1 ///===-- FastISel.cpp - Implementation of the FastISel class --------------===//
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 implementation of the FastISel class.
12 // "Fast" instruction selection is designed to emit very poor code quickly.
13 // Also, it is not designed to be able to do much lowering, so most illegal
14 // types (e.g. i64 on 32-bit targets) and operations are not supported. It is
15 // also not intended to be able to do much optimization, except in a few cases
16 // where doing optimizations reduces overall compile time. For example, folding
17 // constants into immediate fields is often done, because it's cheap and it
18 // reduces the number of instructions later phases have to examine.
20 // "Fast" instruction selection is able to fail gracefully and transfer
21 // control to the SelectionDAG selector for operations that it doesn't
22 // support. In many cases, this allows us to avoid duplicating a lot of
23 // the complicated lowering logic that SelectionDAG currently has.
25 // The intended use for "fast" instruction selection is "-O0" mode
26 // compilation, where the quality of the generated code is irrelevant when
27 // weighed against the speed at which the code can be generated. Also,
28 // at -O0, the LLVM optimizers are not running, and this makes the
29 // compile time of codegen a much higher portion of the overall compile
30 // time. Despite its limitations, "fast" instruction selection is able to
31 // handle enough code on its own to provide noticeable overall speedups
34 // Basic operations are supported in a target-independent way, by reading
35 // the same instruction descriptions that the SelectionDAG selector reads,
36 // and identifying simple arithmetic operations that can be directly selected
37 // from simple operators. More complicated operations currently require
38 // target-specific code.
40 //===----------------------------------------------------------------------===//
42 #include "llvm/Function.h"
43 #include "llvm/GlobalVariable.h"
44 #include "llvm/Instructions.h"
45 #include "llvm/IntrinsicInst.h"
46 #include "llvm/CodeGen/FastISel.h"
47 #include "llvm/CodeGen/MachineInstrBuilder.h"
48 #include "llvm/CodeGen/MachineModuleInfo.h"
49 #include "llvm/CodeGen/MachineRegisterInfo.h"
50 #include "llvm/CodeGen/DwarfWriter.h"
51 #include "llvm/Analysis/DebugInfo.h"
52 #include "llvm/Target/TargetData.h"
53 #include "llvm/Target/TargetInstrInfo.h"
54 #include "llvm/Target/TargetLowering.h"
55 #include "llvm/Target/TargetMachine.h"
56 #include "SelectionDAGBuild.h"
59 unsigned FastISel::getRegForValue(Value *V) {
60 MVT RealVT = TLI.getValueType(V->getType(), /*AllowUnknown=*/true);
61 // Don't handle non-simple values in FastISel.
62 if (!RealVT.isSimple())
65 // Ignore illegal types. We must do this before looking up the value
66 // in ValueMap because Arguments are given virtual registers regardless
67 // of whether FastISel can handle them.
68 MVT::SimpleValueType VT = RealVT.getSimpleVT();
69 if (!TLI.isTypeLegal(VT)) {
70 // Promote MVT::i1 to a legal type though, because it's common and easy.
72 VT = TLI.getTypeToTransformTo(VT).getSimpleVT();
77 // Look up the value to see if we already have a register for it. We
78 // cache values defined by Instructions across blocks, and other values
79 // only locally. This is because Instructions already have the SSA
80 // def-dominatess-use requirement enforced.
81 if (ValueMap.count(V))
83 unsigned Reg = LocalValueMap[V];
87 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
88 if (CI->getValue().getActiveBits() <= 64)
89 Reg = FastEmit_i(VT, VT, ISD::Constant, CI->getZExtValue());
90 } else if (isa<AllocaInst>(V)) {
91 Reg = TargetMaterializeAlloca(cast<AllocaInst>(V));
92 } else if (isa<ConstantPointerNull>(V)) {
93 // Translate this as an integer zero so that it can be
94 // local-CSE'd with actual integer zeros.
