1 //===- X86ISelDAGToDAG.cpp - A DAG pattern matching inst selector for X86 -===//
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 defines a DAG pattern matching instruction selector for X86,
11 // converting from a legalized dag to a X86 dag.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "x86-isel"
17 #include "X86InstrBuilder.h"
18 #include "X86ISelLowering.h"
19 #include "X86MachineFunctionInfo.h"
20 #include "X86RegisterInfo.h"
21 #include "X86Subtarget.h"
22 #include "X86TargetMachine.h"
23 #include "llvm/GlobalValue.h"
24 #include "llvm/Instructions.h"
25 #include "llvm/Intrinsics.h"
26 #include "llvm/Support/CFG.h"
27 #include "llvm/Type.h"
28 #include "llvm/CodeGen/MachineConstantPool.h"
29 #include "llvm/CodeGen/MachineFunction.h"
30 #include "llvm/CodeGen/MachineFrameInfo.h"
31 #include "llvm/CodeGen/MachineInstrBuilder.h"
32 #include "llvm/CodeGen/MachineRegisterInfo.h"
33 #include "llvm/CodeGen/SelectionDAGISel.h"
34 #include "llvm/Target/TargetMachine.h"
35 #include "llvm/Target/TargetOptions.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/MathExtras.h"
39 #include "llvm/Support/Streams.h"
40 #include "llvm/ADT/SmallPtrSet.h"
41 #include "llvm/ADT/Statistic.h"
44 STATISTIC(NumFPKill , "Number of FP_REG_KILL instructions added");
45 STATISTIC(NumLoadMoved, "Number of loads moved below TokenFactor");
47 //===----------------------------------------------------------------------===//
48 // Pattern Matcher Implementation
49 //===----------------------------------------------------------------------===//
52 /// X86ISelAddressMode - This corresponds to X86AddressMode, but uses
53 /// SDValue's instead of register numbers for the leaves of the matched
55 struct X86ISelAddressMode {
61 struct { // This is really a union, discriminated by BaseType!
66 bool isRIPRel; // RIP as base?
74 unsigned Align; // CP alignment.
77 : BaseType(RegBase), isRIPRel(false), Scale(1), IndexReg(), Disp(0),
78 GV(0), CP(0), ES(0), JT(-1), Align(0) {
81 cerr << "X86ISelAddressMode " << this << "\n";
83 if (Base.Reg.getNode() != 0) Base.Reg.getNode()->dump();
85 cerr << " Base.FrameIndex " << Base.FrameIndex << "\n";
86 cerr << "isRIPRel " << isRIPRel << " Scale" << Scale << "\n";
88 if (IndexReg.getNode() != 0) IndexReg.getNode()->dump();
90 cerr << " Disp " << Disp << "\n";
91 cerr << "GV "; if (GV) GV->dump();
93 cerr << " CP "; if (CP) CP->dump();
96 cerr << "ES "; if (ES) cerr << ES; else cerr << "nul";
97 cerr << " JT" << JT << " Align" << Align << "\n";
103 //===--------------------------------------------------------------------===//
104 /// ISel - X86 specific code to select X86 machine instructions for
105 /// SelectionDAG operations.
107 class VISIBILITY_HIDDEN X86DAGToDAGISel : public SelectionDAGISel {
108 /// TM - Keep a reference to X86TargetMachine.
110 X86TargetMachine &TM;
112 /// X86Lowering - This object fully describes how to lower LLVM code to an
113 /// X86-specific SelectionDAG.
114 X86TargetLowering &X86Lowering;
116 /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
117 /// make the right decision when generating code for different targets.
118 const X86Subtarget *Subtarget;
120 /// CurBB - Current BB being isel'd.
122 MachineBasicBlock *CurBB;
124 /// OptForSize - If true, selector should try to optimize for code size
125 /// instead of performance.
129 X86DAGToDAGISel(X86TargetMachine &tm, bool fast)
130 : SelectionDAGISel(*tm.getTargetLowering(), fast),
131 TM(tm), X86Lowering(*TM.getTargetLowering()),
132 Subtarget(&TM.getSubtarget<X86Subtarget>()),
135 virtual const char *getPassName() const {
136 return "X86 DAG->DAG Instruction Selection";
139 /// InstructionSelect - This callback is invoked by
140 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
141 virtual void InstructionSelect();
143 /// InstructionSelectPostProcessing - Post processing of selected and
144 /// scheduled basic blocks.
145 virtual void InstructionSelectPostProcessing();
147 virtual void EmitFunctionEntryCode(Function &Fn, MachineFunction &MF);
149 virtual bool CanBeFoldedBy(SDNode *N, SDNode *U, SDNode *Root) const;
151 // Include the pieces autogenerated from the target description.
152 #include "X86GenDAGISel.inc"
155 SDNode *Select(SDValue N);
156 SDNode *SelectAtomic64(SDNode *Node, unsigned Opc);
158 bool MatchAddress(SDValue N, X86ISelAddressMode &AM,
159 bool isRoot = true, unsigned Depth = 0);
160 bool MatchAddressBase(SDValue N, X86ISelAddressMode &AM,
161 bool isRoot, unsigned Depth);
162 bool SelectAddr(SDValue Op, SDValue N, SDValue &Base,
163 SDValue &Scale, SDValue &Index, SDValue &Disp);
164 bool SelectLEAAddr(SDValue Op, SDValue N, SDValue &Base,
165 SDValue &Scale, SDValue &Index, SDValue &Disp);
166 bool SelectScalarSSELoad(SDValue Op, SDValue Pred,
167 SDValue N, SDValue &Base, SDValue &Scale,
168 SDValue &Index, SDValue &Disp,
169 SDValue &InChain, SDValue &OutChain);
170 bool TryFoldLoad(SDValue P, SDValue N,
171 SDValue &Base, SDValue &Scale,
172 SDValue &Index, SDValue &Disp);
173 void PreprocessForRMW();
174 void PreprocessForFPConvert();
176 /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
177 /// inline asm expressions.
178 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
180 std::vector<SDValue> &OutOps);
182 void EmitSpecialCodeForMain(MachineBasicBlock *BB, MachineFrameInfo *MFI);
184 inline void getAddressOperands(X86ISelAddressMode &AM, SDValue &Base,
185 SDValue &Scale, SDValue &Index,
187 Base = (AM.BaseType == X86ISelAddressMode::FrameIndexBase) ?
188 CurDAG->getTargetFrameIndex(AM.Base.FrameIndex, TLI.getPointerTy()) :
190 Scale = getI8Imm(AM.Scale);
192 // These are 32-bit even in 64-bit mode since RIP relative offset
195 Disp = CurDAG->getTargetGlobalAddress(AM.GV, MVT::i32, AM.Disp);
197 Disp = CurDAG->getTargetConstantPool(AM.CP, MVT::i32,
200 Disp = CurDAG->getTargetExternalSymbol(AM.ES, MVT::i32);
201 else if (AM.JT != -1)
202 Disp = CurDAG->getTargetJumpTable(AM.JT, MVT::i32);
204 Disp = getI32Imm(AM.Disp);
207 /// getI8Imm - Return a target constant with the specified value, of type
209 inline SDValue getI8Imm(unsigned Imm) {
210 return CurDAG->getTargetConstant(Imm, MVT::i8);
213 /// getI16Imm - Return a target constant with the specified value, of type
215 inline SDValue getI16Imm(unsigned Imm) {
216 return CurDAG->getTargetConstant(Imm, MVT::i16);
219 /// getI32Imm - Return a target constant with the specified value, of type
221 inline SDValue getI32Imm(unsigned Imm) {
222 return CurDAG->getTargetConstant(Imm, MVT::i32);
225 /// getGlobalBaseReg - Return an SDNode that returns the value of
226 /// the global base register. Output instructions required to
227 /// initialize the global base register, if necessary.
