1 //===- ARMBaseInstrInfo.cpp - ARM Instruction 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 Base ARM implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "ARMBaseInstrInfo.h"
16 #include "ARMAddressingModes.h"
17 #include "ARMConstantPoolValue.h"
18 #include "ARMGenInstrInfo.inc"
19 #include "ARMMachineFunctionInfo.h"
20 #include "ARMRegisterInfo.h"
21 #include "llvm/Constants.h"
22 #include "llvm/Function.h"
23 #include "llvm/GlobalValue.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/CodeGen/LiveVariables.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineInstrBuilder.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineMemOperand.h"
31 #include "llvm/CodeGen/PseudoSourceValue.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/ErrorHandling.h"
39 EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
40 cl::desc("Enable ARM 2-addr to 3-addr conv"));
42 ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget& STI)
43 : TargetInstrInfoImpl(ARMInsts, array_lengthof(ARMInsts)),
48 ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
49 MachineBasicBlock::iterator &MBBI,
50 LiveVariables *LV) const {
51 // FIXME: Thumb2 support.
56 MachineInstr *MI = MBBI;
57 MachineFunction &MF = *MI->getParent()->getParent();
58 unsigned TSFlags = MI->getDesc().TSFlags;
60 switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
62 case ARMII::IndexModePre:
65 case ARMII::IndexModePost:
69 // Try splitting an indexed load/store to an un-indexed one plus an add/sub
71 unsigned MemOpc = getUnindexedOpcode(MI->getOpcode());
75 MachineInstr *UpdateMI = NULL;
76 MachineInstr *MemMI = NULL;
77 unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
78 const TargetInstrDesc &TID = MI->getDesc();
79 unsigned NumOps = TID.getNumOperands();
80 bool isLoad = !TID.mayStore();
81 const MachineOperand &WB = isLoad ? MI->getOperand(1) : MI->getOperand(0);
82 const MachineOperand &Base = MI->getOperand(2);
83 const MachineOperand &Offset = MI->getOperand(NumOps-3);
84 unsigned WBReg = WB.getReg();
85 unsigned BaseReg = Base.getReg();
86 unsigned OffReg = Offset.getReg();
87 unsigned OffImm = MI->getOperand(NumOps-2).getImm();
88 ARMCC::CondCodes Pred = (ARMCC::CondCodes)MI->getOperand(NumOps-1).getImm();
91 assert(false && "Unknown indexed op!");
93 case ARMII::AddrMode2: {
94 bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
95 unsigned Amt = ARM_AM::getAM2Offset(OffImm);
97 if (ARM_AM::getSOImmVal(Amt) == -1)
98 // Can't encode it in a so_imm operand. This transformation will
99 // add more than 1 instruction. Abandon!
101 UpdateMI = BuildMI(MF, MI->getDebugLoc(),
102 get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
103 .addReg(BaseReg).addImm(Amt)
104 .addImm(Pred).addReg(0).addReg(0);
105 } else if (Amt != 0) {
106 ARM_AM::ShiftOpc ShOpc = ARM_AM::getAM2ShiftOpc(OffImm);
107 unsigned SOOpc = ARM_AM::getSORegOpc(ShOpc, Amt);
108 UpdateMI = BuildMI(MF, MI->getDebugLoc(),
109 get(isSub ? ARM::SUBrs : ARM::ADDrs), WBReg)
110 .addReg(BaseReg).addReg(OffReg).addReg(0).addImm(SOOpc)
111 .addImm(Pred).addReg(0).addReg(0);
113 UpdateMI = BuildMI(MF, MI->getDebugLoc(),
114 get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
115 .addReg(BaseReg).addReg(OffReg)
116 .addImm(Pred).addReg(0).addReg(0);
119 case ARMII::AddrMode3 : {
120 bool isSub = ARM_AM::getAM3Op(OffImm) == ARM_AM::sub;
121 unsigned Amt = ARM_AM::getAM3Offset(OffImm);
123 // Immediate is 8-bits. It's guaranteed to fit in a so_imm operand.
124 UpdateMI = BuildMI(MF, MI->getDebugLoc(),
125 get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
126 .addReg(BaseReg).addImm(Amt)
127 .addImm(Pred).addReg(0).addReg(0);
129 UpdateMI = BuildMI(MF, MI->getDebugLoc(),
130 get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
131 .addReg(BaseReg).addReg(OffReg)
132 .addImm(Pred).addReg(0).addReg(0);
137 std::vector<MachineInstr*> NewMIs;
140 MemMI = BuildMI(MF, MI->getDebugLoc(),
141 get(MemOpc), MI->getOperand(0).getReg())
142 .addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
144 MemMI = BuildMI(MF, MI->getDebugLoc(),
145 get(MemOpc)).addReg(MI->getOperand(1).getReg())
146 .addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
147 NewMIs.push_back(MemMI);
148 NewMIs.push_back(UpdateMI);
151 MemMI = BuildMI(MF, MI->getDebugLoc(),
152 get(MemOpc), MI->getOperand(0).getReg())
153 .addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
155 MemMI = BuildMI(MF, MI->getDebugLoc(),
156 get(MemOpc)).addReg(MI->getOperand(1).getReg())
157 .addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
159 UpdateMI->getOperand(0).setIsDead();
160 NewMIs.push_back(UpdateMI);
161 NewMIs.push_back(MemMI);
164 // Transfer LiveVariables states, kill / dead info.
