1 //===-- IA64ISelLowering.cpp - IA64 DAG Lowering Implementation -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Duraid Madina and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the IA64ISelLowering class.
12 //===----------------------------------------------------------------------===//
14 #include "IA64ISelLowering.h"
15 #include "IA64MachineFunctionInfo.h"
16 #include "IA64TargetMachine.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineInstrBuilder.h"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/CodeGen/SSARegMap.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Function.h"
26 IA64TargetLowering::IA64TargetLowering(TargetMachine &TM)
27 : TargetLowering(TM) {
29 // register class for general registers
30 addRegisterClass(MVT::i64, IA64::GRRegisterClass);
32 // register class for FP registers
33 addRegisterClass(MVT::f64, IA64::FPRegisterClass);
35 // register class for predicate registers
36 addRegisterClass(MVT::i1, IA64::PRRegisterClass);
38 setOperationAction(ISD::BRCONDTWOWAY , MVT::Other, Expand);
39 setOperationAction(ISD::BRTWOWAY_CC , MVT::Other, Expand);
40 setOperationAction(ISD::FP_ROUND_INREG , MVT::f32 , Expand);
42 // We need to handle ISD::RET for void functions ourselves,
43 // so we get a chance to restore ar.pfs before adding a
45 setOperationAction(ISD::RET, MVT::Other, Custom);
47 setSetCCResultType(MVT::i1);
48 setShiftAmountType(MVT::i64);
50 setOperationAction(ISD::EXTLOAD , MVT::i1 , Promote);
52 setOperationAction(ISD::ZEXTLOAD , MVT::i1 , Expand);
54 setOperationAction(ISD::SEXTLOAD , MVT::i1 , Expand);
55 setOperationAction(ISD::SEXTLOAD , MVT::i8 , Expand);
56 setOperationAction(ISD::SEXTLOAD , MVT::i16 , Expand);
57 setOperationAction(ISD::SEXTLOAD , MVT::i32 , Expand);
59 setOperationAction(ISD::FREM , MVT::f32 , Expand);
60 setOperationAction(ISD::FREM , MVT::f64 , Expand);
62 setOperationAction(ISD::UREM , MVT::f32 , Expand);
63 setOperationAction(ISD::UREM , MVT::f64 , Expand);
65 setOperationAction(ISD::MEMMOVE , MVT::Other, Expand);
66 setOperationAction(ISD::MEMSET , MVT::Other, Expand);
67 setOperationAction(ISD::MEMCPY , MVT::Other, Expand);
69 setOperationAction(ISD::SINT_TO_FP , MVT::i1 , Promote);
70 setOperationAction(ISD::UINT_TO_FP , MVT::i1 , Promote);
72 // We don't support sin/cos/sqrt
73 setOperationAction(ISD::FSIN , MVT::f64, Expand);
74 setOperationAction(ISD::FCOS , MVT::f64, Expand);
75 setOperationAction(ISD::FSQRT, MVT::f64, Expand);
76 setOperationAction(ISD::FSIN , MVT::f32, Expand);
77 setOperationAction(ISD::FCOS , MVT::f32, Expand);
78 setOperationAction(ISD::FSQRT, MVT::f32, Expand);
80 // We don't have line number support yet.
81 setOperationAction(ISD::LOCATION, MVT::Other, Expand);
82 setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
83 setOperationAction(ISD::DEBUG_LABEL, MVT::Other, Expand);
85 //IA64 has these, but they are not implemented
86 setOperationAction(ISD::CTTZ , MVT::i64 , Expand);
87 setOperationAction(ISD::CTLZ , MVT::i64 , Expand);
88 setOperationAction(ISD::ROTL , MVT::i64 , Expand);
89 setOperationAction(ISD::ROTR , MVT::i64 , Expand);
90 setOperationAction(ISD::BSWAP, MVT::i64 , Expand); // mux @rev
92 setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
93 setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
94 setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
96 setSchedulingPreference(SchedulingForLatency);
97 setStackPointerRegisterToSaveRestore(IA64::r12);
99 computeRegisterProperties();
101 addLegalFPImmediate(+0.0);
102 addLegalFPImmediate(+1.0);
105 const char *IA64TargetLowering::getTargetNodeName(unsigned Opcode) const {
108 case IA64ISD::GETFD: return "IA64ISD::GETFD";
109 case IA64ISD::BRCALL: return "IA64ISD::BRCALL";
110 case IA64ISD::RET_FLAG: return "IA64ISD::RET_FLAG";
115 /// isFloatingPointZero - Return true if this is 0.0 or -0.0.