229 SDNode *getGlobalBaseReg();
231 /// getTruncateTo8Bit - return an SDNode that implements a subreg based
232 /// truncate of the specified operand to i8. This can be done with tablegen,
233 /// except that this code uses MVT::Flag in a tricky way that happens to
234 /// improve scheduling in some cases.
235 SDNode *getTruncateTo8Bit(SDValue N0);
243 /// findFlagUse - Return use of MVT::Flag value produced by the specified
246 static SDNode *findFlagUse(SDNode *N) {
247 unsigned FlagResNo = N->getNumValues()-1;
248 for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
250 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
251 SDValue Op = User->getOperand(i);
252 if (Op.getNode() == N && Op.getResNo() == FlagResNo)
259 /// findNonImmUse - Return true by reference in "found" if "Use" is an
260 /// non-immediate use of "Def". This function recursively traversing
261 /// up the operand chain ignoring certain nodes.
262 static void findNonImmUse(SDNode *Use, SDNode* Def, SDNode *ImmedUse,
263 SDNode *Root, bool &found,
264 SmallPtrSet<SDNode*, 16> &Visited) {
266 Use->getNodeId() < Def->getNodeId() ||
267 !Visited.insert(Use))
270 for (unsigned i = 0, e = Use->getNumOperands(); !found && i != e; ++i) {
271 SDNode *N = Use->getOperand(i).getNode();
273 if (Use == ImmedUse || Use == Root)
274 continue; // We are not looking for immediate use.
280 // Traverse up the operand chain.
281 findNonImmUse(N, Def, ImmedUse, Root, found, Visited);
285 /// isNonImmUse - Start searching from Root up the DAG to check is Def can
286 /// be reached. Return true if that's the case. However, ignore direct uses
287 /// by ImmedUse (which would be U in the example illustrated in
288 /// CanBeFoldedBy) and by Root (which can happen in the store case).
289 /// FIXME: to be really generic, we should allow direct use by any node
290 /// that is being folded. But realisticly since we only fold loads which
291 /// have one non-chain use, we only need to watch out for load/op/store
292 /// and load/op/cmp case where the root (store / cmp) may reach the load via
293 /// its chain operand.
294 static inline bool isNonImmUse(SDNode *Root, SDNode *Def, SDNode *ImmedUse) {
295 SmallPtrSet<SDNode*, 16> Visited;
297 findNonImmUse(Root, Def, ImmedUse, Root, found, Visited);
302 bool X86DAGToDAGISel::CanBeFoldedBy(SDNode *N, SDNode *U, SDNode *Root) const {
303 if (Fast) return false;
305 // If Root use can somehow reach N through a path that that doesn't contain
306 // U then folding N would create a cycle. e.g. In the following
307 // diagram, Root can reach N through X. If N is folded into into Root, then
308 // X is both a predecessor and a successor of U.
319 // * indicates nodes to be folded together.
321 // If Root produces a flag, then it gets (even more) interesting. Since it
322 // will be "glued" together with its flag use in the scheduler, we need to
323 // check if it might reach N.
342 // If FU (flag use) indirectly reaches N (the load), and Root folds N
343 // (call it Fold), then X is a predecessor of FU and a successor of
344 // Fold. But since Fold and FU are flagged together, this will create
345 // a cycle in the scheduling graph.
347 MVT VT = Root->getValueType(Root->getNumValues()-1);
348 while (VT == MVT::Flag) {
349 SDNode *FU = findFlagUse(Root);
353 VT = Root->getValueType(Root->getNumValues()-1);
356 return !isNonImmUse(Root, N, U);
359 /// MoveBelowTokenFactor - Replace TokenFactor operand with load's chain operand
360 /// and move load below the TokenFactor. Replace store's chain operand with
361 /// load's chain result.
362 static void MoveBelowTokenFactor(SelectionDAG *CurDAG, SDValue Load,
363 SDValue Store, SDValue TF) {
364 SmallVector<SDValue, 4> Ops;
365 for (unsigned i = 0, e = TF.getNode()->getNumOperands(); i != e; ++i)
366 if (Load.getNode() == TF.getOperand(i).getNode())
367 Ops.push_back(Load.getOperand(0));
369 Ops.push_back(TF.getOperand(i));
370 CurDAG->UpdateNodeOperands(TF, &Ops[0], Ops.size());
371 CurDAG->UpdateNodeOperands(Load, TF, Load.getOperand(1), Load.getOperand(2));
372 CurDAG->UpdateNodeOperands(Store, Load.getValue(1), Store.getOperand(1),
373 Store.getOperand(2), Store.getOperand(3));
376 /// isRMWLoad - Return true if N is a load that's part of RMW sub-DAG.
378 static bool isRMWLoad(SDValue N, SDValue Chain, SDValue Address,
380 if (N.getOpcode() == ISD::BIT_CONVERT)
383 LoadSDNode *LD = dyn_cast<LoadSDNode>(N);
384 if (!LD || LD->isVolatile())
386 if (LD->getAddressingMode() != ISD::UNINDEXED)
389 ISD::LoadExtType ExtType = LD->getExtensionType();
390 if (ExtType != ISD::NON_EXTLOAD && ExtType != ISD::EXTLOAD)
394 N.getOperand(1) == Address &&
395 N.getNode()->isOperandOf(Chain.getNode())) {
402 /// MoveBelowCallSeqStart - Replace CALLSEQ_START operand with load's chain
403 /// operand and move load below the call's chain operand.
404 static void MoveBelowCallSeqStart(SelectionDAG *CurDAG, SDValue Load,
405 SDValue Call, SDValue Chain) {
406 SmallVector<SDValue, 8> Ops;
407 for (unsigned i = 0, e = Chain.getNode()->getNumOperands(); i != e; ++i)
408 if (Load.getNode() == Chain.getOperand(i).getNode())
409 Ops.push_back(Load.getOperand(0));
411 Ops.push_back(Chain.getOperand(i));
412 CurDAG->UpdateNodeOperands(Chain, &Ops[0], Ops.size());
413 CurDAG->UpdateNodeOperands(Load, Call.getOperand(0),
414 Load.getOperand(1), Load.getOperand(2));
416 Ops.push_back(SDValue(Load.getNode(), 1));
417 for (unsigned i = 1, e = Call.getNode()->getNumOperands(); i != e; ++i)
418 Ops.push_back(Call.getOperand(i));
419 CurDAG->UpdateNodeOperands(Call, &Ops[0], Ops.size());
422 /// isCalleeLoad - Return true if call address is a load and it can be
423 /// moved below CALLSEQ_START and the chains leading up to the call.
424 /// Return the CALLSEQ_START by reference as a second output.
425 static bool isCalleeLoad(SDValue Callee, SDValue &Chain) {
426 if (Callee.getNode() == Chain.getNode() || !Callee.hasOneUse())
428 LoadSDNode *LD = dyn_cast<LoadSDNode>(Callee.getNode());
431 LD->getAddressingMode() != ISD::UNINDEXED ||
432 LD->getExtensionType() != ISD::NON_EXTLOAD)
435 // Now let's find the callseq_start.
