1 //===- MSP430RegisterInfo.cpp - MSP430 Register Information ---------------===//
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 MSP430 implementation of the TargetRegisterInfo class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "msp430-reg-info"
17 #include "MSP430MachineFunctionInfo.h"
18 #include "MSP430RegisterInfo.h"
19 #include "MSP430TargetMachine.h"
20 #include "llvm/Function.h"
21 #include "llvm/CodeGen/MachineFrameInfo.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineInstrBuilder.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Target/TargetOptions.h"
26 #include "llvm/ADT/BitVector.h"
27 #include "llvm/Support/ErrorHandling.h"
31 // FIXME: Provide proper call frame setup / destroy opcodes.
32 MSP430RegisterInfo::MSP430RegisterInfo(MSP430TargetMachine &tm,
33 const TargetInstrInfo &tii)
34 : MSP430GenRegisterInfo(MSP430::ADJCALLSTACKDOWN, MSP430::ADJCALLSTACKUP),
36 StackAlign = TM.getFrameInfo()->getStackAlignment();
40 MSP430RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
41 const Function* F = MF->getFunction();
42 static const unsigned CalleeSavedRegs[] = {
43 MSP430::FPW, MSP430::R5W, MSP430::R6W, MSP430::R7W,
44 MSP430::R8W, MSP430::R9W, MSP430::R10W, MSP430::R11W,
47 static const unsigned CalleeSavedRegsFP[] = {
48 MSP430::R5W, MSP430::R6W, MSP430::R7W,
49 MSP430::R8W, MSP430::R9W, MSP430::R10W, MSP430::R11W,
52 static const unsigned CalleeSavedRegsIntr[] = {
53 MSP430::FPW, MSP430::R5W, MSP430::R6W, MSP430::R7W,
54 MSP430::R8W, MSP430::R9W, MSP430::R10W, MSP430::R11W,
55 MSP430::R12W, MSP430::R13W, MSP430::R14W, MSP430::R15W,
58 static const unsigned CalleeSavedRegsIntrFP[] = {
59 MSP430::R5W, MSP430::R6W, MSP430::R7W,
60 MSP430::R8W, MSP430::R9W, MSP430::R10W, MSP430::R11W,
61 MSP430::R12W, MSP430::R13W, MSP430::R14W, MSP430::R15W,
66 return (F->getCallingConv() == CallingConv::MSP430_INTR ?
67 CalleeSavedRegsIntrFP : CalleeSavedRegsFP);
69 return (F->getCallingConv() == CallingConv::MSP430_INTR ?
70 CalleeSavedRegsIntr : CalleeSavedRegs);
74 BitVector MSP430RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
75 BitVector Reserved(getNumRegs());
77 // Mark 4 special registers as reserved.
78 Reserved.set(MSP430::PCW);
79 Reserved.set(MSP430::SPW);
80 Reserved.set(MSP430::SRW);
81 Reserved.set(MSP430::CGW);
83 // Mark frame pointer as reserved if needed.
85 Reserved.set(MSP430::FPW);
90 const TargetRegisterClass *
91 MSP430RegisterInfo::getPointerRegClass(unsigned Kind) const {
92 return &MSP430::GR16RegClass;
96 bool MSP430RegisterInfo::hasFP(const MachineFunction &MF) const {
97 const MachineFrameInfo *MFI = MF.getFrameInfo();
99 return (DisableFramePointerElim(MF) ||
100 MF.getFrameInfo()->hasVarSizedObjects() ||
101 MFI->isFrameAddressTaken());
104 bool MSP430RegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
105 return !MF.getFrameInfo()->hasVarSizedObjects();
108 void MSP430RegisterInfo::
109 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
110 MachineBasicBlock::iterator I) const {
111 if (!hasReservedCallFrame(MF)) {
112 // If the stack pointer can be changed after prologue, turn the
113 // adjcallstackup instruction into a 'sub SPW, <amt>' and the
114 // adjcallstackdown instruction into 'add SPW, <amt>'
115 // TODO: consider using push / pop instead of sub + store / add
116 MachineInstr *Old = I;
117 uint64_t Amount = Old->getOperand(0).getImm();
119 // We need to keep the stack aligned properly. To do this, we round the
120 // amount of space needed for the outgoing arguments up to the next
121 // alignment boundary.
