1 //===- BlackfinRegisterInfo.cpp - Blackfin 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 Blackfin implementation of the TargetRegisterInfo
13 //===----------------------------------------------------------------------===//
16 #include "BlackfinRegisterInfo.h"
17 #include "BlackfinSubtarget.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineLocation.h"
24 #include "llvm/CodeGen/RegisterScavenging.h"
25 #include "llvm/Target/TargetFrameLowering.h"
26 #include "llvm/Target/TargetMachine.h"
27 #include "llvm/Target/TargetOptions.h"
28 #include "llvm/Target/TargetInstrInfo.h"
29 #include "llvm/Type.h"
30 #include "llvm/ADT/BitVector.h"
31 #include "llvm/ADT/STLExtras.h"
33 #define GET_REGINFO_MC_DESC
34 #define GET_REGINFO_TARGET_DESC
35 #include "BlackfinGenRegisterInfo.inc"
39 BlackfinRegisterInfo::BlackfinRegisterInfo(BlackfinSubtarget &st,
40 const TargetInstrInfo &tii)
41 : BlackfinGenRegisterInfo(BF::ADJCALLSTACKDOWN, BF::ADJCALLSTACKUP),
46 BlackfinRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
48 static const unsigned CalleeSavedRegs[] = {
53 return CalleeSavedRegs;
57 BlackfinRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
58 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
61 BitVector Reserved(getNumRegs());
73 Reserved.set(CYCLES).set(CYCLES2);
85 bool BlackfinRegisterInfo::
86 requiresRegisterScavenging(const MachineFunction &MF) const {
90 // Emit instructions to add delta to D/P register. ScratchReg must be of the
91 // same class as Reg (P).
92 void BlackfinRegisterInfo::adjustRegister(MachineBasicBlock &MBB,
93 MachineBasicBlock::iterator I,
100 if (isInt<7>(delta)) {
101 BuildMI(MBB, I, DL, TII.get(BF::ADDpp_imm7), Reg)
102 .addReg(Reg) // No kill on two-addr operand
107 // We must load delta into ScratchReg and add that.
108 loadConstant(MBB, I, DL, ScratchReg, delta);
109 if (BF::PRegClass.contains(Reg)) {
110 assert(BF::PRegClass.contains(ScratchReg) &&
111 "ScratchReg must be a P register");
112 BuildMI(MBB, I, DL, TII.get(BF::ADDpp), Reg)
113 .addReg(Reg, RegState::Kill)
114 .addReg(ScratchReg, RegState::Kill);
116 assert(BF::DRegClass.contains(Reg) && "Reg must be a D or P register");
117 assert(BF::DRegClass.contains(ScratchReg) &&
118 "ScratchReg must be a D register");
119 BuildMI(MBB, I, DL, TII.get(BF::ADD), Reg)
120 .addReg(Reg, RegState::Kill)
121 .addReg(ScratchReg, RegState::Kill);
125 // Emit instructions to load a constant into D/P register
126 void BlackfinRegisterInfo::loadConstant(MachineBasicBlock &MBB,
127 MachineBasicBlock::iterator I,
131 if (isInt<7>(value)) {
132 BuildMI(MBB, I, DL, TII.get(BF::LOADimm7), Reg).addImm(value);
136 if (isUInt<16>(value)) {
137 BuildMI(MBB, I, DL, TII.get(BF::LOADuimm16), Reg).addImm(value);
141 if (isInt<16>(value)) {
142 BuildMI(MBB, I, DL, TII.get(BF::LOADimm16), Reg).addImm(value);
146 // We must split into halves
148 TII.get(BF::LOAD16i), getSubReg(Reg, BF::hi16))
149 .addImm((value >> 16) & 0xffff)
150 .addReg(Reg, RegState::ImplicitDefine);
152 TII.get(BF::LOAD16i), getSubReg(Reg, BF::lo16))
153 .addImm(value & 0xffff)
154 .addReg(Reg, RegState::ImplicitKill)
155 .addReg(Reg, RegState::ImplicitDefine);
158 void BlackfinRegisterInfo::
159 eliminateCallFramePseudoInstr(MachineFunction &MF,
160 MachineBasicBlock &MBB,
161 MachineBasicBlock::iterator I) const {
162 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
164 if (!TFI->hasReservedCallFrame(MF)) {
165 int64_t Amount = I->getOperand(0).getImm();
167 assert(Amount%4 == 0 && "Unaligned call frame size");
168 if (I->getOpcode() == BF::ADJCALLSTACKDOWN) {
169 adjustRegister(MBB, I, I->getDebugLoc(), BF::SP, BF::P1, -Amount);
171 assert(I->getOpcode() == BF::ADJCALLSTACKUP &&
172 "Unknown call frame pseudo instruction");
173 adjustRegister(MBB, I, I->getDebugLoc(), BF::SP, BF::P1, Amount);
180 /// findScratchRegister - Find a 'free' register. Try for a call-clobbered
181 /// register first and then a spilled callee-saved register if that fails.