436 while (Chain.getOpcode() != ISD::CALLSEQ_START) {
437 if (!Chain.hasOneUse())
439 Chain = Chain.getOperand(0);
441 return Chain.getOperand(0).getNode() == Callee.getNode();
445 /// PreprocessForRMW - Preprocess the DAG to make instruction selection better.
446 /// This is only run if not in -fast mode (aka -O0).
447 /// This allows the instruction selector to pick more read-modify-write
448 /// instructions. This is a common case:
458 /// [TokenFactor] [Op]
465 /// The fact the store's chain operand != load's chain will prevent the
466 /// (store (op (load))) instruction from being selected. We can transform it to:
485 void X86DAGToDAGISel::PreprocessForRMW() {
486 for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
487 E = CurDAG->allnodes_end(); I != E; ++I) {
488 if (I->getOpcode() == X86ISD::CALL) {
489 /// Also try moving call address load from outside callseq_start to just
490 /// before the call to allow it to be folded.
508 SDValue Chain = I->getOperand(0);
509 SDValue Load = I->getOperand(1);
510 if (!isCalleeLoad(Load, Chain))
512 MoveBelowCallSeqStart(CurDAG, Load, SDValue(I, 0), Chain);
517 if (!ISD::isNON_TRUNCStore(I))
519 SDValue Chain = I->getOperand(0);
521 if (Chain.getNode()->getOpcode() != ISD::TokenFactor)
524 SDValue N1 = I->getOperand(1);
525 SDValue N2 = I->getOperand(2);
526 if ((N1.getValueType().isFloatingPoint() &&
527 !N1.getValueType().isVector()) ||
533 unsigned Opcode = N1.getNode()->getOpcode();
542 case ISD::VECTOR_SHUFFLE: {
543 SDValue N10 = N1.getOperand(0);
544 SDValue N11 = N1.getOperand(1);
545 RModW = isRMWLoad(N10, Chain, N2, Load);
547 RModW = isRMWLoad(N11, Chain, N2, Load);
560 SDValue N10 = N1.getOperand(0);
561 RModW = isRMWLoad(N10, Chain, N2, Load);
567 MoveBelowTokenFactor(CurDAG, Load, SDValue(I, 0), Chain);
574 /// PreprocessForFPConvert - Walk over the dag lowering fpround and fpextend
575 /// nodes that target the FP stack to be store and load to the stack. This is a
576 /// gross hack. We would like to simply mark these as being illegal, but when
577 /// we do that, legalize produces these when it expands calls, then expands
578 /// these in the same legalize pass. We would like dag combine to be able to
579 /// hack on these between the call expansion and the node legalization. As such
580 /// this pass basically does "really late" legalization of these inline with the
582 void X86DAGToDAGISel::PreprocessForFPConvert() {
583 for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
584 E = CurDAG->allnodes_end(); I != E; ) {
585 SDNode *N = I++; // Preincrement iterator to avoid invalidation issues.
586 if (N->getOpcode() != ISD::FP_ROUND && N->getOpcode() != ISD::FP_EXTEND)
589 // If the source and destination are SSE registers, then this is a legal
590 // conversion that should not be lowered.
591 MVT SrcVT = N->getOperand(0).getValueType();
592 MVT DstVT = N->getValueType(0);
593 bool SrcIsSSE = X86Lowering.isScalarFPTypeInSSEReg(SrcVT);
594 bool DstIsSSE = X86Lowering.isScalarFPTypeInSSEReg(DstVT);
595 if (SrcIsSSE && DstIsSSE)
598 if (!SrcIsSSE && !DstIsSSE) {
599 // If this is an FPStack extension, it is a noop.
600 if (N->getOpcode() == ISD::FP_EXTEND)
602 // If this is a value-preserving FPStack truncation, it is a noop.
603 if (N->getConstantOperandVal(1))
607 // Here we could have an FP stack truncation or an FPStack <-> SSE convert.
608 // FPStack has extload and truncstore. SSE can fold direct loads into other
609 // operations. Based on this, decide what we want to do.
611 if (N->getOpcode() == ISD::FP_ROUND)
612 MemVT = DstVT; // FP_ROUND must use DstVT, we can't do a 'trunc load'.
614 MemVT = SrcIsSSE ? SrcVT : DstVT;
616 SDValue MemTmp = CurDAG->CreateStackTemporary(MemVT);
618 // FIXME: optimize the case where the src/dest is a load or store?
619 SDValue Store = CurDAG->getTruncStore(CurDAG->getEntryNode(),
621 MemTmp, NULL, 0, MemVT);
622 SDValue Result = CurDAG->getExtLoad(ISD::EXTLOAD, DstVT, Store, MemTmp,
625 // We're about to replace all uses of the FP_ROUND/FP_EXTEND with the
626 // extload we created. This will cause general havok on the dag because
627 // anything below the conversion could be folded into other existing nodes.
628 // To avoid invalidating 'I', back it up to the convert node.
630 CurDAG->ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
632 // Now that we did that, the node is dead. Increment the iterator to the
633 // next node to process, then delete N.
635 CurDAG->DeleteNode(N);
639 /// InstructionSelectBasicBlock - This callback is invoked by SelectionDAGISel
640 /// when it has created a SelectionDAG for us to codegen.
641 void X86DAGToDAGISel::InstructionSelect() {
642 CurBB = BB; // BB can change as result of isel.
643 const Function *F = CurDAG->getMachineFunction().getFunction();
644 OptForSize = F->hasFnAttr(Attribute::OptimizeForSize);
650 // FIXME: This should only happen when not -fast.
651 PreprocessForFPConvert();
653 // Codegen the basic block.
655 DOUT << "===== Instruction selection begins:\n";
660 DOUT << "===== Instruction selection ends:\n";
663 CurDAG->RemoveDeadNodes();
666 void X86DAGToDAGISel::InstructionSelectPostProcessing() {
667 // If we are emitting FP stack code, scan the basic block to determine if this
668 // block defines any FP values. If so, put an FP_REG_KILL instruction before
669 // the terminator of the block.
671 // Note that FP stack instructions are used in all modes for long double,
672 // so we always need to do this check.
673 // Also note that it's possible for an FP stack register to be live across
674 // an instruction that produces multiple basic blocks (SSE CMOV) so we
675 // must check all the generated basic blocks.
677 // Scan all of the machine instructions in these MBBs, checking for FP
678 // stores. (RFP32 and RFP64 will not exist in SSE mode, but RFP80 might.)
679 MachineFunction::iterator MBBI = CurBB;
680 MachineFunction::iterator EndMBB = BB; ++EndMBB;
681 for (; MBBI != EndMBB; ++MBBI) {
682 MachineBasicBlock *MBB = MBBI;
684 // If this block returns, ignore it. We don't want to insert an FP_REG_KILL
685 // before the return.
687 MachineBasicBlock::iterator EndI = MBB->end();
689 if (EndI->getDesc().isReturn())
693 bool ContainsFPCode = false;
694 for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
695 !ContainsFPCode && I != E; ++I) {
696 if (I->getNumOperands() != 0 && I->getOperand(0).isReg()) {
697 const TargetRegisterClass *clas;
698 for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) {
699 if (I->getOperand(op).isReg() && I->getOperand(op).isDef() &&
700 TargetRegisterInfo::isVirtualRegister(I->getOperand(op).getReg()) &&
701 ((clas = RegInfo->getRegClass(I->getOperand(0).getReg())) ==
702 X86::RFP32RegisterClass ||
703 clas == X86::RFP64RegisterClass ||
704 clas == X86::RFP80RegisterClass)) {
705 ContainsFPCode = true;
711 // Check PHI nodes in successor blocks. These PHI's will be lowered to have
712 // a copy of the input value in this block. In SSE mode, we only care about
714 if (!ContainsFPCode) {
715 // Final check, check LLVM BB's that are successors to the LLVM BB
716 // corresponding to BB for FP PHI nodes.