166 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
167 MachineOperand &MO = MI->getOperand(i);
168 if (MO.isReg() && MO.getReg() &&
169 TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
170 unsigned Reg = MO.getReg();
172 LiveVariables::VarInfo &VI = LV->getVarInfo(Reg);
174 MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
176 LV->addVirtualRegisterDead(Reg, NewMI);
178 if (MO.isUse() && MO.isKill()) {
179 for (unsigned j = 0; j < 2; ++j) {
180 // Look at the two new MI's in reverse order.
181 MachineInstr *NewMI = NewMIs[j];
182 if (!NewMI->readsRegister(Reg))
184 LV->addVirtualRegisterKilled(Reg, NewMI);
185 if (VI.removeKill(MI))
186 VI.Kills.push_back(NewMI);
194 MFI->insert(MBBI, NewMIs[1]);
195 MFI->insert(MBBI, NewMIs[0]);
201 ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
202 MachineBasicBlock *&FBB,
203 SmallVectorImpl<MachineOperand> &Cond,
204 bool AllowModify) const {
205 // If the block has no terminators, it just falls into the block after it.
206 MachineBasicBlock::iterator I = MBB.end();
207 if (I == MBB.begin())
210 while (I->isDebugValue()) {
211 if (I == MBB.begin())
215 if (!isUnpredicatedTerminator(I))
218 // Get the last instruction in the block.
219 MachineInstr *LastInst = I;
221 // If there is only one terminator instruction, process it.
222 unsigned LastOpc = LastInst->getOpcode();
223 if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
224 if (isUncondBranchOpcode(LastOpc)) {
225 TBB = LastInst->getOperand(0).getMBB();
228 if (isCondBranchOpcode(LastOpc)) {
229 // Block ends with fall-through condbranch.
230 TBB = LastInst->getOperand(0).getMBB();
231 Cond.push_back(LastInst->getOperand(1));
232 Cond.push_back(LastInst->getOperand(2));
235 return true; // Can't handle indirect branch.
238 // Get the instruction before it if it is a terminator.
239 MachineInstr *SecondLastInst = I;
241 // If there are three terminators, we don't know what sort of block this is.
242 if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
245 // If the block ends with a B and a Bcc, handle it.
246 unsigned SecondLastOpc = SecondLastInst->getOpcode();
247 if (isCondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
248 TBB = SecondLastInst->getOperand(0).getMBB();
249 Cond.push_back(SecondLastInst->getOperand(1));
250 Cond.push_back(SecondLastInst->getOperand(2));
251 FBB = LastInst->getOperand(0).getMBB();
255 // If the block ends with two unconditional branches, handle it. The second
256 // one is not executed, so remove it.
257 if (isUncondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
258 TBB = SecondLastInst->getOperand(0).getMBB();
261 I->eraseFromParent();
265 // ...likewise if it ends with a branch table followed by an unconditional
266 // branch. The branch folder can create these, and we must get rid of them for
267 // correctness of Thumb constant islands.
268 if ((isJumpTableBranchOpcode(SecondLastOpc) ||
269 isIndirectBranchOpcode(SecondLastOpc)) &&
270 isUncondBranchOpcode(LastOpc)) {
273 I->eraseFromParent();
277 // Otherwise, can't handle this.
282 unsigned ARMBaseInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
283 MachineBasicBlock::iterator I = MBB.end();
284 if (I == MBB.begin()) return 0;
286 while (I->isDebugValue()) {
287 if (I == MBB.begin())
291 if (!isUncondBranchOpcode(I->getOpcode()) &&
292 !isCondBranchOpcode(I->getOpcode()))
295 // Remove the branch.
296 I->eraseFromParent();
300 if (I == MBB.begin()) return 1;
302 if (!isCondBranchOpcode(I->getOpcode()))
305 // Remove the branch.
306 I->eraseFromParent();
311 ARMBaseInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
312 MachineBasicBlock *FBB,
313 const SmallVectorImpl<MachineOperand> &Cond) const {
314 // FIXME this should probably have a DebugLoc argument
317 ARMFunctionInfo *AFI = MBB.getParent()->getInfo<ARMFunctionInfo>();
318 int BOpc = !AFI->isThumbFunction()
319 ? ARM::B : (AFI->isThumb2Function() ? ARM::t2B : ARM::tB);
320 int BccOpc = !AFI->isThumbFunction()
321 ? ARM::Bcc : (AFI->isThumb2Function() ? ARM::t2Bcc : ARM::tBcc);
323 // Shouldn't be a fall through.
324 assert(TBB && "InsertBranch must not be told to insert a fallthrough");
325 assert((Cond.size() == 2 || Cond.size() == 0) &&
326 "ARM branch conditions have two components!");
329 if (Cond.empty()) // Unconditional branch?
330 BuildMI(&MBB, dl, get(BOpc)).addMBB(TBB);
332 BuildMI(&MBB, dl, get(BccOpc)).addMBB(TBB)
333 .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
337 // Two-way conditional branch.