95 Reg = getRegForValue(Constant::getNullValue(TD.getIntPtrType()));
96 } else if (ConstantFP *CF = dyn_cast<ConstantFP>(V)) {
97 Reg = FastEmit_f(VT, VT, ISD::ConstantFP, CF);
100 const APFloat &Flt = CF->getValueAPF();
101 MVT IntVT = TLI.getPointerTy();
104 uint32_t IntBitWidth = IntVT.getSizeInBits();
106 (void) Flt.convertToInteger(x, IntBitWidth, /*isSigned=*/true,
107 APFloat::rmTowardZero, &isExact);
109 APInt IntVal(IntBitWidth, 2, x);
111 unsigned IntegerReg = getRegForValue(ConstantInt::get(IntVal));
113 Reg = FastEmit_r(IntVT.getSimpleVT(), VT, ISD::SINT_TO_FP, IntegerReg);
116 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
117 if (!SelectOperator(CE, CE->getOpcode())) return 0;
118 Reg = LocalValueMap[CE];
119 } else if (isa<UndefValue>(V)) {
120 Reg = createResultReg(TLI.getRegClassFor(VT));
121 BuildMI(MBB, DL, TII.get(TargetInstrInfo::IMPLICIT_DEF), Reg);
124 // If target-independent code couldn't handle the value, give target-specific
126 if (!Reg && isa<Constant>(V))
127 Reg = TargetMaterializeConstant(cast<Constant>(V));
129 // Don't cache constant materializations in the general ValueMap.
130 // To do so would require tracking what uses they dominate.
132 LocalValueMap[V] = Reg;
136 unsigned FastISel::lookUpRegForValue(Value *V) {
137 // Look up the value to see if we already have a register for it. We
138 // cache values defined by Instructions across blocks, and other values
139 // only locally. This is because Instructions already have the SSA
140 // def-dominatess-use requirement enforced.
141 if (ValueMap.count(V))
143 return LocalValueMap[V];
146 /// UpdateValueMap - Update the value map to include the new mapping for this
147 /// instruction, or insert an extra copy to get the result in a previous
148 /// determined register.
149 /// NOTE: This is only necessary because we might select a block that uses
150 /// a value before we select the block that defines the value. It might be
151 /// possible to fix this by selecting blocks in reverse postorder.
152 unsigned FastISel::UpdateValueMap(Value* I, unsigned Reg) {
153 if (!isa<Instruction>(I)) {
154 LocalValueMap[I] = Reg;
158 unsigned &AssignedReg = ValueMap[I];
159 if (AssignedReg == 0)
161 else if (Reg != AssignedReg) {
162 const TargetRegisterClass *RegClass = MRI.getRegClass(Reg);
163 TII.copyRegToReg(*MBB, MBB->end(), AssignedReg,
164 Reg, RegClass, RegClass);
169 unsigned FastISel::getRegForGEPIndex(Value *Idx) {
170 unsigned IdxN = getRegForValue(Idx);
172 // Unhandled operand. Halt "fast" selection and bail.
175 // If the index is smaller or larger than intptr_t, truncate or extend it.
176 MVT PtrVT = TLI.getPointerTy();
177 MVT IdxVT = MVT::getMVT(Idx->getType(), /*HandleUnknown=*/false);
178 if (IdxVT.bitsLT(PtrVT))
179 IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT.getSimpleVT(),
180 ISD::SIGN_EXTEND, IdxN);
181 else if (IdxVT.bitsGT(PtrVT))
182 IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT.getSimpleVT(),
183 ISD::TRUNCATE, IdxN);
187 /// SelectBinaryOp - Select and emit code for a binary operator instruction,
188 /// which has an opcode which directly corresponds to the given ISD opcode.
190 bool FastISel::SelectBinaryOp(User *I, ISD::NodeType ISDOpcode) {
191 MVT VT = MVT::getMVT(I->getType(), /*HandleUnknown=*/true);
192 if (VT == MVT::Other || !VT.isSimple())
193 // Unhandled type. Halt "fast" selection and bail.
196 // We only handle legal types. For example, on x86-32 the instruction
197 // selector contains all of the 64-bit instructions from x86-64,
198 // under the assumption that i64 won't be used if the target doesn't
200 if (!TLI.isTypeLegal(VT)) {
201 // MVT::i1 is special. Allow AND, OR, or XOR because they
202 // don't require additional zeroing, which makes them easy.
204 (ISDOpcode == ISD::AND || ISDOpcode == ISD::OR ||
205 ISDOpcode == ISD::XOR))
206 VT = TLI.getTypeToTransformTo(VT);
211 unsigned Op0 = getRegForValue(I->getOperand(0));
213 // Unhandled operand. Halt "fast" selection and bail.
216 // Check if the second operand is a constant and handle it appropriately.
217 if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
218 unsigned ResultReg = FastEmit_ri(VT.getSimpleVT(), VT.getSimpleVT(),
219 ISDOpcode, Op0, CI->getZExtValue());
220 if (ResultReg != 0) {
221 // We successfully emitted code for the given LLVM Instruction.
