[llvm-commits] CVS: llvm/lib/Target/X86/X86SimpInstrSelector.cpp
Takahiro Kuba
kuba at cs.uiuc.edu
Tue Apr 6 14:36:05 PDT 2004
Changes in directory llvm/lib/Target/X86:
X86SimpInstrSelector.cpp added (r1.1)
---
Log message:
file based off InstSelectSimple.cpp, slowly being replaced by generated code from the really simple X86 instruction selector tablegen backend
---
Diffs of the changes: (+2831 -0)
Index: llvm/lib/Target/X86/X86SimpInstrSelector.cpp
diff -c /dev/null llvm/lib/Target/X86/X86SimpInstrSelector.cpp:1.1
*** /dev/null Tue Apr 6 14:35:27 2004
--- llvm/lib/Target/X86/X86SimpInstrSelector.cpp Tue Apr 6 14:35:17 2004
***************
*** 0 ****
--- 1,2831 ----
+ //===-- InstSelectSimple.cpp - A simple instruction selector for x86 ------===//
+ //
+ // The LLVM Compiler Infrastructure
+ //
+ // This file was developed by the LLVM research group and is distributed under
+ // the University of Illinois Open Source License. See LICENSE.TXT for details.
+ //
+ //===----------------------------------------------------------------------===//
+ //
+ // This file defines a simple peephole instruction selector for the x86 target
+ //
+ //===----------------------------------------------------------------------===//
+
+ #include "X86.h"
+ #include "X86InstrBuilder.h"
+ #include "X86InstrInfo.h"
+ #include "llvm/Constants.h"
+ #include "llvm/DerivedTypes.h"
+ #include "llvm/Function.h"
+ #include "llvm/Instructions.h"
+ #include "llvm/IntrinsicLowering.h"
+ #include "llvm/Pass.h"
+ #include "llvm/CodeGen/MachineConstantPool.h"
+ #include "llvm/CodeGen/MachineFrameInfo.h"
+ #include "llvm/CodeGen/MachineFunction.h"
+ #include "llvm/CodeGen/SSARegMap.h"
+ #include "llvm/Target/MRegisterInfo.h"
+ #include "llvm/Target/TargetMachine.h"
+ #include "llvm/Support/GetElementPtrTypeIterator.h"
+ #include "llvm/Support/InstVisitor.h"
+ #include "llvm/Support/CFG.h"
+ #include "Support/Statistic.h"
+ using namespace llvm;
+
+ namespace {
+ Statistic<>
+ NumFPKill("x86-codegen", "Number of FP_REG_KILL instructions added");
+ }
+
+ namespace {
+ struct ISel : public FunctionPass, InstVisitor<ISel> {
+ TargetMachine &TM;
+ MachineFunction *F; // The function we are compiling into
+ MachineBasicBlock *BB; // The current MBB we are compiling
+ int VarArgsFrameIndex; // FrameIndex for start of varargs area
+ int ReturnAddressIndex; // FrameIndex for the return address
+
+ std::map<Value*, unsigned> RegMap; // Mapping between Val's and SSA Regs
+
+ // MBBMap - Mapping between LLVM BB -> Machine BB
+ std::map<const BasicBlock*, MachineBasicBlock*> MBBMap;
+
+ ISel(TargetMachine &tm) : TM(tm), F(0), BB(0) {}
+
+ /// runOnFunction - Top level implementation of instruction selection for
+ /// the entire function.
+ ///
+ bool runOnFunction(Function &Fn) {
+ // First pass over the function, lower any unknown intrinsic functions
+ // with the IntrinsicLowering class.
+ LowerUnknownIntrinsicFunctionCalls(Fn);
+
+ F = &MachineFunction::construct(&Fn, TM);
+
+ // Create all of the machine basic blocks for the function...
+ for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
+ F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
+
+ BB = &F->front();
+
+ // Set up a frame object for the return address. This is used by the
+ // llvm.returnaddress & llvm.frameaddress intrinisics.
+ ReturnAddressIndex = F->getFrameInfo()->CreateFixedObject(4, -4);
+
+ // Copy incoming arguments off of the stack...
+ LoadArgumentsToVirtualRegs(Fn);
+
+ // Instruction select everything except PHI nodes
+ visit(Fn);
+
+ // Select the PHI nodes
+ SelectPHINodes();
+
+ // Insert the FP_REG_KILL instructions into blocks that need them.
+ InsertFPRegKills();
+
+ RegMap.clear();
+ MBBMap.clear();
+ F = 0;
+ // We always build a machine code representation for the function
+ return true;
+ }
+
+ virtual const char *getPassName() const {
+ return "X86 Simple Instruction Selection";
+ }
+
+ /// visitBasicBlock - This method is called when we are visiting a new basic
+ /// block. This simply creates a new MachineBasicBlock to emit code into
+ /// and adds it to the current MachineFunction. Subsequent visit* for
+ /// instructions will be invoked for all instructions in the basic block.
+ ///
+ void visitBasicBlock(BasicBlock &LLVM_BB) {
+ BB = MBBMap[&LLVM_BB];
+ }
+
+ /// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
+ /// function, lowering any calls to unknown intrinsic functions into the
+ /// equivalent LLVM code.
+ ///
+ void LowerUnknownIntrinsicFunctionCalls(Function &F);
+
+ /// LoadArgumentsToVirtualRegs - Load all of the arguments to this function
+ /// from the stack into virtual registers.
+ ///
+ void LoadArgumentsToVirtualRegs(Function &F);
+
+ /// SelectPHINodes - Insert machine code to generate phis. This is tricky
+ /// because we have to generate our sources into the source basic blocks,
+ /// not the current one.
+ ///
+ void SelectPHINodes();
+
+ /// InsertFPRegKills - Insert FP_REG_KILL instructions into basic blocks
+ /// that need them. This only occurs due to the floating point stackifier
+ /// not being aggressive enough to handle arbitrary global stackification.
+ ///
+ void InsertFPRegKills();
+
+ // Visitation methods for various instructions. These methods simply emit
+ // fixed X86 code for each instruction.
+ //
+
+ // Control flow operators
+ void visitReturnInst(ReturnInst &RI);
+ void visitBranchInst(BranchInst &BI);
+
+ struct ValueRecord {
+ Value *Val;
+ unsigned Reg;
+ const Type *Ty;
+ ValueRecord(unsigned R, const Type *T) : Val(0), Reg(R), Ty(T) {}
+ ValueRecord(Value *V) : Val(V), Reg(0), Ty(V->getType()) {}
+ };
+ void doCall(const ValueRecord &Ret, MachineInstr *CallMI,
+ const std::vector<ValueRecord> &Args);
+ void visitCallInst(CallInst &I);
+ void visitIntrinsicCall(Intrinsic::ID ID, CallInst &I);
+
+ // Arithmetic operators
+ void visitSimpleBinary(BinaryOperator &B, unsigned OpcodeClass);
+ void visitAdd(BinaryOperator &B);// visitSimpleBinary(B, 0); }
+ void visitSub(BinaryOperator &B);// { visitSimpleBinary(B, 1); }
+ void doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI,
+ unsigned DestReg, const Type *DestTy,
+ unsigned Op0Reg, unsigned Op1Reg);
+ void doMultiplyConst(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator MBBI,
+ unsigned DestReg, const Type *DestTy,
+ unsigned Op0Reg, unsigned Op1Val);
+ void visitMul(BinaryOperator &B);
+
+ void visitDiv(BinaryOperator &B) { visitDivRem(B); }
+ void visitRem(BinaryOperator &B) { visitDivRem(B); }
+ void visitDivRem(BinaryOperator &B);
+
+ // Bitwise operators
+ void visitAnd(BinaryOperator &B);// { visitSimpleBinary(B, 2); }
+ void visitOr (BinaryOperator &B);// { visitSimpleBinary(B, 3); }
+ void visitXor(BinaryOperator &B);// { visitSimpleBinary(B, 4); }
+
+ // Comparison operators...
+ void visitSetCondInst(SetCondInst &I);
+ unsigned EmitComparison(unsigned OpNum, Value *Op0, Value *Op1,
+ MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator MBBI);
+
+ // Memory Instructions
+ void visitLoadInst(LoadInst &I);
+ void visitStoreInst(StoreInst &I);
+ void visitGetElementPtrInst(GetElementPtrInst &I);
+ void visitAllocaInst(AllocaInst &I);
+ void visitMallocInst(MallocInst &I);
+ void visitFreeInst(FreeInst &I);
+
+ // Other operators
+ void visitShiftInst(ShiftInst &I);
+ void visitPHINode(PHINode &I) {} // PHI nodes handled by second pass
+ void visitCastInst(CastInst &I);
+ void visitVANextInst(VANextInst &I);
+ void visitVAArgInst(VAArgInst &I);
+
+ void visitInstruction(Instruction &I) {
+ std::cerr << "Cannot instruction select: " << I;
+ abort();
+ }
+
+ /// promote32 - Make a value 32-bits wide, and put it somewhere.
+ ///
+ void promote32(unsigned targetReg, const ValueRecord &VR);
+
+ /// getAddressingMode - Get the addressing mode to use to address the
+ /// specified value. The returned value should be used with addFullAddress.
+ void getAddressingMode(Value *Addr, unsigned &BaseReg, unsigned &Scale,
+ unsigned &IndexReg, unsigned &Disp);
+
+
+ /// getGEPIndex - This is used to fold GEP instructions into X86 addressing
+ /// expressions.
+ void getGEPIndex(MachineBasicBlock *MBB, MachineBasicBlock::iterator IP,
+ std::vector<Value*> &GEPOps,
+ std::vector<const Type*> &GEPTypes, unsigned &BaseReg,
+ unsigned &Scale, unsigned &IndexReg, unsigned &Disp);
+
+ /// isGEPFoldable - Return true if the specified GEP can be completely
+ /// folded into the addressing mode of a load/store or lea instruction.
+ bool isGEPFoldable(MachineBasicBlock *MBB,
+ Value *Src, User::op_iterator IdxBegin,
+ User::op_iterator IdxEnd, unsigned &BaseReg,
+ unsigned &Scale, unsigned &IndexReg, unsigned &Disp);
+
+ /// emitGEPOperation - Common code shared between visitGetElementPtrInst and
+ /// constant expression GEP support.
+ ///
+ void emitGEPOperation(MachineBasicBlock *BB, MachineBasicBlock::iterator IP,
+ Value *Src, User::op_iterator IdxBegin,
+ User::op_iterator IdxEnd, unsigned TargetReg);
+
+ /// emitCastOperation - Common code shared between visitCastInst and
+ /// constant expression cast support.
+ ///
+ void emitCastOperation(MachineBasicBlock *BB,MachineBasicBlock::iterator IP,
+ Value *Src, const Type *DestTy, unsigned TargetReg);
+
+ /// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
+ /// and constant expression support.
+ ///
+ void emitSimpleBinaryOperation(MachineBasicBlock *BB,
+ MachineBasicBlock::iterator IP,
+ Value *Op0, Value *Op1,
+ unsigned OperatorClass, unsigned TargetReg);
+
+ void emitDivRemOperation(MachineBasicBlock *BB,
+ MachineBasicBlock::iterator IP,
+ unsigned Op0Reg, unsigned Op1Reg, bool isDiv,
+ const Type *Ty, unsigned TargetReg);
+
+ /// emitSetCCOperation - Common code shared between visitSetCondInst and
+ /// constant expression support.
+ ///
+ void emitSetCCOperation(MachineBasicBlock *BB,
+ MachineBasicBlock::iterator IP,
+ Value *Op0, Value *Op1, unsigned Opcode,
+ unsigned TargetReg);
+
+ /// emitShiftOperation - Common code shared between visitShiftInst and
+ /// constant expression support.