116 static bool isFloatingPointZero(SDOperand Op) {
117 if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
118 return CFP->isExactlyValue(-0.0) || CFP->isExactlyValue(0.0);
119 else if (Op.getOpcode() == ISD::EXTLOAD || Op.getOpcode() == ISD::LOAD) {
120 // Maybe this has already been legalized into the constant pool?
121 if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op.getOperand(1)))
122 if (ConstantFP *CFP = dyn_cast<ConstantFP>(CP->get()))
123 return CFP->isExactlyValue(-0.0) || CFP->isExactlyValue(0.0);
128 std::vector<SDOperand>
129 IA64TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
130 std::vector<SDOperand> ArgValues;
132 // add beautiful description of IA64 stack frame format
133 // here (from intel 24535803.pdf most likely)
135 MachineFunction &MF = DAG.getMachineFunction();
136 MachineFrameInfo *MFI = MF.getFrameInfo();
138 GP = MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::i64));
139 SP = MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::i64));
140 RP = MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::i64));
142 MachineBasicBlock& BB = MF.front();
144 unsigned args_int[] = {IA64::r32, IA64::r33, IA64::r34, IA64::r35,
145 IA64::r36, IA64::r37, IA64::r38, IA64::r39};
147 unsigned args_FP[] = {IA64::F8, IA64::F9, IA64::F10, IA64::F11,
148 IA64::F12,IA64::F13,IA64::F14, IA64::F15};
154 unsigned used_FPArgs = 0; // how many FP args have been used so far?
156 unsigned ArgOffset = 0;
159 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
161 SDOperand newroot, argt;
162 if(count < 8) { // need to fix this logic? maybe.
164 switch (getValueType(I->getType())) {
166 assert(0 && "ERROR in LowerArgs: can't lower this type of arg.\n");
168 // fixme? (well, will need to for weird FP structy stuff,
169 // see intel ABI docs)
171 //XXX BuildMI(&BB, IA64::IDEF, 0, args_FP[used_FPArgs]);
172 MF.addLiveIn(args_FP[used_FPArgs]); // mark this reg as liveIn
173 // floating point args go into f8..f15 as-needed, the increment
174 argVreg[count] = // is below..:
175 MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::f64));
176 // FP args go into f8..f15 as needed: (hence the ++)
177 argPreg[count] = args_FP[used_FPArgs++];
178 argOpc[count] = IA64::FMOV;
179 argt = newroot = DAG.getCopyFromReg(DAG.getRoot(), argVreg[count],
181 if (I->getType() == Type::FloatTy)
182 argt = DAG.getNode(ISD::FP_ROUND, MVT::f32, argt);
184 case MVT::i1: // NOTE: as far as C abi stuff goes,
185 // bools are just boring old ints
190 //XXX BuildMI(&BB, IA64::IDEF, 0, args_int[count]);
191 MF.addLiveIn(args_int[count]); // mark this register as liveIn
193 MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::i64));
194 argPreg[count] = args_int[count];
195 argOpc[count] = IA64::MOV;
197 DAG.getCopyFromReg(DAG.getRoot(), argVreg[count], MVT::i64);
198 if ( getValueType(I->getType()) != MVT::i64)
199 argt = DAG.getNode(ISD::TRUNCATE, getValueType(I->getType()),
203 } else { // more than 8 args go into the frame
204 // Create the frame index object for this incoming parameter...