222 UpdateValueMap(I, ResultReg);
227 // Check if the second operand is a constant float.
228 if (ConstantFP *CF = dyn_cast<ConstantFP>(I->getOperand(1))) {
229 unsigned ResultReg = FastEmit_rf(VT.getSimpleVT(), VT.getSimpleVT(),
231 if (ResultReg != 0) {
232 // We successfully emitted code for the given LLVM Instruction.
233 UpdateValueMap(I, ResultReg);
238 unsigned Op1 = getRegForValue(I->getOperand(1));
240 // Unhandled operand. Halt "fast" selection and bail.
243 // Now we have both operands in registers. Emit the instruction.
244 unsigned ResultReg = FastEmit_rr(VT.getSimpleVT(), VT.getSimpleVT(),
245 ISDOpcode, Op0, Op1);
247 // Target-specific code wasn't able to find a machine opcode for
248 // the given ISD opcode and type. Halt "fast" selection and bail.
251 // We successfully emitted code for the given LLVM Instruction.
252 UpdateValueMap(I, ResultReg);
256 bool FastISel::SelectGetElementPtr(User *I) {
257 unsigned N = getRegForValue(I->getOperand(0));
259 // Unhandled operand. Halt "fast" selection and bail.
262 const Type *Ty = I->getOperand(0)->getType();
263 MVT::SimpleValueType VT = TLI.getPointerTy().getSimpleVT();
264 for (GetElementPtrInst::op_iterator OI = I->op_begin()+1, E = I->op_end();
267 if (const StructType *StTy = dyn_cast<StructType>(Ty)) {
268 unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
271 uint64_t Offs = TD.getStructLayout(StTy)->getElementOffset(Field);
272 // FIXME: This can be optimized by combining the add with a
274 N = FastEmit_ri_(VT, ISD::ADD, N, Offs, VT);
276 // Unhandled operand. Halt "fast" selection and bail.
279 Ty = StTy->getElementType(Field);
281 Ty = cast<SequentialType>(Ty)->getElementType();
283 // If this is a constant subscript, handle it quickly.
284 if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx)) {
285 if (CI->getZExtValue() == 0) continue;
287 TD.getTypePaddedSize(Ty)*cast<ConstantInt>(CI)->getSExtValue();
288 N = FastEmit_ri_(VT, ISD::ADD, N, Offs, VT);
290 // Unhandled operand. Halt "fast" selection and bail.
295 // N = N + Idx * ElementSize;
296 uint64_t ElementSize = TD.getTypePaddedSize(Ty);
297 unsigned IdxN = getRegForGEPIndex(Idx);
299 // Unhandled operand. Halt "fast" selection and bail.
302 if (ElementSize != 1) {
303 IdxN = FastEmit_ri_(VT, ISD::MUL, IdxN, ElementSize, VT);
305 // Unhandled operand. Halt "fast" selection and bail.
308 N = FastEmit_rr(VT, VT, ISD::ADD, N, IdxN);
310 // Unhandled operand. Halt "fast" selection and bail.
315 // We successfully emitted code for the given LLVM Instruction.
316 UpdateValueMap(I, N);
320 bool FastISel::SelectCall(User *I) {
321 Function *F = cast<CallInst>(I)->getCalledFunction();
322 if (!F) return false;
324 unsigned IID = F->getIntrinsicID();
327 case Intrinsic::dbg_stoppoint: {
328 DbgStopPointInst *SPI = cast<DbgStopPointInst>(I);
329 if (DW && DW->ValidDebugInfo(SPI->getContext())) {
330 DICompileUnit CU(cast<GlobalVariable>(SPI->getContext()));
332 unsigned SrcFile = DW->getOrCreateSourceID(CU.getDirectory(Dir),
334 unsigned Line = SPI->getLine();
335 unsigned Col = SPI->getColumn();
336 unsigned ID = DW->RecordSourceLine(Line, Col, SrcFile);
337 unsigned Idx = MF.getOrCreateDebugLocID(SrcFile, Line, Col);
338 setCurDebugLoc(DebugLoc::get(Idx));
339 const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
340 BuildMI(MBB, DL, II).addImm(ID);
344 case Intrinsic::dbg_region_start: {
345 DbgRegionStartInst *RSI = cast<DbgRegionStartInst>(I);
346 if (DW && DW->ValidDebugInfo(RSI->getContext())) {
348 DW->RecordRegionStart(cast<GlobalVariable>(RSI->getContext()));
349 const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
350 BuildMI(MBB, DL, II).addImm(ID);
354 case Intrinsic::dbg_region_end: {
355 DbgRegionEndInst *REI = cast<DbgRegionEndInst>(I);
356 if (DW && DW->ValidDebugInfo(REI->getContext())) {
358 DW->RecordRegionEnd(cast<GlobalVariable>(REI->getContext()));
359 const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
360 BuildMI(MBB, DL, II).addImm(ID);
364 case Intrinsic::dbg_func_start: {
365 if (!DW) return true;
366 DbgFuncStartInst *FSI = cast<DbgFuncStartInst>(I);
367 Value *SP = FSI->getSubprogram();
369 if (DW->ValidDebugInfo(SP)) {
370 // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is what
371 // (most?) gdb expects.