182 static unsigned findScratchRegister(MachineBasicBlock::iterator II,
184 const TargetRegisterClass *RC,
186 assert(RS && "Register scavenging must be on");
187 unsigned Reg = RS->FindUnusedReg(RC);
189 Reg = RS->scavengeRegister(RC, II, SPAdj);
194 BlackfinRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
195 int SPAdj, RegScavenger *RS) const {
196 MachineInstr &MI = *II;
197 MachineBasicBlock &MBB = *MI.getParent();
198 MachineFunction &MF = *MBB.getParent();
199 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
200 DebugLoc DL = MI.getDebugLoc();
203 for (FIPos=0; !MI.getOperand(FIPos).isFI(); ++FIPos) {
204 assert(FIPos < MI.getNumOperands() &&
205 "Instr doesn't have FrameIndex operand!");
207 int FrameIndex = MI.getOperand(FIPos).getIndex();
208 assert(FIPos+1 < MI.getNumOperands() && MI.getOperand(FIPos+1).isImm());
209 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex)
210 + MI.getOperand(FIPos+1).getImm();
211 unsigned BaseReg = BF::FP;
212 if (TFI->hasFP(MF)) {
213 assert(SPAdj==0 && "Unexpected SP adjust in function with frame pointer");
216 Offset += MF.getFrameInfo()->getStackSize() + SPAdj;
219 bool isStore = false;
221 switch (MI.getOpcode()) {
225 assert(Offset%4 == 0 && "Unaligned i32 stack access");
226 assert(FIPos==1 && "Bad frame index operand");
227 MI.getOperand(FIPos).ChangeToRegister(BaseReg, false);
228 MI.getOperand(FIPos+1).setImm(Offset);
229 if (isUInt<6>(Offset)) {
230 MI.setDesc(TII.get(isStore
231 ? BF::STORE32p_uimm6m4
232 : BF::LOAD32p_uimm6m4));
235 if (BaseReg == BF::FP && isUInt<7>(-Offset)) {
236 MI.setDesc(TII.get(isStore
237 ? BF::STORE32fp_nimm7m4
238 : BF::LOAD32fp_nimm7m4));
239 MI.getOperand(FIPos+1).setImm(-Offset);
242 if (isInt<18>(Offset)) {
243 MI.setDesc(TII.get(isStore
244 ? BF::STORE32p_imm18m4
245 : BF::LOAD32p_imm18m4));
248 // Use RegScavenger to calculate proper offset...