205 ArgOffset = 16 + 8 * (count - 8);
206 int FI = MFI->CreateFixedObject(8, ArgOffset);
208 // Create the SelectionDAG nodes corresponding to a load
209 //from this parameter
210 SDOperand FIN = DAG.getFrameIndex(FI, MVT::i64);
211 argt = newroot = DAG.getLoad(getValueType(I->getType()),
212 DAG.getEntryNode(), FIN, DAG.getSrcValue(NULL));
215 DAG.setRoot(newroot.getValue(1));
216 ArgValues.push_back(argt);
220 // Create a vreg to hold the output of (what will become)
221 // the "alloc" instruction
222 VirtGPR = MF.getSSARegMap()->createVirtualRegister(getRegClassFor(MVT::i64));
223 BuildMI(&BB, IA64::PSEUDO_ALLOC, 0, VirtGPR);
224 // we create a PSEUDO_ALLOC (pseudo)instruction for now
226 BuildMI(&BB, IA64::IDEF, 0, IA64::r1);
229 BuildMI(&BB, IA64::IDEF, 0, IA64::r12);
230 BuildMI(&BB, IA64::IDEF, 0, IA64::rp);
233 BuildMI(&BB, IA64::MOV, 1, GP).addReg(IA64::r1);
236 BuildMI(&BB, IA64::MOV, 1, SP).addReg(IA64::r12);
237 BuildMI(&BB, IA64::MOV, 1, RP).addReg(IA64::rp);
241 unsigned tempOffset=0;
243 // if this is a varargs function, we simply lower llvm.va_start by
244 // pointing to the first entry
247 VarArgsFrameIndex = MFI->CreateFixedObject(8, tempOffset);
250 // here we actually do the moving of args, and store them to the stack
251 // too if this is a varargs function:
252 for (int i = 0; i < count && i < 8; ++i) {
253 BuildMI(&BB, argOpc[i], 1, argVreg[i]).addReg(argPreg[i]);
255 // if this is a varargs function, we copy the input registers to the stack
256 int FI = MFI->CreateFixedObject(8, tempOffset);
257 tempOffset+=8; //XXX: is it safe to use r22 like this?
258 BuildMI(&BB, IA64::MOV, 1, IA64::r22).addFrameIndex(FI);
259 // FIXME: we should use st8.spill here, one day
260 BuildMI(&BB, IA64::ST8, 1, IA64::r22).addReg(argPreg[i]);
264 // Finally, inform the code generator which regs we return values in.
265 // (see the ISD::RET: case in the instruction selector)
266 switch (getValueType(F.getReturnType())) {
267 default: assert(0 && "i have no idea where to return this type!");
268 case MVT::isVoid: break;
274 MF.addLiveOut(IA64::r8);
278 MF.addLiveOut(IA64::F8);
285 std::pair<SDOperand, SDOperand>
286 IA64TargetLowering::LowerCallTo(SDOperand Chain,
287 const Type *RetTy, bool isVarArg,
288 unsigned CallingConv, bool isTailCall,
289 SDOperand Callee, ArgListTy &Args,
292 MachineFunction &MF = DAG.getMachineFunction();
294 unsigned NumBytes = 16;
295 unsigned outRegsUsed = 0;
297 if (Args.size() > 8) {
298 NumBytes += (Args.size() - 8) * 8;
301 outRegsUsed = Args.size();
304 // FIXME? this WILL fail if we ever try to pass around an arg that
305 // consumes more than a single output slot (a 'real' double, int128
306 // some sort of aggregate etc.), as we'll underestimate how many 'outX'
307 // registers we use. Hopefully, the assembler will notice.