372 DISubprogram Subprogram(cast<GlobalVariable>(SP));
373 DICompileUnit CompileUnit = Subprogram.getCompileUnit();
375 unsigned SrcFile = DW->getOrCreateSourceID(CompileUnit.getDirectory(Dir),
376 CompileUnit.getFilename(FN));
378 // Record the source line.
379 unsigned Line = Subprogram.getLineNumber();
380 unsigned LabelID = DW->RecordSourceLine(Line, 0, SrcFile);
381 setCurDebugLoc(DebugLoc::get(MF.getOrCreateDebugLocID(SrcFile, Line, 0)));
384 Subprogram.getLinkageName(SPName);
386 && strcmp(SPName.c_str(), MF.getFunction()->getNameStart())) {
387 // This is a beginning of inlined function.
388 DW->RecordRegionStart(cast<GlobalVariable>(FSI->getSubprogram()),
390 const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
391 BuildMI(MBB, DL, II).addImm(LabelID);
392 DW->RecordInlineInfo(Subprogram.getGV(), LabelID);
394 // llvm.dbg.func_start also defines beginning of function scope.
395 DW->RecordRegionStart(cast<GlobalVariable>(FSI->getSubprogram()));
401 case Intrinsic::dbg_declare: {
402 DbgDeclareInst *DI = cast<DbgDeclareInst>(I);
403 Value *Variable = DI->getVariable();
404 if (DW && DW->ValidDebugInfo(Variable)) {
405 // Determine the address of the declared object.
406 Value *Address = DI->getAddress();
407 if (BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
408 Address = BCI->getOperand(0);
409 AllocaInst *AI = dyn_cast<AllocaInst>(Address);
410 // Don't handle byval struct arguments or VLAs, for example.
412 DenseMap<const AllocaInst*, int>::iterator SI =
413 StaticAllocaMap.find(AI);
414 if (SI == StaticAllocaMap.end()) break; // VLAs.
417 // Determine the debug globalvariable.
418 GlobalValue *GV = cast<GlobalVariable>(Variable);
420 // Build the DECLARE instruction.
421 const TargetInstrDesc &II = TII.get(TargetInstrInfo::DECLARE);
422 BuildMI(MBB, DL, II).addFrameIndex(FI).addGlobalAddress(GV);
426 case Intrinsic::eh_exception: {
427 MVT VT = TLI.getValueType(I->getType());
428 switch (TLI.getOperationAction(ISD::EXCEPTIONADDR, VT)) {
430 case TargetLowering::Expand: {
431 if (!MBB->isLandingPad()) {
432 // FIXME: Mark exception register as live in. Hack for PR1508.
433 unsigned Reg = TLI.getExceptionAddressRegister();
434 if (Reg) MBB->addLiveIn(Reg);
436 unsigned Reg = TLI.getExceptionAddressRegister();
437 const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
438 unsigned ResultReg = createResultReg(RC);
439 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
441 assert(InsertedCopy && "Can't copy address registers!");
442 InsertedCopy = InsertedCopy;
443 UpdateValueMap(I, ResultReg);
449 case Intrinsic::eh_selector_i32:
450 case Intrinsic::eh_selector_i64: {
451 MVT VT = TLI.getValueType(I->getType());
452 switch (TLI.getOperationAction(ISD::EHSELECTION, VT)) {
454 case TargetLowering::Expand: {
455 MVT VT = (IID == Intrinsic::eh_selector_i32 ?
456 MVT::i32 : MVT::i64);
459 if (MBB->isLandingPad())
460 AddCatchInfo(*cast<CallInst>(I), MMI, MBB);
463 CatchInfoLost.insert(cast<CallInst>(I));
465 // FIXME: Mark exception selector register as live in. Hack for PR1508.