717 const BasicBlock *LLVMBB = BB->getBasicBlock();
719 for (succ_const_iterator SI = succ_begin(LLVMBB), E = succ_end(LLVMBB);
720 !ContainsFPCode && SI != E; ++SI) {
721 for (BasicBlock::const_iterator II = SI->begin();
722 (PN = dyn_cast<PHINode>(II)); ++II) {
723 if (PN->getType()==Type::X86_FP80Ty ||
724 (!Subtarget->hasSSE1() && PN->getType()->isFloatingPoint()) ||
725 (!Subtarget->hasSSE2() && PN->getType()==Type::DoubleTy)) {
726 ContainsFPCode = true;
732 // Finally, if we found any FP code, emit the FP_REG_KILL instruction.
733 if (ContainsFPCode) {
734 BuildMI(*MBB, MBBI->getFirstTerminator(),
735 TM.getInstrInfo()->get(X86::FP_REG_KILL));
741 /// EmitSpecialCodeForMain - Emit any code that needs to be executed only in
742 /// the main function.
743 void X86DAGToDAGISel::EmitSpecialCodeForMain(MachineBasicBlock *BB,
744 MachineFrameInfo *MFI) {
745 const TargetInstrInfo *TII = TM.getInstrInfo();
746 if (Subtarget->isTargetCygMing())
747 BuildMI(BB, TII->get(X86::CALLpcrel32)).addExternalSymbol("__main");
750 void X86DAGToDAGISel::EmitFunctionEntryCode(Function &Fn, MachineFunction &MF) {
751 // If this is main, emit special code for main.
752 MachineBasicBlock *BB = MF.begin();
753 if (Fn.hasExternalLinkage() && Fn.getName() == "main")
754 EmitSpecialCodeForMain(BB, MF.getFrameInfo());
757 /// MatchAddress - Add the specified node to the specified addressing mode,
758 /// returning true if it cannot be done. This just pattern matches for the
760 bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM,
761 bool isRoot, unsigned Depth) {
762 bool is64Bit = Subtarget->is64Bit();
763 DOUT << "MatchAddress: "; DEBUG(AM.dump());
766 return MatchAddressBase(N, AM, isRoot, Depth);
768 // RIP relative addressing: %rip + 32-bit displacement!
770 if (!AM.ES && AM.JT != -1 && N.getOpcode() == ISD::Constant) {
771 int64_t Val = cast<ConstantSDNode>(N)->getSExtValue();
772 if (!is64Bit || isInt32(AM.Disp + Val)) {
780 int id = N.getNode()->getNodeId();
781 bool AlreadySelected = isSelected(id); // Already selected, not yet replaced.
783 switch (N.getOpcode()) {
785 case ISD::Constant: {
786 int64_t Val = cast<ConstantSDNode>(N)->getSExtValue();
787 if (!is64Bit || isInt32(AM.Disp + Val)) {
794 case X86ISD::Wrapper: {
795 DOUT << "Wrapper: 64bit " << is64Bit;
796 DOUT << " AM "; DEBUG(AM.dump()); DOUT << "\n";
797 DOUT << "AlreadySelected " << AlreadySelected << "\n";
798 // Under X86-64 non-small code model, GV (and friends) are 64-bits.
799 // Also, base and index reg must be 0 in order to use rip as base.
800 if (is64Bit && (TM.getCodeModel() != CodeModel::Small ||
801 AM.Base.Reg.getNode() || AM.IndexReg.getNode()))
803 if (AM.GV != 0 || AM.CP != 0 || AM.ES != 0 || AM.JT != -1)
805 // If value is available in a register both base and index components have
806 // been picked, we can't fit the result available in the register in the
807 // addressing mode. Duplicate GlobalAddress or ConstantPool as displacement.
808 if (!AlreadySelected || (AM.Base.Reg.getNode() && AM.IndexReg.getNode())) {
809 SDValue N0 = N.getOperand(0);
810 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
811 if (!is64Bit || isInt32(AM.Disp + G->getOffset())) {
812 GlobalValue *GV = G->getGlobal();
814 AM.Disp += G->getOffset();
815 AM.isRIPRel = TM.symbolicAddressesAreRIPRel();
818 } else if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(N0)) {
819 if (!is64Bit || isInt32(AM.Disp + CP->getOffset())) {
820 AM.CP = CP->getConstVal();
821 AM.Align = CP->getAlignment();
822 AM.Disp += CP->getOffset();
823 AM.isRIPRel = TM.symbolicAddressesAreRIPRel();
826 } else if (ExternalSymbolSDNode *S =dyn_cast<ExternalSymbolSDNode>(N0)) {
827 AM.ES = S->getSymbol();
828 AM.isRIPRel = TM.symbolicAddressesAreRIPRel();
830 } else if (JumpTableSDNode *J = dyn_cast<JumpTableSDNode>(N0)) {
831 AM.JT = J->getIndex();
832 AM.isRIPRel = TM.symbolicAddressesAreRIPRel();
839 case ISD::FrameIndex:
840 if (AM.BaseType == X86ISelAddressMode::RegBase
841 && AM.Base.Reg.getNode() == 0) {
842 AM.BaseType = X86ISelAddressMode::FrameIndexBase;
843 AM.Base.FrameIndex = cast<FrameIndexSDNode>(N)->getIndex();
849 if (AlreadySelected || AM.IndexReg.getNode() != 0
850 || AM.Scale != 1 || AM.isRIPRel)
854 *CN = dyn_cast<ConstantSDNode>(N.getNode()->getOperand(1))) {
855 unsigned Val = CN->getZExtValue();
856 if (Val == 1 || Val == 2 || Val == 3) {
858 SDValue ShVal = N.getNode()->getOperand(0);
860 // Okay, we know that we have a scale by now. However, if the scaled
861 // value is an add of something and a constant, we can fold the
862 // constant into the disp field here.
863 if (ShVal.getNode()->getOpcode() == ISD::ADD && ShVal.hasOneUse() &&
864 isa<ConstantSDNode>(ShVal.getNode()->getOperand(1))) {
865 AM.IndexReg = ShVal.getNode()->getOperand(0);
866 ConstantSDNode *AddVal =
867 cast<ConstantSDNode>(ShVal.getNode()->getOperand(1));
868 uint64_t Disp = AM.Disp + (AddVal->getZExtValue() << Val);
869 if (!is64Bit || isInt32(Disp))
883 // A mul_lohi where we need the low part can be folded as a plain multiply.
884 if (N.getResNo() != 0) break;
887 // X*[3,5,9] -> X+X*[2,4,8]
888 if (!AlreadySelected &&
889 AM.BaseType == X86ISelAddressMode::RegBase &&
890 AM.Base.Reg.getNode() == 0 &&
891 AM.IndexReg.getNode() == 0 &&
894 *CN = dyn_cast<ConstantSDNode>(N.getNode()->getOperand(1)))
895 if (CN->getZExtValue() == 3 || CN->getZExtValue() == 5 ||
896 CN->getZExtValue() == 9) {
897 AM.Scale = unsigned(CN->getZExtValue())-1;
899 SDValue MulVal = N.getNode()->getOperand(0);
902 // Okay, we know that we have a scale by now. However, if the scaled
903 // value is an add of something and a constant, we can fold the
904 // constant into the disp field here.
