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)
27 : ARMBaseInstrInfo(STI), RI(*this, STI) {
30 unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
36 Thumb2InstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const {
37 if (MBB.empty()) return false;
39 switch (MBB.back().getOpcode()) {
41 case ARM::t2B: // Uncond branch.
42 case ARM::t2BR_JT: // Jumptable branch.
43 case ARM::tBR_JTr: // Jumptable branch (16-bit version).
45 case ARM::tBX_RET_vararg:
57 Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
58 MachineBasicBlock::iterator I,
59 unsigned DestReg, unsigned SrcReg,
60 const TargetRegisterClass *DestRC,
61 const TargetRegisterClass *SrcRC) const {
62 DebugLoc DL = DebugLoc::getUnknownLoc();
63 if (I != MBB.end()) DL = I->getDebugLoc();
65 if (DestRC == ARM::GPRRegisterClass &&
66 SrcRC == ARM::GPRRegisterClass) {
67 AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2MOVr),
68 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 Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
165 unsigned ThisVal = NumBytes;
166 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
168 } else if (ThisVal < 4096) {
169 Opc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
172 // FIXME: Move this to ARMAddressingModes.h?
173 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
174 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
175 NumBytes &= ~ThisVal;
176 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
177 "Bit extraction didn't work?");
180 // Build the new ADD / SUB.
181 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
182 .addReg(BaseReg, RegState::Kill).addImm(ThisVal)
183 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
189 negativeOffsetOpcode(unsigned opcode)
192 case ARM::t2LDRi12: return ARM::t2LDRi8;
193 case ARM::t2LDRHi12: return ARM::t2LDRHi8;
194 case ARM::t2LDRBi12: return ARM::t2LDRBi8;
195 case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
196 case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
197 case ARM::t2STRi12: return ARM::t2STRi8;
198 case ARM::t2STRBi12: return ARM::t2STRBi8;
199 case ARM::t2STRHi12: return ARM::t2STRHi8;
219 positiveOffsetOpcode(unsigned opcode)
222 case ARM::t2LDRi8: return ARM::t2LDRi12;
223 case ARM::t2LDRHi8: return ARM::t2LDRHi12;
224 case ARM::t2LDRBi8: return ARM::t2LDRBi12;
225 case ARM::t2LDRSHi8: return ARM::t2LDRSHi12;
226 case ARM::t2LDRSBi8: return ARM::t2LDRSBi12;
227 case ARM::t2STRi8: return ARM::t2STRi12;
228 case ARM::t2STRBi8: return ARM::t2STRBi12;
229 case ARM::t2STRHi8: return ARM::t2STRHi12;
234 case ARM::t2LDRSHi12:
235 case ARM::t2LDRSBi12:
249 immediateOffsetOpcode(unsigned opcode)
252 case ARM::t2LDRs: return ARM::t2LDRi12;
253 case ARM::t2LDRHs: return ARM::t2LDRHi12;
254 case ARM::t2LDRBs: return ARM::t2LDRBi12;
255 case ARM::t2LDRSHs: return ARM::t2LDRSHi12;
256 case ARM::t2LDRSBs: return ARM::t2LDRSBi12;
257 case ARM::t2STRs: return ARM::t2STRi12;
258 case ARM::t2STRBs: return ARM::t2STRBi12;
259 case ARM::t2STRHs: return ARM::t2STRHi12;
264 case ARM::t2LDRSHi12:
265 case ARM::t2LDRSBi12:
286 int llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
287 unsigned FrameReg, int Offset,
288 const ARMBaseInstrInfo &TII) {
289 unsigned Opcode = MI.getOpcode();
290 unsigned NewOpc = Opcode;
291 const TargetInstrDesc &Desc = MI.getDesc();
292 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
295 // Memory operands in inline assembly always use AddrModeT2_i12.
296 if (Opcode == ARM::INLINEASM)
297 AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2?
299 if (Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) {
300 Offset += MI.getOperand(FrameRegIdx+1).getImm();
302 // Turn it into a move.
303 MI.setDesc(TII.get(ARM::t2MOVr));
304 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
305 MI.RemoveOperand(FrameRegIdx+1);
312 MI.setDesc(TII.get(ARM::t2SUBri));
315 // Common case: small offset, fits into instruction.
316 if (ARM_AM::getT2SOImmVal(Offset) != -1) {
317 NewOpc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
318 if (NewOpc != Opcode)
319 MI.setDesc(TII.get(NewOpc));
320 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
321 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
324 // Another common case: imm12.
326 NewOpc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
327 if (NewOpc != Opcode)
328 MI.setDesc(TII.get(NewOpc));
329 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
330 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
334 // Otherwise, extract 8 adjacent bits from the immediate into this
336 unsigned RotAmt = CountLeadingZeros_32(Offset);
337 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt);
339 // We will handle these bits from offset, clear them.
340 Offset &= ~ThisImmVal;
342 assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 &&
343 "Bit extraction didn't work?");
344 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
346 // AddrModeT2_so cannot handle any offset. If there is no offset
347 // register then we change to an immediate version.
349 if (AddrMode == ARMII::AddrModeT2_so) {
350 unsigned OffsetReg = MI.getOperand(FrameRegIdx+1).getReg();
351 if (OffsetReg != 0) {
352 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
356 MI.RemoveOperand(FrameRegIdx+1);
357 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0);
358 NewOpc = immediateOffsetOpcode(Opcode);
359 AddrMode = ARMII::AddrModeT2_i12;
362 unsigned NumBits = 0;
364 if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) {
365 // i8 supports only negative, and i12 supports only positive, so
366 // based on Offset sign convert Opcode to the appropriate
368 Offset += MI.getOperand(FrameRegIdx+1).getImm();
370 NewOpc = negativeOffsetOpcode(Opcode);
375 NewOpc = positiveOffsetOpcode(Opcode);
379 // VFP address modes.
380 assert(AddrMode == ARMII::AddrMode5);
381 int InstrOffs=ARM_AM::getAM5Offset(MI.getOperand(FrameRegIdx+1).getImm());
382 if (ARM_AM::getAM5Op(MI.getOperand(FrameRegIdx+1).getImm()) ==ARM_AM::sub)
386 Offset += InstrOffs * 4;
387 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
394 if (NewOpc != Opcode)
395 MI.setDesc(TII.get(NewOpc));
397 MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1);
399 // Attempt to fold address computation
400 // Common case: small offset, fits into instruction.
401 int ImmedOffset = Offset / Scale;
402 unsigned Mask = (1 << NumBits) - 1;
403 if ((unsigned)Offset <= Mask * Scale) {
404 // Replace the FrameIndex with fp/sp
405 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
407 if (AddrMode == ARMII::AddrMode5)
408 // FIXME: Not consistent.
409 ImmedOffset |= 1 << NumBits;
411 ImmedOffset = -ImmedOffset;
413 ImmOp.ChangeToImmediate(ImmedOffset);
417 // Otherwise, offset doesn't fit. Pull in what we can to simplify
418 ImmedOffset = ImmedOffset & Mask;
420 if (AddrMode == ARMII::AddrMode5)
421 // FIXME: Not consistent.
422 ImmedOffset |= 1 << NumBits;
424 ImmedOffset = -ImmedOffset;
426 ImmOp.ChangeToImmediate(ImmedOffset);
427 Offset &= ~(Mask*Scale);
430 return (isSub) ? -Offset : Offset;