1 //===-- InstSelectSimple.cpp - A simple instruction selector for x86 ------===//
3 // This file defines a simple peephole instruction selector for the x86 target
5 //===----------------------------------------------------------------------===//
8 #include "X86InstrInfo.h"
9 #include "X86InstrBuilder.h"
10 #include "llvm/Function.h"
11 #include "llvm/Instructions.h"
12 #include "llvm/DerivedTypes.h"
13 #include "llvm/Constants.h"
14 #include "llvm/Pass.h"
15 #include "llvm/Intrinsics.h"
16 #include "llvm/CodeGen/MachineFunction.h"
17 #include "llvm/CodeGen/MachineInstrBuilder.h"
18 #include "llvm/CodeGen/SSARegMap.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/CodeGen/MachineConstantPool.h"
21 #include "llvm/Target/TargetMachine.h"
22 #include "llvm/Target/MRegisterInfo.h"
23 #include "llvm/Support/InstVisitor.h"
25 /// BMI - A special BuildMI variant that takes an iterator to insert the
26 /// instruction at as well as a basic block. This is the version for when you
27 /// have a destination register in mind.
28 inline static MachineInstrBuilder BMI(MachineBasicBlock *MBB,
29 MachineBasicBlock::iterator &I,
30 int Opcode, unsigned NumOperands,
32 assert(I >= MBB->begin() && I <= MBB->end() && "Bad iterator!");
33 MachineInstr *MI = new MachineInstr(Opcode, NumOperands+1, true, true);
34 I = MBB->insert(I, MI)+1;
35 return MachineInstrBuilder(MI).addReg(DestReg, MOTy::Def);
38 /// BMI - A special BuildMI variant that takes an iterator to insert the
39 /// instruction at as well as a basic block.
40 inline static MachineInstrBuilder BMI(MachineBasicBlock *MBB,
41 MachineBasicBlock::iterator &I,
42 int Opcode, unsigned NumOperands) {
43 assert(I >= MBB->begin() && I <= MBB->end() && "Bad iterator!");
44 MachineInstr *MI = new MachineInstr(Opcode, NumOperands, true, true);
45 I = MBB->insert(I, MI)+1;
46 return MachineInstrBuilder(MI);
51 struct ISel : public FunctionPass, InstVisitor<ISel> {
53 MachineFunction *F; // The function we are compiling into
54 MachineBasicBlock *BB; // The current MBB we are compiling
55 int VarArgsFrameIndex; // FrameIndex for start of varargs area
57 std::map<Value*, unsigned> RegMap; // Mapping between Val's and SSA Regs
59 // MBBMap - Mapping between LLVM BB -> Machine BB
60 std::map<const BasicBlock*, MachineBasicBlock*> MBBMap;
62 ISel(TargetMachine &tm) : TM(tm), F(0), BB(0) {}
64 /// runOnFunction - Top level implementation of instruction selection for
65 /// the entire function.
67 bool runOnFunction(Function &Fn) {
68 F = &MachineFunction::construct(&Fn, TM);
70 // Create all of the machine basic blocks for the function...
71 for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
72 F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
76 // Copy incoming arguments off of the stack...
77 LoadArgumentsToVirtualRegs(Fn);
79 // Instruction select everything except PHI nodes
82 // Select the PHI nodes
88 return false; // We never modify the LLVM itself.
91 virtual const char *getPassName() const {
92 return "X86 Simple Instruction Selection";
95 /// visitBasicBlock - This method is called when we are visiting a new basic
96 /// block. This simply creates a new MachineBasicBlock to emit code into
97 /// and adds it to the current MachineFunction. Subsequent visit* for
98 /// instructions will be invoked for all instructions in the basic block.
100 void visitBasicBlock(BasicBlock &LLVM_BB) {
101 BB = MBBMap[&LLVM_BB];
104 /// LoadArgumentsToVirtualRegs - Load all of the arguments to this function
105 /// from the stack into virtual registers.
107 void LoadArgumentsToVirtualRegs(Function &F);
109 /// SelectPHINodes - Insert machine code to generate phis. This is tricky
110 /// because we have to generate our sources into the source basic blocks,
111 /// not the current one.
113 void SelectPHINodes();
115 // Visitation methods for various instructions. These methods simply emit
116 // fixed X86 code for each instruction.
119 // Control flow operators
120 void visitReturnInst(ReturnInst &RI);
121 void visitBranchInst(BranchInst &BI);
126 ValueRecord(unsigned R, const Type *T) : Reg(R), Ty(T) {}
128 void doCall(const ValueRecord &Ret, MachineInstr *CallMI,
129 const std::vector<ValueRecord> &Args);
130 void visitCallInst(CallInst &I);
131 void visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &I);
133 // Arithmetic operators
134 void visitSimpleBinary(BinaryOperator &B, unsigned OpcodeClass);
135 void visitAdd(BinaryOperator &B) { visitSimpleBinary(B, 0); }
136 void visitSub(BinaryOperator &B) { visitSimpleBinary(B, 1); }
137 void doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator &MBBI,
138 unsigned DestReg, const Type *DestTy,
139 unsigned Op0Reg, unsigned Op1Reg);
140 void visitMul(BinaryOperator &B);
142 void visitDiv(BinaryOperator &B) { visitDivRem(B); }
143 void visitRem(BinaryOperator &B) { visitDivRem(B); }
144 void visitDivRem(BinaryOperator &B);
147 void visitAnd(BinaryOperator &B) { visitSimpleBinary(B, 2); }
148 void visitOr (BinaryOperator &B) { visitSimpleBinary(B, 3); }
149 void visitXor(BinaryOperator &B) { visitSimpleBinary(B, 4); }
151 // Comparison operators...
152 void visitSetCondInst(SetCondInst &I);
153 bool EmitComparisonGetSignedness(unsigned OpNum, Value *Op0, Value *Op1);
155 // Memory Instructions
156 MachineInstr *doFPLoad(MachineBasicBlock *MBB,
157 MachineBasicBlock::iterator &MBBI,
158 const Type *Ty, unsigned DestReg);
159 void visitLoadInst(LoadInst &I);
160 void doFPStore(const Type *Ty, unsigned DestAddrReg, unsigned SrcReg);
161 void visitStoreInst(StoreInst &I);
162 void visitGetElementPtrInst(GetElementPtrInst &I);
163 void visitAllocaInst(AllocaInst &I);
164 void visitMallocInst(MallocInst &I);
165 void visitFreeInst(FreeInst &I);
168 void visitShiftInst(ShiftInst &I);
169 void visitPHINode(PHINode &I) {} // PHI nodes handled by second pass
170 void visitCastInst(CastInst &I);
171 void visitVarArgInst(VarArgInst &I);
173 void visitInstruction(Instruction &I) {
174 std::cerr << "Cannot instruction select: " << I;
178 /// promote32 - Make a value 32-bits wide, and put it somewhere.
180 void promote32(unsigned targetReg, const ValueRecord &VR);
182 /// EmitByteSwap - Byteswap SrcReg into DestReg.
184 void EmitByteSwap(unsigned DestReg, unsigned SrcReg, unsigned Class);
186 /// emitGEPOperation - Common code shared between visitGetElementPtrInst and
187 /// constant expression GEP support.
189 void emitGEPOperation(MachineBasicBlock *BB, MachineBasicBlock::iterator&IP,
190 Value *Src, User::op_iterator IdxBegin,
191 User::op_iterator IdxEnd, unsigned TargetReg);
193 /// emitCastOperation - Common code shared between visitCastInst and
194 /// constant expression cast support.
195 void emitCastOperation(MachineBasicBlock *BB,MachineBasicBlock::iterator&IP,
196 Value *Src, const Type *DestTy, unsigned TargetReg);
198 /// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
199 /// and constant expression support.
200 void emitSimpleBinaryOperation(MachineBasicBlock *BB,
201 MachineBasicBlock::iterator &IP,
202 Value *Op0, Value *Op1,
203 unsigned OperatorClass, unsigned TargetReg);
205 /// copyConstantToRegister - Output the instructions required to put the
206 /// specified constant into the specified register.
208 void copyConstantToRegister(MachineBasicBlock *MBB,
209 MachineBasicBlock::iterator &MBBI,
210 Constant *C, unsigned Reg);
212 /// makeAnotherReg - This method returns the next register number we haven't
215 /// Long values are handled somewhat specially. They are always allocated
216 /// as pairs of 32 bit integer values. The register number returned is the
217 /// lower 32 bits of the long value, and the regNum+1 is the upper 32 bits
218 /// of the long value.
220 unsigned makeAnotherReg(const Type *Ty) {
221 if (Ty == Type::LongTy || Ty == Type::ULongTy) {
222 const TargetRegisterClass *RC =
223 TM.getRegisterInfo()->getRegClassForType(Type::IntTy);
224 // Create the lower part
225 F->getSSARegMap()->createVirtualRegister(RC);
226 // Create the upper part.
227 return F->getSSARegMap()->createVirtualRegister(RC)-1;
230 // Add the mapping of regnumber => reg class to MachineFunction
231 const TargetRegisterClass *RC =
232 TM.getRegisterInfo()->getRegClassForType(Ty);
233 return F->getSSARegMap()->createVirtualRegister(RC);
236 /// getReg - This method turns an LLVM value into a register number. This
237 /// is guaranteed to produce the same register number for a particular value
238 /// every time it is queried.
240 unsigned getReg(Value &V) { return getReg(&V); } // Allow references
241 unsigned getReg(Value *V) {
242 // Just append to the end of the current bb.
243 MachineBasicBlock::iterator It = BB->end();
244 return getReg(V, BB, It);
246 unsigned getReg(Value *V, MachineBasicBlock *MBB,
247 MachineBasicBlock::iterator &IPt) {
248 unsigned &Reg = RegMap[V];
250 Reg = makeAnotherReg(V->getType());
254 // If this operand is a constant, emit the code to copy the constant into
255 // the register here...
257 if (Constant *C = dyn_cast<Constant>(V)) {
258 copyConstantToRegister(MBB, IPt, C, Reg);
259 RegMap.erase(V); // Assign a new name to this constant if ref'd again
260 } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
261 // Move the address of the global into the register
262 BMI(MBB, IPt, X86::MOVir32, 1, Reg).addGlobalAddress(GV);
263 RegMap.erase(V); // Assign a new name to this address if ref'd again
271 /// TypeClass - Used by the X86 backend to group LLVM types by their basic X86
275 cByte, cShort, cInt, cFP, cLong
278 /// getClass - Turn a primitive type into a "class" number which is based on the
279 /// size of the type, and whether or not it is floating point.
281 static inline TypeClass getClass(const Type *Ty) {
282 switch (Ty->getPrimitiveID()) {
283 case Type::SByteTyID:
284 case Type::UByteTyID: return cByte; // Byte operands are class #0
285 case Type::ShortTyID:
286 case Type::UShortTyID: return cShort; // Short operands are class #1
289 case Type::PointerTyID: return cInt; // Int's and pointers are class #2
291 case Type::FloatTyID:
292 case Type::DoubleTyID: return cFP; // Floating Point is #3
295 case Type::ULongTyID: return cLong; // Longs are class #4
297 assert(0 && "Invalid type to getClass!");
298 return cByte; // not reached
302 // getClassB - Just like getClass, but treat boolean values as bytes.
303 static inline TypeClass getClassB(const Type *Ty) {
304 if (Ty == Type::BoolTy) return cByte;
309 /// copyConstantToRegister - Output the instructions required to put the
310 /// specified constant into the specified register.