338 BuildMI(&MBB, dl, get(BccOpc)).addMBB(TBB)
339 .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
340 BuildMI(&MBB, dl, get(BOpc)).addMBB(FBB);
344 bool ARMBaseInstrInfo::
345 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
346 ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
347 Cond[0].setImm(ARMCC::getOppositeCondition(CC));
351 bool ARMBaseInstrInfo::
352 PredicateInstruction(MachineInstr *MI,
353 const SmallVectorImpl<MachineOperand> &Pred) const {
354 unsigned Opc = MI->getOpcode();
355 if (isUncondBranchOpcode(Opc)) {
356 MI->setDesc(get(getMatchingCondBranchOpcode(Opc)));
357 MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm()));
358 MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false));
362 int PIdx = MI->findFirstPredOperandIdx();
364 MachineOperand &PMO = MI->getOperand(PIdx);
365 PMO.setImm(Pred[0].getImm());
366 MI->getOperand(PIdx+1).setReg(Pred[1].getReg());
372 bool ARMBaseInstrInfo::
373 SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1,
374 const SmallVectorImpl<MachineOperand> &Pred2) const {
375 if (Pred1.size() > 2 || Pred2.size() > 2)
378 ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm();
379 ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm();
389 return CC2 == ARMCC::HI;
391 return CC2 == ARMCC::LO || CC2 == ARMCC::EQ;
393 return CC2 == ARMCC::GT;
395 return CC2 == ARMCC::LT;
399 bool ARMBaseInstrInfo::DefinesPredicate(MachineInstr *MI,
400 std::vector<MachineOperand> &Pred) const {
401 // FIXME: This confuses implicit_def with optional CPSR def.
402 const TargetInstrDesc &TID = MI->getDesc();
403 if (!TID.getImplicitDefs() && !TID.hasOptionalDef())
407 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
408 const MachineOperand &MO = MI->getOperand(i);
409 if (MO.isReg() && MO.getReg() == ARM::CPSR) {
418 /// isPredicable - Return true if the specified instruction can be predicated.
419 /// By default, this returns true for every instruction with a
420 /// PredicateOperand.
421 bool ARMBaseInstrInfo::isPredicable(MachineInstr *MI) const {
422 const TargetInstrDesc &TID = MI->getDesc();
423 if (!TID.isPredicable())
426 if ((TID.TSFlags & ARMII::DomainMask) == ARMII::DomainNEON) {
427 ARMFunctionInfo *AFI =
428 MI->getParent()->getParent()->getInfo<ARMFunctionInfo>();
429 return AFI->isThumb2Function();
434 /// FIXME: Works around a gcc miscompilation with -fstrict-aliasing.
436 static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
438 static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
440 assert(JTI < JT.size());
441 return JT[JTI].MBBs.size();
444 /// GetInstSize - Return the size of the specified MachineInstr.
446 unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
447 const MachineBasicBlock &MBB = *MI->getParent();
448 const MachineFunction *MF = MBB.getParent();
449 const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();
451 // Basic size info comes from the TSFlags field.
452 const TargetInstrDesc &TID = MI->getDesc();
453 unsigned TSFlags = TID.TSFlags;
455 unsigned Opc = MI->getOpcode();
456 switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) {
458 // If this machine instr is an inline asm, measure it.
459 if (MI->getOpcode() == ARM::INLINEASM)
460 return getInlineAsmLength(MI->getOperand(0).getSymbolName(), *MAI);
465 llvm_unreachable("Unknown or unset size field for instr!");
466 case TargetOpcode::IMPLICIT_DEF:
467 case TargetOpcode::KILL:
468 case TargetOpcode::DBG_LABEL:
469 case TargetOpcode::EH_LABEL:
470 case TargetOpcode::DBG_VALUE:
475 case ARMII::Size8Bytes: return 8; // ARM instruction x 2.
476 case ARMII::Size4Bytes: return 4; // ARM / Thumb2 instruction.
477 case ARMII::Size2Bytes: return 2; // Thumb1 instruction.
478 case ARMII::SizeSpecial: {
480 case ARM::CONSTPOOL_ENTRY:
481 // If this machine instr is a constant pool entry, its size is recorded as
483 return MI->getOperand(2).getImm();
484 case ARM::Int_eh_sjlj_setjmp:
486 case ARM::tInt_eh_sjlj_setjmp:
488 case ARM::t2Int_eh_sjlj_setjmp:
497 // These are jumptable branches, i.e. a branch followed by an inlined
498 // jumptable. The size is 4 + 4 * number of entries. For TBB, each
499 // entry is one byte; TBH two byte each.
500 unsigned EntrySize = (Opc == ARM::t2TBB)
501 ? 1 : ((Opc == ARM::t2TBH) ? 2 : 4);
502 unsigned NumOps = TID.getNumOperands();
503 MachineOperand JTOP =
504 MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2));
505 unsigned JTI = JTOP.getIndex();
506 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
508 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
509 assert(JTI < JT.size());
510 // Thumb instructions are 2 byte aligned, but JT entries are 4 byte
511 // 4 aligned. The assembler / linker may add 2 byte padding just before
512 // the JT entries. The size does not include this padding; the
513 // constant islands pass does separate bookkeeping for it.