+ ///
+ void emitShiftOperation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Value *Op, Value *ShiftAmount, bool isLeftShift,
+ const Type *ResultTy, unsigned DestReg);
+
+
+ /// copyConstantToRegister - Output the instructions required to put the
+ /// specified constant into the specified register.
+ ///
+ void copyConstantToRegister(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator MBBI,
+ Constant *C, unsigned Reg);
+
+ /// makeAnotherReg - This method returns the next register number we haven't
+ /// yet used.
+ ///
+ /// Long values are handled somewhat specially. They are always allocated
+ /// as pairs of 32 bit integer values. The register number returned is the
+ /// lower 32 bits of the long value, and the regNum+1 is the upper 32 bits
+ /// of the long value.
+ ///
+ unsigned makeAnotherReg(const Type *Ty) {
+ assert(dynamic_cast<const X86RegisterInfo*>(TM.getRegisterInfo()) &&
+ "Current target doesn't have X86 reg info??");
+ const X86RegisterInfo *MRI =
+ static_cast<const X86RegisterInfo*>(TM.getRegisterInfo());
+ if (Ty == Type::LongTy || Ty == Type::ULongTy) {
+ const TargetRegisterClass *RC = MRI->getRegClassForType(Type::IntTy);
+ // Create the lower part
+ F->getSSARegMap()->createVirtualRegister(RC);
+ // Create the upper part.
+ return F->getSSARegMap()->createVirtualRegister(RC)-1;
+ }
+
+ // Add the mapping of regnumber => reg class to MachineFunction
+ const TargetRegisterClass *RC = MRI->getRegClassForType(Ty);
+ return F->getSSARegMap()->createVirtualRegister(RC);
+ }
+
+ /// getReg - This method turns an LLVM value into a register number. This
+ /// is guaranteed to produce the same register number for a particular value
+ /// every time it is queried.
+ ///
+ unsigned getReg(Value &V) { return getReg(&V); } // Allow references
+ unsigned getReg(Value *V) {
+ // Just append to the end of the current bb.
+ MachineBasicBlock::iterator It = BB->end();
+ return getReg(V, BB, It);
+ }
+ unsigned getReg(Value *V, MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IPt) {
+ unsigned &Reg = RegMap[V];
+ if (Reg == 0) {
+ Reg = makeAnotherReg(V->getType());
+ RegMap[V] = Reg;
+ }
+
+ // If this operand is a constant, emit the code to copy the constant into
+ // the register here...
+ //
+ if (Constant *C = dyn_cast<Constant>(V)) {
+ copyConstantToRegister(MBB, IPt, C, Reg);
+ RegMap.erase(V); // Assign a new name to this constant if ref'd again
+ } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+ // Move the address of the global into the register
+ BuildMI(*MBB, IPt, X86::MOV32ri, 1, Reg).addGlobalAddress(GV);
+ RegMap.erase(V); // Assign a new name to this address if ref'd again
+ }
+
+ return Reg;
+ }
+ };
+ }
+
+ /// TypeClass - Used by the X86 backend to group LLVM types by their basic X86
+ /// Representation.
+ ///
+ enum TypeClass {
+ cByte, cShort, cInt, cFP, cLong
+ };
+
+ enum Subclasses {
+ NegOne, PosOne, Cons, Other
+ };
+
+
+
+ /// getClass - Turn a primitive type into a "class" number which is based on the
+ /// size of the type, and whether or not it is floating point.
+ ///
+ static inline TypeClass getClass(const Type *Ty) {
+ switch (Ty->getPrimitiveID()) {
+ case Type::SByteTyID:
+ case Type::UByteTyID: return cByte; // Byte operands are class #0
+ case Type::ShortTyID:
+ case Type::UShortTyID: return cShort; // Short operands are class #1
+ case Type::IntTyID:
+ case Type::UIntTyID:
+ case Type::PointerTyID: return cInt; // Int's and pointers are class #2
+
+ case Type::FloatTyID:
+ case Type::DoubleTyID: return cFP; // Floating Point is #3
+
+ case Type::LongTyID:
+ case Type::ULongTyID: return cLong; // Longs are class #4
+ default:
+ assert(0 && "Invalid type to getClass!");
+ return cByte; // not reached
+ }
+ }
+
+ // getClassB - Just like getClass, but treat boolean values as bytes.
+ static inline TypeClass getClassB(const Type *Ty) {
+ if (Ty == Type::BoolTy) return cByte;
+ return getClass(Ty);
+ }
+
+
+ /// copyConstantToRegister - Output the instructions required to put the
+ /// specified constant into the specified register.
+ ///
+ void ISel::copyConstantToRegister(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Constant *C, unsigned R) {
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+ unsigned Class = 0;
+ switch (CE->getOpcode()) {
+ case Instruction::GetElementPtr:
+ emitGEPOperation(MBB, IP, CE->getOperand(0),
+ CE->op_begin()+1, CE->op_end(), R);
+ return;
+ case Instruction::Cast:
+ emitCastOperation(MBB, IP, CE->getOperand(0), CE->getType(), R);
+ return;
+
+ case Instruction::Xor: ++Class; // FALL THROUGH
+ case Instruction::Or: ++Class; // FALL THROUGH
+ case Instruction::And: ++Class; // FALL THROUGH
+ case Instruction::Sub: ++Class; // FALL THROUGH
+ case Instruction::Add:
+ emitSimpleBinaryOperation(MBB, IP, CE->getOperand(0), CE->getOperand(1),
+ Class, R);
+ return;
+
+ case Instruction::Mul: {
+ unsigned Op0Reg = getReg(CE->getOperand(0), MBB, IP);
+ unsigned Op1Reg = getReg(CE->getOperand(1), MBB, IP);
+ doMultiply(MBB, IP, R, CE->getType(), Op0Reg, Op1Reg);
+ return;
+ }
+ case Instruction::Div:
+ case Instruction::Rem: {
+ unsigned Op0Reg = getReg(CE->getOperand(0), MBB, IP);
+ unsigned Op1Reg = getReg(CE->getOperand(1), MBB, IP);
+ emitDivRemOperation(MBB, IP, Op0Reg, Op1Reg,
+ CE->getOpcode() == Instruction::Div,
+ CE->getType(), R);
+ return;
+ }
+
+ case Instruction::SetNE:
+ case Instruction::SetEQ:
+ case Instruction::SetLT:
+ case Instruction::SetGT:
+ case Instruction::SetLE:
+ case Instruction::SetGE:
+ emitSetCCOperation(MBB, IP, CE->getOperand(0), CE->getOperand(1),
+ CE->getOpcode(), R);
+ return;
+
+ case Instruction::Shl:
+ case Instruction::Shr:
+ emitShiftOperation(MBB, IP, CE->getOperand(0), CE->getOperand(1),
+ CE->getOpcode() == Instruction::Shl, CE->getType(), R);
+ return;
+
+ default:
+ std::cerr << "Offending expr: " << C << "\n";
+ assert(0 && "Constant expression not yet handled!\n");
+ }
+ }
+
+ if (C->getType()->isIntegral()) {
+ unsigned Class = getClassB(C->getType());
+
+ if (Class == cLong) {
+ // Copy the value into the register pair.
+ uint64_t Val = cast<ConstantInt>(C)->getRawValue();
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, R).addImm(Val & 0xFFFFFFFF);
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, R+1).addImm(Val >> 32);
+ return;
+ }
+
+ assert(Class <= cInt && "Type not handled yet!");
+
+ static const unsigned IntegralOpcodeTab[] = {
+ X86::MOV8ri, X86::MOV16ri, X86::MOV32ri
+ };
+
+ if (C->getType() == Type::BoolTy) {
+ BuildMI(*MBB, IP, X86::MOV8ri, 1, R).addImm(C == ConstantBool::True);
+ } else {
+ ConstantInt *CI = cast<ConstantInt>(C);
+ BuildMI(*MBB, IP, IntegralOpcodeTab[Class],1,R).addImm(CI->getRawValue());
+ }
+ } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
+ if (CFP->isExactlyValue(+0.0))
+ BuildMI(*MBB, IP, X86::FLD0, 0, R);
+ else if (CFP->isExactlyValue(+1.0))
+ BuildMI(*MBB, IP, X86::FLD1, 0, R);
+ else {
+ // Otherwise we need to spill the constant to memory...
+ MachineConstantPool *CP = F->getConstantPool();
+ unsigned CPI = CP->getConstantPoolIndex(CFP);
+ const Type *Ty = CFP->getType();
+
+ assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
+ unsigned LoadOpcode = Ty == Type::FloatTy ? X86::FLD32m : X86::FLD64m;
+ addConstantPoolReference(BuildMI(*MBB, IP, LoadOpcode, 4, R), CPI);
+ }
+
+ } else if (isa<ConstantPointerNull>(C)) {
+ // Copy zero (null pointer) to the register.
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, R).addImm(0);
+ } else if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)) {
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, R).addGlobalAddress(CPR->getValue());
+ } else {
+ std::cerr << "Offending constant: " << C << "\n";
+ assert(0 && "Type not handled yet!");
+ }
+ }
+
+ /// LoadArgumentsToVirtualRegs - Load all of the arguments to this function from
+ /// the stack into virtual registers.
+ ///
+ void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
+ // Emit instructions to load the arguments... On entry to a function on the
+ // X86, the stack frame looks like this:
+ //
+ // [ESP] -- return address
+ // [ESP + 4] -- first argument (leftmost lexically)
+ // [ESP + 8] -- second argument, if first argument is four bytes in size
+ // ...
+ //
+ unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
+ MachineFrameInfo *MFI = F->getFrameInfo();
+
+ for (Function::aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
+ unsigned Reg = getReg(*I);
+
+ int FI; // Frame object index
+ switch (getClassB(I->getType())) {
+ case cByte:
+ FI = MFI->CreateFixedObject(1, ArgOffset);
+ addFrameReference(BuildMI(BB, X86::MOV8rm, 4, Reg), FI);
+ break;
+ case cShort:
+ FI = MFI->CreateFixedObject(2, ArgOffset);
+ addFrameReference(BuildMI(BB, X86::MOV16rm, 4, Reg), FI);
+ break;
+ case cInt:
+ FI = MFI->CreateFixedObject(4, ArgOffset);
+ addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Reg), FI);
+ break;
+ case cLong:
+ FI = MFI->CreateFixedObject(8, ArgOffset);
+ addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Reg), FI);
+ addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Reg+1), FI, 4);
+ ArgOffset += 4; // longs require 4 additional bytes
+ break;
+ case cFP:
+ unsigned Opcode;
+ if (I->getType() == Type::FloatTy) {
+ Opcode = X86::FLD32m;
+ FI = MFI->CreateFixedObject(4, ArgOffset);
+ } else {
+ Opcode = X86::FLD64m;
+ FI = MFI->CreateFixedObject(8, ArgOffset);
+ ArgOffset += 4; // doubles require 4 additional bytes
+ }
+ addFrameReference(BuildMI(BB, Opcode, 4, Reg), FI);
+ break;
+ default:
+ assert(0 && "Unhandled argument type!");
+ }
+ ArgOffset += 4; // Each argument takes at least 4 bytes on the stack...
+ }
+
+ // If the function takes variable number of arguments, add a frame offset for
+ // the start of the first vararg value... this is used to expand
+ // llvm.va_start.
+ if (Fn.getFunctionType()->isVarArg())
+ VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
+ }
+
+
+ /// SelectPHINodes - Insert machine code to generate phis. This is tricky
+ /// because we have to generate our sources into the source basic blocks, not
+ /// the current one.
+ ///
+ void ISel::SelectPHINodes() {
+ const TargetInstrInfo &TII = TM.getInstrInfo();
+ const Function &LF = *F->getFunction(); // The LLVM function...