312 void ISel::copyConstantToRegister(MachineBasicBlock *MBB,
313 MachineBasicBlock::iterator &IP,
314 Constant *C, unsigned R) {
315 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
317 switch (CE->getOpcode()) {
318 case Instruction::GetElementPtr:
319 emitGEPOperation(MBB, IP, CE->getOperand(0),
320 CE->op_begin()+1, CE->op_end(), R);
322 case Instruction::Cast:
323 emitCastOperation(MBB, IP, CE->getOperand(0), CE->getType(), R);
326 case Instruction::Xor: ++Class; // FALL THROUGH
327 case Instruction::Or: ++Class; // FALL THROUGH
328 case Instruction::And: ++Class; // FALL THROUGH
329 case Instruction::Sub: ++Class; // FALL THROUGH
330 case Instruction::Add:
331 emitSimpleBinaryOperation(MBB, IP, CE->getOperand(0), CE->getOperand(1),
336 std::cerr << "Offending expr: " << C << "\n";
337 assert(0 && "Constant expressions not yet handled!\n");
341 if (C->getType()->isIntegral()) {
342 unsigned Class = getClassB(C->getType());
344 if (Class == cLong) {
345 // Copy the value into the register pair.
347 if (C->getType()->isSigned())
348 Val = cast<ConstantSInt>(C)->getValue();
350 Val = cast<ConstantUInt>(C)->getValue();
352 BMI(MBB, IP, X86::MOVir32, 1, R).addZImm(Val & 0xFFFFFFFF);
353 BMI(MBB, IP, X86::MOVir32, 1, R+1).addZImm(Val >> 32);
357 assert(Class <= cInt && "Type not handled yet!");
359 static const unsigned IntegralOpcodeTab[] = {
360 X86::MOVir8, X86::MOVir16, X86::MOVir32
363 if (C->getType() == Type::BoolTy) {
364 BMI(MBB, IP, X86::MOVir8, 1, R).addZImm(C == ConstantBool::True);
365 } else if (C->getType()->isSigned()) {
366 ConstantSInt *CSI = cast<ConstantSInt>(C);
367 BMI(MBB, IP, IntegralOpcodeTab[Class], 1, R).addZImm(CSI->getValue());
369 ConstantUInt *CUI = cast<ConstantUInt>(C);
370 BMI(MBB, IP, IntegralOpcodeTab[Class], 1, R).addZImm(CUI->getValue());
372 } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
373 double Value = CFP->getValue();
375 BMI(MBB, IP, X86::FLD0, 0, R);
376 else if (Value == +1.0)
377 BMI(MBB, IP, X86::FLD1, 0, R);
379 // Otherwise we need to spill the constant to memory...
380 MachineConstantPool *CP = F->getConstantPool();
381 unsigned CPI = CP->getConstantPoolIndex(CFP);
382 addConstantPoolReference(doFPLoad(MBB, IP, CFP->getType(), R), CPI);
385 } else if (isa<ConstantPointerNull>(C)) {
386 // Copy zero (null pointer) to the register.
387 BMI(MBB, IP, X86::MOVir32, 1, R).addZImm(0);
388 } else if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)) {
389 unsigned SrcReg = getReg(CPR->getValue(), MBB, IP);
390 BMI(MBB, IP, X86::MOVrr32, 1, R).addReg(SrcReg);
392 std::cerr << "Offending constant: " << C << "\n";
393 assert(0 && "Type not handled yet!");
397 /// LoadArgumentsToVirtualRegs - Load all of the arguments to this function from
398 /// the stack into virtual registers.
400 void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
401 // Emit instructions to load the arguments... On entry to a function on the
402 // X86, the stack frame looks like this:
404 // [ESP] -- return address
405 // [ESP + 4] -- first argument (leftmost lexically)
406 // [ESP + 8] -- second argument, if first argument is four bytes in size
409 unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
410 MachineFrameInfo *MFI = F->getFrameInfo();
412 for (Function::aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
413 unsigned Reg = getReg(*I);
415 int FI; // Frame object index
416 switch (getClassB(I->getType())) {
418 FI = MFI->CreateFixedObject(1, ArgOffset);
419 addFrameReference(BuildMI(BB, X86::MOVmr8, 4, Reg), FI);
422 FI = MFI->CreateFixedObject(2, ArgOffset);
423 addFrameReference(BuildMI(BB, X86::MOVmr16, 4, Reg), FI);
426 FI = MFI->CreateFixedObject(4, ArgOffset);
427 addFrameReference(BuildMI(BB, X86::MOVmr32, 4, Reg), FI);
430 FI = MFI->CreateFixedObject(8, ArgOffset);
431 addFrameReference(BuildMI(BB, X86::MOVmr32, 4, Reg), FI);
432 addFrameReference(BuildMI(BB, X86::MOVmr32, 4, Reg+1), FI, 4);
433 ArgOffset += 4; // longs require 4 additional bytes
437 if (I->getType() == Type::FloatTy) {
438 Opcode = X86::FLDr32;
439 FI = MFI->CreateFixedObject(4, ArgOffset);
441 Opcode = X86::FLDr64;
442 FI = MFI->CreateFixedObject(8, ArgOffset);
443 ArgOffset += 4; // doubles require 4 additional bytes
445 addFrameReference(BuildMI(BB, Opcode, 4, Reg), FI);
448 assert(0 && "Unhandled argument type!");
450 ArgOffset += 4; // Each argument takes at least 4 bytes on the stack...
453 // If the function takes variable number of arguments, add a frame offset for
454 // the start of the first vararg value... this is used to expand
456 if (Fn.getFunctionType()->isVarArg())
457 VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
461 /// SelectPHINodes - Insert machine code to generate phis. This is tricky
462 /// because we have to generate our sources into the source basic blocks, not
465 void ISel::SelectPHINodes() {
466 const TargetInstrInfo &TII = TM.getInstrInfo();
467 const Function &LF = *F->getFunction(); // The LLVM function...
468 for (Function::const_iterator I = LF.begin(), E = LF.end(); I != E; ++I) {
469 const BasicBlock *BB = I;
470 MachineBasicBlock *MBB = MBBMap[I];
472 // Loop over all of the PHI nodes in the LLVM basic block...
473 unsigned NumPHIs = 0;
474 for (BasicBlock::const_iterator I = BB->begin();
475 PHINode *PN = (PHINode*)dyn_cast<PHINode>(I); ++I) {
477 // Create a new machine instr PHI node, and insert it.
478 unsigned PHIReg = getReg(*PN);
479 MachineInstr *PhiMI = BuildMI(X86::PHI, PN->getNumOperands(), PHIReg);
480 MBB->insert(MBB->begin()+NumPHIs++, PhiMI);
482 MachineInstr *LongPhiMI = 0;
483 if (PN->getType() == Type::LongTy || PN->getType() == Type::ULongTy) {
484 LongPhiMI = BuildMI(X86::PHI, PN->getNumOperands(), PHIReg+1);
485 MBB->insert(MBB->begin()+NumPHIs++, LongPhiMI);
488 // PHIValues - Map of blocks to incoming virtual registers. We use this
489 // so that we only initialize one incoming value for a particular block,
490 // even if the block has multiple entries in the PHI node.
492 std::map<MachineBasicBlock*, unsigned> PHIValues;
494 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
495 MachineBasicBlock *PredMBB = MBBMap[PN->getIncomingBlock(i)];
497 std::map<MachineBasicBlock*, unsigned>::iterator EntryIt =
498 PHIValues.lower_bound(PredMBB);
500 if (EntryIt != PHIValues.end() && EntryIt->first == PredMBB) {
501 // We already inserted an initialization of the register for this
502 // predecessor. Recycle it.
503 ValReg = EntryIt->second;
506 // Get the incoming value into a virtual register. If it is not
507 // already available in a virtual register, insert the computation
510 MachineBasicBlock::iterator PI = PredMBB->end();
511 while (PI != PredMBB->begin() &&
512 TII.isTerminatorInstr((*(PI-1))->getOpcode()))
514 ValReg = getReg(PN->getIncomingValue(i), PredMBB, PI);
516 // Remember that we inserted a value for this PHI for this predecessor
517 PHIValues.insert(EntryIt, std::make_pair(PredMBB, ValReg));
520 PhiMI->addRegOperand(ValReg);
521 PhiMI->addMachineBasicBlockOperand(PredMBB);
523 LongPhiMI->addRegOperand(ValReg+1);
524 LongPhiMI->addMachineBasicBlockOperand(PredMBB);
531 // canFoldSetCCIntoBranch - Return the setcc instruction if we can fold it into
532 // the conditional branch instruction which is the only user of the cc
533 // instruction. This is the case if the conditional branch is the only user of
534 // the setcc, and if the setcc is in the same basic block as the conditional
535 // branch. We also don't handle long arguments below, so we reject them here as
538 static SetCondInst *canFoldSetCCIntoBranch(Value *V) {
539 if (SetCondInst *SCI = dyn_cast<SetCondInst>(V))
540 if (SCI->use_size() == 1 && isa<BranchInst>(SCI->use_back()) &&
541 SCI->getParent() == cast<BranchInst>(SCI->use_back())->getParent()) {
542 const Type *Ty = SCI->getOperand(0)->getType();
543 if (Ty != Type::LongTy && Ty != Type::ULongTy)
549 // Return a fixed numbering for setcc instructions which does not depend on the
550 // order of the opcodes.
552 static unsigned getSetCCNumber(unsigned Opcode) {
554 default: assert(0 && "Unknown setcc instruction!");
555 case Instruction::SetEQ: return 0;
556 case Instruction::SetNE: return 1;
557 case Instruction::SetLT: return 2;
558 case Instruction::SetGE: return 3;
559 case Instruction::SetGT: return 4;
560 case Instruction::SetLE: return 5;
564 // LLVM -> X86 signed X86 unsigned
565 // ----- ---------- ------------
566 // seteq -> sete sete
567 // setne -> setne setne
568 // setlt -> setl setb
569 // setge -> setge setae
570 // setgt -> setg seta
571 // setle -> setle setbe
572 static const unsigned SetCCOpcodeTab[2][6] = {
573 {X86::SETEr, X86::SETNEr, X86::SETBr, X86::SETAEr, X86::SETAr, X86::SETBEr},
574 {X86::SETEr, X86::SETNEr, X86::SETLr, X86::SETGEr, X86::SETGr, X86::SETLEr},
577 bool ISel::EmitComparisonGetSignedness(unsigned OpNum, Value *Op0, Value *Op1) {
579 // The arguments are already supposed to be of the same type.
580 const Type *CompTy = Op0->getType();
581 bool isSigned = CompTy->isSigned();
582 unsigned Class = getClassB(CompTy);
583 unsigned Op0r = getReg(Op0);
585 // Special case handling of: cmp R, i
586 if (Class == cByte || Class == cShort || Class == cInt)
587 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
589 if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(CI))
590 Op1v = CSI->getValue();
592 Op1v = cast<ConstantUInt>(CI)->getValue();
593 // Mask off any upper bits of the constant, if there are any...