905 if (MulVal.getNode()->getOpcode() == ISD::ADD && MulVal.hasOneUse() &&
906 isa<ConstantSDNode>(MulVal.getNode()->getOperand(1))) {
907 Reg = MulVal.getNode()->getOperand(0);
908 ConstantSDNode *AddVal =
909 cast<ConstantSDNode>(MulVal.getNode()->getOperand(1));
910 uint64_t Disp = AM.Disp + AddVal->getZExtValue() *
912 if (!is64Bit || isInt32(Disp))
915 Reg = N.getNode()->getOperand(0);
917 Reg = N.getNode()->getOperand(0);
920 AM.IndexReg = AM.Base.Reg = Reg;
927 if (!AlreadySelected) {
928 X86ISelAddressMode Backup = AM;
929 if (!MatchAddress(N.getNode()->getOperand(0), AM, false, Depth+1) &&
930 !MatchAddress(N.getNode()->getOperand(1), AM, false, Depth+1))
933 if (!MatchAddress(N.getNode()->getOperand(1), AM, false, Depth+1) &&
934 !MatchAddress(N.getNode()->getOperand(0), AM, false, Depth+1))
941 // Handle "X | C" as "X + C" iff X is known to have C bits clear.
942 if (AlreadySelected) break;
944 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
945 X86ISelAddressMode Backup = AM;
946 // Start with the LHS as an addr mode.
947 if (!MatchAddress(N.getOperand(0), AM, false) &&
948 // Address could not have picked a GV address for the displacement.
950 // On x86-64, the resultant disp must fit in 32-bits.
951 (!is64Bit || isInt32(AM.Disp + CN->getSExtValue())) &&
952 // Check to see if the LHS & C is zero.
953 CurDAG->MaskedValueIsZero(N.getOperand(0), CN->getAPIntValue())) {
954 AM.Disp += CN->getZExtValue();
962 // Handle "(x << C1) & C2" as "(X & (C2>>C1)) << C1" if safe and if this
963 // allows us to fold the shift into this addressing mode.
964 if (AlreadySelected) break;
965 SDValue Shift = N.getOperand(0);
966 if (Shift.getOpcode() != ISD::SHL) break;
968 // Scale must not be used already.
969 if (AM.IndexReg.getNode() != 0 || AM.Scale != 1) break;
971 // Not when RIP is used as the base.
972 if (AM.isRIPRel) break;
974 ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N.getOperand(1));
975 ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(Shift.getOperand(1));
976 if (!C1 || !C2) break;
978 // Not likely to be profitable if either the AND or SHIFT node has more
979 // than one use (unless all uses are for address computation). Besides,
980 // isel mechanism requires their node ids to be reused.
981 if (!N.hasOneUse() || !Shift.hasOneUse())
984 // Verify that the shift amount is something we can fold.
985 unsigned ShiftCst = C1->getZExtValue();
986 if (ShiftCst != 1 && ShiftCst != 2 && ShiftCst != 3)
989 // Get the new AND mask, this folds to a constant.
990 SDValue NewANDMask = CurDAG->getNode(ISD::SRL, N.getValueType(),
991 SDValue(C2, 0), SDValue(C1, 0));
992 SDValue NewAND = CurDAG->getNode(ISD::AND, N.getValueType(),
993 Shift.getOperand(0), NewANDMask);
994 SDValue NewSHIFT = CurDAG->getNode(ISD::SHL, N.getValueType(),
995 NewAND, SDValue(C1, 0));
996 NewANDMask.getNode()->setNodeId(Shift.getNode()->getNodeId());
997 NewAND.getNode()->setNodeId(N.getNode()->getNodeId());
998 CurDAG->ReplaceAllUsesWith(N, NewSHIFT);
1000 AM.Scale = 1 << ShiftCst;
1001 AM.IndexReg = NewAND;
1006 return MatchAddressBase(N, AM, isRoot, Depth);
1009 /// MatchAddressBase - Helper for MatchAddress. Add the specified node to the
1010 /// specified addressing mode without any further recursion.
1011 bool X86DAGToDAGISel::MatchAddressBase(SDValue N, X86ISelAddressMode &AM,
1012 bool isRoot, unsigned Depth) {
1013 // Is the base register already occupied?
1014 if (AM.BaseType != X86ISelAddressMode::RegBase || AM.Base.Reg.getNode()) {
1015 // If so, check to see if the scale index register is set.
1016 if (AM.IndexReg.getNode() == 0 && !AM.isRIPRel) {
1022 // Otherwise, we cannot select it.
1026 // Default, generate it as a register.
1027 AM.BaseType = X86ISelAddressMode::RegBase;
1032 /// SelectAddr - returns true if it is able pattern match an addressing mode.
1033 /// It returns the operands which make up the maximal addressing mode it can
1034 /// match by reference.
1035 bool X86DAGToDAGISel::SelectAddr(SDValue Op, SDValue N, SDValue &Base,
1036 SDValue &Scale, SDValue &Index,
1038 X86ISelAddressMode AM;
1039 if (MatchAddress(N, AM))
1042 MVT VT = N.getValueType();
1043 if (AM.BaseType == X86ISelAddressMode::RegBase) {
1044 if (!AM.Base.Reg.getNode())
1045 AM.Base.Reg = CurDAG->getRegister(0, VT);
1048 if (!AM.IndexReg.getNode())
1049 AM.IndexReg = CurDAG->getRegister(0, VT);
1051 getAddressOperands(AM, Base, Scale, Index, Disp);
1055 /// SelectScalarSSELoad - Match a scalar SSE load. In particular, we want to
1056 /// match a load whose top elements are either undef or zeros. The load flavor
1057 /// is derived from the type of N, which is either v4f32 or v2f64.
1058 bool X86DAGToDAGISel::SelectScalarSSELoad(SDValue Op, SDValue Pred,
1059 SDValue N, SDValue &Base,
1060 SDValue &Scale, SDValue &Index,
1061 SDValue &Disp, SDValue &InChain,
1062 SDValue &OutChain) {
1063 if (N.getOpcode() == ISD::SCALAR_TO_VECTOR) {
1064 InChain = N.getOperand(0).getValue(1);
1065 if (ISD::isNON_EXTLoad(InChain.getNode()) &&
1066 InChain.getValue(0).hasOneUse() &&
1068 CanBeFoldedBy(N.getNode(), Pred.getNode(), Op.getNode())) {
1069 LoadSDNode *LD = cast<LoadSDNode>(InChain);
1070 if (!SelectAddr(Op, LD->getBasePtr(), Base, Scale, Index, Disp))
1072 OutChain = LD->getChain();
1077 // Also handle the case where we explicitly require zeros in the top
1078 // elements. This is a vector shuffle from the zero vector.
1079 if (N.getOpcode() == X86ISD::VZEXT_MOVL && N.getNode()->hasOneUse() &&
1080 // Check to see if the top elements are all zeros (or bitcast of zeros).
1081 N.getOperand(0).getOpcode() == ISD::SCALAR_TO_VECTOR &&
1082 N.getOperand(0).getNode()->hasOneUse() &&
1083 ISD::isNON_EXTLoad(N.getOperand(0).getOperand(0).getNode()) &&
1084 N.getOperand(0).getOperand(0).hasOneUse()) {
1085 // Okay, this is a zero extending load. Fold it.