+ for (Function::const_iterator I = LF.begin(), E = LF.end(); I != E; ++I) {
+ const BasicBlock *BB = I;
+ MachineBasicBlock &MBB = *MBBMap[I];
+
+ // Loop over all of the PHI nodes in the LLVM basic block...
+ MachineBasicBlock::iterator PHIInsertPoint = MBB.begin();
+ for (BasicBlock::const_iterator I = BB->begin();
+ PHINode *PN = const_cast<PHINode*>(dyn_cast<PHINode>(I)); ++I) {
+
+ // Create a new machine instr PHI node, and insert it.
+ unsigned PHIReg = getReg(*PN);
+ MachineInstr *PhiMI = BuildMI(MBB, PHIInsertPoint,
+ X86::PHI, PN->getNumOperands(), PHIReg);
+
+ MachineInstr *LongPhiMI = 0;
+ if (PN->getType() == Type::LongTy || PN->getType() == Type::ULongTy)
+ LongPhiMI = BuildMI(MBB, PHIInsertPoint,
+ X86::PHI, PN->getNumOperands(), PHIReg+1);
+
+ // PHIValues - Map of blocks to incoming virtual registers. We use this
+ // so that we only initialize one incoming value for a particular block,
+ // even if the block has multiple entries in the PHI node.
+ //
+ std::map<MachineBasicBlock*, unsigned> PHIValues;
+
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+ MachineBasicBlock *PredMBB = MBBMap[PN->getIncomingBlock(i)];
+ unsigned ValReg;
+ std::map<MachineBasicBlock*, unsigned>::iterator EntryIt =
+ PHIValues.lower_bound(PredMBB);
+
+ if (EntryIt != PHIValues.end() && EntryIt->first == PredMBB) {
+ // We already inserted an initialization of the register for this
+ // predecessor. Recycle it.
+ ValReg = EntryIt->second;
+
+ } else {
+ // Get the incoming value into a virtual register.
+ //
+ Value *Val = PN->getIncomingValue(i);
+
+ // If this is a constant or GlobalValue, we may have to insert code
+ // into the basic block to compute it into a virtual register.
+ if (isa<Constant>(Val) || isa<GlobalValue>(Val)) {
+ // Because we don't want to clobber any values which might be in
+ // physical registers with the computation of this constant (which
+ // might be arbitrarily complex if it is a constant expression),
+ // just insert the computation at the top of the basic block.
+ MachineBasicBlock::iterator PI = PredMBB->begin();
+
+ // Skip over any PHI nodes though!
+ while (PI != PredMBB->end() && PI->getOpcode() == X86::PHI)
+ ++PI;
+
+ ValReg = getReg(Val, PredMBB, PI);
+ } else {
+ ValReg = getReg(Val);
+ }
+
+ // Remember that we inserted a value for this PHI for this predecessor
+ PHIValues.insert(EntryIt, std::make_pair(PredMBB, ValReg));
+ }
+
+ PhiMI->addRegOperand(ValReg);
+ PhiMI->addMachineBasicBlockOperand(PredMBB);
+ if (LongPhiMI) {
+ LongPhiMI->addRegOperand(ValReg+1);
+ LongPhiMI->addMachineBasicBlockOperand(PredMBB);
+ }
+ }
+
+ // Now that we emitted all of the incoming values for the PHI node, make
+ // sure to reposition the InsertPoint after the PHI that we just added.
+ // This is needed because we might have inserted a constant into this
+ // block, right after the PHI's which is before the old insert point!
+ PHIInsertPoint = LongPhiMI ? LongPhiMI : PhiMI;
+ ++PHIInsertPoint;
+ }
+ }
+ }
+
+ /// RequiresFPRegKill - The floating point stackifier pass cannot insert
+ /// compensation code on critical edges. As such, it requires that we kill all
+ /// FP registers on the exit from any blocks that either ARE critical edges, or
+ /// branch to a block that has incoming critical edges.
+ ///
+ /// Note that this kill instruction will eventually be eliminated when
+ /// restrictions in the stackifier are relaxed.
+ ///
+ static bool RequiresFPRegKill(const BasicBlock *BB) {
+ #if 0
+ for (succ_const_iterator SI = succ_begin(BB), E = succ_end(BB); SI!=E; ++SI) {
+ const BasicBlock *Succ = *SI;
+ pred_const_iterator PI = pred_begin(Succ), PE = pred_end(Succ);
+ ++PI; // Block have at least one predecessory
+ if (PI != PE) { // If it has exactly one, this isn't crit edge
+ // If this block has more than one predecessor, check all of the
+ // predecessors to see if they have multiple successors. If so, then the
+ // block we are analyzing needs an FPRegKill.
+ for (PI = pred_begin(Succ); PI != PE; ++PI) {
+ const BasicBlock *Pred = *PI;
+ succ_const_iterator SI2 = succ_begin(Pred);
+ ++SI2; // There must be at least one successor of this block.
+ if (SI2 != succ_end(Pred))
+ return true; // Yes, we must insert the kill on this edge.
+ }
+ }
+ }
+ // If we got this far, there is no need to insert the kill instruction.
+ return false;
+ #else
+ return true;
+ #endif
+ }
+
+ // InsertFPRegKills - Insert FP_REG_KILL instructions into basic blocks that
+ // need them. This only occurs due to the floating point stackifier not being
+ // aggressive enough to handle arbitrary global stackification.
+ //
+ // Currently we insert an FP_REG_KILL instruction into each block that uses or
+ // defines a floating point virtual register.
+ //
+ // When the global register allocators (like linear scan) finally update live
+ // variable analysis, we can keep floating point values in registers across
+ // portions of the CFG that do not involve critical edges. This will be a big
+ // win, but we are waiting on the global allocators before we can do this.
+ //
+ // With a bit of work, the floating point stackifier pass can be enhanced to
+ // break critical edges as needed (to make a place to put compensation code),
+ // but this will require some infrastructure improvements as well.
+ //
+ void ISel::InsertFPRegKills() {
+ SSARegMap &RegMap = *F->getSSARegMap();
+
+ for (MachineFunction::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+ for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I!=E; ++I)
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+ MachineOperand& MO = I->getOperand(i);
+ if (MO.isRegister() && MO.getReg()) {
+ unsigned Reg = MO.getReg();
+ if (MRegisterInfo::isVirtualRegister(Reg))
+ if (RegMap.getRegClass(Reg)->getSize() == 10)
+ goto UsesFPReg;
+ }
+ }
+ // If we haven't found an FP register use or def in this basic block, check
+ // to see if any of our successors has an FP PHI node, which will cause a
+ // copy to be inserted into this block.
+ for (succ_const_iterator SI = succ_begin(BB->getBasicBlock()),
+ E = succ_end(BB->getBasicBlock()); SI != E; ++SI) {
+ MachineBasicBlock *SBB = MBBMap[*SI];
+ for (MachineBasicBlock::iterator I = SBB->begin();
+ I != SBB->end() && I->getOpcode() == X86::PHI; ++I) {
+ if (RegMap.getRegClass(I->getOperand(0).getReg())->getSize() == 10)
+ goto UsesFPReg;
+ }
+ }
+ continue;
+ UsesFPReg:
+ // Okay, this block uses an FP register. If the block has successors (ie,
+ // it's not an unwind/return), insert the FP_REG_KILL instruction.
+ if (BB->getBasicBlock()->getTerminator()->getNumSuccessors() &&
+ RequiresFPRegKill(BB->getBasicBlock())) {
+ BuildMI(*BB, BB->getFirstTerminator(), X86::FP_REG_KILL, 0);
+ ++NumFPKill;
+ }
+ }
+ }
+
+
+ // canFoldSetCCIntoBranch - Return the setcc instruction if we can fold it into
+ // the conditional branch instruction which is the only user of the cc
+ // instruction. This is the case if the conditional branch is the only user of
+ // the setcc, and if the setcc is in the same basic block as the conditional
+ // branch. We also don't handle long arguments below, so we reject them here as
+ // well.
+ //
+ static SetCondInst *canFoldSetCCIntoBranch(Value *V) {
+ if (SetCondInst *SCI = dyn_cast<SetCondInst>(V))
+ if (SCI->hasOneUse() && isa<BranchInst>(SCI->use_back()) &&
+ SCI->getParent() == cast<BranchInst>(SCI->use_back())->getParent()) {
+ const Type *Ty = SCI->getOperand(0)->getType();
+ if (Ty != Type::LongTy && Ty != Type::ULongTy)
+ return SCI;
+ }
+ return 0;
+ }
+
+ // Return a fixed numbering for setcc instructions which does not depend on the
+ // order of the opcodes.
+ //
+ static unsigned getSetCCNumber(unsigned Opcode) {
+ switch(Opcode) {
+ default: assert(0 && "Unknown setcc instruction!");
+ case Instruction::SetEQ: return 0;
+ case Instruction::SetNE: return 1;
+ case Instruction::SetLT: return 2;
+ case Instruction::SetGE: return 3;
+ case Instruction::SetGT: return 4;
+ case Instruction::SetLE: return 5;
+ }
+ }
+
+ // LLVM -> X86 signed X86 unsigned
+ // ----- ---------- ------------
+ // seteq -> sete sete
+ // setne -> setne setne
+ // setlt -> setl setb
+ // setge -> setge setae
+ // setgt -> setg seta
+ // setle -> setle setbe
+ // ----
+ // sets // Used by comparison with 0 optimization
+ // setns
+ static const unsigned SetCCOpcodeTab[2][8] = {
+ { X86::SETEr, X86::SETNEr, X86::SETBr, X86::SETAEr, X86::SETAr, X86::SETBEr,
+ 0, 0 },
+ { X86::SETEr, X86::SETNEr, X86::SETLr, X86::SETGEr, X86::SETGr, X86::SETLEr,
+ X86::SETSr, X86::SETNSr },
+ };
+
+ // EmitComparison - This function emits a comparison of the two operands,
+ // returning the extended setcc code to use.
+ unsigned ISel::EmitComparison(unsigned OpNum, Value *Op0, Value *Op1,
+ MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP) {
+ // The arguments are already supposed to be of the same type.
+ const Type *CompTy = Op0->getType();
+ unsigned Class = getClassB(CompTy);
+ unsigned Op0r = getReg(Op0, MBB, IP);
+
+ // Special case handling of: cmp R, i
+ if (Class == cByte || Class == cShort || Class == cInt)
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
+ uint64_t Op1v = cast<ConstantInt>(CI)->getRawValue();
+
+ // Mask off any upper bits of the constant, if there are any...
+ Op1v &= (1ULL << (8 << Class)) - 1;
+
+ // If this is a comparison against zero, emit more efficient code. We
+ // can't handle unsigned comparisons against zero unless they are == or
+ // !=. These should have been strength reduced already anyway.
+ if (Op1v == 0 && (CompTy->isSigned() || OpNum < 2)) {
+ static const unsigned TESTTab[] = {
+ X86::TEST8rr, X86::TEST16rr, X86::TEST32rr
+ };
+ BuildMI(*MBB, IP, TESTTab[Class], 2).addReg(Op0r).addReg(Op0r);
+
+ if (OpNum == 2) return 6; // Map jl -> js
+ if (OpNum == 3) return 7; // Map jg -> jns
+ return OpNum;
+ }
+
+ static const unsigned CMPTab[] = {
+ X86::CMP8ri, X86::CMP16ri, X86::CMP32ri
+ };
+
+ BuildMI(*MBB, IP, CMPTab[Class], 2).addReg(Op0r).addImm(Op1v);
+ return OpNum;
+ }
+
+ // Special case handling of comparison against +/- 0.0
+ if (ConstantFP *CFP = dyn_cast<ConstantFP>(Op1))
+ if (CFP->isExactlyValue(+0.0) || CFP->isExactlyValue(-0.0)) {
+ BuildMI(*MBB, IP, X86::FTST, 1).addReg(Op0r);
+ BuildMI(*MBB, IP, X86::FNSTSW8r, 0);
+ BuildMI(*MBB, IP, X86::SAHF, 1);
+ return OpNum;
+ }
+
+ unsigned Op1r = getReg(Op1, MBB, IP);
+ switch (Class) {
+ default: assert(0 && "Unknown type class!");
+ // Emit: cmp <var1>, <var2> (do the comparison). We can
+ // compare 8-bit with 8-bit, 16-bit with 16-bit, 32-bit with
+ // 32-bit.