466 unsigned Reg = TLI.getExceptionSelectorRegister();
467 if (Reg) MBB->addLiveIn(Reg);
470 unsigned Reg = TLI.getExceptionSelectorRegister();
471 const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
472 unsigned ResultReg = createResultReg(RC);
473 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
475 assert(InsertedCopy && "Can't copy address registers!");
476 InsertedCopy = InsertedCopy;
477 UpdateValueMap(I, ResultReg);
480 getRegForValue(Constant::getNullValue(I->getType()));
481 UpdateValueMap(I, ResultReg);
492 bool FastISel::SelectCast(User *I, ISD::NodeType Opcode) {
493 MVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
494 MVT DstVT = TLI.getValueType(I->getType());
496 if (SrcVT == MVT::Other || !SrcVT.isSimple() ||
497 DstVT == MVT::Other || !DstVT.isSimple())
498 // Unhandled type. Halt "fast" selection and bail.
501 // Check if the destination type is legal. Or as a special case,
502 // it may be i1 if we're doing a truncate because that's
503 // easy and somewhat common.
504 if (!TLI.isTypeLegal(DstVT))
505 if (DstVT != MVT::i1 || Opcode != ISD::TRUNCATE)
506 // Unhandled type. Halt "fast" selection and bail.
509 // Check if the source operand is legal. Or as a special case,
510 // it may be i1 if we're doing zero-extension because that's
511 // easy and somewhat common.
512 if (!TLI.isTypeLegal(SrcVT))
513 if (SrcVT != MVT::i1 || Opcode != ISD::ZERO_EXTEND)
514 // Unhandled type. Halt "fast" selection and bail.
517 unsigned InputReg = getRegForValue(I->getOperand(0));
519 // Unhandled operand. Halt "fast" selection and bail.
522 // If the operand is i1, arrange for the high bits in the register to be zero.
523 if (SrcVT == MVT::i1) {
524 SrcVT = TLI.getTypeToTransformTo(SrcVT);
525 InputReg = FastEmitZExtFromI1(SrcVT.getSimpleVT(), InputReg);
529 // If the result is i1, truncate to the target's type for i1 first.
530 if (DstVT == MVT::i1)
531 DstVT = TLI.getTypeToTransformTo(DstVT);
533 unsigned ResultReg = FastEmit_r(SrcVT.getSimpleVT(),
540 UpdateValueMap(I, ResultReg);
544 bool FastISel::SelectBitCast(User *I) {
545 // If the bitcast doesn't change the type, just use the operand value.
546 if (I->getType() == I->getOperand(0)->getType()) {
547 unsigned Reg = getRegForValue(I->getOperand(0));
550 UpdateValueMap(I, Reg);
554 // Bitcasts of other values become reg-reg copies or BIT_CONVERT operators.
555 MVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
556 MVT DstVT = TLI.getValueType(I->getType());
558 if (SrcVT == MVT::Other || !SrcVT.isSimple() ||
559 DstVT == MVT::Other || !DstVT.isSimple() ||
560 !TLI.isTypeLegal(SrcVT) || !TLI.isTypeLegal(DstVT))
561 // Unhandled type. Halt "fast" selection and bail.
564 unsigned Op0 = getRegForValue(I->getOperand(0));
566 // Unhandled operand. Halt "fast" selection and bail.
569 // First, try to perform the bitcast by inserting a reg-reg copy.
570 unsigned ResultReg = 0;
571 if (SrcVT.getSimpleVT() == DstVT.getSimpleVT()) {
572 TargetRegisterClass* SrcClass = TLI.getRegClassFor(SrcVT);
573 TargetRegisterClass* DstClass = TLI.getRegClassFor(DstVT);
574 ResultReg = createResultReg(DstClass);
576 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
577 Op0, DstClass, SrcClass);
582 // If the reg-reg copy failed, select a BIT_CONVERT opcode.
584 ResultReg = FastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(),
585 ISD::BIT_CONVERT, Op0);
590 UpdateValueMap(I, ResultReg);
595 FastISel::SelectInstruction(Instruction *I) {
596 return SelectOperator(I, I->getOpcode());
599 /// FastEmitBranch - Emit an unconditional branch to the given block,
600 /// unless it is the immediate (fall-through) successor, and update
603 FastISel::FastEmitBranch(MachineBasicBlock *MSucc) {
604 MachineFunction::iterator NextMBB =
605 next(MachineFunction::iterator(MBB));
607 if (MBB->isLayoutSuccessor(MSucc)) {
608 // The unconditional fall-through case, which needs no instructions.
610 // The unconditional branch case.