594 Op1v &= (1ULL << (8 << Class)) - 1;
597 case cByte: BuildMI(BB, X86::CMPri8, 2).addReg(Op0r).addZImm(Op1v);break;
598 case cShort: BuildMI(BB, X86::CMPri16,2).addReg(Op0r).addZImm(Op1v);break;
599 case cInt: BuildMI(BB, X86::CMPri32,2).addReg(Op0r).addZImm(Op1v);break;
601 assert(0 && "Invalid class!");
606 unsigned Op1r = getReg(Op1);
608 default: assert(0 && "Unknown type class!");
609 // Emit: cmp <var1>, <var2> (do the comparison). We can
610 // compare 8-bit with 8-bit, 16-bit with 16-bit, 32-bit with
613 BuildMI(BB, X86::CMPrr8, 2).addReg(Op0r).addReg(Op1r);
616 BuildMI(BB, X86::CMPrr16, 2).addReg(Op0r).addReg(Op1r);
619 BuildMI(BB, X86::CMPrr32, 2).addReg(Op0r).addReg(Op1r);
622 BuildMI(BB, X86::FpUCOM, 2).addReg(Op0r).addReg(Op1r);
623 BuildMI(BB, X86::FNSTSWr8, 0);
624 BuildMI(BB, X86::SAHF, 1);
625 isSigned = false; // Compare with unsigned operators
629 if (OpNum < 2) { // seteq, setne
630 unsigned LoTmp = makeAnotherReg(Type::IntTy);
631 unsigned HiTmp = makeAnotherReg(Type::IntTy);
632 unsigned FinalTmp = makeAnotherReg(Type::IntTy);
633 BuildMI(BB, X86::XORrr32, 2, LoTmp).addReg(Op0r).addReg(Op1r);
634 BuildMI(BB, X86::XORrr32, 2, HiTmp).addReg(Op0r+1).addReg(Op1r+1);
635 BuildMI(BB, X86::ORrr32, 2, FinalTmp).addReg(LoTmp).addReg(HiTmp);
636 break; // Allow the sete or setne to be generated from flags set by OR
638 // Emit a sequence of code which compares the high and low parts once
639 // each, then uses a conditional move to handle the overflow case. For
640 // example, a setlt for long would generate code like this:
642 // AL = lo(op1) < lo(op2) // Signedness depends on operands
643 // BL = hi(op1) < hi(op2) // Always unsigned comparison
644 // dest = hi(op1) == hi(op2) ? AL : BL;
647 // FIXME: This would be much better if we had hierarchical register
648 // classes! Until then, hardcode registers so that we can deal with their
649 // aliases (because we don't have conditional byte moves).
651 BuildMI(BB, X86::CMPrr32, 2).addReg(Op0r).addReg(Op1r);
652 BuildMI(BB, SetCCOpcodeTab[0][OpNum], 0, X86::AL);
653 BuildMI(BB, X86::CMPrr32, 2).addReg(Op0r+1).addReg(Op1r+1);
654 BuildMI(BB, SetCCOpcodeTab[isSigned][OpNum], 0, X86::BL);
655 BuildMI(BB, X86::CMOVErr16, 2, X86::BX).addReg(X86::BX).addReg(X86::AX);
656 // NOTE: visitSetCondInst knows that the value is dumped into the BL
657 // register at this point for long values...
665 /// SetCC instructions - Here we just emit boilerplate code to set a byte-sized
666 /// register, then move it to wherever the result should be.
668 void ISel::visitSetCondInst(SetCondInst &I) {
669 if (canFoldSetCCIntoBranch(&I)) return; // Fold this into a branch...
671 unsigned OpNum = getSetCCNumber(I.getOpcode());
672 unsigned DestReg = getReg(I);
673 bool isSigned = EmitComparisonGetSignedness(OpNum, I.getOperand(0),
676 if (getClassB(I.getOperand(0)->getType()) != cLong || OpNum < 2) {
677 // Handle normal comparisons with a setcc instruction...
678 BuildMI(BB, SetCCOpcodeTab[isSigned][OpNum], 0, DestReg);
680 // Handle long comparisons by copying the value which is already in BL into
681 // the register we want...
682 BuildMI(BB, X86::MOVrr8, 1, DestReg).addReg(X86::BL);
686 /// promote32 - Emit instructions to turn a narrow operand into a 32-bit-wide
687 /// operand, in the specified target register.
688 void ISel::promote32(unsigned targetReg, const ValueRecord &VR) {
689 bool isUnsigned = VR.Ty->isUnsigned();
690 switch (getClassB(VR.Ty)) {
692 // Extend value into target register (8->32)
694 BuildMI(BB, X86::MOVZXr32r8, 1, targetReg).addReg(VR.Reg);
696 BuildMI(BB, X86::MOVSXr32r8, 1, targetReg).addReg(VR.Reg);
699 // Extend value into target register (16->32)
701 BuildMI(BB, X86::MOVZXr32r16, 1, targetReg).addReg(VR.Reg);
703 BuildMI(BB, X86::MOVSXr32r16, 1, targetReg).addReg(VR.Reg);
706 // Move value into target register (32->32)
707 BuildMI(BB, X86::MOVrr32, 1, targetReg).addReg(VR.Reg);
710 assert(0 && "Unpromotable operand class in promote32");
714 /// 'ret' instruction - Here we are interested in meeting the x86 ABI. As such,
715 /// we have the following possibilities:
717 /// ret void: No return value, simply emit a 'ret' instruction
718 /// ret sbyte, ubyte : Extend value into EAX and return
719 /// ret short, ushort: Extend value into EAX and return
720 /// ret int, uint : Move value into EAX and return
721 /// ret pointer : Move value into EAX and return
722 /// ret long, ulong : Move value into EAX/EDX and return
723 /// ret float/double : Top of FP stack
725 void ISel::visitReturnInst(ReturnInst &I) {
726 if (I.getNumOperands() == 0) {
727 BuildMI(BB, X86::RET, 0); // Just emit a 'ret' instruction
731 Value *RetVal = I.getOperand(0);
732 unsigned RetReg = getReg(RetVal);
733 switch (getClassB(RetVal->getType())) {
734 case cByte: // integral return values: extend or move into EAX and return
737 promote32(X86::EAX, ValueRecord(RetReg, RetVal->getType()));
738 // Declare that EAX is live on exit
739 BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::EAX).addReg(X86::ESP);
741 case cFP: // Floats & Doubles: Return in ST(0)
742 BuildMI(BB, X86::FpSETRESULT, 1).addReg(RetReg);
743 // Declare that top-of-stack is live on exit
744 BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::ST0).addReg(X86::ESP);
747 BuildMI(BB, X86::MOVrr32, 1, X86::EAX).addReg(RetReg);
748 BuildMI(BB, X86::MOVrr32, 1, X86::EDX).addReg(RetReg+1);
749 // Declare that EAX & EDX are live on exit
750 BuildMI(BB, X86::IMPLICIT_USE, 3).addReg(X86::EAX).addReg(X86::EDX).addReg(X86::ESP);
755 // Emit a 'ret' instruction
756 BuildMI(BB, X86::RET, 0);
759 // getBlockAfter - Return the basic block which occurs lexically after the
761 static inline BasicBlock *getBlockAfter(BasicBlock *BB) {
762 Function::iterator I = BB; ++I; // Get iterator to next block
763 return I != BB->getParent()->end() ? &*I : 0;
766 /// visitBranchInst - Handle conditional and unconditional branches here. Note
767 /// that since code layout is frozen at this point, that if we are trying to
768 /// jump to a block that is the immediate successor of the current block, we can
769 /// just make a fall-through (but we don't currently).
771 void ISel::visitBranchInst(BranchInst &BI) {
772 BasicBlock *NextBB = getBlockAfter(BI.getParent()); // BB after current one
774 if (!BI.isConditional()) { // Unconditional branch?
775 if (BI.getSuccessor(0) != NextBB)
776 BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
780 // See if we can fold the setcc into the branch itself...
781 SetCondInst *SCI = canFoldSetCCIntoBranch(BI.getCondition());
783 // Nope, cannot fold setcc into this branch. Emit a branch on a condition
784 // computed some other way...
785 unsigned condReg = getReg(BI.getCondition());
786 BuildMI(BB, X86::CMPri8, 2).addReg(condReg).addZImm(0);
787 if (BI.getSuccessor(1) == NextBB) {
788 if (BI.getSuccessor(0) != NextBB)
789 BuildMI(BB, X86::JNE, 1).addPCDisp(BI.getSuccessor(0));
791 BuildMI(BB, X86::JE, 1).addPCDisp(BI.getSuccessor(1));
793 if (BI.getSuccessor(0) != NextBB)
794 BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
799 unsigned OpNum = getSetCCNumber(SCI->getOpcode());
800 bool isSigned = EmitComparisonGetSignedness(OpNum, SCI->getOperand(0),
803 // LLVM -> X86 signed X86 unsigned
804 // ----- ---------- ------------
811 static const unsigned OpcodeTab[2][6] = {
812 { X86::JE, X86::JNE, X86::JB, X86::JAE, X86::JA, X86::JBE },
813 { X86::JE, X86::JNE, X86::JL, X86::JGE, X86::JG, X86::JLE },
816 if (BI.getSuccessor(0) != NextBB) {
817 BuildMI(BB, OpcodeTab[isSigned][OpNum], 1).addPCDisp(BI.getSuccessor(0));
818 if (BI.getSuccessor(1) != NextBB)
819 BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(1));
821 // Change to the inverse condition...
822 if (BI.getSuccessor(1) != NextBB) {
824 BuildMI(BB, OpcodeTab[isSigned][OpNum], 1).addPCDisp(BI.getSuccessor(1));
830 /// doCall - This emits an abstract call instruction, setting up the arguments
831 /// and the return value as appropriate. For the actual function call itself,
832 /// it inserts the specified CallMI instruction into the stream.
834 void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
835 const std::vector<ValueRecord> &Args) {
837 // Count how many bytes are to be pushed on the stack...
838 unsigned NumBytes = 0;
841 for (unsigned i = 0, e = Args.size(); i != e; ++i)
842 switch (getClassB(Args[i].Ty)) {
843 case cByte: case cShort: case cInt:
844 NumBytes += 4; break;
846 NumBytes += 8; break;
848 NumBytes += Args[i].Ty == Type::FloatTy ? 4 : 8;
850 default: assert(0 && "Unknown class!");
853 // Adjust the stack pointer for the new arguments...
854 BuildMI(BB, X86::ADJCALLSTACKDOWN, 1).addZImm(NumBytes);
856 // Arguments go on the stack in reverse order, as specified by the ABI.
857 unsigned ArgOffset = 0;
858 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
859 unsigned ArgReg = Args[i].Reg;
860 switch (getClassB(Args[i].Ty)) {
863 // Promote arg to 32 bits wide into a temporary register...
864 unsigned R = makeAnotherReg(Type::UIntTy);
865 promote32(R, Args[i]);
866 addRegOffset(BuildMI(BB, X86::MOVrm32, 5),
867 X86::ESP, ArgOffset).addReg(R);
871 addRegOffset(BuildMI(BB, X86::MOVrm32, 5),
872 X86::ESP, ArgOffset).addReg(ArgReg);
875 addRegOffset(BuildMI(BB, X86::MOVrm32, 5),
876 X86::ESP, ArgOffset).addReg(ArgReg);
877 addRegOffset(BuildMI(BB, X86::MOVrm32, 5),
878 X86::ESP, ArgOffset+4).addReg(ArgReg+1);
879 ArgOffset += 4; // 8 byte entry, not 4.
883 if (Args[i].Ty == Type::FloatTy) {
884 addRegOffset(BuildMI(BB, X86::FSTr32, 5),
885 X86::ESP, ArgOffset).addReg(ArgReg);
887 assert(Args[i].Ty == Type::DoubleTy && "Unknown FP type!");
888 addRegOffset(BuildMI(BB, X86::FSTr64, 5),
889 X86::ESP, ArgOffset).addReg(ArgReg);
890 ArgOffset += 4; // 8 byte entry, not 4.
894 default: assert(0 && "Unknown class!");
899 BuildMI(BB, X86::ADJCALLSTACKDOWN, 1).addZImm(0);
902 BB->push_back(CallMI);
904 BuildMI(BB, X86::ADJCALLSTACKUP, 1).addZImm(NumBytes);
906 // If there is a return value, scavenge the result from the location the call
909 if (Ret.Ty != Type::VoidTy) {
910 unsigned DestClass = getClassB(Ret.Ty);
915 // Integral results are in %eax, or the appropriate portion
917 static const unsigned regRegMove[] = {
918 X86::MOVrr8, X86::MOVrr16, X86::MOVrr32
920 static const unsigned AReg[] = { X86::AL, X86::AX, X86::EAX };
921 BuildMI(BB, regRegMove[DestClass], 1, Ret.Reg).addReg(AReg[DestClass]);
924 case cFP: // Floating-point return values live in %ST(0)
925 BuildMI(BB, X86::FpGETRESULT, 1, Ret.Reg);
927 case cLong: // Long values are left in EDX:EAX
928 BuildMI(BB, X86::MOVrr32, 1, Ret.Reg).addReg(X86::EAX);
929 BuildMI(BB, X86::MOVrr32, 1, Ret.Reg+1).addReg(X86::EDX);
931 default: assert(0 && "Unknown class!");
937 /// visitCallInst - Push args on stack and do a procedure call instruction.