250 llvm_unreachable("Stack frame offset too big");
254 assert(MI.getOperand(0).isReg() && "ADD instruction needs a register");
255 unsigned DestReg = MI.getOperand(0).getReg();
256 // We need to produce a stack offset in a P register. We emit:
259 assert(FIPos==1 && "Bad frame index operand");
260 loadConstant(MBB, II, DL, DestReg, Offset);
261 MI.getOperand(1).ChangeToRegister(DestReg, false, false, true);
262 MI.getOperand(2).ChangeToRegister(BaseReg, false);
268 assert(Offset%2 == 0 && "Unaligned i16 stack access");
269 assert(FIPos==1 && "Bad frame index operand");
270 // We need a P register to use as an address
271 unsigned ScratchReg = findScratchRegister(II, RS, &BF::PRegClass, SPAdj);
272 assert(ScratchReg && "Could not scavenge register");
273 loadConstant(MBB, II, DL, ScratchReg, Offset);
274 BuildMI(MBB, II, DL, TII.get(BF::ADDpp), ScratchReg)
275 .addReg(ScratchReg, RegState::Kill)
277 MI.setDesc(TII.get(isStore ? BF::STORE16pi : BF::LOAD16pi));
278 MI.getOperand(1).ChangeToRegister(ScratchReg, false, false, true);
283 // This is an AnyCC spill, we need a scratch register.
284 assert(FIPos==1 && "Bad frame index operand");
285 MachineOperand SpillReg = MI.getOperand(0);
286 unsigned ScratchReg = findScratchRegister(II, RS, &BF::DRegClass, SPAdj);
287 assert(ScratchReg && "Could not scavenge register");
288 if (SpillReg.getReg()==BF::NCC) {
289 BuildMI(MBB, II, DL, TII.get(BF::MOVENCC_z), ScratchReg)
290 .addOperand(SpillReg);
291 BuildMI(MBB, II, DL, TII.get(BF::BITTGL), ScratchReg)
292 .addReg(ScratchReg).addImm(0);
294 BuildMI(MBB, II, DL, TII.get(BF::MOVECC_zext), ScratchReg)
295 .addOperand(SpillReg);
298 MI.setDesc(TII.get(BF::STORE8p_imm16));
299 MI.getOperand(0).ChangeToRegister(ScratchReg, false, false, true);
300 MI.getOperand(FIPos).ChangeToRegister(BaseReg, false);
301 MI.getOperand(FIPos+1).setImm(Offset);
305 // This is an restore, we need a scratch register.
306 assert(FIPos==1 && "Bad frame index operand");
307 MachineOperand SpillReg = MI.getOperand(0);
308 unsigned ScratchReg = findScratchRegister(II, RS, &BF::DRegClass, SPAdj);
309 assert(ScratchReg && "Could not scavenge register");
310 MI.setDesc(TII.get(BF::LOAD32p_imm16_8z));
311 MI.getOperand(0).ChangeToRegister(ScratchReg, true);
312 MI.getOperand(FIPos).ChangeToRegister(BaseReg, false);
313 MI.getOperand(FIPos+1).setImm(Offset);
315 if (SpillReg.getReg()==BF::CC) {
317 BuildMI(MBB, II, DL, TII.get(BF::MOVECC_nz), BF::CC)
318 .addReg(ScratchReg, RegState::Kill);
320 // Restore NCC (CC = D==0)
321 BuildMI(MBB, II, DL, TII.get(BF::SETEQri_not), BF::NCC)
322 .addReg(ScratchReg, RegState::Kill)
328 llvm_unreachable("Cannot eliminate frame index");
333 unsigned BlackfinRegisterInfo::getRARegister() const {
338 BlackfinRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
339 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
341 return TFI->hasFP(MF) ? BF::FP : BF::SP;
344 unsigned BlackfinRegisterInfo::getEHExceptionRegister() const {
345 llvm_unreachable("What is the exception register");
349 unsigned BlackfinRegisterInfo::getEHHandlerRegister() const {
350 llvm_unreachable("What is the exception handler register");
354 int BlackfinRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
355 llvm_unreachable("What is the dwarf register number");
359 int BlackfinRegisterInfo::getLLVMRegNum(unsigned DwarfRegNum,
361 llvm_unreachable("What is the dwarf register number");