+ case cByte:
+ BuildMI(*MBB, IP, X86::CMP8rr, 2).addReg(Op0r).addReg(Op1r);
+ break;
+ case cShort:
+ BuildMI(*MBB, IP, X86::CMP16rr, 2).addReg(Op0r).addReg(Op1r);
+ break;
+ case cInt:
+ BuildMI(*MBB, IP, X86::CMP32rr, 2).addReg(Op0r).addReg(Op1r);
+ break;
+ case cFP:
+ BuildMI(*MBB, IP, X86::FpUCOM, 2).addReg(Op0r).addReg(Op1r);
+ BuildMI(*MBB, IP, X86::FNSTSW8r, 0);
+ BuildMI(*MBB, IP, X86::SAHF, 1);
+ break;
+
+ case cLong:
+ if (OpNum < 2) { // seteq, setne
+ unsigned LoTmp = makeAnotherReg(Type::IntTy);
+ unsigned HiTmp = makeAnotherReg(Type::IntTy);
+ unsigned FinalTmp = makeAnotherReg(Type::IntTy);
+ BuildMI(*MBB, IP, X86::XOR32rr, 2, LoTmp).addReg(Op0r).addReg(Op1r);
+ BuildMI(*MBB, IP, X86::XOR32rr, 2, HiTmp).addReg(Op0r+1).addReg(Op1r+1);
+ BuildMI(*MBB, IP, X86::OR32rr, 2, FinalTmp).addReg(LoTmp).addReg(HiTmp);
+ break; // Allow the sete or setne to be generated from flags set by OR
+ } else {
+ // Emit a sequence of code which compares the high and low parts once
+ // each, then uses a conditional move to handle the overflow case. For
+ // example, a setlt for long would generate code like this:
+ //
+ // AL = lo(op1) < lo(op2) // Signedness depends on operands
+ // BL = hi(op1) < hi(op2) // Always unsigned comparison
+ // dest = hi(op1) == hi(op2) ? AL : BL;
+ //
+
+ // FIXME: This would be much better if we had hierarchical register
+ // classes! Until then, hardcode registers so that we can deal with their
+ // aliases (because we don't have conditional byte moves).
+ //
+ BuildMI(*MBB, IP, X86::CMP32rr, 2).addReg(Op0r).addReg(Op1r);
+ BuildMI(*MBB, IP, SetCCOpcodeTab[0][OpNum], 0, X86::AL);
+ BuildMI(*MBB, IP, X86::CMP32rr, 2).addReg(Op0r+1).addReg(Op1r+1);
+ BuildMI(*MBB, IP, SetCCOpcodeTab[CompTy->isSigned()][OpNum], 0, X86::BL);
+ BuildMI(*MBB, IP, X86::IMPLICIT_DEF, 0, X86::BH);
+ BuildMI(*MBB, IP, X86::IMPLICIT_DEF, 0, X86::AH);
+ BuildMI(*MBB, IP, X86::CMOVE16rr, 2, X86::BX).addReg(X86::BX)
+ .addReg(X86::AX);
+ // NOTE: visitSetCondInst knows that the value is dumped into the BL
+ // register at this point for long values...
+ return OpNum;
+ }
+ }
+ return OpNum;
+ }
+
+
+ /// SetCC instructions - Here we just emit boilerplate code to set a byte-sized
+ /// register, then move it to wherever the result should be.
+ ///
+ void ISel::visitSetCondInst(SetCondInst &I) {
+ if (canFoldSetCCIntoBranch(&I)) return; // Fold this into a branch...
+
+ unsigned DestReg = getReg(I);
+ MachineBasicBlock::iterator MII = BB->end();
+ emitSetCCOperation(BB, MII, I.getOperand(0), I.getOperand(1), I.getOpcode(),
+ DestReg);
+ }
+
+ /// emitSetCCOperation - Common code shared between visitSetCondInst and
+ /// constant expression support.
+ ///
+ void ISel::emitSetCCOperation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Value *Op0, Value *Op1, unsigned Opcode,
+ unsigned TargetReg) {
+ unsigned OpNum = getSetCCNumber(Opcode);
+ OpNum = EmitComparison(OpNum, Op0, Op1, MBB, IP);
+
+ const Type *CompTy = Op0->getType();
+ unsigned CompClass = getClassB(CompTy);
+ bool isSigned = CompTy->isSigned() && CompClass != cFP;
+
+ if (CompClass != cLong || OpNum < 2) {
+ // Handle normal comparisons with a setcc instruction...
+ BuildMI(*MBB, IP, SetCCOpcodeTab[isSigned][OpNum], 0, TargetReg);
+ } else {
+ // Handle long comparisons by copying the value which is already in BL into
+ // the register we want...
+ BuildMI(*MBB, IP, X86::MOV8rr, 1, TargetReg).addReg(X86::BL);
+ }
+ }
+
+
+
+
+ /// promote32 - Emit instructions to turn a narrow operand into a 32-bit-wide
+ /// operand, in the specified target register.
+ ///
+ void ISel::promote32(unsigned targetReg, const ValueRecord &VR) {
+ bool isUnsigned = VR.Ty->isUnsigned();
+
+ // Make sure we have the register number for this value...
+ unsigned Reg = VR.Val ? getReg(VR.Val) : VR.Reg;
+
+ switch (getClassB(VR.Ty)) {
+ case cByte:
+ // Extend value into target register (8->32)
+ if (isUnsigned)
+ BuildMI(BB, X86::MOVZX32rr8, 1, targetReg).addReg(Reg);
+ else
+ BuildMI(BB, X86::MOVSX32rr8, 1, targetReg).addReg(Reg);
+ break;
+ case cShort:
+ // Extend value into target register (16->32)
+ if (isUnsigned)
+ BuildMI(BB, X86::MOVZX32rr16, 1, targetReg).addReg(Reg);
+ else
+ BuildMI(BB, X86::MOVSX32rr16, 1, targetReg).addReg(Reg);
+ break;
+ case cInt:
+ // Move value into target register (32->32)
+ BuildMI(BB, X86::MOV32rr, 1, targetReg).addReg(Reg);
+ break;
+ default:
+ assert(0 && "Unpromotable operand class in promote32");
+ }
+ }
+
+ /// 'ret' instruction - Here we are interested in meeting the x86 ABI. As such,
+ /// we have the following possibilities:
+ ///
+ /// ret void: No return value, simply emit a 'ret' instruction
+ /// ret sbyte, ubyte : Extend value into EAX and return
+ /// ret short, ushort: Extend value into EAX and return
+ /// ret int, uint : Move value into EAX and return
+ /// ret pointer : Move value into EAX and return
+ /// ret long, ulong : Move value into EAX/EDX and return
+ /// ret float/double : Top of FP stack
+ ///
+ void ISel::visitReturnInst(ReturnInst &I) {
+ if (I.getNumOperands() == 0) {
+ BuildMI(BB, X86::RET, 0); // Just emit a 'ret' instruction
+ return;
+ }
+
+ Value *RetVal = I.getOperand(0);
+ unsigned RetReg = getReg(RetVal);
+ switch (getClassB(RetVal->getType())) {
+ case cByte: // integral return values: extend or move into EAX and return
+ case cShort:
+ case cInt:
+ promote32(X86::EAX, ValueRecord(RetReg, RetVal->getType()));
+ // Declare that EAX is live on exit
+ BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::EAX).addReg(X86::ESP);
+ break;
+ case cFP: // Floats & Doubles: Return in ST(0)
+ BuildMI(BB, X86::FpSETRESULT, 1).addReg(RetReg);
+ // Declare that top-of-stack is live on exit
+ BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::ST0).addReg(X86::ESP);
+ break;
+ case cLong:
+ BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(RetReg);
+ BuildMI(BB, X86::MOV32rr, 1, X86::EDX).addReg(RetReg+1);
+ // Declare that EAX & EDX are live on exit
+ BuildMI(BB, X86::IMPLICIT_USE, 3).addReg(X86::EAX).addReg(X86::EDX)
+ .addReg(X86::ESP);
+ break;
+ default:
+ visitInstruction(I);
+ }
+ // Emit a 'ret' instruction
+ BuildMI(BB, X86::RET, 0);
+ }
+
+ // getBlockAfter - Return the basic block which occurs lexically after the
+ // specified one.
+ static inline BasicBlock *getBlockAfter(BasicBlock *BB) {
+ Function::iterator I = BB; ++I; // Get iterator to next block
+ return I != BB->getParent()->end() ? &*I : 0;
+ }
+
+ /// visitBranchInst - Handle conditional and unconditional branches here. Note
+ /// that since code layout is frozen at this point, that if we are trying to
+ /// jump to a block that is the immediate successor of the current block, we can
+ /// just make a fall-through (but we don't currently).
+ ///
+ void ISel::visitBranchInst(BranchInst &BI) {
+ BasicBlock *NextBB = getBlockAfter(BI.getParent()); // BB after current one
+
+ if (!BI.isConditional()) { // Unconditional branch?
+ if (BI.getSuccessor(0) != NextBB)
+ BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
+ return;
+ }
+
+ // See if we can fold the setcc into the branch itself...
+ SetCondInst *SCI = canFoldSetCCIntoBranch(BI.getCondition());
+ if (SCI == 0) {
+ // Nope, cannot fold setcc into this branch. Emit a branch on a condition
+ // computed some other way...
+ unsigned condReg = getReg(BI.getCondition());
+ BuildMI(BB, X86::CMP8ri, 2).addReg(condReg).addImm(0);
+ if (BI.getSuccessor(1) == NextBB) {
+ if (BI.getSuccessor(0) != NextBB)
+ BuildMI(BB, X86::JNE, 1).addPCDisp(BI.getSuccessor(0));
+ } else {
+ BuildMI(BB, X86::JE, 1).addPCDisp(BI.getSuccessor(1));
+
+ if (BI.getSuccessor(0) != NextBB)
+ BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
+ }
+ return;
+ }
+
+ unsigned OpNum = getSetCCNumber(SCI->getOpcode());
+ MachineBasicBlock::iterator MII = BB->end();
+ OpNum = EmitComparison(OpNum, SCI->getOperand(0), SCI->getOperand(1), BB,MII);
+
+ const Type *CompTy = SCI->getOperand(0)->getType();
+ bool isSigned = CompTy->isSigned() && getClassB(CompTy) != cFP;
+
+
+ // LLVM -> X86 signed X86 unsigned
+ // ----- ---------- ------------
+ // seteq -> je je
+ // setne -> jne jne
+ // setlt -> jl jb
+ // setge -> jge jae
+ // setgt -> jg ja
+ // setle -> jle jbe
+ // ----
+ // js // Used by comparison with 0 optimization
+ // jns
+
+ static const unsigned OpcodeTab[2][8] = {
+ { X86::JE, X86::JNE, X86::JB, X86::JAE, X86::JA, X86::JBE, 0, 0 },
+ { X86::JE, X86::JNE, X86::JL, X86::JGE, X86::JG, X86::JLE,
+ X86::JS, X86::JNS },
+ };
+
+ if (BI.getSuccessor(0) != NextBB) {
+ BuildMI(BB, OpcodeTab[isSigned][OpNum], 1).addPCDisp(BI.getSuccessor(0));
+ if (BI.getSuccessor(1) != NextBB)
+ BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(1));
+ } else {
+ // Change to the inverse condition...