938 void ISel::visitCallInst(CallInst &CI) {
939 MachineInstr *TheCall;
940 if (Function *F = CI.getCalledFunction()) {
941 // Is it an intrinsic function call?
942 if (LLVMIntrinsic::ID ID = (LLVMIntrinsic::ID)F->getIntrinsicID()) {
943 visitIntrinsicCall(ID, CI); // Special intrinsics are not handled here
947 // Emit a CALL instruction with PC-relative displacement.
948 TheCall = BuildMI(X86::CALLpcrel32, 1).addGlobalAddress(F, true);
949 } else { // Emit an indirect call...
950 unsigned Reg = getReg(CI.getCalledValue());
951 TheCall = BuildMI(X86::CALLr32, 1).addReg(Reg);
954 std::vector<ValueRecord> Args;
955 for (unsigned i = 1, e = CI.getNumOperands(); i != e; ++i)
956 Args.push_back(ValueRecord(getReg(CI.getOperand(i)),
957 CI.getOperand(i)->getType()));
959 unsigned DestReg = CI.getType() != Type::VoidTy ? getReg(CI) : 0;
960 doCall(ValueRecord(DestReg, CI.getType()), TheCall, Args);
963 void ISel::visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &CI) {
964 unsigned TmpReg1, TmpReg2;
966 case LLVMIntrinsic::va_start:
967 // Get the address of the first vararg value...
968 TmpReg1 = makeAnotherReg(Type::UIntTy);
969 addFrameReference(BuildMI(BB, X86::LEAr32, 5, TmpReg1), VarArgsFrameIndex);
970 TmpReg2 = getReg(CI.getOperand(1));
971 addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
974 case LLVMIntrinsic::va_end: return; // Noop on X86
975 case LLVMIntrinsic::va_copy:
976 TmpReg1 = getReg(CI.getOperand(2)); // Get existing va_list
977 TmpReg2 = getReg(CI.getOperand(1)); // Get va_list* to store into
978 addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
981 case LLVMIntrinsic::longjmp:
982 BuildMI(X86::CALLpcrel32, 1).addExternalSymbol("abort", true);
985 case LLVMIntrinsic::setjmp:
986 // Setjmp always returns zero...
987 BuildMI(BB, X86::MOVir32, 1, getReg(CI)).addZImm(0);
989 default: assert(0 && "Unknown intrinsic for X86!");
994 /// visitSimpleBinary - Implement simple binary operators for integral types...
995 /// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or, 4 for
997 void ISel::visitSimpleBinary(BinaryOperator &B, unsigned OperatorClass) {
998 unsigned DestReg = getReg(B);
999 MachineBasicBlock::iterator MI = BB->end();
1000 emitSimpleBinaryOperation(BB, MI, B.getOperand(0), B.getOperand(1),
1001 OperatorClass, DestReg);
1004 /// visitSimpleBinary - Implement simple binary operators for integral types...
1005 /// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or,
1008 /// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
1009 /// and constant expression support.
1010 void ISel::emitSimpleBinaryOperation(MachineBasicBlock *BB,
1011 MachineBasicBlock::iterator &IP,
1012 Value *Op0, Value *Op1,
1013 unsigned OperatorClass,unsigned TargetReg){
1014 unsigned Class = getClassB(Op0->getType());
1015 if (!isa<ConstantInt>(Op1) || Class == cLong) {
1016 static const unsigned OpcodeTab[][4] = {
1017 // Arithmetic operators
1018 { X86::ADDrr8, X86::ADDrr16, X86::ADDrr32, X86::FpADD }, // ADD
1019 { X86::SUBrr8, X86::SUBrr16, X86::SUBrr32, X86::FpSUB }, // SUB
1021 // Bitwise operators
1022 { X86::ANDrr8, X86::ANDrr16, X86::ANDrr32, 0 }, // AND
1023 { X86:: ORrr8, X86:: ORrr16, X86:: ORrr32, 0 }, // OR
1024 { X86::XORrr8, X86::XORrr16, X86::XORrr32, 0 }, // XOR
1027 bool isLong = false;
1028 if (Class == cLong) {
1030 Class = cInt; // Bottom 32 bits are handled just like ints
1033 unsigned Opcode = OpcodeTab[OperatorClass][Class];
1034 assert(Opcode && "Floating point arguments to logical inst?");
1035 unsigned Op0r = getReg(Op0, BB, IP);
1036 unsigned Op1r = getReg(Op1, BB, IP);
1037 BMI(BB, IP, Opcode, 2, TargetReg).addReg(Op0r).addReg(Op1r);
1039 if (isLong) { // Handle the upper 32 bits of long values...
1040 static const unsigned TopTab[] = {
1041 X86::ADCrr32, X86::SBBrr32, X86::ANDrr32, X86::ORrr32, X86::XORrr32
1043 BMI(BB, IP, TopTab[OperatorClass], 2,
1044 TargetReg+1).addReg(Op0r+1).addReg(Op1r+1);
1047 // Special case: op Reg, <const>
1048 ConstantInt *Op1C = cast<ConstantInt>(Op1);
1050 static const unsigned OpcodeTab[][3] = {
1051 // Arithmetic operators
1052 { X86::ADDri8, X86::ADDri16, X86::ADDri32 }, // ADD
1053 { X86::SUBri8, X86::SUBri16, X86::SUBri32 }, // SUB
1055 // Bitwise operators
1056 { X86::ANDri8, X86::ANDri16, X86::ANDri32 }, // AND
1057 { X86:: ORri8, X86:: ORri16, X86:: ORri32 }, // OR
1058 { X86::XORri8, X86::XORri16, X86::XORri32 }, // XOR
1061 assert(Class < 3 && "General code handles 64-bit integer types!");
1062 unsigned Opcode = OpcodeTab[OperatorClass][Class];
1063 unsigned Op0r = getReg(Op0, BB, IP);
1065 if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(Op1C))
1066 Op1v = CSI->getValue();
1068 Op1v = cast<ConstantUInt>(Op1C)->getValue();
1070 // Mask off any upper bits of the constant, if there are any...
1071 Op1v &= (1ULL << (8 << Class)) - 1;
1072 BMI(BB, IP, Opcode, 2, TargetReg).addReg(Op0r).addZImm(Op1v);
1076 /// doMultiply - Emit appropriate instructions to multiply together the
1077 /// registers op0Reg and op1Reg, and put the result in DestReg. The type of the
1078 /// result should be given as DestTy.
1080 void ISel::doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator &MBBI,
1081 unsigned DestReg, const Type *DestTy,
1082 unsigned op0Reg, unsigned op1Reg) {
1083 unsigned Class = getClass(DestTy);
1085 case cFP: // Floating point multiply
1086 BMI(BB, MBBI, X86::FpMUL, 2, DestReg).addReg(op0Reg).addReg(op1Reg);
1090 BMI(BB, MBBI, Class == cInt ? X86::IMULr32 : X86::IMULr16, 2, DestReg)
1091 .addReg(op0Reg).addReg(op1Reg);
1094 // Must use the MUL instruction, which forces use of AL...
1095 BMI(MBB, MBBI, X86::MOVrr8, 1, X86::AL).addReg(op0Reg);
1096 BMI(MBB, MBBI, X86::MULr8, 1).addReg(op1Reg);
1097 BMI(MBB, MBBI, X86::MOVrr8, 1, DestReg).addReg(X86::AL);
1100 case cLong: assert(0 && "doMultiply cannot operate on LONG values!");
1104 /// visitMul - Multiplies are not simple binary operators because they must deal
1105 /// with the EAX register explicitly.
1107 void ISel::visitMul(BinaryOperator &I) {
1108 unsigned Op0Reg = getReg(I.getOperand(0));
1109 unsigned Op1Reg = getReg(I.getOperand(1));
1110 unsigned DestReg = getReg(I);
1112 // Simple scalar multiply?
1113 if (I.getType() != Type::LongTy && I.getType() != Type::ULongTy) {
1114 MachineBasicBlock::iterator MBBI = BB->end();
1115 doMultiply(BB, MBBI, DestReg, I.getType(), Op0Reg, Op1Reg);
1117 // Long value. We have to do things the hard way...
1118 // Multiply the two low parts... capturing carry into EDX
1119 BuildMI(BB, X86::MOVrr32, 1, X86::EAX).addReg(Op0Reg);
1120 BuildMI(BB, X86::MULr32, 1).addReg(Op1Reg); // AL*BL
1122 unsigned OverflowReg = makeAnotherReg(Type::UIntTy);
1123 BuildMI(BB, X86::MOVrr32, 1, DestReg).addReg(X86::EAX); // AL*BL
1124 BuildMI(BB, X86::MOVrr32, 1, OverflowReg).addReg(X86::EDX); // AL*BL >> 32
1126 MachineBasicBlock::iterator MBBI = BB->end();
1127 unsigned AHBLReg = makeAnotherReg(Type::UIntTy); // AH*BL
1128 BMI(BB, MBBI, X86::IMULr32, 2, AHBLReg).addReg(Op0Reg+1).addReg(Op1Reg);
1130 unsigned AHBLplusOverflowReg = makeAnotherReg(Type::UIntTy);
1131 BuildMI(BB, X86::ADDrr32, 2, // AH*BL+(AL*BL >> 32)
1132 AHBLplusOverflowReg).addReg(AHBLReg).addReg(OverflowReg);
1135 unsigned ALBHReg = makeAnotherReg(Type::UIntTy); // AL*BH
1136 BMI(BB, MBBI, X86::IMULr32, 2, ALBHReg).addReg(Op0Reg).addReg(Op1Reg+1);
1138 BuildMI(BB, X86::ADDrr32, 2, // AL*BH + AH*BL + (AL*BL >> 32)
1139 DestReg+1).addReg(AHBLplusOverflowReg).addReg(ALBHReg);
1144 /// visitDivRem - Handle division and remainder instructions... these
1145 /// instruction both require the same instructions to be generated, they just
1146 /// select the result from a different register. Note that both of these
1147 /// instructions work differently for signed and unsigned operands.
1149 void ISel::visitDivRem(BinaryOperator &I) {
1150 unsigned Class = getClass(I.getType());
1151 unsigned Op0Reg = getReg(I.getOperand(0));
1152 unsigned Op1Reg = getReg(I.getOperand(1));
1153 unsigned ResultReg = getReg(I);
1156 case cFP: // Floating point divide
1157 if (I.getOpcode() == Instruction::Div)
1158 BuildMI(BB, X86::FpDIV, 2, ResultReg).addReg(Op0Reg).addReg(Op1Reg);
1159 else { // Floating point remainder...
