1 //===- Thumb2InstrInfo.cpp - Thumb-2 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 Thumb-2 implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "ARMInstrInfo.h"
16 #include "ARMAddressingModes.h"
17 #include "ARMGenInstrInfo.inc"
18 #include "ARMMachineFunctionInfo.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "Thumb2InstrInfo.h"
26 Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI) : RI(*this, STI) {
29 unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
35 Thumb2InstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const {
36 if (MBB.empty()) return false;
38 switch (MBB.back().getOpcode()) {
40 case ARM::t2B: // Uncond branch.
41 case ARM::t2BR_JT: // Jumptable branch.
42 case ARM::t2TBB: // Table branch byte.
43 case ARM::t2TBH: // Table branch halfword.
44 case ARM::tBR_JTr: // Jumptable branch (16-bit version).
46 case ARM::tBX_RET_vararg:
58 Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
59 MachineBasicBlock::iterator I,
60 unsigned DestReg, unsigned SrcReg,
61 const TargetRegisterClass *DestRC,
62 const TargetRegisterClass *SrcRC) const {
63 DebugLoc DL = DebugLoc::getUnknownLoc();
64 if (I != MBB.end()) DL = I->getDebugLoc();
66 if (DestRC == ARM::GPRRegisterClass &&
67 SrcRC == ARM::GPRRegisterClass) {
68 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2gpr), DestReg).addReg(SrcReg);
70 } else if (DestRC == ARM::GPRRegisterClass &&
71 SrcRC == ARM::tGPRRegisterClass) {
72 BuildMI(MBB, I, DL, get(ARM::tMOVtgpr2gpr), DestReg).addReg(SrcReg);
74 } else if (DestRC == ARM::tGPRRegisterClass &&
75 SrcRC == ARM::GPRRegisterClass) {
76 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2tgpr), DestReg).addReg(SrcReg);
80 // Handle SPR, DPR, and QPR copies.
81 return ARMBaseInstrInfo::copyRegToReg(MBB, I, DestReg, SrcReg, DestRC, SrcRC);
84 void Thumb2InstrInfo::
85 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
86 unsigned SrcReg, bool isKill, int FI,
87 const TargetRegisterClass *RC) const {
88 DebugLoc DL = DebugLoc::getUnknownLoc();
89 if (I != MBB.end()) DL = I->getDebugLoc();
91 if (RC == ARM::GPRRegisterClass) {
92 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2STRi12))
93 .addReg(SrcReg, getKillRegState(isKill))
94 .addFrameIndex(FI).addImm(0));
98 ARMBaseInstrInfo::storeRegToStackSlot(MBB, I, SrcReg, isKill, FI, RC);
101 void Thumb2InstrInfo::
102 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
103 unsigned DestReg, int FI,
104 const TargetRegisterClass *RC) const {
105 DebugLoc DL = DebugLoc::getUnknownLoc();
106 if (I != MBB.end()) DL = I->getDebugLoc();
108 if (RC == ARM::GPRRegisterClass) {
109 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2LDRi12), DestReg)
110 .addFrameIndex(FI).addImm(0));
114 ARMBaseInstrInfo::loadRegFromStackSlot(MBB, I, DestReg, FI, RC);
118 void llvm::emitT2RegPlusImmediate(MachineBasicBlock &MBB,
119 MachineBasicBlock::iterator &MBBI, DebugLoc dl,
120 unsigned DestReg, unsigned BaseReg, int NumBytes,
121 ARMCC::CondCodes Pred, unsigned PredReg,
122 const ARMBaseInstrInfo &TII) {
123 bool isSub = NumBytes < 0;
124 if (isSub) NumBytes = -NumBytes;
126 // If profitable, use a movw or movt to materialize the offset.
127 // FIXME: Use the scavenger to grab a scratch register.
128 if (DestReg != ARM::SP && DestReg != BaseReg &&
130 ARM_AM::getT2SOImmVal(NumBytes) == -1) {
132 if (NumBytes < 65536) {
133 // Use a movw to materialize the 16-bit constant.
134 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVi16), DestReg)
136 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
138 } else if ((NumBytes & 0xffff) == 0) {
139 // Use a movt to materialize the 32-bit constant.