1086 LoadSDNode *LD = cast<LoadSDNode>(N.getOperand(0).getOperand(0));
1087 if (!SelectAddr(Op, LD->getBasePtr(), Base, Scale, Index, Disp))
1089 OutChain = LD->getChain();
1090 InChain = SDValue(LD, 1);
1097 /// SelectLEAAddr - it calls SelectAddr and determines if the maximal addressing
1098 /// mode it matches can be cost effectively emitted as an LEA instruction.
1099 bool X86DAGToDAGISel::SelectLEAAddr(SDValue Op, SDValue N,
1100 SDValue &Base, SDValue &Scale,
1101 SDValue &Index, SDValue &Disp) {
1102 X86ISelAddressMode AM;
1103 if (MatchAddress(N, AM))
1106 MVT VT = N.getValueType();
1107 unsigned Complexity = 0;
1108 if (AM.BaseType == X86ISelAddressMode::RegBase)
1109 if (AM.Base.Reg.getNode())
1112 AM.Base.Reg = CurDAG->getRegister(0, VT);
1113 else if (AM.BaseType == X86ISelAddressMode::FrameIndexBase)
1116 if (AM.IndexReg.getNode())
1119 AM.IndexReg = CurDAG->getRegister(0, VT);
1121 // Don't match just leal(,%reg,2). It's cheaper to do addl %reg, %reg, or with
1126 // FIXME: We are artificially lowering the criteria to turn ADD %reg, $GA
1127 // to a LEA. This is determined with some expermentation but is by no means
1128 // optimal (especially for code size consideration). LEA is nice because of
1129 // its three-address nature. Tweak the cost function again when we can run
1130 // convertToThreeAddress() at register allocation time.
1131 if (AM.GV || AM.CP || AM.ES || AM.JT != -1) {
1132 // For X86-64, we should always use lea to materialize RIP relative
1134 if (Subtarget->is64Bit())
1140 if (AM.Disp && (AM.Base.Reg.getNode() || AM.IndexReg.getNode()))
1143 if (Complexity > 2) {
1144 getAddressOperands(AM, Base, Scale, Index, Disp);
1150 bool X86DAGToDAGISel::TryFoldLoad(SDValue P, SDValue N,
1151 SDValue &Base, SDValue &Scale,
1152 SDValue &Index, SDValue &Disp) {
1153 if (ISD::isNON_EXTLoad(N.getNode()) &&
1155 CanBeFoldedBy(N.getNode(), P.getNode(), P.getNode()))
1156 return SelectAddr(P, N.getOperand(1), Base, Scale, Index, Disp);
1160 /// getGlobalBaseReg - Return an SDNode that returns the value of
1161 /// the global base register. Output instructions required to
1162 /// initialize the global base register, if necessary.
1164 SDNode *X86DAGToDAGISel::getGlobalBaseReg() {
1165 MachineFunction *MF = CurBB->getParent();
1166 unsigned GlobalBaseReg = TM.getInstrInfo()->getGlobalBaseReg(MF);
1167 return CurDAG->getRegister(GlobalBaseReg, TLI.getPointerTy()).getNode();
1170 static SDNode *FindCallStartFromCall(SDNode *Node) {
1171 if (Node->getOpcode() == ISD::CALLSEQ_START) return Node;
1172 assert(Node->getOperand(0).getValueType() == MVT::Other &&
1173 "Node doesn't have a token chain argument!");
1174 return FindCallStartFromCall(Node->getOperand(0).getNode());
1177 /// getTruncateTo8Bit - return an SDNode that implements a subreg based
1178 /// truncate of the specified operand to i8. This can be done with tablegen,
1179 /// except that this code uses MVT::Flag in a tricky way that happens to
1180 /// improve scheduling in some cases.
1181 SDNode *X86DAGToDAGISel::getTruncateTo8Bit(SDValue N0) {
1182 assert(!Subtarget->is64Bit() &&
1183 "getTruncateTo8Bit is only needed on x86-32!");
1184 SDValue SRIdx = CurDAG->getTargetConstant(1, MVT::i32); // SubRegSet 1
1186 // Ensure that the source register has an 8-bit subreg on 32-bit targets
1188 MVT N0VT = N0.getValueType();
1189 switch (N0VT.getSimpleVT()) {
1190 default: assert(0 && "Unknown truncate!");
1192 Opc = X86::MOV16to16_;
1195 Opc = X86::MOV32to32_;
1199 // The use of MVT::Flag here is not strictly accurate, but it helps
1200 // scheduling in some cases.
1201 N0 = SDValue(CurDAG->getTargetNode(Opc, N0VT, MVT::Flag, N0), 0);
1202 return CurDAG->getTargetNode(X86::EXTRACT_SUBREG,
1203 MVT::i8, N0, SRIdx, N0.getValue(1));
1206 SDNode *X86DAGToDAGISel::SelectAtomic64(SDNode *Node, unsigned Opc) {
1207 SDValue Chain = Node->getOperand(0);
1208 SDValue In1 = Node->getOperand(1);
1209 SDValue In2L = Node->getOperand(2);
1210 SDValue In2H = Node->getOperand(3);
1211 SDValue Tmp0, Tmp1, Tmp2, Tmp3;
1212 if (!SelectAddr(In1, In1, Tmp0, Tmp1, Tmp2, Tmp3))
1214 SDValue LSI = Node->getOperand(4); // MemOperand
1215 AddToISelQueue(Tmp0);
1216 AddToISelQueue(Tmp1);
1217 AddToISelQueue(Tmp2);
1218 AddToISelQueue(Tmp3);
1219 AddToISelQueue(In2L);
1220 AddToISelQueue(In2H);
1221 // For now, don't select the MemOperand object, we don't know how.
1222 AddToISelQueue(Chain);
1223 const SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, In2L, In2H, LSI, Chain };
1224 return CurDAG->getTargetNode(Opc, MVT::i32, MVT::i32, MVT::Other, Ops, 8);
1227 SDNode *X86DAGToDAGISel::Select(SDValue N) {
1228 SDNode *Node = N.getNode();
1229 MVT NVT = Node->getValueType(0);
1231 unsigned Opcode = Node->getOpcode();
1234 DOUT << std::string(Indent, ' ') << "Selecting: ";
1235 DEBUG(Node->dump(CurDAG));
1240 if (Node->isMachineOpcode()) {
1242 DOUT << std::string(Indent-2, ' ') << "== ";
1243 DEBUG(Node->dump(CurDAG));
1247 return NULL; // Already selected.
1252 case X86ISD::GlobalBaseReg:
1253 return getGlobalBaseReg();
1255 case X86ISD::ATOMOR64_DAG:
1256 return SelectAtomic64(Node, X86::ATOMOR6432);
1257 case X86ISD::ATOMXOR64_DAG:
1258 return SelectAtomic64(Node, X86::ATOMXOR6432);
1259 case X86ISD::ATOMADD64_DAG:
1260 return SelectAtomic64(Node, X86::ATOMADD6432);
1261 case X86ISD::ATOMSUB64_DAG:
1262 return SelectAtomic64(Node, X86::ATOMSUB6432);
1263 case X86ISD::ATOMNAND64_DAG:
1264 return SelectAtomic64(Node, X86::ATOMNAND6432);
1265 case X86ISD::ATOMAND64_DAG:
1266 return SelectAtomic64(Node, X86::ATOMAND6432);
1267 case X86ISD::ATOMSWAP64_DAG:
1268 return SelectAtomic64(Node, X86::ATOMSWAP6432);
1270 case ISD::SMUL_LOHI:
1271 case ISD::UMUL_LOHI: {
1272 SDValue N0 = Node->getOperand(0);
1273 SDValue N1 = Node->getOperand(1);
1275 bool isSigned = Opcode == ISD::SMUL_LOHI;
1277 switch (NVT.getSimpleVT()) {
1278 default: assert(0 && "Unsupported VT!");
1279 case MVT::i8: Opc = X86::MUL8r; MOpc = X86::MUL8m; break;
1280 case MVT::i16: Opc = X86::MUL16r; MOpc = X86::MUL16m; break;
1281 case MVT::i32: Opc = X86::MUL32r; MOpc = X86::MUL32m; break;
1282 case MVT::i64: Opc = X86::MUL64r; MOpc = X86::MUL64m; break;
1285 switch (NVT.getSimpleVT()) {
1286 default: assert(0 && "Unsupported VT!");
1287 case MVT::i8: Opc = X86::IMUL8r; MOpc = X86::IMUL8m; break;
1288 case MVT::i16: Opc = X86::IMUL16r; MOpc = X86::IMUL16m; break;
1289 case MVT::i32: Opc = X86::IMUL32r; MOpc = X86::IMUL32m; break;
1290 case MVT::i64: Opc = X86::IMUL64r; MOpc = X86::IMUL64m; break;
1293 unsigned LoReg, HiReg;
1294 switch (NVT.getSimpleVT()) {
1295 default: assert(0 && "Unsupported VT!");
1296 case MVT::i8: LoReg = X86::AL; HiReg = X86::AH; break;
1297 case MVT::i16: LoReg = X86::AX; HiReg = X86::DX; break;
1298 case MVT::i32: LoReg = X86::EAX; HiReg = X86::EDX; break;
1299 case MVT::i64: LoReg = X86::RAX; HiReg = X86::RDX; break;
1302 SDValue Tmp0, Tmp1, Tmp2, Tmp3;
1303 bool foldedLoad = TryFoldLoad(N, N1, Tmp0, Tmp1, Tmp2, Tmp3);
1304 // multiplty is commmutative
1306 foldedLoad = TryFoldLoad(N, N0, Tmp0, Tmp1, Tmp2, Tmp3);
1312 SDValue InFlag = CurDAG->getCopyToReg(CurDAG->getEntryNode(), LoReg,
1313 N0, SDValue()).getValue(1);
1316 AddToISelQueue(N1.getOperand(0));
1317 AddToISelQueue(Tmp0);
1318 AddToISelQueue(Tmp1);
1319 AddToISelQueue(Tmp2);
1320 AddToISelQueue(Tmp3);
1321 SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N1.getOperand(0), InFlag };
1323 CurDAG->getTargetNode(MOpc, MVT::Other, MVT::Flag, Ops, 6);
1324 InFlag = SDValue(CNode, 1);
1325 // Update the chain.
1326 ReplaceUses(N1.getValue(1), SDValue(CNode, 0));
1330 SDValue(CurDAG->getTargetNode(Opc, MVT::Flag, N1, InFlag), 0);
1333 // Copy the low half of the result, if it is needed.
1334 if (!N.getValue(0).use_empty()) {
1335 SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1336 LoReg, NVT, InFlag);
1337 InFlag = Result.getValue(2);
1338 ReplaceUses(N.getValue(0), Result);
1340 DOUT << std::string(Indent-2, ' ') << "=> ";
1341 DEBUG(Result.getNode()->dump(CurDAG));
1345 // Copy the high half of the result, if it is needed.
1346 if (!N.getValue(1).use_empty()) {
1348 if (HiReg == X86::AH && Subtarget->is64Bit()) {
1349 // Prevent use of AH in a REX instruction by referencing AX instead.
1350 // Shift it down 8 bits.
1351 Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1352 X86::AX, MVT::i16, InFlag);
1353 InFlag = Result.getValue(2);
1354 Result = SDValue(CurDAG->getTargetNode(X86::SHR16ri, MVT::i16, Result,
1355 CurDAG->getTargetConstant(8, MVT::i8)), 0);
1356 // Then truncate it down to i8.
1357 SDValue SRIdx = CurDAG->getTargetConstant(1, MVT::i32); // SubRegSet 1
1358 Result = SDValue(CurDAG->getTargetNode(X86::EXTRACT_SUBREG,
1359 MVT::i8, Result, SRIdx), 0);
1361 Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1362 HiReg, NVT, InFlag);
1363 InFlag = Result.getValue(2);
1365 ReplaceUses(N.getValue(1), Result);
1367 DOUT << std::string(Indent-2, ' ') << "=> ";
1368 DEBUG(Result.getNode()->dump(CurDAG));
1381 case ISD::UDIVREM: {
1382 SDValue N0 = Node->getOperand(0);
1383 SDValue N1 = Node->getOperand(1);
1385 bool isSigned = Opcode == ISD::SDIVREM;
1387 switch (NVT.getSimpleVT()) {
1388 default: assert(0 && "Unsupported VT!");
1389 case MVT::i8: Opc = X86::DIV8r; MOpc = X86::DIV8m; break;
1390 case MVT::i16: Opc = X86::DIV16r; MOpc = X86::DIV16m; break;
1391 case MVT::i32: Opc = X86::DIV32r; MOpc = X86::DIV32m; break;
1392 case MVT::i64: Opc = X86::DIV64r; MOpc = X86::DIV64m; break;
1395 switch (NVT.getSimpleVT()) {
1396 default: assert(0 && "Unsupported VT!");
1397 case MVT::i8: Opc = X86::IDIV8r; MOpc = X86::IDIV8m; break;
1398 case MVT::i16: Opc = X86::IDIV16r; MOpc = X86::IDIV16m; break;
1399 case MVT::i32: Opc = X86::IDIV32r; MOpc = X86::IDIV32m; break;
1400 case MVT::i64: Opc = X86::IDIV64r; MOpc = X86::IDIV64m; break;
1403 unsigned LoReg, HiReg;
1404 unsigned ClrOpcode, SExtOpcode;
1405 switch (NVT.getSimpleVT()) {
1406 default: assert(0 && "Unsupported VT!");
1408 LoReg = X86::AL; HiReg = X86::AH;
1410 SExtOpcode = X86::CBW;
1413 LoReg = X86::AX; HiReg = X86::DX;
1414 ClrOpcode = X86::MOV16r0;
1415 SExtOpcode = X86::CWD;
1418 LoReg = X86::EAX; HiReg = X86::EDX;
1419 ClrOpcode = X86::MOV32r0;
1420 SExtOpcode = X86::CDQ;
1423 LoReg = X86::RAX; HiReg = X86::RDX;
1424 ClrOpcode = X86::MOV64r0;
1425 SExtOpcode = X86::CQO;
1429 SDValue Tmp0, Tmp1, Tmp2, Tmp3;
1430 bool foldedLoad = TryFoldLoad(N, N1, Tmp0, Tmp1, Tmp2, Tmp3);
1433 if (NVT == MVT::i8 && !isSigned) {
1434 // Special case for div8, just use a move with zero extension to AX to
1435 // clear the upper 8 bits (AH).