+ if (BI.getSuccessor(1) != NextBB) {
+ OpNum ^= 1;
+ BuildMI(BB, OpcodeTab[isSigned][OpNum], 1).addPCDisp(BI.getSuccessor(1));
+ }
+ }
+ }
+
+
+ /// doCall - This emits an abstract call instruction, setting up the arguments
+ /// and the return value as appropriate. For the actual function call itself,
+ /// it inserts the specified CallMI instruction into the stream.
+ ///
+ void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
+ const std::vector<ValueRecord> &Args) {
+
+ // Count how many bytes are to be pushed on the stack...
+ unsigned NumBytes = 0;
+
+ if (!Args.empty()) {
+ for (unsigned i = 0, e = Args.size(); i != e; ++i)
+ switch (getClassB(Args[i].Ty)) {
+ case cByte: case cShort: case cInt:
+ NumBytes += 4; break;
+ case cLong:
+ NumBytes += 8; break;
+ case cFP:
+ NumBytes += Args[i].Ty == Type::FloatTy ? 4 : 8;
+ break;
+ default: assert(0 && "Unknown class!");
+ }
+
+ // Adjust the stack pointer for the new arguments...
+ BuildMI(BB, X86::ADJCALLSTACKDOWN, 1).addImm(NumBytes);
+
+ // Arguments go on the stack in reverse order, as specified by the ABI.
+ unsigned ArgOffset = 0;
+ for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+ unsigned ArgReg;
+ switch (getClassB(Args[i].Ty)) {
+ case cByte:
+ case cShort:
+ if (Args[i].Val && isa<ConstantInt>(Args[i].Val)) {
+ // Zero/Sign extend constant, then stuff into memory.
+ ConstantInt *Val = cast<ConstantInt>(Args[i].Val);
+ Val = cast<ConstantInt>(ConstantExpr::getCast(Val, Type::IntTy));
+ addRegOffset(BuildMI(BB, X86::MOV32mi, 5), X86::ESP, ArgOffset)
+ .addImm(Val->getRawValue() & 0xFFFFFFFF);
+ } else {
+ // Promote arg to 32 bits wide into a temporary register...
+ ArgReg = makeAnotherReg(Type::UIntTy);
+ promote32(ArgReg, Args[i]);
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ }
+ break;
+ case cInt:
+ if (Args[i].Val && isa<ConstantInt>(Args[i].Val)) {
+ unsigned Val = cast<ConstantInt>(Args[i].Val)->getRawValue();
+ addRegOffset(BuildMI(BB, X86::MOV32mi, 5),
+ X86::ESP, ArgOffset).addImm(Val);
+ } else {
+ ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ }
+ break;
+ case cLong:
+ ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset+4).addReg(ArgReg+1);
+ ArgOffset += 4; // 8 byte entry, not 4.
+ break;
+
+ case cFP:
+ ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
+ if (Args[i].Ty == Type::FloatTy) {
+ addRegOffset(BuildMI(BB, X86::FST32m, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ } else {
+ assert(Args[i].Ty == Type::DoubleTy && "Unknown FP type!");
+ addRegOffset(BuildMI(BB, X86::FST64m, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ ArgOffset += 4; // 8 byte entry, not 4.
+ }
+ break;
+
+ default: assert(0 && "Unknown class!");
+ }
+ ArgOffset += 4;
+ }
+ } else {
+ BuildMI(BB, X86::ADJCALLSTACKDOWN, 1).addImm(0);
+ }
+
+ BB->push_back(CallMI);
+
+ BuildMI(BB, X86::ADJCALLSTACKUP, 1).addImm(NumBytes);
+
+ // If there is a return value, scavenge the result from the location the call
+ // leaves it in...
+ //
+ if (Ret.Ty != Type::VoidTy) {
+ unsigned DestClass = getClassB(Ret.Ty);
+ switch (DestClass) {
+ case cByte:
+ case cShort:
+ case cInt: {
+ // Integral results are in %eax, or the appropriate portion
+ // thereof.
+ static const unsigned regRegMove[] = {
+ X86::MOV8rr, X86::MOV16rr, X86::MOV32rr
+ };
+ static const unsigned AReg[] = { X86::AL, X86::AX, X86::EAX };
+ BuildMI(BB, regRegMove[DestClass], 1, Ret.Reg).addReg(AReg[DestClass]);
+ break;
+ }
+ case cFP: // Floating-point return values live in %ST(0)
+ BuildMI(BB, X86::FpGETRESULT, 1, Ret.Reg);
+ break;
+ case cLong: // Long values are left in EDX:EAX
+ BuildMI(BB, X86::MOV32rr, 1, Ret.Reg).addReg(X86::EAX);
+ BuildMI(BB, X86::MOV32rr, 1, Ret.Reg+1).addReg(X86::EDX);
+ break;
+ default: assert(0 && "Unknown class!");
+ }
+ }
+ }
+
+
+ /// visitCallInst - Push args on stack and do a procedure call instruction.
+ void ISel::visitCallInst(CallInst &CI) {
+ MachineInstr *TheCall;
+ if (Function *F = CI.getCalledFunction()) {
+ // Is it an intrinsic function call?
+ if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
+ visitIntrinsicCall(ID, CI); // Special intrinsics are not handled here
+ return;
+ }
+
+ // Emit a CALL instruction with PC-relative displacement.
+ TheCall = BuildMI(X86::CALLpcrel32, 1).addGlobalAddress(F, true);
+ } else { // Emit an indirect call...
+ unsigned Reg = getReg(CI.getCalledValue());
+ TheCall = BuildMI(X86::CALL32r, 1).addReg(Reg);
+ }
+
+ std::vector<ValueRecord> Args;
+ for (unsigned i = 1, e = CI.getNumOperands(); i != e; ++i)
+ Args.push_back(ValueRecord(CI.getOperand(i)));
+
+ unsigned DestReg = CI.getType() != Type::VoidTy ? getReg(CI) : 0;
+ doCall(ValueRecord(DestReg, CI.getType()), TheCall, Args);
+ }
+
+
+ /// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
+ /// function, lowering any calls to unknown intrinsic functions into the
+ /// equivalent LLVM code.
+ ///
+ void ISel::LowerUnknownIntrinsicFunctionCalls(Function &F) {
+ for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
+ if (CallInst *CI = dyn_cast<CallInst>(I++))
+ if (Function *F = CI->getCalledFunction())
+ switch (F->getIntrinsicID()) {
+ case Intrinsic::not_intrinsic:
+ case Intrinsic::vastart:
+ case Intrinsic::vacopy:
+ case Intrinsic::vaend:
+ case Intrinsic::returnaddress:
+ case Intrinsic::frameaddress:
+ case Intrinsic::memcpy:
+ case Intrinsic::memset:
+ // We directly implement these intrinsics
+ break;
+ default:
+ // All other intrinsic calls we must lower.
+ Instruction *Before = CI->getPrev();
+ TM.getIntrinsicLowering().LowerIntrinsicCall(CI);
+ if (Before) { // Move iterator to instruction after call
+ I = Before; ++I;
+ } else {
+ I = BB->begin();
+ }
+ }
+
+ }
+
+ void ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) {
+ unsigned TmpReg1, TmpReg2;
+ switch (ID) {
+ case Intrinsic::vastart:
+ // Get the address of the first vararg value...
+ TmpReg1 = getReg(CI);
+ addFrameReference(BuildMI(BB, X86::LEA32r, 5, TmpReg1), VarArgsFrameIndex);
+ return;
+
+ case Intrinsic::vacopy:
+ TmpReg1 = getReg(CI);
+ TmpReg2 = getReg(CI.getOperand(1));
+ BuildMI(BB, X86::MOV32rr, 1, TmpReg1).addReg(TmpReg2);
+ return;
+ case Intrinsic::vaend: return; // Noop on X86
+
+ case Intrinsic::returnaddress:
+ case Intrinsic::frameaddress:
+ TmpReg1 = getReg(CI);
+ if (cast<Constant>(CI.getOperand(1))->isNullValue()) {
+ if (ID == Intrinsic::returnaddress) {
+ // Just load the return address
+ addFrameReference(BuildMI(BB, X86::MOV32rm, 4, TmpReg1),
+ ReturnAddressIndex);
+ } else {
+ addFrameReference(BuildMI(BB, X86::LEA32r, 4, TmpReg1),
+ ReturnAddressIndex, -4);
+ }
+ } else {
+ // Values other than zero are not implemented yet.
+ BuildMI(BB, X86::MOV32ri, 1, TmpReg1).addImm(0);
+ }
+ return;
+
+ case Intrinsic::memcpy: {
+ assert(CI.getNumOperands() == 5 && "Illegal llvm.memcpy call!");
+ unsigned Align = 1;
+ if (ConstantInt *AlignC = dyn_cast<ConstantInt>(CI.getOperand(4))) {
+ Align = AlignC->getRawValue();
+ if (Align == 0) Align = 1;
+ }
+
+ // Turn the byte code into # iterations
+ unsigned CountReg;
+ unsigned Opcode;
+ switch (Align & 3) {
+ case 2: // WORD aligned
+ if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) {
+ CountReg = getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/2));
+ } else {
+ CountReg = makeAnotherReg(Type::IntTy);
+ unsigned ByteReg = getReg(CI.getOperand(3));
+ BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1);
+ }
+ Opcode = X86::REP_MOVSW;
+ break;
+ case 0: // DWORD aligned
+ if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) {
+ CountReg = getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/4));
+ } else {
+ CountReg = makeAnotherReg(Type::IntTy);
+ unsigned ByteReg = getReg(CI.getOperand(3));
+ BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2);
+ }
+ Opcode = X86::REP_MOVSD;
+ break;
+ default: // BYTE aligned
+ CountReg = getReg(CI.getOperand(3));
+ Opcode = X86::REP_MOVSB;
+ break;
+ }
+
+ // No matter what the alignment is, we put the source in ESI, the
+ // destination in EDI, and the count in ECX.
+ TmpReg1 = getReg(CI.getOperand(1));
+ TmpReg2 = getReg(CI.getOperand(2));
+ BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg);
+ BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1);
+ BuildMI(BB, X86::MOV32rr, 1, X86::ESI).addReg(TmpReg2);
+ BuildMI(BB, Opcode, 0);
+ return;
+ }
+ case Intrinsic::memset: {
+ assert(CI.getNumOperands() == 5 && "Illegal llvm.memset call!");
+ unsigned Align = 1;
+ if (ConstantInt *AlignC = dyn_cast<ConstantInt>(CI.getOperand(4))) {
+ Align = AlignC->getRawValue();
+ if (Align == 0) Align = 1;
+ }
+
+ // Turn the byte code into # iterations
+ unsigned CountReg;
+ unsigned Opcode;
+ if (ConstantInt *ValC = dyn_cast<ConstantInt>(CI.getOperand(2))) {
+ unsigned Val = ValC->getRawValue() & 255;
+
+ // If the value is a constant, then we can potentially use larger copies.