514 // FIXME: If we know the size of the function is less than (1 << 16) *2
515 // bytes, we can use 16-bit entries instead. Then there won't be an
517 unsigned InstSize = (Opc == ARM::tBR_JTr || Opc == ARM::t2BR_JT) ? 2 : 4;
518 unsigned NumEntries = getNumJTEntries(JT, JTI);
519 if (Opc == ARM::t2TBB && (NumEntries & 1))
520 // Make sure the instruction that follows TBB is 2-byte aligned.
521 // FIXME: Constant island pass should insert an "ALIGN" instruction
524 return NumEntries * EntrySize + InstSize;
527 // Otherwise, pseudo-instruction sizes are zero.
532 return 0; // Not reached
535 /// Return true if the instruction is a register to register move and
536 /// leave the source and dest operands in the passed parameters.
539 ARMBaseInstrInfo::isMoveInstr(const MachineInstr &MI,
540 unsigned &SrcReg, unsigned &DstReg,
541 unsigned& SrcSubIdx, unsigned& DstSubIdx) const {
542 SrcSubIdx = DstSubIdx = 0; // No sub-registers.
544 switch (MI.getOpcode()) {
550 SrcReg = MI.getOperand(1).getReg();
551 DstReg = MI.getOperand(0).getReg();
556 case ARM::tMOVgpr2tgpr:
557 case ARM::tMOVtgpr2gpr:
558 case ARM::tMOVgpr2gpr:
560 assert(MI.getDesc().getNumOperands() >= 2 &&
561 MI.getOperand(0).isReg() &&
562 MI.getOperand(1).isReg() &&
563 "Invalid ARM MOV instruction");
564 SrcReg = MI.getOperand(1).getReg();
565 DstReg = MI.getOperand(0).getReg();
574 ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
575 int &FrameIndex) const {
576 switch (MI->getOpcode()) {
579 case ARM::t2LDRs: // FIXME: don't use t2LDRs to access frame.
580 if (MI->getOperand(1).isFI() &&
581 MI->getOperand(2).isReg() &&
582 MI->getOperand(3).isImm() &&
583 MI->getOperand(2).getReg() == 0 &&
584 MI->getOperand(3).getImm() == 0) {
585 FrameIndex = MI->getOperand(1).getIndex();
586 return MI->getOperand(0).getReg();
591 if (MI->getOperand(1).isFI() &&
592 MI->getOperand(2).isImm() &&
593 MI->getOperand(2).getImm() == 0) {
594 FrameIndex = MI->getOperand(1).getIndex();
595 return MI->getOperand(0).getReg();
600 if (MI->getOperand(1).isFI() &&
601 MI->getOperand(2).isImm() &&
602 MI->getOperand(2).getImm() == 0) {
603 FrameIndex = MI->getOperand(1).getIndex();
604 return MI->getOperand(0).getReg();
613 ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
614 int &FrameIndex) const {
615 switch (MI->getOpcode()) {
618 case ARM::t2STRs: // FIXME: don't use t2STRs to access frame.
619 if (MI->getOperand(1).isFI() &&
620 MI->getOperand(2).isReg() &&
621 MI->getOperand(3).isImm() &&
622 MI->getOperand(2).getReg() == 0 &&
623 MI->getOperand(3).getImm() == 0) {
624 FrameIndex = MI->getOperand(1).getIndex();
625 return MI->getOperand(0).getReg();
630 if (MI->getOperand(1).isFI() &&
631 MI->getOperand(2).isImm() &&
632 MI->getOperand(2).getImm() == 0) {
633 FrameIndex = MI->getOperand(1).getIndex();
634 return MI->getOperand(0).getReg();
639 if (MI->getOperand(1).isFI() &&
640 MI->getOperand(2).isImm() &&
641 MI->getOperand(2).getImm() == 0) {
642 FrameIndex = MI->getOperand(1).getIndex();
643 return MI->getOperand(0).getReg();
652 ARMBaseInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
653 MachineBasicBlock::iterator I,
654 unsigned DestReg, unsigned SrcReg,
655 const TargetRegisterClass *DestRC,
656 const TargetRegisterClass *SrcRC) const {
658 if (I != MBB.end()) DL = I->getDebugLoc();
660 // tGPR is used sometimes in ARM instructions that need to avoid using
661 // certain registers. Just treat it as GPR here.
662 if (DestRC == ARM::tGPRRegisterClass)
663 DestRC = ARM::GPRRegisterClass;
664 if (SrcRC == ARM::tGPRRegisterClass)
665 SrcRC = ARM::GPRRegisterClass;
667 // Allow DPR / DPR_VFP2 / DPR_8 cross-class copies.
668 if (DestRC == ARM::DPR_8RegisterClass)
669 DestRC = ARM::DPR_VFP2RegisterClass;
670 if (SrcRC == ARM::DPR_8RegisterClass)
671 SrcRC = ARM::DPR_VFP2RegisterClass;
673 // Allow QPR / QPR_VFP2 / QPR_8 cross-class copies.
674 if (DestRC == ARM::QPR_VFP2RegisterClass ||
675 DestRC == ARM::QPR_8RegisterClass)
676 DestRC = ARM::QPRRegisterClass;
677 if (SrcRC == ARM::QPR_VFP2RegisterClass ||
678 SrcRC == ARM::QPR_8RegisterClass)
679 SrcRC = ARM::QPRRegisterClass;
681 // Disallow copies of unequal sizes.