1160 MachineInstr *TheCall =
1161 BuildMI(X86::CALLpcrel32, 1).addExternalSymbol("fmod", true);
1162 std::vector<ValueRecord> Args;
1163 Args.push_back(ValueRecord(Op0Reg, Type::DoubleTy));
1164 Args.push_back(ValueRecord(Op1Reg, Type::DoubleTy));
1165 doCall(ValueRecord(ResultReg, Type::DoubleTy), TheCall, Args);
1169 static const char *FnName[] =
1170 { "__moddi3", "__divdi3", "__umoddi3", "__udivdi3" };
1172 unsigned NameIdx = I.getType()->isUnsigned()*2;
1173 NameIdx += I.getOpcode() == Instruction::Div;
1174 MachineInstr *TheCall =
1175 BuildMI(X86::CALLpcrel32, 1).addExternalSymbol(FnName[NameIdx], true);
1177 std::vector<ValueRecord> Args;
1178 Args.push_back(ValueRecord(Op0Reg, Type::LongTy));
1179 Args.push_back(ValueRecord(Op1Reg, Type::LongTy));
1180 doCall(ValueRecord(ResultReg, Type::LongTy), TheCall, Args);
1183 case cByte: case cShort: case cInt:
1184 break; // Small integerals, handled below...
1185 default: assert(0 && "Unknown class!");
1188 static const unsigned Regs[] ={ X86::AL , X86::AX , X86::EAX };
1189 static const unsigned MovOpcode[]={ X86::MOVrr8, X86::MOVrr16, X86::MOVrr32 };
1190 static const unsigned SarOpcode[]={ X86::SARir8, X86::SARir16, X86::SARir32 };
1191 static const unsigned ClrOpcode[]={ X86::XORrr8, X86::XORrr16, X86::XORrr32 };
1192 static const unsigned ExtRegs[] ={ X86::AH , X86::DX , X86::EDX };
1194 static const unsigned DivOpcode[][4] = {
1195 { X86::DIVr8 , X86::DIVr16 , X86::DIVr32 , 0 }, // Unsigned division
1196 { X86::IDIVr8, X86::IDIVr16, X86::IDIVr32, 0 }, // Signed division
1199 bool isSigned = I.getType()->isSigned();
1200 unsigned Reg = Regs[Class];
1201 unsigned ExtReg = ExtRegs[Class];
1203 // Put the first operand into one of the A registers...
1204 BuildMI(BB, MovOpcode[Class], 1, Reg).addReg(Op0Reg);
1207 // Emit a sign extension instruction...
1208 unsigned ShiftResult = makeAnotherReg(I.getType());
1209 BuildMI(BB, SarOpcode[Class], 2, ShiftResult).addReg(Op0Reg).addZImm(31);
1210 BuildMI(BB, MovOpcode[Class], 1, ExtReg).addReg(ShiftResult);
1212 // If unsigned, emit a zeroing instruction... (reg = xor reg, reg)
1213 BuildMI(BB, ClrOpcode[Class], 2, ExtReg).addReg(ExtReg).addReg(ExtReg);
1216 // Emit the appropriate divide or remainder instruction...
1217 BuildMI(BB, DivOpcode[isSigned][Class], 1).addReg(Op1Reg);
1219 // Figure out which register we want to pick the result out of...
1220 unsigned DestReg = (I.getOpcode() == Instruction::Div) ? Reg : ExtReg;
1222 // Put the result into the destination register...
1223 BuildMI(BB, MovOpcode[Class], 1, ResultReg).addReg(DestReg);
1227 /// Shift instructions: 'shl', 'sar', 'shr' - Some special cases here
1228 /// for constant immediate shift values, and for constant immediate
1229 /// shift values equal to 1. Even the general case is sort of special,
1230 /// because the shift amount has to be in CL, not just any old register.
1232 void ISel::visitShiftInst(ShiftInst &I) {
1233 unsigned SrcReg = getReg(I.getOperand(0));
1234 unsigned DestReg = getReg(I);
1235 bool isLeftShift = I.getOpcode() == Instruction::Shl;
1236 bool isSigned = I.getType()->isSigned();
1237 unsigned Class = getClass(I.getType());
1239 static const unsigned ConstantOperand[][4] = {
1240 { X86::SHRir8, X86::SHRir16, X86::SHRir32, X86::SHRDir32 }, // SHR
1241 { X86::SARir8, X86::SARir16, X86::SARir32, X86::SHRDir32 }, // SAR
1242 { X86::SHLir8, X86::SHLir16, X86::SHLir32, X86::SHLDir32 }, // SHL
1243 { X86::SHLir8, X86::SHLir16, X86::SHLir32, X86::SHLDir32 }, // SAL = SHL
1246 static const unsigned NonConstantOperand[][4] = {
1247 { X86::SHRrr8, X86::SHRrr16, X86::SHRrr32 }, // SHR
1248 { X86::SARrr8, X86::SARrr16, X86::SARrr32 }, // SAR
1249 { X86::SHLrr8, X86::SHLrr16, X86::SHLrr32 }, // SHL
1250 { X86::SHLrr8, X86::SHLrr16, X86::SHLrr32 }, // SAL = SHL
1253 // Longs, as usual, are handled specially...
1254 if (Class == cLong) {
1255 // If we have a constant shift, we can generate much more efficient code
1256 // than otherwise...
1258 if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(I.getOperand(1))) {
1259 unsigned Amount = CUI->getValue();
1261 const unsigned *Opc = ConstantOperand[isLeftShift*2+isSigned];
1263 BuildMI(BB, Opc[3], 3,
1264 DestReg+1).addReg(SrcReg+1).addReg(SrcReg).addZImm(Amount);
1265 BuildMI(BB, Opc[2], 2, DestReg).addReg(SrcReg).addZImm(Amount);
1267 BuildMI(BB, Opc[3], 3,
1268 DestReg).addReg(SrcReg ).addReg(SrcReg+1).addZImm(Amount);
1269 BuildMI(BB, Opc[2], 2, DestReg+1).addReg(SrcReg+1).addZImm(Amount);
1271 } else { // Shifting more than 32 bits
1274 BuildMI(BB, X86::SHLir32, 2,DestReg+1).addReg(SrcReg).addZImm(Amount);
1275 BuildMI(BB, X86::MOVir32, 1,DestReg ).addZImm(0);
1277 unsigned Opcode = isSigned ? X86::SARir32 : X86::SHRir32;
1278 BuildMI(BB, Opcode, 2, DestReg).addReg(SrcReg+1).addZImm(Amount);
1279 BuildMI(BB, X86::MOVir32, 1, DestReg+1).addZImm(0);
1283 unsigned TmpReg = makeAnotherReg(Type::IntTy);
1285 if (!isLeftShift && isSigned) {
1286 // If this is a SHR of a Long, then we need to do funny sign extension
1287 // stuff. TmpReg gets the value to use as the high-part if we are
1288 // shifting more than 32 bits.
1289 BuildMI(BB, X86::SARir32, 2, TmpReg).addReg(SrcReg).addZImm(31);
1291 // Other shifts use a fixed zero value if the shift is more than 32
1293 BuildMI(BB, X86::MOVir32, 1, TmpReg).addZImm(0);
1296 // Initialize CL with the shift amount...
1297 unsigned ShiftAmount = getReg(I.getOperand(1));
1298 BuildMI(BB, X86::MOVrr8, 1, X86::CL).addReg(ShiftAmount);
1300 unsigned TmpReg2 = makeAnotherReg(Type::IntTy);
1301 unsigned TmpReg3 = makeAnotherReg(Type::IntTy);
1303 // TmpReg2 = shld inHi, inLo
1304 BuildMI(BB, X86::SHLDrr32, 2, TmpReg2).addReg(SrcReg+1).addReg(SrcReg);
1305 // TmpReg3 = shl inLo, CL
1306 BuildMI(BB, X86::SHLrr32, 1, TmpReg3).addReg(SrcReg);
1308 // Set the flags to indicate whether the shift was by more than 32 bits.
1309 BuildMI(BB, X86::TESTri8, 2).addReg(X86::CL).addZImm(32);
1311 // DestHi = (>32) ? TmpReg3 : TmpReg2;
1312 BuildMI(BB, X86::CMOVNErr32, 2,
1313 DestReg+1).addReg(TmpReg2).addReg(TmpReg3);
1314 // DestLo = (>32) ? TmpReg : TmpReg3;
1315 BuildMI(BB, X86::CMOVNErr32, 2, DestReg).addReg(TmpReg3).addReg(TmpReg);
1317 // TmpReg2 = shrd inLo, inHi
1318 BuildMI(BB, X86::SHRDrr32, 2, TmpReg2).addReg(SrcReg).addReg(SrcReg+1);
1319 // TmpReg3 = s[ah]r inHi, CL
1320 BuildMI(BB, isSigned ? X86::SARrr32 : X86::SHRrr32, 1, TmpReg3)
1323 // Set the flags to indicate whether the shift was by more than 32 bits.
1324 BuildMI(BB, X86::TESTri8, 2).addReg(X86::CL).addZImm(32);
1326 // DestLo = (>32) ? TmpReg3 : TmpReg2;
1327 BuildMI(BB, X86::CMOVNErr32, 2,
1328 DestReg).addReg(TmpReg2).addReg(TmpReg3);
1330 // DestHi = (>32) ? TmpReg : TmpReg3;
1331 BuildMI(BB, X86::CMOVNErr32, 2,
1332 DestReg+1).addReg(TmpReg3).addReg(TmpReg);
1338 if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(I.getOperand(1))) {
1339 // The shift amount is constant, guaranteed to be a ubyte. Get its value.
1340 assert(CUI->getType() == Type::UByteTy && "Shift amount not a ubyte?");
1342 const unsigned *Opc = ConstantOperand[isLeftShift*2+isSigned];
1343 BuildMI(BB, Opc[Class], 2, DestReg).addReg(SrcReg).addZImm(CUI->getValue());
1344 } else { // The shift amount is non-constant.
1345 BuildMI(BB, X86::MOVrr8, 1, X86::CL).addReg(getReg(I.getOperand(1)));
1347 const unsigned *Opc = NonConstantOperand[isLeftShift*2+isSigned];
1348 BuildMI(BB, Opc[Class], 1, DestReg).addReg(SrcReg);
1353 /// doFPLoad - This method is used to load an FP value from memory using the
1354 /// current endianness. NOTE: This method returns a partially constructed load
1355 /// instruction which needs to have the memory source filled in still.
1357 MachineInstr *ISel::doFPLoad(MachineBasicBlock *MBB,
1358 MachineBasicBlock::iterator &MBBI,
1359 const Type *Ty, unsigned DestReg) {
1360 assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
1361 unsigned LoadOpcode = Ty == Type::FloatTy ? X86::FLDr32 : X86::FLDr64;
1363 if (TM.getTargetData().isLittleEndian()) // fast path...
1364 return BMI(MBB, MBBI, LoadOpcode, 4, DestReg);
1366 // If we are big-endian, start by creating an LEA instruction to represent the
1367 // address of the memory location to load from...
1369 unsigned SrcAddrReg = makeAnotherReg(Type::UIntTy);
1370 MachineInstr *Result = BMI(MBB, MBBI, X86::LEAr32, 5, SrcAddrReg);
1372 // Allocate a temporary stack slot to transform the value into...
1373 int FrameIdx = F->getFrameInfo()->CreateStackObject(Ty, TM.getTargetData());
1375 // Perform the bswaps 32 bits at a time...