+ switch (Align & 3) {
+ case 2: // WORD aligned
+ if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) {
+ CountReg =getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/2));
+ } else {
+ CountReg = makeAnotherReg(Type::IntTy);
+ unsigned ByteReg = getReg(CI.getOperand(3));
+ BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1);
+ }
+ BuildMI(BB, X86::MOV16ri, 1, X86::AX).addImm((Val << 8) | Val);
+ Opcode = X86::REP_STOSW;
+ break;
+ case 0: // DWORD aligned
+ if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) {
+ CountReg =getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/4));
+ } else {
+ CountReg = makeAnotherReg(Type::IntTy);
+ unsigned ByteReg = getReg(CI.getOperand(3));
+ BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2);
+ }
+ Val = (Val << 8) | Val;
+ BuildMI(BB, X86::MOV32ri, 1, X86::EAX).addImm((Val << 16) | Val);
+ Opcode = X86::REP_STOSD;
+ break;
+ default: // BYTE aligned
+ CountReg = getReg(CI.getOperand(3));
+ BuildMI(BB, X86::MOV8ri, 1, X86::AL).addImm(Val);
+ Opcode = X86::REP_STOSB;
+ break;
+ }
+ } else {
+ // If it's not a constant value we are storing, just fall back. We could
+ // try to be clever to form 16 bit and 32 bit values, but we don't yet.
+ unsigned ValReg = getReg(CI.getOperand(2));
+ BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(ValReg);
+ CountReg = getReg(CI.getOperand(3));
+ Opcode = X86::REP_STOSB;
+ }
+
+ // No matter what the alignment is, we put the source in ESI, the
+ // destination in EDI, and the count in ECX.
+ TmpReg1 = getReg(CI.getOperand(1));
+ //TmpReg2 = getReg(CI.getOperand(2));
+ BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg);
+ BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1);
+ BuildMI(BB, Opcode, 0);
+ return;
+ }
+
+ default: assert(0 && "Error: unknown intrinsics should have been lowered!");
+ }
+ }
+
+ static bool isSafeToFoldLoadIntoInstruction(LoadInst &LI, Instruction &User) {
+ if (LI.getParent() != User.getParent())
+ return false;
+ BasicBlock::iterator It = &LI;
+ // Check all of the instructions between the load and the user. We should
+ // really use alias analysis here, but for now we just do something simple.
+ for (++It; It != BasicBlock::iterator(&User); ++It) {
+ switch (It->getOpcode()) {
+ case Instruction::Store:
+ case Instruction::Call:
+ case Instruction::Invoke:
+ return false;
+ }
+ }
+ return true;
+ }
+
+
+ /// visitSimpleBinary - Implement simple binary operators for integral types...
+ /// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or, 4 for
+ /// Xor.
+ ///
+ void ISel::visitSimpleBinary(BinaryOperator &B, unsigned OperatorClass) {
+ unsigned DestReg = getReg(B);
+ MachineBasicBlock::iterator MI = BB->end();
+ Value *Op0 = B.getOperand(0), *Op1 = B.getOperand(1);
+
+ // Special case: op Reg, load [mem]
+ if (isa<LoadInst>(Op0) && !isa<LoadInst>(Op1))
+ if (!B.swapOperands())
+ std::swap(Op0, Op1); // Make sure any loads are in the RHS.
+
+ unsigned Class = getClassB(B.getType());
+ if (isa<LoadInst>(Op1) && Class < cFP &&
+ isSafeToFoldLoadIntoInstruction(*cast<LoadInst>(Op1), B)) {
+
+ static const unsigned OpcodeTab[][3] = {
+ // Arithmetic operators
+ { X86::ADD8rm, X86::ADD16rm, X86::ADD32rm }, // ADD
+ { X86::SUB8rm, X86::SUB16rm, X86::SUB32rm }, // SUB
+
+ // Bitwise operators
+ { X86::AND8rm, X86::AND16rm, X86::AND32rm }, // AND
+ { X86:: OR8rm, X86:: OR16rm, X86:: OR32rm }, // OR
+ { X86::XOR8rm, X86::XOR16rm, X86::XOR32rm }, // XOR
+ };
+
+ assert(Class < cFP && "General code handles 64-bit integer types!");
+ unsigned Opcode = OpcodeTab[OperatorClass][Class];
+
+ unsigned BaseReg, Scale, IndexReg, Disp;
+ getAddressingMode(cast<LoadInst>(Op1)->getOperand(0), BaseReg,
+ Scale, IndexReg, Disp);
+
+ unsigned Op0r = getReg(Op0);
+ addFullAddress(BuildMI(BB, Opcode, 2, DestReg).addReg(Op0r),
+ BaseReg, Scale, IndexReg, Disp);
+ return;
+ }
+
+ emitSimpleBinaryOperation(BB, MI, Op0, Op1, OperatorClass, DestReg);
+ }
+
+ /// emitSimpleBinaryOperation - Implement simple binary operators for integral
+ /// types... OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for
+ /// Or, 4 for Xor.
+ ///
+ /// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
+ /// and constant expression support.
+ ///
+ void ISel::emitSimpleBinaryOperation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Value *Op0, Value *Op1,
+ unsigned OperatorClass, unsigned DestReg) {
+ unsigned Class = getClassB(Op0->getType());
+
+ // sub 0, X -> neg X
+ if (OperatorClass == 1 && Class != cLong)
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op0)) {
+ if (CI->isNullValue()) {
+ unsigned op1Reg = getReg(Op1, MBB, IP);
+ switch (Class) {
+ default: assert(0 && "Unknown class for this function!");
+ case cByte:
+ BuildMI(*MBB, IP, X86::NEG8r, 1, DestReg).addReg(op1Reg);
+ return;
+ case cShort:
+ BuildMI(*MBB, IP, X86::NEG16r, 1, DestReg).addReg(op1Reg);
+ return;
+ case cInt:
+ BuildMI(*MBB, IP, X86::NEG32r, 1, DestReg).addReg(op1Reg);
+ return;
+ }
+ }
+ } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(Op0))
+ if (CFP->isExactlyValue(-0.0)) {
+ // -0.0 - X === -X
+ unsigned op1Reg = getReg(Op1, MBB, IP);
+ BuildMI(*MBB, IP, X86::FCHS, 1, DestReg).addReg(op1Reg);
+ return;
+ }
+
+ // Special case: op Reg, <const>
+ if (Class != cLong && isa<ConstantInt>(Op1)) {
+ ConstantInt *Op1C = cast<ConstantInt>(Op1);
+ unsigned Op0r = getReg(Op0, MBB, IP);
+
+ // xor X, -1 -> not X
+ if (OperatorClass == 4 && Op1C->isAllOnesValue()) {
+ static unsigned const NOTTab[] = { X86::NOT8r, X86::NOT16r, X86::NOT32r };
+ BuildMI(*MBB, IP, NOTTab[Class], 1, DestReg).addReg(Op0r);
+ return;
+ }
+
+ // add X, -1 -> dec X
+ if (OperatorClass == 0 && Op1C->isAllOnesValue()) {
+ static unsigned const DECTab[] = { X86::DEC8r, X86::DEC16r, X86::DEC32r };
+ BuildMI(*MBB, IP, DECTab[Class], 1, DestReg).addReg(Op0r);
+ return;
+ }
+
+ // add X, 1 -> inc X
+ if (OperatorClass == 0 && Op1C->equalsInt(1)) {
+ static unsigned const DECTab[] = { X86::INC8r, X86::INC16r, X86::INC32r };
+ BuildMI(*MBB, IP, DECTab[Class], 1, DestReg).addReg(Op0r);
+ return;
+ }
+
+ static const unsigned OpcodeTab[][3] = {
+ // Arithmetic operators
+ { X86::ADD8ri, X86::ADD16ri, X86::ADD32ri }, // ADD
+ { X86::SUB8ri, X86::SUB16ri, X86::SUB32ri }, // SUB
+
+ // Bitwise operators
+ { X86::AND8ri, X86::AND16ri, X86::AND32ri }, // AND
+ { X86:: OR8ri, X86:: OR16ri, X86:: OR32ri }, // OR
+ { X86::XOR8ri, X86::XOR16ri, X86::XOR32ri }, // XOR
+ };
+
+ assert(Class < cFP && "General code handles 64-bit integer types!");
+ unsigned Opcode = OpcodeTab[OperatorClass][Class];
+
+
+ uint64_t Op1v = cast<ConstantInt>(Op1C)->getRawValue();
+ BuildMI(*MBB, IP, Opcode, 5, DestReg).addReg(Op0r).addImm(Op1v);
+ return;
+ }
+
+ // Finally, handle the general case now.
+ static const unsigned OpcodeTab[][4] = {
+ // Arithmetic operators
+ { X86::ADD8rr, X86::ADD16rr, X86::ADD32rr, X86::FpADD }, // ADD
+ { X86::SUB8rr, X86::SUB16rr, X86::SUB32rr, X86::FpSUB }, // SUB
+
+ // Bitwise operators
+ { X86::AND8rr, X86::AND16rr, X86::AND32rr, 0 }, // AND
+ { X86:: OR8rr, X86:: OR16rr, X86:: OR32rr, 0 }, // OR
+ { X86::XOR8rr, X86::XOR16rr, X86::XOR32rr, 0 }, // XOR
+ };
+
+ bool isLong = false;
+ if (Class == cLong) {
+ isLong = true;
+ Class = cInt; // Bottom 32 bits are handled just like ints
+ }
+
+ unsigned Opcode = OpcodeTab[OperatorClass][Class];
+ assert(Opcode && "Floating point arguments to logical inst?");
+ unsigned Op0r = getReg(Op0, MBB, IP);
+ unsigned Op1r = getReg(Op1, MBB, IP);
+ BuildMI(*MBB, IP, Opcode, 2, DestReg).addReg(Op0r).addReg(Op1r);
+
+ if (isLong) { // Handle the upper 32 bits of long values...
+ static const unsigned TopTab[] = {
+ X86::ADC32rr, X86::SBB32rr, X86::AND32rr, X86::OR32rr, X86::XOR32rr
+ };
+ BuildMI(*MBB, IP, TopTab[OperatorClass], 2,
+ DestReg+1).addReg(Op0r+1).addReg(Op1r+1);
+ }
+ }
+
+ /// doMultiply - Emit appropriate instructions to multiply together the
+ /// registers op0Reg and op1Reg, and put the result in DestReg. The type of the
+ /// result should be given as DestTy.
+ ///
+ void ISel::doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI,
+ unsigned DestReg, const Type *DestTy,
+ unsigned op0Reg, unsigned op1Reg) {
+ unsigned Class = getClass(DestTy);
+ switch (Class) {
+ case cFP: // Floating point multiply
+ BuildMI(*MBB, MBBI, X86::FpMUL, 2, DestReg).addReg(op0Reg).addReg(op1Reg);
+ return;
+ case cInt:
+ case cShort:
+ BuildMI(*MBB, MBBI, Class == cInt ? X86::IMUL32rr:X86::IMUL16rr, 2, DestReg)
+ .addReg(op0Reg).addReg(op1Reg);
+ return;
+ case cByte:
+ // Must use the MUL instruction, which forces use of AL...
+ BuildMI(*MBB, MBBI, X86::MOV8rr, 1, X86::AL).addReg(op0Reg);
+ BuildMI(*MBB, MBBI, X86::MUL8r, 1).addReg(op1Reg);
+ BuildMI(*MBB, MBBI, X86::MOV8rr, 1, DestReg).addReg(X86::AL);
+ return;
+ default:
+ case cLong: assert(0 && "doMultiply cannot operate on LONG values!");
+ }
+ }
+
+ // ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
+ // returns zero when the input is not exactly a power of two.
+ static unsigned ExactLog2(unsigned Val) {
+ if (Val == 0) return 0;
+ unsigned Count = 0;
+ while (Val != 1) {
+ if (Val & 1) return 0;
+ Val >>= 1;
+ ++Count;
+ }
+ return Count+1;
+ }
+
+ void ISel::doMultiplyConst(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ unsigned DestReg, const Type *DestTy,
+ unsigned op0Reg, unsigned ConstRHS) {
+ unsigned Class = getClass(DestTy);
+
+ // If the element size is exactly a power of 2, use a shift to get it.