682 if (DestRC != SrcRC && DestRC->getSize() != SrcRC->getSize())
685 if (DestRC == ARM::GPRRegisterClass) {
686 if (SrcRC == ARM::SPRRegisterClass)
687 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VMOVRS), DestReg)
690 AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::MOVr),
691 DestReg).addReg(SrcReg)));
695 if (DestRC == ARM::SPRRegisterClass)
696 Opc = (SrcRC == ARM::GPRRegisterClass ? ARM::VMOVSR : ARM::VMOVS);
697 else if (DestRC == ARM::DPRRegisterClass)
699 else if (DestRC == ARM::DPR_VFP2RegisterClass ||
700 SrcRC == ARM::DPR_VFP2RegisterClass)
701 // Always use neon reg-reg move if source or dest is NEON-only regclass.
702 Opc = ARM::VMOVDneon;
703 else if (DestRC == ARM::QPRRegisterClass)
708 AddDefaultPred(BuildMI(MBB, I, DL, get(Opc), DestReg)
715 void ARMBaseInstrInfo::
716 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
717 unsigned SrcReg, bool isKill, int FI,
718 const TargetRegisterClass *RC) const {
720 if (I != MBB.end()) DL = I->getDebugLoc();
721 MachineFunction &MF = *MBB.getParent();
722 MachineFrameInfo &MFI = *MF.getFrameInfo();
723 unsigned Align = MFI.getObjectAlignment(FI);
725 MachineMemOperand *MMO =
726 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
727 MachineMemOperand::MOStore, 0,
728 MFI.getObjectSize(FI),
731 // tGPR is used sometimes in ARM instructions that need to avoid using
732 // certain registers. Just treat it as GPR here.
733 if (RC == ARM::tGPRRegisterClass)
734 RC = ARM::GPRRegisterClass;
736 if (RC == ARM::GPRRegisterClass) {
737 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::STR))
738 .addReg(SrcReg, getKillRegState(isKill))
739 .addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO));
740 } else if (RC == ARM::DPRRegisterClass ||
741 RC == ARM::DPR_VFP2RegisterClass ||
742 RC == ARM::DPR_8RegisterClass) {
743 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRD))
744 .addReg(SrcReg, getKillRegState(isKill))
745 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
746 } else if (RC == ARM::SPRRegisterClass) {
747 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRS))
748 .addReg(SrcReg, getKillRegState(isKill))
749 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
751 assert((RC == ARM::QPRRegisterClass ||
752 RC == ARM::QPR_VFP2RegisterClass) && "Unknown regclass!");
753 // FIXME: Neon instructions should support predicates
754 if (Align >= 16 && (getRegisterInfo().canRealignStack(MF))) {
755 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1q))
756 .addFrameIndex(FI).addImm(128)
758 .addReg(SrcReg, getKillRegState(isKill)));
760 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMQ)).
761 addReg(SrcReg, getKillRegState(isKill))
763 .addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4))
764 .addMemOperand(MMO));
769 void ARMBaseInstrInfo::
770 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
771 unsigned DestReg, int FI,
772 const TargetRegisterClass *RC) const {
774 if (I != MBB.end()) DL = I->getDebugLoc();
775 MachineFunction &MF = *MBB.getParent();
776 MachineFrameInfo &MFI = *MF.getFrameInfo();
777 unsigned Align = MFI.getObjectAlignment(FI);
779 MachineMemOperand *MMO =
780 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
781 MachineMemOperand::MOLoad, 0,
782 MFI.getObjectSize(FI),
785 // tGPR is used sometimes in ARM instructions that need to avoid using
786 // certain registers. Just treat it as GPR here.
787 if (RC == ARM::tGPRRegisterClass)
788 RC = ARM::GPRRegisterClass;
790 if (RC == ARM::GPRRegisterClass) {
791 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::LDR), DestReg)
792 .addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO));
793 } else if (RC == ARM::DPRRegisterClass ||
794 RC == ARM::DPR_VFP2RegisterClass ||
795 RC == ARM::DPR_8RegisterClass) {
796 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRD), DestReg)
797 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
798 } else if (RC == ARM::SPRRegisterClass) {
799 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRS), DestReg)
800 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
802 assert((RC == ARM::QPRRegisterClass ||
803 RC == ARM::QPR_VFP2RegisterClass ||
804 RC == ARM::QPR_8RegisterClass) && "Unknown regclass!");
806 && (getRegisterInfo().canRealignStack(MF))) {
807 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1q), DestReg)
808 .addFrameIndex(FI).addImm(128)
809 .addMemOperand(MMO));
811 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMQ), DestReg)
813 .addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4))
814 .addMemOperand(MMO));
819 MachineInstr *ARMBaseInstrInfo::
820 foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
821 const SmallVectorImpl<unsigned> &Ops, int FI) const {
822 if (Ops.size() != 1) return NULL;
824 unsigned OpNum = Ops[0];
825 unsigned Opc = MI->getOpcode();
826 MachineInstr *NewMI = NULL;
827 if (Opc == ARM::MOVr || Opc == ARM::t2MOVr) {
828 // If it is updating CPSR, then it cannot be folded.