308 MF.getInfo<IA64FunctionInfo>()->outRegsUsed=
309 std::max(outRegsUsed, MF.getInfo<IA64FunctionInfo>()->outRegsUsed);
311 // keep stack frame 16-byte aligned
312 //assert(NumBytes==((NumBytes+15) & ~15) && "stack frame not 16-byte aligned!");
313 NumBytes = (NumBytes+15) & ~15;
315 Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
316 DAG.getConstant(NumBytes, getPointerTy()));
318 SDOperand StackPtr, NullSV;
319 std::vector<SDOperand> Stores;
320 std::vector<SDOperand> Converts;
321 std::vector<SDOperand> RegValuesToPass;
322 unsigned ArgOffset = 16;
324 for (unsigned i = 0, e = Args.size(); i != e; ++i)
326 SDOperand Val = Args[i].first;
327 MVT::ValueType ObjectVT = Val.getValueType();
328 SDOperand ValToStore(0, 0), ValToConvert(0, 0);
331 default: assert(0 && "unexpected argument type!");
336 //promote to 64-bits, sign/zero extending based on type
338 if(Args[i].second->isSigned())
339 Val = DAG.getNode(ISD::SIGN_EXTEND, MVT::i64, Val);
341 Val = DAG.getNode(ISD::ZERO_EXTEND, MVT::i64, Val);
345 if(RegValuesToPass.size() >= 8) {
348 RegValuesToPass.push_back(Val);
353 Val = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Val);
356 if(RegValuesToPass.size() >= 8) {
359 RegValuesToPass.push_back(Val);
360 if(1 /* TODO: if(calling external or varadic function)*/ ) {
361 ValToConvert = Val; // additionally pass this FP value as an int
369 StackPtr = DAG.getRegister(IA64::r12, MVT::i64);
370 NullSV = DAG.getSrcValue(NULL);
372 SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
373 PtrOff = DAG.getNode(ISD::ADD, MVT::i64, StackPtr, PtrOff);
374 Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
375 ValToStore, PtrOff, NullSV));
376 ArgOffset += ObjSize;
379 if(ValToConvert.Val) {
380 Converts.push_back(DAG.getNode(IA64ISD::GETFD, MVT::i64, ValToConvert));
384 // Emit all stores, make sure they occur before any copies into physregs.
386 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Stores);
388 static const unsigned IntArgRegs[] = {
389 IA64::out0, IA64::out1, IA64::out2, IA64::out3,
390 IA64::out4, IA64::out5, IA64::out6, IA64::out7
393 static const unsigned FPArgRegs[] = {
394 IA64::F8, IA64::F9, IA64::F10, IA64::F11,
395 IA64::F12, IA64::F13, IA64::F14, IA64::F15
400 // save the current GP, SP and RP : FIXME: do we need to do all 3 always?
401 SDOperand GPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r1, MVT::i64, InFlag);
402 Chain = GPBeforeCall.getValue(1);
403 InFlag = Chain.getValue(2);
404 SDOperand SPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r12, MVT::i64, InFlag);
405 Chain = SPBeforeCall.getValue(1);
406 InFlag = Chain.getValue(2);
407 SDOperand RPBeforeCall = DAG.getCopyFromReg(Chain, IA64::rp, MVT::i64, InFlag);
408 Chain = RPBeforeCall.getValue(1);
409 InFlag = Chain.getValue(2);
411 // Build a sequence of copy-to-reg nodes chained together with token chain
412 // and flag operands which copy the outgoing integer args into regs out[0-7]
413 // mapped 1:1 and the FP args into regs F8-F15 "lazily"
414 // TODO: for performance, we should only copy FP args into int regs when we
415 // know this is required (i.e. for varardic or external (unknown) functions)
417 // first to the FP->(integer representation) conversions, these are
418 // flagged for now, but shouldn't have to be (TODO)
419 unsigned seenConverts = 0;
420 for (unsigned i = 0, e = RegValuesToPass.size(); i != e; ++i) {
421 if(MVT::isFloatingPoint(RegValuesToPass[i].getValueType())) {
422 Chain = DAG.getCopyToReg(Chain, IntArgRegs[i], Converts[seenConverts++], InFlag);
423 InFlag = Chain.getValue(1);
427 // next copy args into the usual places, these are flagged
428 unsigned usedFPArgs = 0;