+ if (unsigned Shift = ExactLog2(ConstRHS)) {
+ switch (Class) {
+ default: assert(0 && "Unknown class for this function!");
+ case cByte:
+ BuildMI(*MBB, IP, X86::SHL32ri,2, DestReg).addReg(op0Reg).addImm(Shift-1);
+ return;
+ case cShort:
+ BuildMI(*MBB, IP, X86::SHL32ri,2, DestReg).addReg(op0Reg).addImm(Shift-1);
+ return;
+ case cInt:
+ BuildMI(*MBB, IP, X86::SHL32ri,2, DestReg).addReg(op0Reg).addImm(Shift-1);
+ return;
+ }
+ }
+
+ if (Class == cShort) {
+ BuildMI(*MBB, IP, X86::IMUL16rri,2,DestReg).addReg(op0Reg).addImm(ConstRHS);
+ return;
+ } else if (Class == cInt) {
+ BuildMI(*MBB, IP, X86::IMUL32rri,2,DestReg).addReg(op0Reg).addImm(ConstRHS);
+ return;
+ }
+
+ // Most general case, emit a normal multiply...
+ static const unsigned MOVriTab[] = {
+ X86::MOV8ri, X86::MOV16ri, X86::MOV32ri
+ };
+
+ unsigned TmpReg = makeAnotherReg(DestTy);
+ BuildMI(*MBB, IP, MOVriTab[Class], 1, TmpReg).addImm(ConstRHS);
+
+ // Emit a MUL to multiply the register holding the index by
+ // elementSize, putting the result in OffsetReg.
+ doMultiply(MBB, IP, DestReg, DestTy, op0Reg, TmpReg);
+ }
+
+ /// visitMul - Multiplies are not simple binary operators because they must deal
+ /// with the EAX register explicitly.
+ ///
+ void ISel::visitMul(BinaryOperator &I) {
+ unsigned Op0Reg = getReg(I.getOperand(0));
+ unsigned DestReg = getReg(I);
+
+ // Simple scalar multiply?
+ if (I.getType() != Type::LongTy && I.getType() != Type::ULongTy) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(1))) {
+ unsigned Val = (unsigned)CI->getRawValue(); // Cannot be 64-bit constant
+ MachineBasicBlock::iterator MBBI = BB->end();
+ doMultiplyConst(BB, MBBI, DestReg, I.getType(), Op0Reg, Val);
+ } else {
+ unsigned Op1Reg = getReg(I.getOperand(1));
+ MachineBasicBlock::iterator MBBI = BB->end();
+ doMultiply(BB, MBBI, DestReg, I.getType(), Op0Reg, Op1Reg);
+ }
+ } else {
+ unsigned Op1Reg = getReg(I.getOperand(1));
+
+ // Long value. We have to do things the hard way...
+ // Multiply the two low parts... capturing carry into EDX
+ BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Op0Reg);
+ BuildMI(BB, X86::MUL32r, 1).addReg(Op1Reg); // AL*BL
+
+ unsigned OverflowReg = makeAnotherReg(Type::UIntTy);
+ BuildMI(BB, X86::MOV32rr, 1, DestReg).addReg(X86::EAX); // AL*BL
+ BuildMI(BB, X86::MOV32rr, 1, OverflowReg).addReg(X86::EDX); // AL*BL >> 32
+
+ MachineBasicBlock::iterator MBBI = BB->end();
+ unsigned AHBLReg = makeAnotherReg(Type::UIntTy); // AH*BL
+ BuildMI(*BB, MBBI, X86::IMUL32rr,2,AHBLReg).addReg(Op0Reg+1).addReg(Op1Reg);
+
+ unsigned AHBLplusOverflowReg = makeAnotherReg(Type::UIntTy);
+ BuildMI(*BB, MBBI, X86::ADD32rr, 2, // AH*BL+(AL*BL >> 32)
+ AHBLplusOverflowReg).addReg(AHBLReg).addReg(OverflowReg);
+
+ MBBI = BB->end();
+ unsigned ALBHReg = makeAnotherReg(Type::UIntTy); // AL*BH
+ BuildMI(*BB, MBBI, X86::IMUL32rr,2,ALBHReg).addReg(Op0Reg).addReg(Op1Reg+1);
+
+ BuildMI(*BB, MBBI, X86::ADD32rr, 2, // AL*BH + AH*BL + (AL*BL >> 32)
+ DestReg+1).addReg(AHBLplusOverflowReg).addReg(ALBHReg);
+ }
+ }
+
+
+ /// visitDivRem - Handle division and remainder instructions... these
+ /// instruction both require the same instructions to be generated, they just
+ /// select the result from a different register. Note that both of these
+ /// instructions work differently for signed and unsigned operands.
+ ///
+ void ISel::visitDivRem(BinaryOperator &I) {
+ unsigned Op0Reg = getReg(I.getOperand(0));
+ unsigned Op1Reg = getReg(I.getOperand(1));
+ unsigned ResultReg = getReg(I);
+
+ MachineBasicBlock::iterator IP = BB->end();
+ emitDivRemOperation(BB, IP, Op0Reg, Op1Reg, I.getOpcode() == Instruction::Div,
+ I.getType(), ResultReg);
+ }
+
+ void ISel::emitDivRemOperation(MachineBasicBlock *BB,
+ MachineBasicBlock::iterator IP,
+ unsigned Op0Reg, unsigned Op1Reg, bool isDiv,
+ const Type *Ty, unsigned ResultReg) {
+ unsigned Class = getClass(Ty);
+ switch (Class) {
+ case cFP: // Floating point divide
+ if (isDiv) {
+ BuildMI(*BB, IP, X86::FpDIV, 2, ResultReg).addReg(Op0Reg).addReg(Op1Reg);
+ } else { // Floating point remainder...
+ MachineInstr *TheCall =
+ BuildMI(X86::CALLpcrel32, 1).addExternalSymbol("fmod", true);
+ std::vector<ValueRecord> Args;
+ Args.push_back(ValueRecord(Op0Reg, Type::DoubleTy));
+ Args.push_back(ValueRecord(Op1Reg, Type::DoubleTy));
+ doCall(ValueRecord(ResultReg, Type::DoubleTy), TheCall, Args);
+ }
+ return;
+ case cLong: {
+ static const char *FnName[] =
+ { "__moddi3", "__divdi3", "__umoddi3", "__udivdi3" };
+
+ unsigned NameIdx = Ty->isUnsigned()*2 + isDiv;
+ MachineInstr *TheCall =
+ BuildMI(X86::CALLpcrel32, 1).addExternalSymbol(FnName[NameIdx], true);
+
+ std::vector<ValueRecord> Args;
+ Args.push_back(ValueRecord(Op0Reg, Type::LongTy));
+ Args.push_back(ValueRecord(Op1Reg, Type::LongTy));
+ doCall(ValueRecord(ResultReg, Type::LongTy), TheCall, Args);
+ return;
+ }
+ case cByte: case cShort: case cInt:
+ break; // Small integrals, handled below...
+ default: assert(0 && "Unknown class!");
+ }
+
+ static const unsigned Regs[] ={ X86::AL , X86::AX , X86::EAX };
+ static const unsigned MovOpcode[]={ X86::MOV8rr, X86::MOV16rr, X86::MOV32rr };
+ static const unsigned SarOpcode[]={ X86::SAR8ri, X86::SAR16ri, X86::SAR32ri };
+ static const unsigned ClrOpcode[]={ X86::MOV8ri, X86::MOV16ri, X86::MOV32ri };
+ static const unsigned ExtRegs[] ={ X86::AH , X86::DX , X86::EDX };
+
+ static const unsigned DivOpcode[][4] = {
+ { X86::DIV8r , X86::DIV16r , X86::DIV32r , 0 }, // Unsigned division
+ { X86::IDIV8r, X86::IDIV16r, X86::IDIV32r, 0 }, // Signed division
+ };
+
+ bool isSigned = Ty->isSigned();
+ unsigned Reg = Regs[Class];
+ unsigned ExtReg = ExtRegs[Class];
+
+ // Put the first operand into one of the A registers...
+ BuildMI(*BB, IP, MovOpcode[Class], 1, Reg).addReg(Op0Reg);
+
+ if (isSigned) {
+ // Emit a sign extension instruction...
+ unsigned ShiftResult = makeAnotherReg(Ty);
+ BuildMI(*BB, IP, SarOpcode[Class], 2,ShiftResult).addReg(Op0Reg).addImm(31);
+ BuildMI(*BB, IP, MovOpcode[Class], 1, ExtReg).addReg(ShiftResult);
+ } else {
+ // If unsigned, emit a zeroing instruction... (reg = 0)
+ BuildMI(*BB, IP, ClrOpcode[Class], 2, ExtReg).addImm(0);
+ }
+
+ // Emit the appropriate divide or remainder instruction...
+ BuildMI(*BB, IP, DivOpcode[isSigned][Class], 1).addReg(Op1Reg);
+
+ // Figure out which register we want to pick the result out of...
+ unsigned DestReg = isDiv ? Reg : ExtReg;
+
+ // Put the result into the destination register...
+ BuildMI(*BB, IP, MovOpcode[Class], 1, ResultReg).addReg(DestReg);
+ }
+
+
+ /// Shift instructions: 'shl', 'sar', 'shr' - Some special cases here
+ /// for constant immediate shift values, and for constant immediate
+ /// shift values equal to 1. Even the general case is sort of special,
+ /// because the shift amount has to be in CL, not just any old register.
+ ///
+ void ISel::visitShiftInst(ShiftInst &I) {
+ MachineBasicBlock::iterator IP = BB->end ();
+ emitShiftOperation (BB, IP, I.getOperand (0), I.getOperand (1),
+ I.getOpcode () == Instruction::Shl, I.getType (),
+ getReg (I));
+ }
+
+ /// emitShiftOperation - Common code shared between visitShiftInst and
+ /// constant expression support.
+ void ISel::emitShiftOperation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Value *Op, Value *ShiftAmount, bool isLeftShift,
+ const Type *ResultTy, unsigned DestReg) {
+ unsigned SrcReg = getReg (Op, MBB, IP);
+ bool isSigned = ResultTy->isSigned ();
+ unsigned Class = getClass (ResultTy);
+
+ static const unsigned ConstantOperand[][4] = {
+ { X86::SHR8ri, X86::SHR16ri, X86::SHR32ri, X86::SHRD32rri8 }, // SHR
+ { X86::SAR8ri, X86::SAR16ri, X86::SAR32ri, X86::SHRD32rri8 }, // SAR
+ { X86::SHL8ri, X86::SHL16ri, X86::SHL32ri, X86::SHLD32rri8 }, // SHL
+ { X86::SHL8ri, X86::SHL16ri, X86::SHL32ri, X86::SHLD32rri8 }, // SAL = SHL
+ };
+
+ static const unsigned NonConstantOperand[][4] = {
+ { X86::SHR8rCL, X86::SHR16rCL, X86::SHR32rCL }, // SHR
+ { X86::SAR8rCL, X86::SAR16rCL, X86::SAR32rCL }, // SAR
+ { X86::SHL8rCL, X86::SHL16rCL, X86::SHL32rCL }, // SHL
+ { X86::SHL8rCL, X86::SHL16rCL, X86::SHL32rCL }, // SAL = SHL
+ };
+
+ // Longs, as usual, are handled specially...
+ if (Class == cLong) {
+ // If we have a constant shift, we can generate much more efficient code
+ // than otherwise...