611 TII.InsertBranch(*MBB, MSucc, NULL, SmallVector<MachineOperand, 0>());
613 MBB->addSuccessor(MSucc);
617 FastISel::SelectOperator(User *I, unsigned Opcode) {
619 case Instruction::Add: {
620 ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FADD : ISD::ADD;
621 return SelectBinaryOp(I, Opc);
623 case Instruction::Sub: {
624 ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FSUB : ISD::SUB;
625 return SelectBinaryOp(I, Opc);
627 case Instruction::Mul: {
628 ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FMUL : ISD::MUL;
629 return SelectBinaryOp(I, Opc);
631 case Instruction::SDiv:
632 return SelectBinaryOp(I, ISD::SDIV);
633 case Instruction::UDiv:
634 return SelectBinaryOp(I, ISD::UDIV);
635 case Instruction::FDiv:
636 return SelectBinaryOp(I, ISD::FDIV);
637 case Instruction::SRem:
638 return SelectBinaryOp(I, ISD::SREM);
639 case Instruction::URem:
640 return SelectBinaryOp(I, ISD::UREM);
641 case Instruction::FRem:
642 return SelectBinaryOp(I, ISD::FREM);
643 case Instruction::Shl:
644 return SelectBinaryOp(I, ISD::SHL);
645 case Instruction::LShr:
646 return SelectBinaryOp(I, ISD::SRL);
647 case Instruction::AShr:
648 return SelectBinaryOp(I, ISD::SRA);
649 case Instruction::And:
650 return SelectBinaryOp(I, ISD::AND);
651 case Instruction::Or:
652 return SelectBinaryOp(I, ISD::OR);
653 case Instruction::Xor:
654 return SelectBinaryOp(I, ISD::XOR);
656 case Instruction::GetElementPtr:
657 return SelectGetElementPtr(I);
659 case Instruction::Br: {
660 BranchInst *BI = cast<BranchInst>(I);
662 if (BI->isUnconditional()) {
663 BasicBlock *LLVMSucc = BI->getSuccessor(0);
664 MachineBasicBlock *MSucc = MBBMap[LLVMSucc];
665 FastEmitBranch(MSucc);
669 // Conditional branches are not handed yet.
670 // Halt "fast" selection and bail.
674 case Instruction::Unreachable:
678 case Instruction::PHI:
679 // PHI nodes are already emitted.
682 case Instruction::Alloca:
683 // FunctionLowering has the static-sized case covered.
684 if (StaticAllocaMap.count(cast<AllocaInst>(I)))
687 // Dynamic-sized alloca is not handled yet.
690 case Instruction::Call:
691 return SelectCall(I);
693 case Instruction::BitCast:
694 return SelectBitCast(I);
696 case Instruction::FPToSI:
697 return SelectCast(I, ISD::FP_TO_SINT);
698 case Instruction::ZExt:
699 return SelectCast(I, ISD::ZERO_EXTEND);
700 case Instruction::SExt:
701 return SelectCast(I, ISD::SIGN_EXTEND);
702 case Instruction::Trunc:
703 return SelectCast(I, ISD::TRUNCATE);
704 case Instruction::SIToFP:
705 return SelectCast(I, ISD::SINT_TO_FP);
707 case Instruction::IntToPtr: // Deliberate fall-through.
708 case Instruction::PtrToInt: {
709 MVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
710 MVT DstVT = TLI.getValueType(I->getType());
711 if (DstVT.bitsGT(SrcVT))
712 return SelectCast(I, ISD::ZERO_EXTEND);
713 if (DstVT.bitsLT(SrcVT))
714 return SelectCast(I, ISD::TRUNCATE);
715 unsigned Reg = getRegForValue(I->getOperand(0));
716 if (Reg == 0) return false;
717 UpdateValueMap(I, Reg);
722 // Unhandled instruction. Halt "fast" selection and bail.