1376 unsigned TmpReg1 = makeAnotherReg(Type::UIntTy);
1377 unsigned TmpReg2 = makeAnotherReg(Type::UIntTy);
1378 addDirectMem(BMI(MBB, MBBI, X86::MOVmr32, 4, TmpReg1), SrcAddrReg);
1379 BMI(MBB, MBBI, X86::BSWAPr32, 1, TmpReg2).addReg(TmpReg1);
1380 unsigned Offset = (Ty == Type::DoubleTy) << 2;
1381 addFrameReference(BMI(MBB, MBBI, X86::MOVrm32, 5),
1382 FrameIdx, Offset).addReg(TmpReg2);
1384 if (Ty == Type::DoubleTy) { // Swap the other 32 bits of a double value...
1385 TmpReg1 = makeAnotherReg(Type::UIntTy);
1386 TmpReg2 = makeAnotherReg(Type::UIntTy);
1388 addRegOffset(BMI(MBB, MBBI, X86::MOVmr32, 4, TmpReg1), SrcAddrReg, 4);
1389 BMI(MBB, MBBI, X86::BSWAPr32, 1, TmpReg2).addReg(TmpReg1);
1390 unsigned Offset = (Ty == Type::DoubleTy) << 2;
1391 addFrameReference(BMI(MBB, MBBI, X86::MOVrm32,5), FrameIdx).addReg(TmpReg2);
1394 // Now we can reload the final byteswapped result into the final destination.
1395 addFrameReference(BMI(MBB, MBBI, LoadOpcode, 4, DestReg), FrameIdx);
1399 /// EmitByteSwap - Byteswap SrcReg into DestReg.
1401 void ISel::EmitByteSwap(unsigned DestReg, unsigned SrcReg, unsigned Class) {
1402 // Emit the byte swap instruction...
1405 // No byteswap necessary for 8 bit value...
1406 BuildMI(BB, X86::MOVrr8, 1, DestReg).addReg(SrcReg);
1409 // Use the 32 bit bswap instruction to do a 32 bit swap...
1410 BuildMI(BB, X86::BSWAPr32, 1, DestReg).addReg(SrcReg);
1414 // For 16 bit we have to use an xchg instruction, because there is no
1415 // 16-bit bswap. XCHG is necessarily not in SSA form, so we force things
1416 // into AX to do the xchg.
1418 BuildMI(BB, X86::MOVrr16, 1, X86::AX).addReg(SrcReg);
1419 BuildMI(BB, X86::XCHGrr8, 2).addReg(X86::AL, MOTy::UseAndDef)
1420 .addReg(X86::AH, MOTy::UseAndDef);
1421 BuildMI(BB, X86::MOVrr16, 1, DestReg).addReg(X86::AX);
1423 default: assert(0 && "Cannot byteswap this class!");
1428 /// visitLoadInst - Implement LLVM load instructions in terms of the x86 'mov'
1429 /// instruction. The load and store instructions are the only place where we
1430 /// need to worry about the memory layout of the target machine.
1432 void ISel::visitLoadInst(LoadInst &I) {
1433 bool isLittleEndian = TM.getTargetData().isLittleEndian();
1434 bool hasLongPointers = TM.getTargetData().getPointerSize() == 8;
1435 unsigned SrcAddrReg = getReg(I.getOperand(0));
1436 unsigned DestReg = getReg(I);
1438 unsigned Class = getClassB(I.getType());
1441 MachineBasicBlock::iterator MBBI = BB->end();
1442 addDirectMem(doFPLoad(BB, MBBI, I.getType(), DestReg), SrcAddrReg);
1445 case cLong: case cInt: case cShort: case cByte:
1446 break; // Integers of various sizes handled below
1447 default: assert(0 && "Unknown memory class!");
1450 // We need to adjust the input pointer if we are emulating a big-endian
1451 // long-pointer target. On these systems, the pointer that we are interested
1452 // in is in the upper part of the eight byte memory image of the pointer. It
1453 // also happens to be byte-swapped, but this will be handled later.
1455 if (!isLittleEndian && hasLongPointers && isa<PointerType>(I.getType())) {
1456 unsigned R = makeAnotherReg(Type::UIntTy);
1457 BuildMI(BB, X86::ADDri32, 2, R).addReg(SrcAddrReg).addZImm(4);
1461 unsigned IReg = DestReg;
1462 if (!isLittleEndian) // If big endian we need an intermediate stage
1463 DestReg = makeAnotherReg(Class != cLong ? I.getType() : Type::UIntTy);
1465 static const unsigned Opcode[] = {
1466 X86::MOVmr8, X86::MOVmr16, X86::MOVmr32, 0, X86::MOVmr32
1468 addDirectMem(BuildMI(BB, Opcode[Class], 4, DestReg), SrcAddrReg);
1470 // Handle long values now...
1471 if (Class == cLong) {
1472 if (isLittleEndian) {
1473 addRegOffset(BuildMI(BB, X86::MOVmr32, 4, DestReg+1), SrcAddrReg, 4);
1475 EmitByteSwap(IReg+1, DestReg, cInt);
1476 unsigned TempReg = makeAnotherReg(Type::IntTy);
1477 addRegOffset(BuildMI(BB, X86::MOVmr32, 4, TempReg), SrcAddrReg, 4);
1478 EmitByteSwap(IReg, TempReg, cInt);
1483 if (!isLittleEndian)
1484 EmitByteSwap(IReg, DestReg, Class);
1488 /// doFPStore - This method is used to store an FP value to memory using the
1489 /// current endianness.
1491 void ISel::doFPStore(const Type *Ty, unsigned DestAddrReg, unsigned SrcReg) {
1492 assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
1493 unsigned StoreOpcode = Ty == Type::FloatTy ? X86::FSTr32 : X86::FSTr64;
1495 if (TM.getTargetData().isLittleEndian()) { // fast path...
1496 addDirectMem(BuildMI(BB, StoreOpcode,5), DestAddrReg).addReg(SrcReg);
1500 // Allocate a temporary stack slot to transform the value into...
1501 int FrameIdx = F->getFrameInfo()->CreateStackObject(Ty, TM.getTargetData());
1502 unsigned SrcAddrReg = makeAnotherReg(Type::UIntTy);
1503 addFrameReference(BuildMI(BB, X86::LEAr32, 5, SrcAddrReg), FrameIdx);
1505 // Store the value into a temporary stack slot...
1506 addDirectMem(BuildMI(BB, StoreOpcode, 5), SrcAddrReg).addReg(SrcReg);
1508 // Perform the bswaps 32 bits at a time...
1509 unsigned TmpReg1 = makeAnotherReg(Type::UIntTy);
1510 unsigned TmpReg2 = makeAnotherReg(Type::UIntTy);
1511 addDirectMem(BuildMI(BB, X86::MOVmr32, 4, TmpReg1), SrcAddrReg);
1512 BuildMI(BB, X86::BSWAPr32, 1, TmpReg2).addReg(TmpReg1);
1513 unsigned Offset = (Ty == Type::DoubleTy) << 2;
1514 addRegOffset(BuildMI(BB, X86::MOVrm32, 5),
1515 DestAddrReg, Offset).addReg(TmpReg2);
1517 if (Ty == Type::DoubleTy) { // Swap the other 32 bits of a double value...
1518 TmpReg1 = makeAnotherReg(Type::UIntTy);
1519 TmpReg2 = makeAnotherReg(Type::UIntTy);
1521 addRegOffset(BuildMI(BB, X86::MOVmr32, 4, TmpReg1), SrcAddrReg, 4);
1522 BuildMI(BB, X86::BSWAPr32, 1, TmpReg2).addReg(TmpReg1);
1523 unsigned Offset = (Ty == Type::DoubleTy) << 2;
1524 addDirectMem(BuildMI(BB, X86::MOVrm32, 5), DestAddrReg).addReg(TmpReg2);
1529 /// visitStoreInst - Implement LLVM store instructions in terms of the x86 'mov'
1532 void ISel::visitStoreInst(StoreInst &I) {
1533 bool isLittleEndian = TM.getTargetData().isLittleEndian();
1534 bool hasLongPointers = TM.getTargetData().getPointerSize() == 8;
1535 unsigned ValReg = getReg(I.getOperand(0));
1536 unsigned AddressReg = getReg(I.getOperand(1));
1538 unsigned Class = getClassB(I.getOperand(0)->getType());
1541 if (isLittleEndian) {
1542 addDirectMem(BuildMI(BB, X86::MOVrm32, 1+4), AddressReg).addReg(ValReg);
1543 addRegOffset(BuildMI(BB, X86::MOVrm32, 1+4),
1544 AddressReg, 4).addReg(ValReg+1);
1546 unsigned T1 = makeAnotherReg(Type::IntTy);
1547 unsigned T2 = makeAnotherReg(Type::IntTy);
1548 EmitByteSwap(T1, ValReg , cInt);
1549 EmitByteSwap(T2, ValReg+1, cInt);
1550 addDirectMem(BuildMI(BB, X86::MOVrm32, 1+4), AddressReg).addReg(T2);
1551 addRegOffset(BuildMI(BB, X86::MOVrm32, 1+4), AddressReg, 4).addReg(T1);
1555 doFPStore(I.getOperand(0)->getType(), AddressReg, ValReg);
1557 case cInt: case cShort: case cByte:
1558 break; // Integers of various sizes handled below
1559 default: assert(0 && "Unknown memory class!");
1562 if (!isLittleEndian && hasLongPointers &&
1563 isa<PointerType>(I.getOperand(0)->getType())) {
1564 unsigned R = makeAnotherReg(Type::UIntTy);
1565 BuildMI(BB, X86::ADDri32, 2, R).addReg(AddressReg).addZImm(4);
1569 if (!isLittleEndian && Class != cByte) {
1570 unsigned R = makeAnotherReg(I.getOperand(0)->getType());
1571 EmitByteSwap(R, ValReg, Class);
1575 static const unsigned Opcode[] = { X86::MOVrm8, X86::MOVrm16, X86::MOVrm32 };
1576 addDirectMem(BuildMI(BB, Opcode[Class], 1+4), AddressReg).addReg(ValReg);
1580 /// visitCastInst - Here we have various kinds of copying with or without
1581 /// sign extension going on.
1582 void ISel::visitCastInst(CastInst &CI) {
1583 Value *Op = CI.getOperand(0);
1584 // If this is a cast from a 32-bit integer to a Long type, and the only uses
1585 // of the case are GEP instructions, then the cast does not need to be
1586 // generated explicitly, it will be folded into the GEP.
1587 if (CI.getType() == Type::LongTy &&
1588 (Op->getType() == Type::IntTy || Op->getType() == Type::UIntTy)) {
1589 bool AllUsesAreGEPs = true;
1590 for (Value::use_iterator I = CI.use_begin(), E = CI.use_end(); I != E; ++I)
1591 if (!isa<GetElementPtrInst>(*I)) {
1592 AllUsesAreGEPs = false;
1596 // No need to codegen this cast if all users are getelementptr instrs...
1597 if (AllUsesAreGEPs) return;
1600 unsigned DestReg = getReg(CI);
1601 MachineBasicBlock::iterator MI = BB->end();
1602 emitCastOperation(BB, MI, Op, CI.getType(), DestReg);
1605 /// emitCastOperation - Common code shared between visitCastInst and
1606 /// constant expression cast support.
