrameInfo *MFI = MF.getFrameInfo();
559 const Function *F = MF.getFunction();
560 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
561 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
562 F->hasFnAttr(Attribute::StackAlignment));
564 // FIXME: Currently we don't support stack realignment for functions with
565 // variable-sized allocas.
566 // FIXME: It's more complicated than this...
567 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
569 "Stack realignment in presence of dynamic allocas is not supported");
571 // If we've requested that we force align the stack do so now.
573 return canRealignStack(MF);
575 return requiresRealignment && canRealignStack(MF);
578 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
579 unsigned Reg, int &FrameIdx) const {
580 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
582 if (Reg == FramePtr && TFI->hasFP(MF)) {
583 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
589 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
592 return X86::SUB64ri8;
593 return X86::SUB64ri32;
596 return X86::SUB32ri8;
601 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
604 return X86::ADD64ri8;
605 return X86::ADD64ri32;
608 return X86::ADD32ri8;
613 void X86RegisterInfo::
614 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
615 MachineBasicBlock::iterator I) const {
616 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
617 bool reseveCallFrame = TFI->hasReservedCallFrame(MF);
618 int Opcode = I->getOpcode();
619 bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
620 DebugLoc DL = I->getDebugLoc();
621 uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
622 uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
625 if (!reseveCallFrame) {
626 // If the stack pointer can be changed after prologue, turn the
627 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
628 // adjcallstackdown instruction into 'add ESP, <amt>'
629 // TODO: consider using push / pop instead of sub + store / add
633 // We need to keep the stack aligned properly. To do this, we round the
634 // amount of space needed for the outgoing arguments up to the next
635 // alignment boundary.
636 unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
637 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
639 MachineInstr *New = 0;
640 if (Opcode == TII.getCallFrameSetupOpcode()) {
641 New = BuildMI(MF, DL, TII.get(getSUBriOpcode(Is64Bit, Amount)),
646 assert(Opcode == TII.getCallFrameDestroyOpcode());
648 // Factor out the amount the callee already popped.
652 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
653 New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
654 .addReg(StackPtr).addImm(Amount);
659 // The EFLAGS implicit def is dead.
660 New->getOperand(3).setIsDead();
662 // Replace the pseudo instruction with a new instruction.
669 if (Opcode == TII.getCallFrameDestroyOpcode() && CalleeAmt) {
670 // If we are performing frame pointer elimination and if the callee pops
671 // something off the stack pointer, add it back. We do this until we have
672 // more advanced stack pointer tracking ability.
673 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
674 MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
675 .addReg(StackPtr).addImm(CalleeAmt);
677 // The EFLAGS implicit def is dead.
678 New->getOperand(3).setIsDead();
680 // We are not tracking the stack pointer adjustment by the callee, so make
681 // sure we restore the stack pointer immediately after the call, there may
682 // be spill code inserted between the CALL and ADJCALLSTACKUP instructions.
683 MachineBasicBlock::iterator B = MBB.begin();
684 while (I != B && !llvm::prior(I)->getDesc().isCall())
691 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
692 int SPAdj, RegScavenger *RS) const{
693 assert(SPAdj == 0 && "Unexpected");
696 MachineInstr &MI = *II;
697 MachineFunction &MF = *MI.getParent()->getParent();
698 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
700 while (!MI.getOperand(i).isFI()) {
702 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
705 int FrameIndex = MI.getOperand(i).getIndex();
708 unsigned Opc = MI.getOpcode();
709 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
710 if (needsStackRealignment(MF))
711 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
715 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
717 // This must be part of a four operand memory reference. Replace the
718 // FrameIndex with base register with EBP. Add an offset to the offset.
719 MI.getOperand(i).ChangeToRegister(BasePtr, false);
721 // Now add the frame object offset to the offset from EBP.
724 // Tail call jmp happens after FP is popped.
725 const MachineFrameInfo *MFI = MF.getFrameInfo();
726 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
728 FIOffset = TFI->getFrameIndexOffset(MF, FrameIndex);
730 if (MI.getOperand(i+3).isImm()) {
731 // Offset is a 32-bit integer.
732 int Imm = (int)(MI.getOperand(i + 3).getImm());
733 int Offset = FIOffset + Imm;
734 assert((!Is64Bit || isInt<32>((long long)FIOffset + Imm)) &&
735 "Requesting 64-bit offset in 32-bit immediate!");
736 MI.getOperand(i + 3).ChangeToImmediate(Offset);
738 // Offset is symbolic. This is extremely rare.
739 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
740 MI.getOperand(i+3).setOffset(Offset);
744 unsigned X86RegisterInfo::getRARegister() const {
745 return Is64Bit ? X86::RIP // Should have dwarf #16.
746 : X86::EIP; // Should have dwarf #8.
749 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
750 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
751 return TFI->hasFP(MF) ? FramePtr : StackPtr;
754 unsigned X86RegisterInfo::getEHExceptionRegister() const {
755 llvm_unreachable("What is the exception register");
759 unsigned X86RegisterInfo::getEHHandlerRegister() const {
760 llvm_unreachable("What is the exception handler register");
765 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
766 switch (VT.getSimpleVT().SimpleTy) {
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:
784 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
786 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
788 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
790 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
792 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
794 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
796 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
798 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
800 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
802 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
804 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
806 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
808 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
810 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
812 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
814 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
821 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
823 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
825 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
827 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
829 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
831 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
833 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
835 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
837 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
839 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
841 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
843 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
845 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
847 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
849 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
851 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
857 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
859 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
861 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
863 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
865 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
867 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
869 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
871 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
873 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
875 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
877 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
879 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
881 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
883 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
885 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
887 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
893 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
895 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
897 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
899 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
901 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
903 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
905 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
907 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
909 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
911 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
913 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
915 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
917 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
919 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
921 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
923 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
933 struct MSAH : public MachineFunctionPass {
935 MSAH() : MachineFunctionPass(ID) {}
937 virtual bool runOnMachineFunction(MachineFunction &MF) {
938 const X86TargetMachine *TM =
939 static_cast<const X86TargetMachine *>(&MF.getTarget());
940 const TargetFrameLowering *TFI = TM->getFrameLowering();
941 MachineRegisterInfo &RI = MF.getRegInfo();
942 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
943 unsigned StackAlignment = TFI->getStackAlignment();
945 // Be over-conservative: scan over all vreg defs and find whether vector
946 // registers are used. If yes, there is a possibility that vector register
947 // will be spilled and thus require dynamic stack realignment.
948 for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
949 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
950 if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
951 FuncInfo->setReserveFP(true);
959 virtual const char *getPassName() const {
960 return "X86 Maximal Stack Alignment Check";
963 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
964 AU.setPreservesCFG();
965 MachineFunctionPass::getAnalysisUsage(AU);
973 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }