1 //===-- X86RegisterInfo.cpp - X86 Register Information --------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the X86 implementation of the TargetRegisterInfo class.
11 // This file is responsible for the frame pointer elimination optimization
12 // on X86.
13 //
14 //===----------------------------------------------------------------------===//
15
16 #include "X86RegisterInfo.h"
17 #include "X86FrameLowering.h"
18 #include "X86InstrBuilder.h"
19 #include "X86MachineFunctionInfo.h"
20 #include "X86Subtarget.h"
21 #include "X86TargetMachine.h"
22 #include "llvm/ADT/BitVector.h"
23 #include "llvm/ADT/STLExtras.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineFunctionPass.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineModuleInfo.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/MachineValueType.h"
31 #include "llvm/IR/Constants.h"
32 #include "llvm/IR/Function.h"
33 #include "llvm/IR/Type.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/ErrorHandling.h"
37 #include "llvm/Target/TargetFrameLowering.h"
38 #include "llvm/Target/TargetInstrInfo.h"
39 #include "llvm/Target/TargetMachine.h"
40 #include "llvm/Target/TargetOptions.h"
41
42 using namespace llvm;
43
44 #define GET_REGINFO_TARGET_DESC
45 #include "X86GenRegisterInfo.inc"
46
47 static cl::opt<bool>
48 EnableBasePointer("x86-use-base-pointer", cl::Hidden, cl::init(true),
49 cl::desc("Enable use of a base pointer for complex stack frames"));
50
X86RegisterInfo(const Triple & TT)51 X86RegisterInfo::X86RegisterInfo(const Triple &TT)
52 : X86GenRegisterInfo((TT.isArch64Bit() ? X86::RIP : X86::EIP),
53 X86_MC::getDwarfRegFlavour(TT, false),
54 X86_MC::getDwarfRegFlavour(TT, true),
55 (TT.isArch64Bit() ? X86::RIP : X86::EIP)) {
56 X86_MC::InitLLVM2SEHRegisterMapping(this);
57
58 // Cache some information.
59 Is64Bit = TT.isArch64Bit();
60 IsWin64 = Is64Bit && TT.isOSWindows();
61
62 // Use a callee-saved register as the base pointer. These registers must
63 // not conflict with any ABI requirements. For example, in 32-bit mode PIC
64 // requires GOT in the EBX register before function calls via PLT GOT pointer.
65 if (Is64Bit) {
66 SlotSize = 8;
67 // This matches the simplified 32-bit pointer code in the data layout
68 // computation.
69 // FIXME: Should use the data layout?
70 bool Use64BitReg = TT.getEnvironment() != Triple::GNUX32;
71 StackPtr = Use64BitReg ? X86::RSP : X86::ESP;
72 FramePtr = Use64BitReg ? X86::RBP : X86::EBP;
73 BasePtr = Use64BitReg ? X86::RBX : X86::EBX;
74 } else {
75 SlotSize = 4;
76 StackPtr = X86::ESP;
77 FramePtr = X86::EBP;
78 BasePtr = X86::ESI;
79 }
80 }
81
82 bool
trackLivenessAfterRegAlloc(const MachineFunction & MF) const83 X86RegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
84 // ExeDepsFixer and PostRAScheduler require liveness.
85 return true;
86 }
87
88 int
getSEHRegNum(unsigned i) const89 X86RegisterInfo::getSEHRegNum(unsigned i) const {
90 return getEncodingValue(i);
91 }
92
93 const TargetRegisterClass *
getSubClassWithSubReg(const TargetRegisterClass * RC,unsigned Idx) const94 X86RegisterInfo::getSubClassWithSubReg(const TargetRegisterClass *RC,
95 unsigned Idx) const {
96 // The sub_8bit sub-register index is more constrained in 32-bit mode.
97 // It behaves just like the sub_8bit_hi index.
98 if (!Is64Bit && Idx == X86::sub_8bit)
99 Idx = X86::sub_8bit_hi;
100
101 // Forward to TableGen's default version.
102 return X86GenRegisterInfo::getSubClassWithSubReg(RC, Idx);
103 }
104
105 const TargetRegisterClass *
getMatchingSuperRegClass(const TargetRegisterClass * A,const TargetRegisterClass * B,unsigned SubIdx) const106 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
107 const TargetRegisterClass *B,
108 unsigned SubIdx) const {
109 // The sub_8bit sub-register index is more constrained in 32-bit mode.
110 if (!Is64Bit && SubIdx == X86::sub_8bit) {
111 A = X86GenRegisterInfo::getSubClassWithSubReg(A, X86::sub_8bit_hi);
112 if (!A)
113 return nullptr;
114 }
115 return X86GenRegisterInfo::getMatchingSuperRegClass(A, B, SubIdx);
116 }
117
118 const TargetRegisterClass *
getLargestLegalSuperClass(const TargetRegisterClass * RC,const MachineFunction & MF) const119 X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
120 const MachineFunction &MF) const {
121 // Don't allow super-classes of GR8_NOREX. This class is only used after
122 // extracting sub_8bit_hi sub-registers. The H sub-registers cannot be copied
123 // to the full GR8 register class in 64-bit mode, so we cannot allow the
124 // reigster class inflation.
125 //
126 // The GR8_NOREX class is always used in a way that won't be constrained to a
127 // sub-class, so sub-classes like GR8_ABCD_L are allowed to expand to the
128 // full GR8 class.
129 if (RC == &X86::GR8_NOREXRegClass)
130 return RC;
131
132 const TargetRegisterClass *Super = RC;
133 TargetRegisterClass::sc_iterator I = RC->getSuperClasses();
134 do {
135 switch (Super->getID()) {
136 case X86::GR8RegClassID:
137 case X86::GR16RegClassID:
138 case X86::GR32RegClassID:
139 case X86::GR64RegClassID:
140 case X86::FR32RegClassID:
141 case X86::FR64RegClassID:
142 case X86::RFP32RegClassID:
143 case X86::RFP64RegClassID:
144 case X86::RFP80RegClassID:
145 case X86::VR128RegClassID:
146 case X86::VR256RegClassID:
147 // Don't return a super-class that would shrink the spill size.
148 // That can happen with the vector and float classes.
149 if (Super->getSize() == RC->getSize())
150 return Super;
151 }
152 Super = *I++;
153 } while (Super);
154 return RC;
155 }
156
157 const TargetRegisterClass *
getPointerRegClass(const MachineFunction & MF,unsigned Kind) const158 X86RegisterInfo::getPointerRegClass(const MachineFunction &MF,
159 unsigned Kind) const {
160 const X86Subtarget &Subtarget = MF.getSubtarget<X86Subtarget>();
161 switch (Kind) {
162 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
163 case 0: // Normal GPRs.
164 if (Subtarget.isTarget64BitLP64())
165 return &X86::GR64RegClass;
166 return &X86::GR32RegClass;
167 case 1: // Normal GPRs except the stack pointer (for encoding reasons).
168 if (Subtarget.isTarget64BitLP64())
169 return &X86::GR64_NOSPRegClass;
170 return &X86::GR32_NOSPRegClass;
171 case 2: // NOREX GPRs.
172 if (Subtarget.isTarget64BitLP64())
173 return &X86::GR64_NOREXRegClass;
174 return &X86::GR32_NOREXRegClass;
175 case 3: // NOREX GPRs except the stack pointer (for encoding reasons).
176 if (Subtarget.isTarget64BitLP64())
177 return &X86::GR64_NOREX_NOSPRegClass;
178 return &X86::GR32_NOREX_NOSPRegClass;
179 case 4: // Available for tailcall (not callee-saved GPRs).
180 return getGPRsForTailCall(MF);
181 }
182 }
183
184 const TargetRegisterClass *
getGPRsForTailCall(const MachineFunction & MF) const185 X86RegisterInfo::getGPRsForTailCall(const MachineFunction &MF) const {
186 const Function *F = MF.getFunction();
187 if (IsWin64 || (F && F->getCallingConv() == CallingConv::X86_64_Win64))
188 return &X86::GR64_TCW64RegClass;
189 else if (Is64Bit)
190 return &X86::GR64_TCRegClass;
191
192 bool hasHipeCC = (F ? F->getCallingConv() == CallingConv::HiPE : false);
193 if (hasHipeCC)
194 return &X86::GR32RegClass;
195 return &X86::GR32_TCRegClass;
196 }
197
198 const TargetRegisterClass *
getCrossCopyRegClass(const TargetRegisterClass * RC) const199 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
200 if (RC == &X86::CCRRegClass) {
201 if (Is64Bit)
202 return &X86::GR64RegClass;
203 else
204 return &X86::GR32RegClass;
205 }
206 return RC;
207 }
208
209 unsigned
getRegPressureLimit(const TargetRegisterClass * RC,MachineFunction & MF) const210 X86RegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
211 MachineFunction &MF) const {
212 const X86FrameLowering *TFI = getFrameLowering(MF);
213
214 unsigned FPDiff = TFI->hasFP(MF) ? 1 : 0;
215 switch (RC->getID()) {
216 default:
217 return 0;
218 case X86::GR32RegClassID:
219 return 4 - FPDiff;
220 case X86::GR64RegClassID:
221 return 12 - FPDiff;
222 case X86::VR128RegClassID:
223 return Is64Bit ? 10 : 4;
224 case X86::VR64RegClassID:
225 return 4;
226 }
227 }
228
229 const MCPhysReg *
getCalleeSavedRegs(const MachineFunction * MF) const230 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
231 const X86Subtarget &Subtarget = MF->getSubtarget<X86Subtarget>();
232 bool HasSSE = Subtarget.hasSSE1();
233 bool HasAVX = Subtarget.hasAVX();
234 bool HasAVX512 = Subtarget.hasAVX512();
235 bool CallsEHReturn = MF->getMMI().callsEHReturn();
236
237 assert(MF && "MachineFunction required");
238 switch (MF->getFunction()->getCallingConv()) {
239 case CallingConv::GHC:
240 case CallingConv::HiPE:
241 return CSR_NoRegs_SaveList;
242 case CallingConv::AnyReg:
243 if (HasAVX)
244 return CSR_64_AllRegs_AVX_SaveList;
245 return CSR_64_AllRegs_SaveList;
246 case CallingConv::PreserveMost:
247 return CSR_64_RT_MostRegs_SaveList;
248 case CallingConv::PreserveAll:
249 if (HasAVX)
250 return CSR_64_RT_AllRegs_AVX_SaveList;
251 return CSR_64_RT_AllRegs_SaveList;
252 case CallingConv::CXX_FAST_TLS:
253 if (Is64Bit)
254 return CSR_64_TLS_Darwin_SaveList;
255 break;
256 case CallingConv::Intel_OCL_BI: {
257 if (HasAVX512 && IsWin64)
258 return CSR_Win64_Intel_OCL_BI_AVX512_SaveList;
259 if (HasAVX512 && Is64Bit)
260 return CSR_64_Intel_OCL_BI_AVX512_SaveList;
261 if (HasAVX && IsWin64)
262 return CSR_Win64_Intel_OCL_BI_AVX_SaveList;
263 if (HasAVX && Is64Bit)
264 return CSR_64_Intel_OCL_BI_AVX_SaveList;
265 if (!HasAVX && !IsWin64 && Is64Bit)
266 return CSR_64_Intel_OCL_BI_SaveList;
267 break;
268 }
269 case CallingConv::HHVM:
270 return CSR_64_HHVM_SaveList;
271 case CallingConv::Cold:
272 if (Is64Bit)
273 return CSR_64_MostRegs_SaveList;
274 break;
275 case CallingConv::X86_64_Win64:
276 return CSR_Win64_SaveList;
277 case CallingConv::X86_64_SysV:
278 if (CallsEHReturn)
279 return CSR_64EHRet_SaveList;
280 return CSR_64_SaveList;
281 case CallingConv::X86_INTR:
282 if (Is64Bit) {
283 if (HasAVX)
284 return CSR_64_AllRegs_AVX_SaveList;
285 else
286 return CSR_64_AllRegs_SaveList;
287 } else {
288 if (HasSSE)
289 return CSR_32_AllRegs_SSE_SaveList;
290 else
291 return CSR_32_AllRegs_SaveList;
292 }
293 default:
294 break;
295 }
296
297 if (Is64Bit) {
298 if (IsWin64)
299 return CSR_Win64_SaveList;
300 if (CallsEHReturn)
301 return CSR_64EHRet_SaveList;
302 return CSR_64_SaveList;
303 }
304 if (CallsEHReturn)
305 return CSR_32EHRet_SaveList;
306 return CSR_32_SaveList;
307 }
308
309 const uint32_t *
getCallPreservedMask(const MachineFunction & MF,CallingConv::ID CC) const310 X86RegisterInfo::getCallPreservedMask(const MachineFunction &MF,
311 CallingConv::ID CC) const {
312 const X86Subtarget &Subtarget = MF.getSubtarget<X86Subtarget>();
313 bool HasSSE = Subtarget.hasSSE1();
314 bool HasAVX = Subtarget.hasAVX();
315 bool HasAVX512 = Subtarget.hasAVX512();
316
317 switch (CC) {
318 case CallingConv::GHC:
319 case CallingConv::HiPE:
320 return CSR_NoRegs_RegMask;
321 case CallingConv::AnyReg:
322 if (HasAVX)
323 return CSR_64_AllRegs_AVX_RegMask;
324 return CSR_64_AllRegs_RegMask;
325 case CallingConv::PreserveMost:
326 return CSR_64_RT_MostRegs_RegMask;
327 case CallingConv::PreserveAll:
328 if (HasAVX)
329 return CSR_64_RT_AllRegs_AVX_RegMask;
330 return CSR_64_RT_AllRegs_RegMask;
331 case CallingConv::CXX_FAST_TLS:
332 if (Is64Bit)
333 return CSR_64_TLS_Darwin_RegMask;
334 break;
335 case CallingConv::Intel_OCL_BI: {
336 if (HasAVX512 && IsWin64)
337 return CSR_Win64_Intel_OCL_BI_AVX512_RegMask;
338 if (HasAVX512 && Is64Bit)
339 return CSR_64_Intel_OCL_BI_AVX512_RegMask;
340 if (HasAVX && IsWin64)
341 return CSR_Win64_Intel_OCL_BI_AVX_RegMask;
342 if (HasAVX && Is64Bit)
343 return CSR_64_Intel_OCL_BI_AVX_RegMask;
344 if (!HasAVX && !IsWin64 && Is64Bit)
345 return CSR_64_Intel_OCL_BI_RegMask;
346 break;
347 }
348 case CallingConv::HHVM:
349 return CSR_64_HHVM_RegMask;
350 case CallingConv::Cold:
351 if (Is64Bit)
352 return CSR_64_MostRegs_RegMask;
353 break;
354 case CallingConv::X86_64_Win64:
355 return CSR_Win64_RegMask;
356 case CallingConv::X86_64_SysV:
357 return CSR_64_RegMask;
358 case CallingConv::X86_INTR:
359 if (Is64Bit) {
360 if (HasAVX)
361 return CSR_64_AllRegs_AVX_RegMask;
362 else
363 return CSR_64_AllRegs_RegMask;
364 } else {
365 if (HasSSE)
366 return CSR_32_AllRegs_SSE_RegMask;
367 else
368 return CSR_32_AllRegs_RegMask;
369 }
370 default:
371 break;
372 }
373
374 // Unlike getCalleeSavedRegs(), we don't have MMI so we can't check
375 // callsEHReturn().
376 if (Is64Bit) {
377 if (IsWin64)
378 return CSR_Win64_RegMask;
379 return CSR_64_RegMask;
380 }
381 return CSR_32_RegMask;
382 }
383
384 const uint32_t*
getNoPreservedMask() const385 X86RegisterInfo::getNoPreservedMask() const {
386 return CSR_NoRegs_RegMask;
387 }
388
getDarwinTLSCallPreservedMask() const389 const uint32_t *X86RegisterInfo::getDarwinTLSCallPreservedMask() const {
390 return CSR_64_TLS_Darwin_RegMask;
391 }
392
getReservedRegs(const MachineFunction & MF) const393 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
394 BitVector Reserved(getNumRegs());
395 const X86FrameLowering *TFI = getFrameLowering(MF);
396
397 // Set the stack-pointer register and its aliases as reserved.
398 for (MCSubRegIterator I(X86::RSP, this, /*IncludeSelf=*/true); I.isValid();
399 ++I)
400 Reserved.set(*I);
401
402 // Set the instruction pointer register and its aliases as reserved.
403 for (MCSubRegIterator I(X86::RIP, this, /*IncludeSelf=*/true); I.isValid();
404 ++I)
405 Reserved.set(*I);
406
407 // Set the frame-pointer register and its aliases as reserved if needed.
408 if (TFI->hasFP(MF)) {
409 for (MCSubRegIterator I(X86::RBP, this, /*IncludeSelf=*/true); I.isValid();
410 ++I)
411 Reserved.set(*I);
412 }
413
414 // Set the base-pointer register and its aliases as reserved if needed.
415 if (hasBasePointer(MF)) {
416 CallingConv::ID CC = MF.getFunction()->getCallingConv();
417 const uint32_t *RegMask = getCallPreservedMask(MF, CC);
418 if (MachineOperand::clobbersPhysReg(RegMask, getBaseRegister()))
419 report_fatal_error(
420 "Stack realignment in presence of dynamic allocas is not supported with"
421 "this calling convention.");
422
423 unsigned BasePtr = getX86SubSuperRegister(getBaseRegister(), MVT::i64,
424 false);
425 for (MCSubRegIterator I(BasePtr, this, /*IncludeSelf=*/true);
426 I.isValid(); ++I)
427 Reserved.set(*I);
428 }
429
430 // Mark the segment registers as reserved.
431 Reserved.set(X86::CS);
432 Reserved.set(X86::SS);
433 Reserved.set(X86::DS);
434 Reserved.set(X86::ES);
435 Reserved.set(X86::FS);
436 Reserved.set(X86::GS);
437
438 // Mark the floating point stack registers as reserved.
439 for (unsigned n = 0; n != 8; ++n)
440 Reserved.set(X86::ST0 + n);
441
442 // Reserve the registers that only exist in 64-bit mode.
443 if (!Is64Bit) {
444 // These 8-bit registers are part of the x86-64 extension even though their
445 // super-registers are old 32-bits.
446 Reserved.set(X86::SIL);
447 Reserved.set(X86::DIL);
448 Reserved.set(X86::BPL);
449 Reserved.set(X86::SPL);
450
451 for (unsigned n = 0; n != 8; ++n) {
452 // R8, R9, ...
453 for (MCRegAliasIterator AI(X86::R8 + n, this, true); AI.isValid(); ++AI)
454 Reserved.set(*AI);
455
456 // XMM8, XMM9, ...
457 for (MCRegAliasIterator AI(X86::XMM8 + n, this, true); AI.isValid(); ++AI)
458 Reserved.set(*AI);
459 }
460 }
461 if (!Is64Bit || !MF.getSubtarget<X86Subtarget>().hasAVX512()) {
462 for (unsigned n = 16; n != 32; ++n) {
463 for (MCRegAliasIterator AI(X86::XMM0 + n, this, true); AI.isValid(); ++AI)
464 Reserved.set(*AI);
465 }
466 }
467
468 return Reserved;
469 }
470
adjustStackMapLiveOutMask(uint32_t * Mask) const471 void X86RegisterInfo::adjustStackMapLiveOutMask(uint32_t *Mask) const {
472 // Check if the EFLAGS register is marked as live-out. This shouldn't happen,
473 // because the calling convention defines the EFLAGS register as NOT
474 // preserved.
475 //
476 // Unfortunatelly the EFLAGS show up as live-out after branch folding. Adding
477 // an assert to track this and clear the register afterwards to avoid
478 // unnecessary crashes during release builds.
479 assert(!(Mask[X86::EFLAGS / 32] & (1U << (X86::EFLAGS % 32))) &&
480 "EFLAGS are not live-out from a patchpoint.");
481
482 // Also clean other registers that don't need preserving (IP).
483 for (auto Reg : {X86::EFLAGS, X86::RIP, X86::EIP, X86::IP})
484 Mask[Reg / 32] &= ~(1U << (Reg % 32));
485 }
486
487 //===----------------------------------------------------------------------===//
488 // Stack Frame Processing methods
489 //===----------------------------------------------------------------------===//
490
CantUseSP(const MachineFrameInfo * MFI)491 static bool CantUseSP(const MachineFrameInfo *MFI) {
492 return MFI->hasVarSizedObjects() || MFI->hasOpaqueSPAdjustment();
493 }
494
hasBasePointer(const MachineFunction & MF) const495 bool X86RegisterInfo::hasBasePointer(const MachineFunction &MF) const {
496 const MachineFrameInfo *MFI = MF.getFrameInfo();
497
498 if (!EnableBasePointer)
499 return false;
500
501 // When we need stack realignment, we can't address the stack from the frame
502 // pointer. When we have dynamic allocas or stack-adjusting inline asm, we
503 // can't address variables from the stack pointer. MS inline asm can
504 // reference locals while also adjusting the stack pointer. When we can't
505 // use both the SP and the FP, we need a separate base pointer register.
506 bool CantUseFP = needsStackRealignment(MF);
507 return CantUseFP && CantUseSP(MFI);
508 }
509
canRealignStack(const MachineFunction & MF) const510 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
511 if (!TargetRegisterInfo::canRealignStack(MF))
512 return false;
513
514 const MachineFrameInfo *MFI = MF.getFrameInfo();
515 const MachineRegisterInfo *MRI = &MF.getRegInfo();
516
517 // Stack realignment requires a frame pointer. If we already started
518 // register allocation with frame pointer elimination, it is too late now.
519 if (!MRI->canReserveReg(FramePtr))
520 return false;
521
522 // If a base pointer is necessary. Check that it isn't too late to reserve
523 // it.
524 if (CantUseSP(MFI))
525 return MRI->canReserveReg(BasePtr);
526 return true;
527 }
528
hasReservedSpillSlot(const MachineFunction & MF,unsigned Reg,int & FrameIdx) const529 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
530 unsigned Reg, int &FrameIdx) const {
531 // Since X86 defines assignCalleeSavedSpillSlots which always return true
532 // this function neither used nor tested.
533 llvm_unreachable("Unused function on X86. Otherwise need a test case.");
534 }
535
536 void
eliminateFrameIndex(MachineBasicBlock::iterator II,int SPAdj,unsigned FIOperandNum,RegScavenger * RS) const537 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
538 int SPAdj, unsigned FIOperandNum,
539 RegScavenger *RS) const {
540 MachineInstr &MI = *II;
541 MachineFunction &MF = *MI.getParent()->getParent();
542 const X86FrameLowering *TFI = getFrameLowering(MF);
543 int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
544 unsigned BasePtr;
545
546 unsigned Opc = MI.getOpcode();
547 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm ||
548 Opc == X86::TCRETURNmi || Opc == X86::TCRETURNmi64;
549
550 if (hasBasePointer(MF))
551 BasePtr = (FrameIndex < 0 ? FramePtr : getBaseRegister());
552 else if (needsStackRealignment(MF))
553 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
554 else if (AfterFPPop)
555 BasePtr = StackPtr;
556 else
557 BasePtr = (TFI->hasFP(MF) ? FramePtr : StackPtr);
558
559 // LOCAL_ESCAPE uses a single offset, with no register. It only works in the
560 // simple FP case, and doesn't work with stack realignment. On 32-bit, the
561 // offset is from the traditional base pointer location. On 64-bit, the
562 // offset is from the SP at the end of the prologue, not the FP location. This
563 // matches the behavior of llvm.frameaddress.
564 unsigned IgnoredFrameReg;
565 if (Opc == TargetOpcode::LOCAL_ESCAPE) {
566 MachineOperand &FI = MI.getOperand(FIOperandNum);
567 int Offset;
568 Offset = TFI->getFrameIndexReference(MF, FrameIndex, IgnoredFrameReg);
569 FI.ChangeToImmediate(Offset);
570 return;
571 }
572
573 // For LEA64_32r when BasePtr is 32-bits (X32) we can use full-size 64-bit
574 // register as source operand, semantic is the same and destination is
575 // 32-bits. It saves one byte per lea in code since 0x67 prefix is avoided.
576 if (Opc == X86::LEA64_32r && X86::GR32RegClass.contains(BasePtr))
577 BasePtr = getX86SubSuperRegister(BasePtr, MVT::i64, false);
578
579 // This must be part of a four operand memory reference. Replace the
580 // FrameIndex with base register with EBP. Add an offset to the offset.
581 MI.getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
582
583 // Now add the frame object offset to the offset from EBP.
584 int FIOffset;
585 if (AfterFPPop) {
586 // Tail call jmp happens after FP is popped.
587 const MachineFrameInfo *MFI = MF.getFrameInfo();
588 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI->getOffsetOfLocalArea();
589 } else
590 FIOffset = TFI->getFrameIndexReference(MF, FrameIndex, IgnoredFrameReg);
591
592 if (BasePtr == StackPtr)
593 FIOffset += SPAdj;
594
595 // The frame index format for stackmaps and patchpoints is different from the
596 // X86 format. It only has a FI and an offset.
597 if (Opc == TargetOpcode::STACKMAP || Opc == TargetOpcode::PATCHPOINT) {
598 assert(BasePtr == FramePtr && "Expected the FP as base register");
599 int64_t Offset = MI.getOperand(FIOperandNum + 1).getImm() + FIOffset;
600 MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
601 return;
602 }
603
604 if (MI.getOperand(FIOperandNum+3).isImm()) {
605 // Offset is a 32-bit integer.
606 int Imm = (int)(MI.getOperand(FIOperandNum + 3).getImm());
607 int Offset = FIOffset + Imm;
608 assert((!Is64Bit || isInt<32>((long long)FIOffset + Imm)) &&
609 "Requesting 64-bit offset in 32-bit immediate!");
610 MI.getOperand(FIOperandNum + 3).ChangeToImmediate(Offset);
611 } else {
612 // Offset is symbolic. This is extremely rare.
613 uint64_t Offset = FIOffset +
614 (uint64_t)MI.getOperand(FIOperandNum+3).getOffset();
615 MI.getOperand(FIOperandNum + 3).setOffset(Offset);
616 }
617 }
618
getFrameRegister(const MachineFunction & MF) const619 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
620 const X86FrameLowering *TFI = getFrameLowering(MF);
621 return TFI->hasFP(MF) ? FramePtr : StackPtr;
622 }
623
624 unsigned
getPtrSizedFrameRegister(const MachineFunction & MF) const625 X86RegisterInfo::getPtrSizedFrameRegister(const MachineFunction &MF) const {
626 const X86Subtarget &Subtarget = MF.getSubtarget<X86Subtarget>();
627 unsigned FrameReg = getFrameRegister(MF);
628 if (Subtarget.isTarget64BitILP32())
629 FrameReg = getX86SubSuperRegister(FrameReg, MVT::i32, false);
630 return FrameReg;
631 }
632
633 namespace llvm {
getX86SubSuperRegisterOrZero(unsigned Reg,MVT::SimpleValueType VT,bool High)634 unsigned getX86SubSuperRegisterOrZero(unsigned Reg, MVT::SimpleValueType VT,
635 bool High) {
636 switch (VT) {
637 default: return 0;
638 case MVT::i8:
639 if (High) {
640 switch (Reg) {
641 default: return getX86SubSuperRegister(Reg, MVT::i64);
642 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
643 return X86::SI;
644 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
645 return X86::DI;
646 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
647 return X86::BP;
648 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
649 return X86::SP;
650 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
651 return X86::AH;
652 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
653 return X86::DH;
654 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
655 return X86::CH;
656 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
657 return X86::BH;
658 }
659 } else {
660 switch (Reg) {
661 default: return 0;
662 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
663 return X86::AL;
664 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
665 return X86::DL;
666 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
667 return X86::CL;
668 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
669 return X86::BL;
670 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
671 return X86::SIL;
672 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
673 return X86::DIL;
674 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
675 return X86::BPL;
676 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
677 return X86::SPL;
678 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
679 return X86::R8B;
680 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
681 return X86::R9B;
682 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
683 return X86::R10B;
684 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
685 return X86::R11B;
686 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