727 FastISel::FastISel(MachineFunction &mf,
728 MachineModuleInfo *mmi,
730 DenseMap<const Value *, unsigned> &vm,
731 DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
732 DenseMap<const AllocaInst *, int> &am
734 , SmallSet<Instruction*, 8> &cil
747 MRI(MF.getRegInfo()),
748 MFI(*MF.getFrameInfo()),
749 MCP(*MF.getConstantPool()),
751 TD(*TM.getTargetData()),
752 TII(*TM.getInstrInfo()),
753 TLI(*TM.getTargetLowering()) {
756 FastISel::~FastISel() {}
758 unsigned FastISel::FastEmit_(MVT::SimpleValueType, MVT::SimpleValueType,
763 unsigned FastISel::FastEmit_r(MVT::SimpleValueType, MVT::SimpleValueType,
764 ISD::NodeType, unsigned /*Op0*/) {
768 unsigned FastISel::FastEmit_rr(MVT::SimpleValueType, MVT::SimpleValueType,
769 ISD::NodeType, unsigned /*Op0*/,
774 unsigned FastISel::FastEmit_i(MVT::SimpleValueType, MVT::SimpleValueType,
775 ISD::NodeType, uint64_t /*Imm*/) {
779 unsigned FastISel::FastEmit_f(MVT::SimpleValueType, MVT::SimpleValueType,
780 ISD::NodeType, ConstantFP * /*FPImm*/) {
784 unsigned FastISel::FastEmit_ri(MVT::SimpleValueType, MVT::SimpleValueType,
785 ISD::NodeType, unsigned /*Op0*/,
790 unsigned FastISel::FastEmit_rf(MVT::SimpleValueType, MVT::SimpleValueType,
791 ISD::NodeType, unsigned /*Op0*/,
792 ConstantFP * /*FPImm*/) {
796 unsigned FastISel::FastEmit_rri(MVT::SimpleValueType, MVT::SimpleValueType,
798 unsigned /*Op0*/, unsigned /*Op1*/,
803 /// FastEmit_ri_ - This method is a wrapper of FastEmit_ri. It first tries
804 /// to emit an instruction with an immediate operand using FastEmit_ri.
805 /// If that fails, it materializes the immediate into a register and try
806 /// FastEmit_rr instead.
807 unsigned FastISel::FastEmit_ri_(MVT::SimpleValueType VT, ISD::NodeType Opcode,
808 unsigned Op0, uint64_t Imm,
809 MVT::SimpleValueType ImmType) {
810 // First check if immediate type is legal. If not, we can't use the ri form.
811 unsigned ResultReg = FastEmit_ri(VT, VT, Opcode, Op0, Imm);
814 unsigned MaterialReg = FastEmit_i(ImmType, ImmType, ISD::Constant, Imm);
815 if (MaterialReg == 0)
817 return FastEmit_rr(VT, VT, Opcode, Op0, MaterialReg);
820 /// FastEmit_rf_ - This method is a wrapper of FastEmit_ri. It first tries
821 /// to emit an instruction with a floating-point immediate operand using
822 /// FastEmit_rf. If that fails, it materializes the immediate into a register
823 /// and try FastEmit_rr instead.
824 unsigned FastISel::FastEmit_rf_(MVT::SimpleValueType VT, ISD::NodeType Opcode,
825 unsigned Op0, ConstantFP *FPImm,
826 MVT::SimpleValueType ImmType) {
827 // First check if immediate type is legal. If not, we can't use the rf form.
828 unsigned ResultReg = FastEmit_rf(VT, VT, Opcode, Op0, FPImm);
832 // Materialize the constant in a register.
833 unsigned MaterialReg = FastEmit_f(ImmType, ImmType, ISD::ConstantFP, FPImm);
834 if (MaterialReg == 0) {
835 // If the target doesn't have a way to directly enter a floating-point
836 // value into a register, use an alternate approach.
837 // TODO: The current approach only supports floating-point constants
838 // that can be constructed by conversion from integer values. This should
839 // be replaced by code that creates a load from a constant-pool entry,
840 // which will require some target-specific work.