1436 SDValue Tmp0, Tmp1, Tmp2, Tmp3, Move, Chain;
1437 if (TryFoldLoad(N, N0, Tmp0, Tmp1, Tmp2, Tmp3)) {
1438 SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N0.getOperand(0) };
1439 AddToISelQueue(N0.getOperand(0));
1440 AddToISelQueue(Tmp0);
1441 AddToISelQueue(Tmp1);
1442 AddToISelQueue(Tmp2);
1443 AddToISelQueue(Tmp3);
1445 SDValue(CurDAG->getTargetNode(X86::MOVZX16rm8, MVT::i16, MVT::Other,
1447 Chain = Move.getValue(1);
1448 ReplaceUses(N0.getValue(1), Chain);
1452 SDValue(CurDAG->getTargetNode(X86::MOVZX16rr8, MVT::i16, N0), 0);
1453 Chain = CurDAG->getEntryNode();
1455 Chain = CurDAG->getCopyToReg(Chain, X86::AX, Move, SDValue());
1456 InFlag = Chain.getValue(1);
1460 CurDAG->getCopyToReg(CurDAG->getEntryNode(),
1461 LoReg, N0, SDValue()).getValue(1);
1463 // Sign extend the low part into the high part.
1465 SDValue(CurDAG->getTargetNode(SExtOpcode, MVT::Flag, InFlag), 0);
1467 // Zero out the high part, effectively zero extending the input.
1468 SDValue ClrNode = SDValue(CurDAG->getTargetNode(ClrOpcode, NVT), 0);
1469 InFlag = CurDAG->getCopyToReg(CurDAG->getEntryNode(), HiReg,
1470 ClrNode, InFlag).getValue(1);
1475 AddToISelQueue(N1.getOperand(0));
1476 AddToISelQueue(Tmp0);
1477 AddToISelQueue(Tmp1);
1478 AddToISelQueue(Tmp2);
1479 AddToISelQueue(Tmp3);
1480 SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N1.getOperand(0), InFlag };
1482 CurDAG->getTargetNode(MOpc, MVT::Other, MVT::Flag, Ops, 6);
1483 InFlag = SDValue(CNode, 1);
1484 // Update the chain.
1485 ReplaceUses(N1.getValue(1), SDValue(CNode, 0));
1489 SDValue(CurDAG->getTargetNode(Opc, MVT::Flag, N1, InFlag), 0);
1492 // Copy the division (low) result, if it is needed.
1493 if (!N.getValue(0).use_empty()) {
1494 SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1495 LoReg, NVT, InFlag);
1496 InFlag = Result.getValue(2);
1497 ReplaceUses(N.getValue(0), Result);
1499 DOUT << std::string(Indent-2, ' ') << "=> ";
1500 DEBUG(Result.getNode()->dump(CurDAG));
1504 // Copy the remainder (high) result, if it is needed.
1505 if (!N.getValue(1).use_empty()) {
1507 if (HiReg == X86::AH && Subtarget->is64Bit()) {
1508 // Prevent use of AH in a REX instruction by referencing AX instead.
1509 // Shift it down 8 bits.
1510 Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1511 X86::AX, MVT::i16, InFlag);
1512 InFlag = Result.getValue(2);
1513 Result = SDValue(CurDAG->getTargetNode(X86::SHR16ri, MVT::i16, Result,
1514 CurDAG->getTargetConstant(8, MVT::i8)), 0);
1515 // Then truncate it down to i8.
1516 SDValue SRIdx = CurDAG->getTargetConstant(1, MVT::i32); // SubRegSet 1
1517 Result = SDValue(CurDAG->getTargetNode(X86::EXTRACT_SUBREG,
1518 MVT::i8, Result, SRIdx), 0);
1520 Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
1521 HiReg, NVT, InFlag);
1522 InFlag = Result.getValue(2);
1524 ReplaceUses(N.getValue(1), Result);
1526 DOUT << std::string(Indent-2, ' ') << "=> ";
1527 DEBUG(Result.getNode()->dump(CurDAG));
1539 case ISD::SIGN_EXTEND_INREG: {
1540 MVT SVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
1541 if (SVT == MVT::i8 && !Subtarget->is64Bit()) {
1542 SDValue N0 = Node->getOperand(0);
1545 SDValue TruncOp = SDValue(getTruncateTo8Bit(N0), 0);
1547 switch (NVT.getSimpleVT()) {
1548 default: assert(0 && "Unknown sign_extend_inreg!");
1550 Opc = X86::MOVSX16rr8;
1553 Opc = X86::MOVSX32rr8;
1557 SDNode *ResNode = CurDAG->getTargetNode(Opc, NVT, TruncOp);
1560 DOUT << std::string(Indent-2, ' ') << "=> ";
1561 DEBUG(TruncOp.getNode()->dump(CurDAG));
1563 DOUT << std::string(Indent-2, ' ') << "=> ";
1564 DEBUG(ResNode->dump(CurDAG));
1573 case ISD::TRUNCATE: {
1574 if (NVT == MVT::i8 && !Subtarget->is64Bit()) {
1575 SDValue Input = Node->getOperand(0);
1576 AddToISelQueue(Node->getOperand(0));
1577 SDNode *ResNode = getTruncateTo8Bit(Input);
1580 DOUT << std::string(Indent-2, ' ') << "=> ";
1581 DEBUG(ResNode->dump(CurDAG));
1590 case ISD::DECLARE: {
1591 // Handle DECLARE nodes here because the second operand may have been
1592 // wrapped in X86ISD::Wrapper.
1593 SDValue Chain = Node->getOperand(0);
1594 SDValue N1 = Node->getOperand(1);
1595 SDValue N2 = Node->getOperand(2);
1596 if (!isa<FrameIndexSDNode>(N1))
1598 int FI = cast<FrameIndexSDNode>(N1)->getIndex();
1599 if (N2.getOpcode() == ISD::ADD &&
1600 N2.getOperand(0).getOpcode() == X86ISD::GlobalBaseReg)
1601 N2 = N2.getOperand(1);
1602 if (N2.getOpcode() == X86ISD::Wrapper &&
1603 isa<GlobalAddressSDNode>(N2.getOperand(0))) {
1605 cast<GlobalAddressSDNode>(N2.getOperand(0))->getGlobal();
1606 SDValue Tmp1 = CurDAG->getTargetFrameIndex(FI, TLI.getPointerTy());
1607 SDValue Tmp2 = CurDAG->getTargetGlobalAddress(GV, TLI.getPointerTy());
1608 AddToISelQueue(Chain);
1609 SDValue Ops[] = { Tmp1, Tmp2, Chain };
1610 return CurDAG->getTargetNode(TargetInstrInfo::DECLARE,
1611 MVT::Other, Ops, 3);
1617 SDNode *ResNode = SelectCode(N);
1620 DOUT << std::string(Indent-2, ' ') << "=> ";
1621 if (ResNode == NULL || ResNode == N.getNode())
1622 DEBUG(N.getNode()->dump(CurDAG));
1624 DEBUG(ResNode->dump(CurDAG));
1632 bool X86DAGToDAGISel::
1633 SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
1634 std::vector<SDValue> &OutOps) {
1635 SDValue Op0, Op1, Op2, Op3;
1636 switch (ConstraintCode) {
1637 case 'o': // offsetable ??
1638 case 'v': // not offsetable ??
1639 default: return true;
1641 if (!SelectAddr(Op, Op, Op0, Op1, Op2, Op3))
1646 OutOps.push_back(Op0);
1647 OutOps.push_back(Op1);
1648 OutOps.push_back(Op2);
1649 OutOps.push_back(Op3);
1650 AddToISelQueue(Op0);
1651 AddToISelQueue(Op1);
1652 AddToISelQueue(Op2);
1653 AddToISelQueue(Op3);
1657 /// createX86ISelDag - This pass converts a legalized DAG into a
1658 /// X86-specific DAG, ready for instruction scheduling.
1660 FunctionPass *llvm::createX86ISelDag(X86TargetMachine &TM, bool Fast) {
1661 return new X86DAGToDAGISel(TM, Fast);