687 return X86::R12B;
688 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
689 return X86::R13B;
690 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
691 return X86::R14B;
692 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
693 return X86::R15B;
694 }
695 }
696 case MVT::i16:
697 switch (Reg) {
698 default: return 0;
699 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
700 return X86::AX;
701 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
702 return X86::DX;
703 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
704 return X86::CX;
705 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
706 return X86::BX;
707 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
708 return X86::SI;
709 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
710 return X86::DI;
711 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
712 return X86::BP;
713 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
714 return X86::SP;
715 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
716 return X86::R8W;
717 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
718 return X86::R9W;
719 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
720 return X86::R10W;
721 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
722 return X86::R11W;
723 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
724 return X86::R12W;
725 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
726 return X86::R13W;
727 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
728 return X86::R14W;
729 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
730 return X86::R15W;
731 }
732 case MVT::i32:
733 switch (Reg) {
734 default: return 0;
735 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
736 return X86::EAX;
737 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
738 return X86::EDX;
739 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
740 return X86::ECX;
741 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
742 return X86::EBX;
743 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
744 return X86::ESI;
745 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
746 return X86::EDI;
747 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
748 return X86::EBP;
749 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
750 return X86::ESP;
751 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
752 return X86::R8D;
753 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
754 return X86::R9D;
755 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
756 return X86::R10D;
757 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
758 return X86::R11D;
759 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
760 return X86::R12D;
761 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
762 return X86::R13D;
763 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
764 return X86::R14D;
765 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
766 return X86::R15D;
767 }
768 case MVT::i64:
769 switch (Reg) {
770 default: return 0;
771 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
772 return X86::RAX;
773 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
774 return X86::RDX;
775 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
776 return X86::RCX;
777 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
778 return X86::RBX;
779 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
780 return X86::RSI;
781 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
782 return X86::RDI;
783 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
784 return X86::RBP;
785 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
786 return X86::RSP;
787 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
788 return X86::R8;
789 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
790 return X86::R9;
791 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
792 return X86::R10;
793 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
794 return X86::R11;
795 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
796 return X86::R12;
797 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
798 return X86::R13;
799 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
800 return X86::R14;
801 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
802 return X86::R15;
803 }
804 }
805 }
806
getX86SubSuperRegister(unsigned Reg,MVT::SimpleValueType VT,bool High)807 unsigned getX86SubSuperRegister(unsigned Reg, MVT::SimpleValueType VT,
808 bool High) {
809 unsigned Res = getX86SubSuperRegisterOrZero(Reg, VT, High);
810 if (Res == 0)
811 llvm_unreachable("Unexpected register or VT");
812 return Res;
813 }
814
get512BitSuperRegister(unsigned Reg)815 unsigned get512BitSuperRegister(unsigned Reg) {
816 if (Reg >= X86::XMM0 && Reg <= X86::XMM31)
817 return X86::ZMM0 + (Reg - X86::XMM0);
818 if (Reg >= X86::YMM0 && Reg <= X86::YMM31)
819 return X86::ZMM0 + (Reg - X86::YMM0);
820 if (Reg >= X86::ZMM0 && Reg <= X86::ZMM31)
821 return Reg;
822 llvm_unreachable("Unexpected SIMD register");
823 }
824
825 }
826