829 if (MI->getOperand(4).getReg() == ARM::CPSR && !MI->getOperand(4).isDead())
831 unsigned Pred = MI->getOperand(2).getImm();
832 unsigned PredReg = MI->getOperand(3).getReg();
833 if (OpNum == 0) { // move -> store
834 unsigned SrcReg = MI->getOperand(1).getReg();
835 unsigned SrcSubReg = MI->getOperand(1).getSubReg();
836 bool isKill = MI->getOperand(1).isKill();
837 bool isUndef = MI->getOperand(1).isUndef();
838 if (Opc == ARM::MOVr)
839 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::STR))
841 getKillRegState(isKill) | getUndefRegState(isUndef),
843 .addFrameIndex(FI).addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
845 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::t2STRi12))
847 getKillRegState(isKill) | getUndefRegState(isUndef),
849 .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
850 } else { // move -> load
851 unsigned DstReg = MI->getOperand(0).getReg();
852 unsigned DstSubReg = MI->getOperand(0).getSubReg();
853 bool isDead = MI->getOperand(0).isDead();
854 bool isUndef = MI->getOperand(0).isUndef();
855 if (Opc == ARM::MOVr)
856 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::LDR))
859 getDeadRegState(isDead) |
860 getUndefRegState(isUndef), DstSubReg)
861 .addFrameIndex(FI).addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
863 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::t2LDRi12))
866 getDeadRegState(isDead) |
867 getUndefRegState(isUndef), DstSubReg)
868 .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
870 } else if (Opc == ARM::tMOVgpr2gpr ||
871 Opc == ARM::tMOVtgpr2gpr ||
872 Opc == ARM::tMOVgpr2tgpr) {
873 if (OpNum == 0) { // move -> store
874 unsigned SrcReg = MI->getOperand(1).getReg();
875 unsigned SrcSubReg = MI->getOperand(1).getSubReg();
876 bool isKill = MI->getOperand(1).isKill();
877 bool isUndef = MI->getOperand(1).isUndef();
878 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::t2STRi12))
880 getKillRegState(isKill) | getUndefRegState(isUndef),
882 .addFrameIndex(FI).addImm(0).addImm(ARMCC::AL).addReg(0);
883 } else { // move -> load
884 unsigned DstReg = MI->getOperand(0).getReg();
885 unsigned DstSubReg = MI->getOperand(0).getSubReg();
886 bool isDead = MI->getOperand(0).isDead();
887 bool isUndef = MI->getOperand(0).isUndef();
888 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::t2LDRi12))
891 getDeadRegState(isDead) |
892 getUndefRegState(isUndef),
894 .addFrameIndex(FI).addImm(0).addImm(ARMCC::AL).addReg(0);
896 } else if (Opc == ARM::VMOVS) {
897 unsigned Pred = MI->getOperand(2).getImm();
898 unsigned PredReg = MI->getOperand(3).getReg();
899 if (OpNum == 0) { // move -> store
900 unsigned SrcReg = MI->getOperand(1).getReg();
901 unsigned SrcSubReg = MI->getOperand(1).getSubReg();
902 bool isKill = MI->getOperand(1).isKill();
903 bool isUndef = MI->getOperand(1).isUndef();
904 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::VSTRS))
905 .addReg(SrcReg, getKillRegState(isKill) | getUndefRegState(isUndef),
908 .addImm(0).addImm(Pred).addReg(PredReg);
909 } else { // move -> load
910 unsigned DstReg = MI->getOperand(0).getReg();
911 unsigned DstSubReg = MI->getOperand(0).getSubReg();
912 bool isDead = MI->getOperand(0).isDead();
913 bool isUndef = MI->getOperand(0).isUndef();
914 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::VLDRS))
917 getDeadRegState(isDead) |
918 getUndefRegState(isUndef),
920 .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
923 else if (Opc == ARM::VMOVD) {
924 unsigned Pred = MI->getOperand(2).getImm();
925 unsigned PredReg = MI->getOperand(3).getReg();
926 if (OpNum == 0) { // move -> store
927 unsigned SrcReg = MI->getOperand(1).getReg();
928 unsigned SrcSubReg = MI->getOperand(1).getSubReg();
929 bool isKill = MI->getOperand(1).isKill();
930 bool isUndef = MI->getOperand(1).isUndef();
931 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::VSTRD))
933 getKillRegState(isKill) | getUndefRegState(isUndef),
935 .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
936 } else { // move -> load
937 unsigned DstReg = MI->getOperand(0).getReg();
938 unsigned DstSubReg = MI->getOperand(0).getSubReg();
939 bool isDead = MI->getOperand(0).isDead();
940 bool isUndef = MI->getOperand(0).isUndef();
941 NewMI = BuildMI(MF, MI->getDebugLoc(), get(ARM::VLDRD))
944 getDeadRegState(isDead) |
945 getUndefRegState(isUndef),
947 .addFrameIndex(FI).addImm(0).addImm(Pred).addReg(PredReg);
955 ARMBaseInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
957 const SmallVectorImpl<unsigned> &Ops,
958 MachineInstr* LoadMI) const {
964 ARMBaseInstrInfo::canFoldMemoryOperand(const MachineInstr *MI,
965 const SmallVectorImpl<unsigned> &Ops) const {
966 if (Ops.size() != 1) return false;
968 unsigned Opc = MI->getOpcode();
969 if (Opc == ARM::MOVr || Opc == ARM::t2MOVr) {
970 // If it is updating CPSR, then it cannot be folded.