429 for (unsigned i = 0, e = RegValuesToPass.size(); i != e; ++i) {
430 Chain = DAG.getCopyToReg(Chain,
431 MVT::isInteger(RegValuesToPass[i].getValueType()) ?
432 IntArgRegs[i] : FPArgRegs[usedFPArgs++],
433 RegValuesToPass[i], InFlag);
434 InFlag = Chain.getValue(1);
437 // If the callee is a GlobalAddress node (quite common, every direct call is)
438 // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
440 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
441 Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i64);
445 std::vector<MVT::ValueType> NodeTys;
446 std::vector<SDOperand> CallOperands;
447 NodeTys.push_back(MVT::Other); // Returns a chain
448 NodeTys.push_back(MVT::Flag); // Returns a flag for retval copy to use.
449 CallOperands.push_back(Chain);
450 CallOperands.push_back(Callee);
452 // emit the call itself
454 CallOperands.push_back(InFlag);
456 assert(0 && "this should never happen!\n");
458 /* out with the old...
459 Chain = SDOperand(DAG.getCall(NodeTys, Chain, Callee, InFlag), 0);
461 Chain = SDOperand(DAG.getCall(NodeTys, Chain, Callee), 0);
463 // to make way for a hack:
464 Chain = DAG.getNode(IA64ISD::BRCALL, NodeTys, CallOperands);
465 InFlag = Chain.getValue(1);
467 // restore the GP, SP and RP after the call
468 Chain = DAG.getCopyToReg(Chain, IA64::r1, GPBeforeCall, InFlag);
469 InFlag = Chain.getValue(1);
470 Chain = DAG.getCopyToReg(Chain, IA64::r12, SPBeforeCall, InFlag);
471 InFlag = Chain.getValue(1);
472 Chain = DAG.getCopyToReg(Chain, IA64::rp, RPBeforeCall, InFlag);
473 InFlag = Chain.getValue(1);
475 std::vector<MVT::ValueType> RetVals;
476 RetVals.push_back(MVT::Other);
477 RetVals.push_back(MVT::Flag);
479 MVT::ValueType RetTyVT = getValueType(RetTy);
481 if (RetTyVT != MVT::isVoid) {
483 default: assert(0 && "Unknown value type to return!");
484 case MVT::i1: { // bools are just like other integers (returned in r8)
485 // we *could* fall through to the truncate below, but this saves a
486 // few redundant predicate ops
487 SDOperand boolInR8 = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64, InFlag);
488 InFlag = boolInR8.getValue(2);
489 Chain = boolInR8.getValue(1);
490 SDOperand zeroReg = DAG.getCopyFromReg(Chain, IA64::r0, MVT::i64, InFlag);
491 InFlag = zeroReg.getValue(2);
492 Chain = zeroReg.getValue(1);
494 RetVal = DAG.getSetCC(MVT::i1, boolInR8, zeroReg, ISD::SETNE);
500 RetVal = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64, InFlag);
501 Chain = RetVal.getValue(1);
503 // keep track of whether it is sign or zero extended (todo: bools?)