140 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVTi16), DestReg)
142 .addImm(NumBytes >> 16)
143 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
149 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2SUBrr), DestReg)
150 .addReg(BaseReg, RegState::Kill)
151 .addReg(DestReg, RegState::Kill)
152 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
154 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2ADDrr), DestReg)
155 .addReg(DestReg, RegState::Kill)
156 .addReg(BaseReg, RegState::Kill)
157 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
164 unsigned ThisVal = NumBytes;
166 if (DestReg == ARM::SP && BaseReg != ARM::SP) {
167 // mov sp, rn. Note t2MOVr cannot be used.
168 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr),DestReg).addReg(BaseReg);
173 if (BaseReg == ARM::SP) {
175 if (DestReg == ARM::SP && (ThisVal < ((1 << 7)-1) * 4)) {
176 assert((ThisVal & 3) == 0 && "Stack update is not multiple of 4?");
177 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
178 // FIXME: Fix Thumb1 immediate encoding.
179 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
180 .addReg(BaseReg).addImm(ThisVal/4);
185 // sub rd, sp, so_imm
186 Opc = isSub ? ARM::t2SUBrSPi : ARM::t2ADDrSPi;
187 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
190 // FIXME: Move this to ARMAddressingModes.h?
191 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
192 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
193 NumBytes &= ~ThisVal;
194 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
195 "Bit extraction didn't work?");
198 assert(DestReg != ARM::SP && BaseReg != ARM::SP);
199 Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
200 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
202 } else if (ThisVal < 4096) {
203 Opc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
206 // FIXME: Move this to ARMAddressingModes.h?
207 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
208 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
209 NumBytes &= ~ThisVal;
210 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
211 "Bit extraction didn't work?");
215 // Build the new ADD / SUB.
216 AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
217 .addReg(BaseReg, RegState::Kill)
225 negativeOffsetOpcode(unsigned opcode)
228 case ARM::t2LDRi12: return ARM::t2LDRi8;
229 case ARM::t2LDRHi12: return ARM::t2LDRHi8;
230 case ARM::t2LDRBi12: return ARM::t2LDRBi8;
231 case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
232 case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
233 case ARM::t2STRi12: return ARM::t2STRi8;
234 case ARM::t2STRBi12: return ARM::t2STRBi8;
235 case ARM::t2STRHi12: return ARM::t2STRHi8;
255 positiveOffsetOpcode(unsigned opcode)
258 case ARM::t2LDRi8: return ARM::t2LDRi12;
259 case ARM::t2LDRHi8: return ARM::t2LDRHi12;
260 case ARM::t2LDRBi8: return ARM::t2LDRBi12;
261 case ARM::t2LDRSHi8: return ARM::t2LDRSHi12;
262 case ARM::t2LDRSBi8: return ARM::t2LDRSBi12;
263 case ARM::t2STRi8: return ARM::t2STRi12;
264 case ARM::t2STRBi8: return ARM::t2STRBi12;
265 case ARM::t2STRHi8: return ARM::t2STRHi12;
270 case ARM::t2LDRSHi12:
271 case ARM::t2LDRSBi12:
285 immediateOffsetOpcode(unsigned opcode)
288 case ARM::t2LDRs: return ARM::t2LDRi12;
289 case ARM::t2LDRHs: return ARM::t2LDRHi12;
290 case ARM::t2LDRBs: return ARM::t2LDRBi12;
291 case ARM::t2LDRSHs: return ARM::t2LDRSHi12;
292 case ARM::t2LDRSBs: return ARM::t2LDRSBi12;
293 case ARM::t2STRs: return ARM::t2STRi12;
294 case ARM::t2STRBs: return ARM::t2STRBi12;
295 case ARM::t2STRHs: return ARM::t2STRHi12;
300 case ARM::t2LDRSHi12:
301 case ARM::t2LDRSBi12:
322 int llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
323 unsigned FrameReg, int Offset,
324 const ARMBaseInstrInfo &TII) {
325 unsigned Opcode = MI.getOpcode();
326 const TargetInstrDesc &Desc = MI.getDesc();
327 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
330 // Memory operands in inline assembly always use AddrModeT2_i12.