1607 void ISel::emitCastOperation(MachineBasicBlock *BB,
1608 MachineBasicBlock::iterator &IP,
1609 Value *Src, const Type *DestTy,
1611 unsigned SrcReg = getReg(Src, BB, IP);
1612 const Type *SrcTy = Src->getType();
1613 unsigned SrcClass = getClassB(SrcTy);
1614 unsigned DestClass = getClassB(DestTy);
1616 // Implement casts to bool by using compare on the operand followed by set if
1617 // not zero on the result.
1618 if (DestTy == Type::BoolTy) {
1621 BMI(BB, IP, X86::TESTrr8, 2).addReg(SrcReg).addReg(SrcReg);
1624 BMI(BB, IP, X86::TESTrr16, 2).addReg(SrcReg).addReg(SrcReg);
1627 BMI(BB, IP, X86::TESTrr32, 2).addReg(SrcReg).addReg(SrcReg);
1630 unsigned TmpReg = makeAnotherReg(Type::IntTy);
1631 BMI(BB, IP, X86::ORrr32, 2, TmpReg).addReg(SrcReg).addReg(SrcReg+1);
1635 assert(0 && "FIXME: implement cast FP to bool");
1639 // If the zero flag is not set, then the value is true, set the byte to
1641 BMI(BB, IP, X86::SETNEr, 1, DestReg);
1645 static const unsigned RegRegMove[] = {
1646 X86::MOVrr8, X86::MOVrr16, X86::MOVrr32, X86::FpMOV, X86::MOVrr32
1649 // Implement casts between values of the same type class (as determined by
1650 // getClass) by using a register-to-register move.
1651 if (SrcClass == DestClass) {
1652 if (SrcClass <= cInt || (SrcClass == cFP && SrcTy == DestTy)) {
1653 BMI(BB, IP, RegRegMove[SrcClass], 1, DestReg).addReg(SrcReg);
1654 } else if (SrcClass == cFP) {
1655 if (SrcTy == Type::FloatTy) { // double -> float
1656 assert(DestTy == Type::DoubleTy && "Unknown cFP member!");
1657 BMI(BB, IP, X86::FpMOV, 1, DestReg).addReg(SrcReg);
1658 } else { // float -> double
1659 assert(SrcTy == Type::DoubleTy && DestTy == Type::FloatTy &&
1660 "Unknown cFP member!");
1661 // Truncate from double to float by storing to memory as short, then
1663 unsigned FltAlign = TM.getTargetData().getFloatAlignment();
1664 int FrameIdx = F->getFrameInfo()->CreateStackObject(4, FltAlign);
1665 addFrameReference(BMI(BB, IP, X86::FSTr32, 5), FrameIdx).addReg(SrcReg);
1666 addFrameReference(BMI(BB, IP, X86::FLDr32, 5, DestReg), FrameIdx);
1668 } else if (SrcClass == cLong) {
1669 BMI(BB, IP, X86::MOVrr32, 1, DestReg).addReg(SrcReg);
1670 BMI(BB, IP, X86::MOVrr32, 1, DestReg+1).addReg(SrcReg+1);
1672 assert(0 && "Cannot handle this type of cast instruction!");
1678 // Handle cast of SMALLER int to LARGER int using a move with sign extension
1679 // or zero extension, depending on whether the source type was signed.
1680 if (SrcClass <= cInt && (DestClass <= cInt || DestClass == cLong) &&
1681 SrcClass < DestClass) {
1682 bool isLong = DestClass == cLong;
1683 if (isLong) DestClass = cInt;
1685 static const unsigned Opc[][4] = {
1686 { X86::MOVSXr16r8, X86::MOVSXr32r8, X86::MOVSXr32r16, X86::MOVrr32 }, // s
1687 { X86::MOVZXr16r8, X86::MOVZXr32r8, X86::MOVZXr32r16, X86::MOVrr32 } // u
1690 bool isUnsigned = SrcTy->isUnsigned();
1691 BMI(BB, IP, Opc[isUnsigned][SrcClass + DestClass - 1], 1,
1692 DestReg).addReg(SrcReg);
1694 if (isLong) { // Handle upper 32 bits as appropriate...
1695 if (isUnsigned) // Zero out top bits...
1696 BMI(BB, IP, X86::MOVir32, 1, DestReg+1).addZImm(0);
1697 else // Sign extend bottom half...
1698 BMI(BB, IP, X86::SARir32, 2, DestReg+1).addReg(DestReg).addZImm(31);
1703 // Special case long -> int ...
1704 if (SrcClass == cLong && DestClass == cInt) {
1705 BMI(BB, IP, X86::MOVrr32, 1, DestReg).addReg(SrcReg);
1709 // Handle cast of LARGER int to SMALLER int using a move to EAX followed by a
1710 // move out of AX or AL.
1711 if ((SrcClass <= cInt || SrcClass == cLong) && DestClass <= cInt
1712 && SrcClass > DestClass) {
1713 static const unsigned AReg[] = { X86::AL, X86::AX, X86::EAX, 0, X86::EAX };
1714 BMI(BB, IP, RegRegMove[SrcClass], 1, AReg[SrcClass]).addReg(SrcReg);
1715 BMI(BB, IP, RegRegMove[DestClass], 1, DestReg).addReg(AReg[DestClass]);
1719 // Handle casts from integer to floating point now...
1720 if (DestClass == cFP) {
1721 // Promote the integer to a type supported by FLD. We do this because there
1722 // are no unsigned FLD instructions, so we must promote an unsigned value to
1723 // a larger signed value, then use FLD on the larger value.
1725 const Type *PromoteType = 0;
1726 unsigned PromoteOpcode;
1727 switch (SrcTy->getPrimitiveID()) {
1728 case Type::BoolTyID:
1729 case Type::SByteTyID:
1730 // We don't have the facilities for directly loading byte sized data from
1731 // memory (even signed). Promote it to 16 bits.
1732 PromoteType = Type::ShortTy;
1733 PromoteOpcode = X86::MOVSXr16r8;
1735 case Type::UByteTyID:
1736 PromoteType = Type::ShortTy;
1737 PromoteOpcode = X86::MOVZXr16r8;
1739 case Type::UShortTyID:
1740 PromoteType = Type::IntTy;
1741 PromoteOpcode = X86::MOVZXr32r16;
1743 case Type::UIntTyID: {
1744 // Make a 64 bit temporary... and zero out the top of it...
1745 unsigned TmpReg = makeAnotherReg(Type::LongTy);
1746 BMI(BB, IP, X86::MOVrr32, 1, TmpReg).addReg(SrcReg);
1747 BMI(BB, IP, X86::MOVir32, 1, TmpReg+1).addZImm(0);
1748 SrcTy = Type::LongTy;
1753 case Type::ULongTyID:
1754 assert("FIXME: not implemented: cast ulong X to fp type!");
1755 default: // No promotion needed...
1760 unsigned TmpReg = makeAnotherReg(PromoteType);
1761 BMI(BB, IP, SrcTy->isSigned() ? X86::MOVSXr16r8 : X86::MOVZXr16r8,
1762 1, TmpReg).addReg(SrcReg);
1763 SrcTy = PromoteType;
1764 SrcClass = getClass(PromoteType);
1768 // Spill the integer to memory and reload it from there...
1770 F->getFrameInfo()->CreateStackObject(SrcTy, TM.getTargetData());
1772 if (SrcClass == cLong) {
1773 addFrameReference(BMI(BB, IP, X86::MOVrm32, 5), FrameIdx).addReg(SrcReg);
1774 addFrameReference(BMI(BB, IP, X86::MOVrm32, 5),
1775 FrameIdx, 4).addReg(SrcReg+1);
1777 static const unsigned Op1[] = { X86::MOVrm8, X86::MOVrm16, X86::MOVrm32 };
1778 addFrameReference(BMI(BB, IP, Op1[SrcClass], 5), FrameIdx).addReg(SrcReg);
1781 static const unsigned Op2[] =
1782 { 0/*byte*/, X86::FILDr16, X86::FILDr32, 0/*FP*/, X86::FILDr64 };
1783 addFrameReference(BMI(BB, IP, Op2[SrcClass], 5, DestReg), FrameIdx);
1787 // Handle casts from floating point to integer now...
1788 if (SrcClass == cFP) {
1789 // Change the floating point control register to use "round towards zero"
1790 // mode when truncating to an integer value.
1792 int CWFrameIdx = F->getFrameInfo()->CreateStackObject(2, 2);
1793 addFrameReference(BMI(BB, IP, X86::FNSTCWm16, 4), CWFrameIdx);
1795 // Load the old value of the high byte of the control word...
1796 unsigned HighPartOfCW = makeAnotherReg(Type::UByteTy);
1797 addFrameReference(BMI(BB, IP, X86::MOVmr8, 4, HighPartOfCW), CWFrameIdx, 1);
1799 // Set the high part to be round to zero...
1800 addFrameReference(BMI(BB, IP, X86::MOVim8, 5), CWFrameIdx, 1).addZImm(12);
1802 // Reload the modified control word now...
1803 addFrameReference(BMI(BB, IP, X86::FLDCWm16, 4), CWFrameIdx);
1805 // Restore the memory image of control word to original value
1806 addFrameReference(BMI(BB, IP, X86::MOVrm8, 5),
1807 CWFrameIdx, 1).addReg(HighPartOfCW);
1809 // We don't have the facilities for directly storing byte sized data to
1810 // memory. Promote it to 16 bits. We also must promote unsigned values to
1811 // larger classes because we only have signed FP stores.
1812 unsigned StoreClass = DestClass;
1813 const Type *StoreTy = DestTy;
1814 if (StoreClass == cByte || DestTy->isUnsigned())
1815 switch (StoreClass) {
1816 case cByte: StoreTy = Type::ShortTy; StoreClass = cShort; break;
1817 case cShort: StoreTy = Type::IntTy; StoreClass = cInt; break;
1818 case cInt: StoreTy = Type::LongTy; StoreClass = cLong; break;
1819 // The following treatment of cLong may not be perfectly right,
1820 // but it survives chains of casts of the form
1821 // double->ulong->double.
1822 case cLong: StoreTy = Type::LongTy; StoreClass = cLong; break;
1823 default: assert(0 && "Unknown store class!");
1826 // Spill the integer to memory and reload it from there...
1828 F->getFrameInfo()->CreateStackObject(StoreTy, TM.getTargetData());
1830 static const unsigned Op1[] =
1831 { 0, X86::FISTr16, X86::FISTr32, 0, X86::FISTPr64 };
1832 addFrameReference(BMI(BB, IP, Op1[StoreClass], 5), FrameIdx).addReg(SrcReg);
1834 if (DestClass == cLong) {
1835 addFrameReference(BMI(BB, IP, X86::MOVmr32, 4, DestReg), FrameIdx);
1836 addFrameReference(BMI(BB, IP, X86::MOVmr32, 4, DestReg+1), FrameIdx, 4);
1838 static const unsigned Op2[] = { X86::MOVmr8, X86::MOVmr16, X86::MOVmr32 };
1839 addFrameReference(BMI(BB, IP, Op2[DestClass], 4, DestReg), FrameIdx);
1842 // Reload the original control word now...
1843 addFrameReference(BMI(BB, IP, X86::FLDCWm16, 4), CWFrameIdx);
1847 // Anything we haven't handled already, we can't (yet) handle at all.
1848 assert(0 && "Unhandled cast instruction!");
1852 /// visitVarArgInst - Implement the va_arg instruction...
1854 void ISel::visitVarArgInst(VarArgInst &I) {
1855 unsigned SrcReg = getReg(I.getOperand(0));
1856 unsigned DestReg = getReg(I);
1858 // Load the va_list into a register...