971 return MI->getOperand(4).getReg() != ARM::CPSR ||
972 MI->getOperand(4).isDead();
973 } else if (Opc == ARM::tMOVgpr2gpr ||
974 Opc == ARM::tMOVtgpr2gpr ||
975 Opc == ARM::tMOVgpr2tgpr) {
977 } else if (Opc == ARM::VMOVS || Opc == ARM::VMOVD) {
979 } else if (Opc == ARM::VMOVDneon || Opc == ARM::VMOVQ) {
980 return false; // FIXME
986 /// Create a copy of a const pool value. Update CPI to the new index and return
988 static unsigned duplicateCPV(MachineFunction &MF, unsigned &CPI) {
989 MachineConstantPool *MCP = MF.getConstantPool();
990 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
992 const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
993 assert(MCPE.isMachineConstantPoolEntry() &&
994 "Expecting a machine constantpool entry!");
995 ARMConstantPoolValue *ACPV =
996 static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
998 unsigned PCLabelId = AFI->createConstPoolEntryUId();
999 ARMConstantPoolValue *NewCPV = 0;
1000 if (ACPV->isGlobalValue())
1001 NewCPV = new ARMConstantPoolValue(ACPV->getGV(), PCLabelId,
1003 else if (ACPV->isExtSymbol())
1004 NewCPV = new ARMConstantPoolValue(MF.getFunction()->getContext(),
1005 ACPV->getSymbol(), PCLabelId, 4);
1006 else if (ACPV->isBlockAddress())
1007 NewCPV = new ARMConstantPoolValue(ACPV->getBlockAddress(), PCLabelId,
1008 ARMCP::CPBlockAddress, 4);
1010 llvm_unreachable("Unexpected ARM constantpool value type!!");
1011 CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
1015 void ARMBaseInstrInfo::
1016 reMaterialize(MachineBasicBlock &MBB,
1017 MachineBasicBlock::iterator I,
1018 unsigned DestReg, unsigned SubIdx,
1019 const MachineInstr *Orig,
1020 const TargetRegisterInfo *TRI) const {
1021 if (SubIdx && TargetRegisterInfo::isPhysicalRegister(DestReg)) {
1022 DestReg = TRI->getSubReg(DestReg, SubIdx);
1026 unsigned Opcode = Orig->getOpcode();
1029 MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
1030 MI->getOperand(0).setReg(DestReg);
1034 case ARM::tLDRpci_pic:
1035 case ARM::t2LDRpci_pic: {
1036 MachineFunction &MF = *MBB.getParent();
1037 unsigned CPI = Orig->getOperand(1).getIndex();
1038 unsigned PCLabelId = duplicateCPV(MF, CPI);
1039 MachineInstrBuilder MIB = BuildMI(MBB, I, Orig->getDebugLoc(), get(Opcode),
1041 .addConstantPoolIndex(CPI).addImm(PCLabelId);
1042 (*MIB).setMemRefs(Orig->memoperands_begin(), Orig->memoperands_end());
1047 MachineInstr *NewMI = prior(I);
1048 NewMI->getOperand(0).setSubReg(SubIdx);
1052 ARMBaseInstrInfo::duplicate(MachineInstr *Orig, MachineFunction &MF) const {
1053 MachineInstr *MI = TargetInstrInfoImpl::duplicate(Orig, MF);
1054 switch(Orig->getOpcode()) {
1055 case ARM::tLDRpci_pic:
1056 case ARM::t2LDRpci_pic: {
1057 unsigned CPI = Orig->getOperand(1).getIndex();
1058 unsigned PCLabelId = duplicateCPV(MF, CPI);
1059 Orig->getOperand(1).setIndex(CPI);
1060 Orig->getOperand(2).setImm(PCLabelId);
1067 bool ARMBaseInstrInfo::produceSameValue(const MachineInstr *MI0,
1068 const MachineInstr *MI1) const {
1069 int Opcode = MI0->getOpcode();
1070 if (Opcode == ARM::t2LDRpci ||
1071 Opcode == ARM::t2LDRpci_pic ||
1072 Opcode == ARM::tLDRpci ||
1073 Opcode == ARM::tLDRpci_pic) {
1074 if (MI1->getOpcode() != Opcode)
1076 if (MI0->getNumOperands() != MI1->getNumOperands())
1079 const MachineOperand &MO0 = MI0->getOperand(1);
1080 const MachineOperand &MO1 = MI1->getOperand(1);
1081 if (MO0.getOffset() != MO1.getOffset())
1084 const MachineFunction *MF = MI0->getParent()->getParent();
1085 const MachineConstantPool *MCP = MF->getConstantPool();
1086 int CPI0 = MO0.getIndex();
1087 int CPI1 = MO1.getIndex();
1088 const MachineConstantPoolEntry &MCPE0 = MCP->getConstants()[CPI0];
1089 const MachineConstantPoolEntry &MCPE1 = MCP->getConstants()[CPI1];
1090 ARMConstantPoolValue *ACPV0 =
1091 static_cast<ARMConstantPoolValue*>(MCPE0.Val.MachineCPVal);
1092 ARMConstantPoolValue *ACPV1 =
1093 static_cast<ARMConstantPoolValue*>(MCPE1.Val.MachineCPVal);
1094 return ACPV0->hasSameValue(ACPV1);
1097 return MI0->isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
1100 /// getInstrPredicate - If instruction is predicated, returns its predicate
1101 /// condition, otherwise returns AL. It also returns the condition code
1102 /// register by reference.