331 if (Opcode == ARM::INLINEASM)
332 AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2?
334 if (Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) {
335 Offset += MI.getOperand(FrameRegIdx+1).getImm();
337 bool isSP = FrameReg == ARM::SP;
339 // Turn it into a move.
340 MI.setDesc(TII.get(ARM::tMOVgpr2gpr));
341 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
342 MI.RemoveOperand(FrameRegIdx+1);
349 MI.setDesc(TII.get(isSP ? ARM::t2SUBrSPi : ARM::t2SUBri));
351 MI.setDesc(TII.get(isSP ? ARM::t2ADDrSPi : ARM::t2ADDri));
354 // Common case: small offset, fits into instruction.
355 if (ARM_AM::getT2SOImmVal(Offset) != -1) {
356 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
357 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
360 // Another common case: imm12.
362 unsigned NewOpc = isSP
363 ? (isSub ? ARM::t2SUBrSPi12 : ARM::t2ADDrSPi12)
364 : (isSub ? ARM::t2SUBri12 : ARM::t2ADDri12);
365 MI.setDesc(TII.get(NewOpc));
366 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
367 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
371 // Otherwise, extract 8 adjacent bits from the immediate into this
373 unsigned RotAmt = CountLeadingZeros_32(Offset);
374 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt);
376 // We will handle these bits from offset, clear them.
377 Offset &= ~ThisImmVal;
379 assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 &&
380 "Bit extraction didn't work?");
381 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
383 // AddrModeT2_so cannot handle any offset. If there is no offset
384 // register then we change to an immediate version.
385 unsigned NewOpc = Opcode;
386 if (AddrMode == ARMII::AddrModeT2_so) {
387 unsigned OffsetReg = MI.getOperand(FrameRegIdx+1).getReg();
388 if (OffsetReg != 0) {
389 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
393 MI.RemoveOperand(FrameRegIdx+1);
394 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0);
395 NewOpc = immediateOffsetOpcode(Opcode);
396 AddrMode = ARMII::AddrModeT2_i12;
399 unsigned NumBits = 0;
401 if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) {
402 // i8 supports only negative, and i12 supports only positive, so
403 // based on Offset sign convert Opcode to the appropriate
405 Offset += MI.getOperand(FrameRegIdx+1).getImm();
407 NewOpc = negativeOffsetOpcode(Opcode);
412 NewOpc = positiveOffsetOpcode(Opcode);
416 // VFP address modes.
417 assert(AddrMode == ARMII::AddrMode5);
418 int InstrOffs=ARM_AM::getAM5Offset(MI.getOperand(FrameRegIdx+1).getImm());
419 if (ARM_AM::getAM5Op(MI.getOperand(FrameRegIdx+1).getImm()) ==ARM_AM::sub)
423 Offset += InstrOffs * 4;
424 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
431 if (NewOpc != Opcode)
432 MI.setDesc(TII.get(NewOpc));
434 MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1);
436 // Attempt to fold address computation
437 // Common case: small offset, fits into instruction.
438 int ImmedOffset = Offset / Scale;
439 unsigned Mask = (1 << NumBits) - 1;
440 if ((unsigned)Offset <= Mask * Scale) {
441 // Replace the FrameIndex with fp/sp
442 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
444 if (AddrMode == ARMII::AddrMode5)
445 // FIXME: Not consistent.
446 ImmedOffset |= 1 << NumBits;
448 ImmedOffset = -ImmedOffset;
450 ImmOp.ChangeToImmediate(ImmedOffset);
454 // Otherwise, offset doesn't fit. Pull in what we can to simplify
455 ImmedOffset = ImmedOffset & Mask;
457 if (AddrMode == ARMII::AddrMode5)
458 // FIXME: Not consistent.
459 ImmedOffset |= 1 << NumBits;
461 ImmedOffset = -ImmedOffset;
462 if (ImmedOffset == 0)
463 // Change the opcode back if the encoded offset is zero.
464 MI.setDesc(TII.get(positiveOffsetOpcode(NewOpc)));
467 ImmOp.ChangeToImmediate(ImmedOffset);
468 Offset &= ~(Mask*Scale);
471 return (isSub) ? -Offset : Offset;