122 Amount = (Amount+StackAlign-1)/StackAlign*StackAlign;
124 MachineInstr *New = 0;
125 if (Old->getOpcode() == getCallFrameSetupOpcode()) {
126 New = BuildMI(MF, Old->getDebugLoc(),
127 TII.get(MSP430::SUB16ri), MSP430::SPW)
128 .addReg(MSP430::SPW).addImm(Amount);
130 assert(Old->getOpcode() == getCallFrameDestroyOpcode());
131 // factor out the amount the callee already popped.
132 uint64_t CalleeAmt = Old->getOperand(1).getImm();
135 New = BuildMI(MF, Old->getDebugLoc(),
136 TII.get(MSP430::ADD16ri), MSP430::SPW)
137 .addReg(MSP430::SPW).addImm(Amount);
141 // The SRW implicit def is dead.
142 New->getOperand(3).setIsDead();
144 // Replace the pseudo instruction with a new instruction...
148 } else if (I->getOpcode() == getCallFrameDestroyOpcode()) {
149 // If we are performing frame pointer elimination and if the callee pops
150 // something off the stack pointer, add it back.
151 if (uint64_t CalleeAmt = I->getOperand(1).getImm()) {
152 MachineInstr *Old = I;
154 BuildMI(MF, Old->getDebugLoc(), TII.get(MSP430::SUB16ri),
155 MSP430::SPW).addReg(MSP430::SPW).addImm(CalleeAmt);
156 // The SRW implicit def is dead.
157 New->getOperand(3).setIsDead();
167 MSP430RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
168 int SPAdj, FrameIndexValue *Value,
169 RegScavenger *RS) const {
170 assert(SPAdj == 0 && "Unexpected");
173 MachineInstr &MI = *II;
174 MachineBasicBlock &MBB = *MI.getParent();
175 MachineFunction &MF = *MBB.getParent();
176 DebugLoc dl = MI.getDebugLoc();
177 while (!MI.getOperand(i).isFI()) {
179 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
182 int FrameIndex = MI.getOperand(i).getIndex();
184 unsigned BasePtr = (hasFP(MF) ? MSP430::FPW : MSP430::SPW);
185 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
191 Offset += MF.getFrameInfo()->getStackSize();
193 Offset += 2; // Skip the saved FPW
195 // Fold imm into offset
196 Offset += MI.getOperand(i+1).getImm();
198 if (MI.getOpcode() == MSP430::ADD16ri) {
199 // This is actually "load effective address" of the stack slot
200 // instruction. We have only two-address instructions, thus we need to
201 // expand it into mov + add
203 MI.setDesc(TII.get(MSP430::MOV16rr));
204 MI.getOperand(i).ChangeToRegister(BasePtr, false);
209 // We need to materialize the offset via add instruction.
210 unsigned DstReg = MI.getOperand(0).getReg();
212 BuildMI(MBB, llvm::next(II), dl, TII.get(MSP430::SUB16ri), DstReg)
213 .addReg(DstReg).addImm(-Offset);
215 BuildMI(MBB, llvm::next(II), dl, TII.get(MSP430::ADD16ri), DstReg)
216 .addReg(DstReg).addImm(Offset);
221 MI.getOperand(i).ChangeToRegister(BasePtr, false);
222 MI.getOperand(i+1).ChangeToImmediate(Offset);
227 MSP430RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF)
229 // Create a frame entry for the FPW register that must be saved.
231 int ATTRIBUTE_UNUSED FrameIdx =
232 MF.getFrameInfo()->CreateFixedObject(2, -4, true);
233 assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
234 "Slot for FPW register must be last in order to be found!");
239 void MSP430RegisterInfo::emitPrologue(MachineFunction &MF) const {
240 MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
241 MachineFrameInfo *MFI = MF.getFrameInfo();
242 MSP430MachineFunctionInfo *MSP430FI = MF.getInfo<MSP430MachineFunctionInfo>();
243 MachineBasicBlock::iterator MBBI = MBB.begin();
244 DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
246 // Get the number of bytes to allocate from the FrameInfo.
247 uint64_t StackSize = MFI->getStackSize();
249 uint64_t NumBytes = 0;
251 // Calculate required stack adjustment
252 uint64_t FrameSize = StackSize - 2;
253 NumBytes = FrameSize - MSP430FI->getCalleeSavedFrameSize();
255 // Get the offset of the stack slot for the EBP register... which is
256 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
257 // Update the frame offset adjustment.
258 MFI->setOffsetAdjustment(-NumBytes);
260 // Save FPW into the appropriate stack slot...