841 const APFloat &Flt = FPImm->getValueAPF();
842 MVT IntVT = TLI.getPointerTy();
845 uint32_t IntBitWidth = IntVT.getSizeInBits();
847 (void) Flt.convertToInteger(x, IntBitWidth, /*isSigned=*/true,
848 APFloat::rmTowardZero, &isExact);
851 APInt IntVal(IntBitWidth, 2, x);
853 unsigned IntegerReg = FastEmit_i(IntVT.getSimpleVT(), IntVT.getSimpleVT(),
854 ISD::Constant, IntVal.getZExtValue());
857 MaterialReg = FastEmit_r(IntVT.getSimpleVT(), VT,
858 ISD::SINT_TO_FP, IntegerReg);
859 if (MaterialReg == 0)
862 return FastEmit_rr(VT, VT, Opcode, Op0, MaterialReg);
865 unsigned FastISel::createResultReg(const TargetRegisterClass* RC) {
866 return MRI.createVirtualRegister(RC);
869 unsigned FastISel::FastEmitInst_(unsigned MachineInstOpcode,
870 const TargetRegisterClass* RC) {
871 unsigned ResultReg = createResultReg(RC);
872 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
874 BuildMI(MBB, DL, II, ResultReg);
878 unsigned FastISel::FastEmitInst_r(unsigned MachineInstOpcode,
879 const TargetRegisterClass *RC,
881 unsigned ResultReg = createResultReg(RC);
882 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
884 if (II.getNumDefs() >= 1)
885 BuildMI(MBB, DL, II, ResultReg).addReg(Op0);
887 BuildMI(MBB, DL, II).addReg(Op0);
888 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
889 II.ImplicitDefs[0], RC, RC);
897 unsigned FastISel::FastEmitInst_rr(unsigned MachineInstOpcode,
898 const TargetRegisterClass *RC,
899 unsigned Op0, unsigned Op1) {
900 unsigned ResultReg = createResultReg(RC);
901 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
903 if (II.getNumDefs() >= 1)
904 BuildMI(MBB, DL, II, ResultReg).addReg(Op0).addReg(Op1);
906 BuildMI(MBB, DL, II).addReg(Op0).addReg(Op1);
907 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
908 II.ImplicitDefs[0], RC, RC);
915 unsigned FastISel::FastEmitInst_ri(unsigned MachineInstOpcode,
916 const TargetRegisterClass *RC,
917 unsigned Op0, uint64_t Imm) {
918 unsigned ResultReg = createResultReg(RC);
919 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
921 if (II.getNumDefs() >= 1)
922 BuildMI(MBB, DL, II, ResultReg).addReg(Op0).addImm(Imm);
924 BuildMI(MBB, DL, II).addReg(Op0).addImm(Imm);
925 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
926 II.ImplicitDefs[0], RC, RC);
933 unsigned FastISel::FastEmitInst_rf(unsigned MachineInstOpcode,
934 const TargetRegisterClass *RC,
935 unsigned Op0, ConstantFP *FPImm) {
936 unsigned ResultReg = createResultReg(RC);
937 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
939 if (II.getNumDefs() >= 1)
940 BuildMI(MBB, DL, II, ResultReg).addReg(Op0).addFPImm(FPImm);
942 BuildMI(MBB, DL, II).addReg(Op0).addFPImm(FPImm);
943 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
944 II.ImplicitDefs[0], RC, RC);
951 unsigned FastISel::FastEmitInst_rri(unsigned MachineInstOpcode,
952 const TargetRegisterClass *RC,
953 unsigned Op0, unsigned Op1, uint64_t Imm) {
954 unsigned ResultReg = createResultReg(RC);
955 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
957 if (II.getNumDefs() >= 1)
958 BuildMI(MBB, DL, II, ResultReg).addReg(Op0).addReg(Op1).addImm(Imm);
960 BuildMI(MBB, DL, II).addReg(Op0).addReg(Op1).addImm(Imm);
961 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
962 II.ImplicitDefs[0], RC, RC);
969 unsigned FastISel::FastEmitInst_i(unsigned MachineInstOpcode,
970 const TargetRegisterClass *RC,
972 unsigned ResultReg = createResultReg(RC);
973 const TargetInstrDesc &II = TII.get(MachineInstOpcode);
975 if (II.getNumDefs() >= 1)
976 BuildMI(MBB, DL, II, ResultReg).addImm(Imm);
978 BuildMI(MBB, DL, II).addImm(Imm);
979 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
980 II.ImplicitDefs[0], RC, RC);
987 unsigned FastISel::FastEmitInst_extractsubreg(MVT::SimpleValueType RetVT,
988 unsigned Op0, uint32_t Idx) {
989 const TargetRegisterClass* RC = MRI.getRegClass(Op0);
991 unsigned ResultReg = createResultReg(TLI.getRegClassFor(RetVT));
992 const TargetInstrDesc &II = TII.get(TargetInstrInfo::EXTRACT_SUBREG);
994 if (II.getNumDefs() >= 1)
995 BuildMI(MBB, DL, II, ResultReg).addReg(Op0).addImm(Idx);
997 BuildMI(MBB, DL, II).addReg(Op0).addImm(Idx);
998 bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
999 II.ImplicitDefs[0], RC, RC);
1006 /// FastEmitZExtFromI1 - Emit MachineInstrs to compute the value of Op
1007 /// with all but the least significant bit set to zero.
1008 unsigned FastISel::FastEmitZExtFromI1(MVT::SimpleValueType VT, unsigned Op) {
1009 return FastEmit_ri(VT, VT, ISD::AND, Op, 1);