1859 unsigned VAList = makeAnotherReg(Type::UIntTy);
1860 addDirectMem(BuildMI(BB, X86::MOVmr32, 4, VAList), SrcReg);
1863 switch (I.getType()->getPrimitiveID()) {
1866 assert(0 && "Error: bad type for va_arg instruction!");
1868 case Type::PointerTyID:
1869 case Type::UIntTyID:
1872 addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
1874 case Type::ULongTyID:
1875 case Type::LongTyID:
1877 addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
1878 addRegOffset(BuildMI(BB, X86::MOVmr32, 4, DestReg+1), VAList, 4);
1880 case Type::DoubleTyID:
1882 addDirectMem(BuildMI(BB, X86::FLDr64, 4, DestReg), VAList);
1886 // Increment the VAList pointer...
1887 unsigned NextVAList = makeAnotherReg(Type::UIntTy);
1888 BuildMI(BB, X86::ADDri32, 2, NextVAList).addReg(VAList).addZImm(Size);
1890 // Update the VAList in memory...
1891 addDirectMem(BuildMI(BB, X86::MOVrm32, 5), SrcReg).addReg(NextVAList);
1895 // ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
1896 // returns zero when the input is not exactly a power of two.
1897 static unsigned ExactLog2(unsigned Val) {
1898 if (Val == 0) return 0;
1901 if (Val & 1) return 0;
1908 void ISel::visitGetElementPtrInst(GetElementPtrInst &I) {
1909 unsigned outputReg = getReg(I);
1910 MachineBasicBlock::iterator MI = BB->end();
1911 emitGEPOperation(BB, MI, I.getOperand(0),
1912 I.op_begin()+1, I.op_end(), outputReg);
1915 void ISel::emitGEPOperation(MachineBasicBlock *MBB,
1916 MachineBasicBlock::iterator &IP,
1917 Value *Src, User::op_iterator IdxBegin,
1918 User::op_iterator IdxEnd, unsigned TargetReg) {
1919 const TargetData &TD = TM.getTargetData();
1920 const Type *Ty = Src->getType();
1921 unsigned BaseReg = getReg(Src, MBB, IP);
1923 // GEPs have zero or more indices; we must perform a struct access
1924 // or array access for each one.
1925 for (GetElementPtrInst::op_iterator oi = IdxBegin,
1926 oe = IdxEnd; oi != oe; ++oi) {
1928 unsigned NextReg = BaseReg;
1929 if (const StructType *StTy = dyn_cast<StructType>(Ty)) {
1930 // It's a struct access. idx is the index into the structure,
1931 // which names the field. This index must have ubyte type.
1932 const ConstantUInt *CUI = cast<ConstantUInt>(idx);
1933 assert(CUI->getType() == Type::UByteTy
1934 && "Funny-looking structure index in GEP");
1935 // Use the TargetData structure to pick out what the layout of
1936 // the structure is in memory. Since the structure index must
1937 // be constant, we can get its value and use it to find the
1938 // right byte offset from the StructLayout class's list of
1939 // structure member offsets.
1940 unsigned idxValue = CUI->getValue();
1941 unsigned FieldOff = TD.getStructLayout(StTy)->MemberOffsets[idxValue];
1943 NextReg = makeAnotherReg(Type::UIntTy);
1944 // Emit an ADD to add FieldOff to the basePtr.
1945 BMI(MBB, IP, X86::ADDri32, 2,NextReg).addReg(BaseReg).addZImm(FieldOff);
1947 // The next type is the member of the structure selected by the
1949 Ty = StTy->getElementTypes()[idxValue];
1950 } else if (const SequentialType *SqTy = cast<SequentialType>(Ty)) {
1951 // It's an array or pointer access: [ArraySize x ElementType].
1953 // idx is the index into the array. Unlike with structure
1954 // indices, we may not know its actual value at code-generation
1956 assert(idx->getType() == Type::LongTy && "Bad GEP array index!");
1958 // Most GEP instructions use a [cast (int/uint) to LongTy] as their
1959 // operand on X86. Handle this case directly now...
1960 if (CastInst *CI = dyn_cast<CastInst>(idx))
1961 if (CI->getOperand(0)->getType() == Type::IntTy ||
1962 CI->getOperand(0)->getType() == Type::UIntTy)
1963 idx = CI->getOperand(0);
1965 // We want to add BaseReg to(idxReg * sizeof ElementType). First, we
1966 // must find the size of the pointed-to type (Not coincidentally, the next
1967 // type is the type of the elements in the array).
1968 Ty = SqTy->getElementType();
1969 unsigned elementSize = TD.getTypeSize(Ty);
1971 // If idxReg is a constant, we don't need to perform the multiply!
1972 if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(idx)) {
1973 if (!CSI->isNullValue()) {
1974 unsigned Offset = elementSize*CSI->getValue();
1975 NextReg = makeAnotherReg(Type::UIntTy);
1976 BMI(MBB, IP, X86::ADDri32, 2,NextReg).addReg(BaseReg).addZImm(Offset);
1978 } else if (elementSize == 1) {
1979 // If the element size is 1, we don't have to multiply, just add
1980 unsigned idxReg = getReg(idx, MBB, IP);
1981 NextReg = makeAnotherReg(Type::UIntTy);
1982 BMI(MBB, IP, X86::ADDrr32, 2, NextReg).addReg(BaseReg).addReg(idxReg);
1984 unsigned idxReg = getReg(idx, MBB, IP);
1985 unsigned OffsetReg = makeAnotherReg(Type::UIntTy);
1986 if (unsigned Shift = ExactLog2(elementSize)) {
1987 // If the element size is exactly a power of 2, use a shift to get it.
1988 BMI(MBB, IP, X86::SHLir32, 2,
1989 OffsetReg).addReg(idxReg).addZImm(Shift-1);
1991 // Most general case, emit a multiply...
1992 unsigned elementSizeReg = makeAnotherReg(Type::LongTy);
1993 BMI(MBB, IP, X86::MOVir32, 1, elementSizeReg).addZImm(elementSize);
1995 // Emit a MUL to multiply the register holding the index by
1996 // elementSize, putting the result in OffsetReg.
1997 doMultiply(MBB, IP, OffsetReg, Type::IntTy, idxReg, elementSizeReg);
1999 // Emit an ADD to add OffsetReg to the basePtr.
2000 NextReg = makeAnotherReg(Type::UIntTy);
2001 BMI(MBB, IP, X86::ADDrr32, 2,NextReg).addReg(BaseReg).addReg(OffsetReg);
2004 // Now that we are here, further indices refer to subtypes of this
2005 // one, so we don't need to worry about BaseReg itself, anymore.
2008 // After we have processed all the indices, the result is left in
2009 // BaseReg. Move it to the register where we were expected to
2010 // put the answer. A 32-bit move should do it, because we are in
2012 BMI(MBB, IP, X86::MOVrr32, 1, TargetReg).addReg(BaseReg);
2016 /// visitAllocaInst - If this is a fixed size alloca, allocate space from the
2017 /// frame manager, otherwise do it the hard way.
2019 void ISel::visitAllocaInst(AllocaInst &I) {
2020 // Find the data size of the alloca inst's getAllocatedType.
2021 const Type *Ty = I.getAllocatedType();
2022 unsigned TySize = TM.getTargetData().getTypeSize(Ty);
2024 // If this is a fixed size alloca in the entry block for the function,
2025 // statically stack allocate the space.
2027 if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(I.getArraySize())) {
2028 if (I.getParent() == I.getParent()->getParent()->begin()) {
2029 TySize *= CUI->getValue(); // Get total allocated size...
2030 unsigned Alignment = TM.getTargetData().getTypeAlignment(Ty);
2032 // Create a new stack object using the frame manager...
2033 int FrameIdx = F->getFrameInfo()->CreateStackObject(TySize, Alignment);
2034 addFrameReference(BuildMI(BB, X86::LEAr32, 5, getReg(I)), FrameIdx);
2039 // Create a register to hold the temporary result of multiplying the type size
2040 // constant by the variable amount.
2041 unsigned TotalSizeReg = makeAnotherReg(Type::UIntTy);
2042 unsigned SrcReg1 = getReg(I.getArraySize());
2043 unsigned SizeReg = makeAnotherReg(Type::UIntTy);
2044 BuildMI(BB, X86::MOVir32, 1, SizeReg).addZImm(TySize);
2046 // TotalSizeReg = mul <numelements>, <TypeSize>
2047 MachineBasicBlock::iterator MBBI = BB->end();
2048 doMultiply(BB, MBBI, TotalSizeReg, Type::UIntTy, SrcReg1, SizeReg);
2050 // AddedSize = add <TotalSizeReg>, 15
2051 unsigned AddedSizeReg = makeAnotherReg(Type::UIntTy);
2052 BuildMI(BB, X86::ADDri32, 2, AddedSizeReg).addReg(TotalSizeReg).addZImm(15);
2054 // AlignedSize = and <AddedSize>, ~15
2055 unsigned AlignedSize = makeAnotherReg(Type::UIntTy);
2056 BuildMI(BB, X86::ANDri32, 2, AlignedSize).addReg(AddedSizeReg).addZImm(~15);
2058 // Subtract size from stack pointer, thereby allocating some space.
2059 BuildMI(BB, X86::SUBrr32, 2, X86::ESP).addReg(X86::ESP).addReg(AlignedSize);
2061 // Put a pointer to the space into the result register, by copying
2062 // the stack pointer.
2063 BuildMI(BB, X86::MOVrr32, 1, getReg(I)).addReg(X86::ESP);
2065 // Inform the Frame Information that we have just allocated a variable-sized
2067 F->getFrameInfo()->CreateVariableSizedObject();
2070 /// visitMallocInst - Malloc instructions are code generated into direct calls
2071 /// to the library malloc.
2073 void ISel::visitMallocInst(MallocInst &I) {
2074 unsigned AllocSize = TM.getTargetData().getTypeSize(I.getAllocatedType());
2077 if (ConstantUInt *C = dyn_cast<ConstantUInt>(I.getOperand(0))) {
2078 Arg = getReg(ConstantUInt::get(Type::UIntTy, C->getValue() * AllocSize));
2080 Arg = makeAnotherReg(Type::UIntTy);
2081 unsigned Op0Reg = getReg(ConstantUInt::get(Type::UIntTy, AllocSize));
2082 unsigned Op1Reg = getReg(I.getOperand(0));
2083 MachineBasicBlock::iterator MBBI = BB->end();
2084 doMultiply(BB, MBBI, Arg, Type::UIntTy, Op0Reg, Op1Reg);
2089 std::vector<ValueRecord> Args;
2090 Args.push_back(ValueRecord(Arg, Type::UIntTy));
2091 MachineInstr *TheCall = BuildMI(X86::CALLpcrel32,
2092 1).addExternalSymbol("malloc", true);
2093 doCall(ValueRecord(getReg(I), I.getType()), TheCall, Args);
2097 /// visitFreeInst - Free instructions are code gen'd to call the free libc
2100 void ISel::visitFreeInst(FreeInst &I) {
2101 std::vector<ValueRecord> Args;
2102 Args.push_back(ValueRecord(getReg(I.getOperand(0)),
2103 I.getOperand(0)->getType()));
2104 MachineInstr *TheCall = BuildMI(X86::CALLpcrel32,
2105 1).addExternalSymbol("free", true);
2106 doCall(ValueRecord(0, Type::VoidTy), TheCall, Args);
2110 /// createSimpleX86InstructionSelector - This pass converts an LLVM function
2111 /// into a machine code representation is a very simple peep-hole fashion. The
2112 /// generated code sucks but the implementation is nice and simple.
2114 Pass *createSimpleX86InstructionSelector(TargetMachine &TM) {
2115 return new ISel(TM);