261 BuildMI(MBB, MBBI, DL, TII.get(MSP430::PUSH16r))
262 .addReg(MSP430::FPW, RegState::Kill);
264 // Update FPW with the new base value...
265 BuildMI(MBB, MBBI, DL, TII.get(MSP430::MOV16rr), MSP430::FPW)
266 .addReg(MSP430::SPW);
268 // Mark the FramePtr as live-in in every block except the entry.
269 for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
271 I->addLiveIn(MSP430::FPW);
274 NumBytes = StackSize - MSP430FI->getCalleeSavedFrameSize();
276 // Skip the callee-saved push instructions.
277 while (MBBI != MBB.end() && (MBBI->getOpcode() == MSP430::PUSH16r))
280 if (MBBI != MBB.end())
281 DL = MBBI->getDebugLoc();
283 if (NumBytes) { // adjust stack pointer: SPW -= numbytes
284 // If there is an SUB16ri of SPW immediately before this instruction, merge
286 //NumBytes -= mergeSPUpdates(MBB, MBBI, true);
287 // If there is an ADD16ri or SUB16ri of SPW immediately after this
288 // instruction, merge the two instructions.
289 // mergeSPUpdatesDown(MBB, MBBI, &NumBytes);
293 BuildMI(MBB, MBBI, DL, TII.get(MSP430::SUB16ri), MSP430::SPW)
294 .addReg(MSP430::SPW).addImm(NumBytes);
295 // The SRW implicit def is dead.
296 MI->getOperand(3).setIsDead();
301 void MSP430RegisterInfo::emitEpilogue(MachineFunction &MF,
302 MachineBasicBlock &MBB) const {
303 const MachineFrameInfo *MFI = MF.getFrameInfo();
304 MSP430MachineFunctionInfo *MSP430FI = MF.getInfo<MSP430MachineFunctionInfo>();
305 MachineBasicBlock::iterator MBBI = prior(MBB.end());
306 unsigned RetOpcode = MBBI->getOpcode();
307 DebugLoc DL = MBBI->getDebugLoc();
311 case MSP430::RETI: break; // These are ok
313 llvm_unreachable("Can only insert epilog into returning blocks");
316 // Get the number of bytes to allocate from the FrameInfo
317 uint64_t StackSize = MFI->getStackSize();
318 unsigned CSSize = MSP430FI->getCalleeSavedFrameSize();
319 uint64_t NumBytes = 0;
322 // Calculate required stack adjustment
323 uint64_t FrameSize = StackSize - 2;
324 NumBytes = FrameSize - CSSize;
327 BuildMI(MBB, MBBI, DL, TII.get(MSP430::POP16r), MSP430::FPW);
329 NumBytes = StackSize - CSSize;
331 // Skip the callee-saved pop instructions.
332 while (MBBI != MBB.begin()) {
333 MachineBasicBlock::iterator PI = prior(MBBI);
334 unsigned Opc = PI->getOpcode();
335 if (Opc != MSP430::POP16r && !PI->getDesc().isTerminator())
340 DL = MBBI->getDebugLoc();
342 // If there is an ADD16ri or SUB16ri of SPW immediately before this
343 // instruction, merge the two instructions.
344 //if (NumBytes || MFI->hasVarSizedObjects())
345 // mergeSPUpdatesUp(MBB, MBBI, StackPtr, &NumBytes);
347 if (MFI->hasVarSizedObjects()) {
348 BuildMI(MBB, MBBI, DL,
349 TII.get(MSP430::MOV16rr), MSP430::SPW).addReg(MSP430::FPW);
352 BuildMI(MBB, MBBI, DL,
353 TII.get(MSP430::SUB16ri), MSP430::SPW)
354 .addReg(MSP430::SPW).addImm(CSSize);
355 // The SRW implicit def is dead.
356 MI->getOperand(3).setIsDead();
359 // adjust stack pointer back: SPW += numbytes
362 BuildMI(MBB, MBBI, DL, TII.get(MSP430::ADD16ri), MSP430::SPW)
363 .addReg(MSP430::SPW).addImm(NumBytes);
364 // The SRW implicit def is dead.
365 MI->getOperand(3).setIsDead();
370 unsigned MSP430RegisterInfo::getRARegister() const {
374 unsigned MSP430RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
375 return hasFP(MF) ? MSP430::FPW : MSP430::SPW;
378 int MSP430RegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
379 llvm_unreachable("Not implemented yet!");
383 #include "MSP430GenRegisterInfo.inc"