1104 llvm::getInstrPredicate(const MachineInstr *MI, unsigned &PredReg) {
1105 int PIdx = MI->findFirstPredOperandIdx();
1111 PredReg = MI->getOperand(PIdx+1).getReg();
1112 return (ARMCC::CondCodes)MI->getOperand(PIdx).getImm();
1116 int llvm::getMatchingCondBranchOpcode(int Opc) {
1119 else if (Opc == ARM::tB)
1121 else if (Opc == ARM::t2B)
1124 llvm_unreachable("Unknown unconditional branch opcode!");
1129 void llvm::emitARMRegPlusImmediate(MachineBasicBlock &MBB,
1130 MachineBasicBlock::iterator &MBBI, DebugLoc dl,
1131 unsigned DestReg, unsigned BaseReg, int NumBytes,
1132 ARMCC::CondCodes Pred, unsigned PredReg,
1133 const ARMBaseInstrInfo &TII) {
1134 bool isSub = NumBytes < 0;
1135 if (isSub) NumBytes = -NumBytes;
1138 unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
1139 unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
1140 assert(ThisVal && "Didn't extract field correctly");
1142 // We will handle these bits from offset, clear them.
1143 NumBytes &= ~ThisVal;
1145 assert(ARM_AM::getSOImmVal(ThisVal) != -1 && "Bit extraction didn't work?");
1147 // Build the new ADD / SUB.
1148 unsigned Opc = isSub ? ARM::SUBri : ARM::ADDri;
1149 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
1150 .addReg(BaseReg, RegState::Kill).addImm(ThisVal)
1151 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
1156 bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
1157 unsigned FrameReg, int &Offset,
1158 const ARMBaseInstrInfo &TII) {
1159 unsigned Opcode = MI.getOpcode();
1160 const TargetInstrDesc &Desc = MI.getDesc();
1161 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
1164 // Memory operands in inline assembly always use AddrMode2.
1165 if (Opcode == ARM::INLINEASM)
1166 AddrMode = ARMII::AddrMode2;
1168 if (Opcode == ARM::ADDri) {
1169 Offset += MI.getOperand(FrameRegIdx+1).getImm();
1171 // Turn it into a move.
1172 MI.setDesc(TII.get(ARM::MOVr));
1173 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
1174 MI.RemoveOperand(FrameRegIdx+1);
1177 } else if (Offset < 0) {
1180 MI.setDesc(TII.get(ARM::SUBri));
1183 // Common case: small offset, fits into instruction.
1184 if (ARM_AM::getSOImmVal(Offset) != -1) {
1185 // Replace the FrameIndex with sp / fp
1186 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
1187 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
1192 // Otherwise, pull as much of the immedidate into this ADDri/SUBri
1194 unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
1195 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
1197 // We will handle these bits from offset, clear them.
1198 Offset &= ~ThisImmVal;
1200 // Get the properly encoded SOImmVal field.
1201 assert(ARM_AM::getSOImmVal(ThisImmVal) != -1 &&
1202 "Bit extraction didn't work?");
1203 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
1205 unsigned ImmIdx = 0;
1207 unsigned NumBits = 0;
1210 case ARMII::AddrMode2: {
1211 ImmIdx = FrameRegIdx+2;
1212 InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
1213 if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1218 case ARMII::AddrMode3: {
1219 ImmIdx = FrameRegIdx+2;
1220 InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
1221 if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1226 case ARMII::AddrMode4:
1227 case ARMII::AddrMode6:
1228 // Can't fold any offset even if it's zero.
1230 case ARMII::AddrMode5: {
1231 ImmIdx = FrameRegIdx+1;
1232 InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
1233 if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1240 llvm_unreachable("Unsupported addressing mode!");
1244 Offset += InstrOffs * Scale;
1245 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
1251 // Attempt to fold address comp. if opcode has offset bits
1253 // Common case: small offset, fits into instruction.
1254 MachineOperand &ImmOp = MI.getOperand(ImmIdx);
1255 int ImmedOffset = Offset / Scale;
1256 unsigned Mask = (1 << NumBits) - 1;
1257 if ((unsigned)Offset <= Mask * Scale) {
1258 // Replace the FrameIndex with sp
1259 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
1261 ImmedOffset |= 1 << NumBits;
1262 ImmOp.ChangeToImmediate(ImmedOffset);
1267 // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
1268 ImmedOffset = ImmedOffset & Mask;
1270 ImmedOffset |= 1 << NumBits;
1271 ImmOp.ChangeToImmediate(ImmedOffset);
1272 Offset &= ~(Mask*Scale);
1276 Offset = (isSub) ? -Offset : Offset;