505 RetVal = DAG.getNode(RetTy->isSigned() ? ISD::AssertSext :ISD::AssertZext,
506 MVT::i64, RetVal, DAG.getValueType(RetTyVT));
508 RetVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, RetVal);
511 RetVal = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64, InFlag);
512 Chain = RetVal.getValue(1);
513 InFlag = RetVal.getValue(2); // XXX dead
516 RetVal = DAG.getCopyFromReg(Chain, IA64::F8, MVT::f64, InFlag);
517 Chain = RetVal.getValue(1);
518 RetVal = DAG.getNode(ISD::TRUNCATE, MVT::f32, RetVal);
521 RetVal = DAG.getCopyFromReg(Chain, IA64::F8, MVT::f64, InFlag);
522 Chain = RetVal.getValue(1);
523 InFlag = RetVal.getValue(2); // XXX dead
528 Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
529 DAG.getConstant(NumBytes, getPointerTy()));
531 return std::make_pair(RetVal, Chain);
534 SDOperand IA64TargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
536 SDOperand Copy, InFlag;
537 SDOperand AR_PFSVal = DAG.getCopyFromReg(Chain, this->VirtGPR,
539 Chain = AR_PFSVal.getValue(1);
541 switch (Op.getValueType()) {
542 default: assert(0 && "Unknown type to return! (promote?)");
544 Copy = DAG.getCopyToReg(Chain, IA64::r8, Op, InFlag);
547 Copy = DAG.getCopyToReg(Chain, IA64::F8, Op, InFlag);
551 Chain = Copy.getValue(0);
552 InFlag = Copy.getValue(1);
553 // we need to copy VirtGPR (the vreg (to become a real reg)) that holds
554 // the output of this function's alloc instruction back into ar.pfs
555 // before we return. this copy must not float up above the last
556 // outgoing call in this function - we flag this to the ret instruction
557 Chain = DAG.getCopyToReg(Chain, IA64::AR_PFS, AR_PFSVal, InFlag);
558 InFlag = Chain.getValue(1);
560 // and then just emit a 'ret' instruction
561 std::vector<MVT::ValueType> NodeTys;
562 std::vector<SDOperand> RetOperands;
563 NodeTys.push_back(MVT::Other);
564 NodeTys.push_back(MVT::Flag);
565 RetOperands.push_back(Chain);
566 RetOperands.push_back(InFlag);
568 return DAG.getNode(IA64ISD::RET_FLAG, NodeTys, RetOperands);
569 // return DAG.getNode(IA64ISD::RET_FLAG, MVT::Other, MVT::Other, Copy, Chain, InFlag);
573 IA64TargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP,
574 Value *VAListV, SelectionDAG &DAG) {
575 // vastart just stores the address of the VarArgsFrameIndex slot.
576 SDOperand FR = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i64);
577 return DAG.getNode(ISD::STORE, MVT::Other, Chain, FR,
578 VAListP, DAG.getSrcValue(VAListV));
581 std::pair<SDOperand,SDOperand> IA64TargetLowering::
582 LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
583 const Type *ArgTy, SelectionDAG &DAG) {
585 MVT::ValueType ArgVT = getValueType(ArgTy);
586 SDOperand Val = DAG.getLoad(MVT::i64, Chain,
587 VAListP, DAG.getSrcValue(VAListV));
588 SDOperand Result = DAG.getLoad(ArgVT, DAG.getEntryNode(), Val,
589 DAG.getSrcValue(NULL));
591 if (ArgVT == MVT::i32 || ArgVT == MVT::f32)
594 assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) &&
595 "Other types should have been promoted for varargs!");
598 Val = DAG.getNode(ISD::ADD, Val.getValueType(), Val,
599 DAG.getConstant(Amt, Val.getValueType()));
600 Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain,
601 Val, VAListP, DAG.getSrcValue(VAListV));
602 return std::make_pair(Result, Chain);
607 std::pair<SDOperand, SDOperand> IA64TargetLowering::
608 LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
610 assert(0 && "LowerFrameReturnAddress unimplemented");
614 SDOperand IA64TargetLowering::
615 LowerOperation(SDOperand Op, SelectionDAG &DAG) {
616 switch (Op.getOpcode()) {
617 default: assert(0 && "Should not custom lower this!");
618 case ISD::RET: { // the DAGgy stuff takes care of
619 // restoring ar.pfs before adding a br.ret for functions
620 // that return something, but we need to take care of stuff
621 // that returns void manually, so here it is:
622 assert(Op.getNumOperands()==1 &&
623 "trying to custom lower a return other than void! (numops!=1)");
625 SDOperand Chain = Op.getOperand(0);
626 SDOperand AR_PFSVal = DAG.getCopyFromReg(Chain, this->VirtGPR,
628 Chain = AR_PFSVal.getValue(1);
629 Chain = DAG.getCopyToReg(Chain, IA64::AR_PFS, AR_PFSVal);
631 // and then just emit a 'ret' instruction
632 return DAG.getNode(IA64ISD::RET_FLAG, MVT::Other, Chain);