+ //
+ if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(ShiftAmount)) {
+ unsigned Amount = CUI->getValue();
+ if (Amount < 32) {
+ const unsigned *Opc = ConstantOperand[isLeftShift*2+isSigned];
+ if (isLeftShift) {
+ BuildMI(*MBB, IP, Opc[3], 3,
+ DestReg+1).addReg(SrcReg+1).addReg(SrcReg).addImm(Amount);
+ BuildMI(*MBB, IP, Opc[2], 2, DestReg).addReg(SrcReg).addImm(Amount);
+ } else {
+ BuildMI(*MBB, IP, Opc[3], 3,
+ DestReg).addReg(SrcReg ).addReg(SrcReg+1).addImm(Amount);
+ BuildMI(*MBB, IP, Opc[2],2,DestReg+1).addReg(SrcReg+1).addImm(Amount);
+ }
+ } else { // Shifting more than 32 bits
+ Amount -= 32;
+ if (isLeftShift) {
+ BuildMI(*MBB, IP, X86::SHL32ri, 2,
+ DestReg + 1).addReg(SrcReg).addImm(Amount);
+ BuildMI(*MBB, IP, X86::MOV32ri, 1,
+ DestReg).addImm(0);
+ } else {
+ unsigned Opcode = isSigned ? X86::SAR32ri : X86::SHR32ri;
+ BuildMI(*MBB, IP, Opcode, 2, DestReg).addReg(SrcReg+1).addImm(Amount);
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, DestReg+1).addImm(0);
+ }
+ }
+ } else {
+ unsigned TmpReg = makeAnotherReg(Type::IntTy);
+
+ if (!isLeftShift && isSigned) {
+ // If this is a SHR of a Long, then we need to do funny sign extension
+ // stuff. TmpReg gets the value to use as the high-part if we are
+ // shifting more than 32 bits.
+ BuildMI(*MBB, IP, X86::SAR32ri, 2, TmpReg).addReg(SrcReg).addImm(31);
+ } else {
+ // Other shifts use a fixed zero value if the shift is more than 32
+ // bits.
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, TmpReg).addImm(0);
+ }
+
+ // Initialize CL with the shift amount...
+ unsigned ShiftAmountReg = getReg(ShiftAmount, MBB, IP);
+ BuildMI(*MBB, IP, X86::MOV8rr, 1, X86::CL).addReg(ShiftAmountReg);
+
+ unsigned TmpReg2 = makeAnotherReg(Type::IntTy);
+ unsigned TmpReg3 = makeAnotherReg(Type::IntTy);
+ if (isLeftShift) {
+ // TmpReg2 = shld inHi, inLo
+ BuildMI(*MBB, IP, X86::SHLD32rrCL,2,TmpReg2).addReg(SrcReg+1)
+ .addReg(SrcReg);
+ // TmpReg3 = shl inLo, CL
+ BuildMI(*MBB, IP, X86::SHL32rCL, 1, TmpReg3).addReg(SrcReg);
+
+ // Set the flags to indicate whether the shift was by more than 32 bits.
+ BuildMI(*MBB, IP, X86::TEST8ri, 2).addReg(X86::CL).addImm(32);
+
+ // DestHi = (>32) ? TmpReg3 : TmpReg2;
+ BuildMI(*MBB, IP, X86::CMOVNE32rr, 2,
+ DestReg+1).addReg(TmpReg2).addReg(TmpReg3);
+ // DestLo = (>32) ? TmpReg : TmpReg3;
+ BuildMI(*MBB, IP, X86::CMOVNE32rr, 2,
+ DestReg).addReg(TmpReg3).addReg(TmpReg);
+ } else {
+ // TmpReg2 = shrd inLo, inHi
+ BuildMI(*MBB, IP, X86::SHRD32rrCL,2,TmpReg2).addReg(SrcReg)
+ .addReg(SrcReg+1);
+ // TmpReg3 = s[ah]r inHi, CL
+ BuildMI(*MBB, IP, isSigned ? X86::SAR32rCL : X86::SHR32rCL, 1, TmpReg3)
+ .addReg(SrcReg+1);
+
+ // Set the flags to indicate whether the shift was by more than 32 bits.
+ BuildMI(*MBB, IP, X86::TEST8ri, 2).addReg(X86::CL).addImm(32);
+
+ // DestLo = (>32) ? TmpReg3 : TmpReg2;
+ BuildMI(*MBB, IP, X86::CMOVNE32rr, 2,
+ DestReg).addReg(TmpReg2).addReg(TmpReg3);
+
+ // DestHi = (>32) ? TmpReg : TmpReg3;
+ BuildMI(*MBB, IP, X86::CMOVNE32rr, 2,
+ DestReg+1).addReg(TmpReg3).addReg(TmpReg);
+ }
+ }
+ return;
+ }
+
+ if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(ShiftAmount)) {
+ // The shift amount is constant, guaranteed to be a ubyte. Get its value.
+ assert(CUI->getType() == Type::UByteTy && "Shift amount not a ubyte?");
+
+ const unsigned *Opc = ConstantOperand[isLeftShift*2+isSigned];
+ BuildMI(*MBB, IP, Opc[Class], 2,
+ DestReg).addReg(SrcReg).addImm(CUI->getValue());
+ } else { // The shift amount is non-constant.
+ unsigned ShiftAmountReg = getReg (ShiftAmount, MBB, IP);
+ BuildMI(*MBB, IP, X86::MOV8rr, 1, X86::CL).addReg(ShiftAmountReg);
+
+ const unsigned *Opc = NonConstantOperand[isLeftShift*2+isSigned];
+ BuildMI(*MBB, IP, Opc[Class], 1, DestReg).addReg(SrcReg);
+ }
+ }
+
+
+ void ISel::getAddressingMode(Value *Addr, unsigned &BaseReg, unsigned &Scale,
+ unsigned &IndexReg, unsigned &Disp) {
+ BaseReg = 0; Scale = 1; IndexReg = 0; Disp = 0;
+ if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr)) {
+ if (isGEPFoldable(BB, GEP->getOperand(0), GEP->op_begin()+1, GEP->op_end(),
+ BaseReg, Scale, IndexReg, Disp))
+ return;
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr)) {
+ if (CE->getOpcode() == Instruction::GetElementPtr)
+ if (isGEPFoldable(BB, CE->getOperand(0), CE->op_begin()+1, CE->op_end(),
+ BaseReg, Scale, IndexReg, Disp))
+ return;
+ }
+
+ // If it's not foldable, reset addr mode.
+ BaseReg = getReg(Addr);
+ Scale = 1; IndexReg = 0; Disp = 0;
+ }
+
+
+ /// visitLoadInst - Implement LLVM load instructions in terms of the x86 'mov'
+ /// instruction. The load and store instructions are the only place where we
+ /// need to worry about the memory layout of the target machine.
+ ///
+ void ISel::visitLoadInst(LoadInst &I) {
+ // Check to see if this load instruction is going to be folded into a binary
+ // instruction, like add. If so, we don't want to emit it. Wouldn't a real
+ // pattern matching instruction selector be nice?
+ if (I.hasOneUse() && getClassB(I.getType()) < cFP) {
+ Instruction *User = cast<Instruction>(I.use_back());
+ switch (User->getOpcode()) {
+ default: User = 0; break;
+ case Instruction::Add:
+ case Instruction::Sub:
+ case Instruction::And:
+ case Instruction::Or:
+ case Instruction::Xor:
+ break;
+ }
+
+ if (User) {
+ // Okay, we found a user. If the load is the first operand and there is
+ // no second operand load, reverse the operand ordering. Note that this
+ // can fail for a subtract (ie, no change will be made).
+ if (!isa<LoadInst>(User->getOperand(1)))
+ cast<BinaryOperator>(User)->swapOperands();
+
+ // Okay, now that everything is set up, if this load is used by the second
+ // operand, and if there are no instructions that invalidate the load
+ // before the binary operator, eliminate the load.
+ if (User->getOperand(1) == &I &&
+ isSafeToFoldLoadIntoInstruction(I, *User))
+ return; // Eliminate the load!
+ }
+ }
+
+ unsigned DestReg = getReg(I);
+ unsigned BaseReg = 0, Scale = 1, IndexReg = 0, Disp = 0;
+ getAddressingMode(I.getOperand(0), BaseReg, Scale, IndexReg, Disp);
+
+ unsigned Class = getClassB(I.getType());
+ if (Class == cLong) {
+ addFullAddress(BuildMI(BB, X86::MOV32rm, 4, DestReg),
+ BaseReg, Scale, IndexReg, Disp);
+ addFullAddress(BuildMI(BB, X86::MOV32rm, 4, DestReg+1),
+ BaseReg, Scale, IndexReg, Disp+4);
+ return;
+ }
+
+ static const unsigned Opcodes[] = {
+ X86::MOV8rm, X86::MOV16rm, X86::MOV32rm, X86::FLD32m
+ };
+ unsigned Opcode = Opcodes[Class];
+ if (I.getType() == Type::DoubleTy) Opcode = X86::FLD64m;
+ addFullAddress(BuildMI(BB, Opcode, 4, DestReg),
+ BaseReg, Scale, IndexReg, Disp);
+ }
+
+ /// visitStoreInst - Implement LLVM store instructions in terms of the x86 'mov'
+ /// instruction.
+ ///
+ void ISel::visitStoreInst(StoreInst &I) {
+ unsigned BaseReg, Scale, IndexReg, Disp;
+ getAddressingMode(I.getOperand(1), BaseReg, Scale, IndexReg, Disp);
+
+ const Type *ValTy = I.getOperand(0)->getType();
+ unsigned Class = getClassB(ValTy);
+
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(0))) {
+ uint64_t Val = CI->getRawValue();
+ if (Class == cLong) {
+ addFullAddress(BuildMI(BB, X86::MOV32mi, 5),
+ BaseReg, Scale, IndexReg, Disp).addImm(Val & ~0U);
+ addFullAddress(BuildMI(BB, X86::MOV32mi, 5),
+ BaseReg, Scale, IndexReg, Disp+4).addImm(Val>>32);
+ } else {
+ static const unsigned Opcodes[] = {
+ X86::MOV8mi, X86::MOV16mi, X86::MOV32mi
+ };
+ unsigned Opcode = Opcodes[Class];
+ addFullAddress(BuildMI(BB, Opcode, 5),
+ BaseReg, Scale, IndexReg, Disp).addImm(Val);
+ }
+ } else if (ConstantBool *CB = dyn_cast<ConstantBool>(I.getOperand(0))) {
+ addFullAddress(BuildMI(BB, X86::MOV8mi, 5),
+ BaseReg, Scale, IndexReg, Disp).addImm(CB->getValue());
+ } else {
+ if (Class == cLong) {
+ unsigned ValReg = getReg(I.getOperand(0));
+ addFullAddress(BuildMI(BB, X86::MOV32mr, 5),
+ BaseReg, Scale, IndexReg, Disp).addReg(ValReg);
+ addFullAddress(BuildMI(BB, X86::MOV32mr, 5),
+ BaseReg, Scale, IndexReg, Disp+4).addReg(ValReg+1);
+ } else {
+ unsigned ValReg = getReg(I.getOperand(0));
+ static const unsigned Opcodes[] = {
+ X86::MOV8mr, X86::MOV16mr, X86::MOV32mr, X86::FST32m
+ };
+ unsigned Opcode = Opcodes[Class];
+ if (ValTy == Type::DoubleTy) Opcode = X86::FST64m;
+ addFullAddress(BuildMI(BB, Opcode, 1+4),
+ BaseReg, Scale, IndexReg, Disp).addReg(ValReg);
+ }
+ }
+ }
+
+
+ /// visitCastInst - Here we have various kinds of copying with or without sign
+ /// extension going on.
+ ///
+ void ISel::visitCastInst(CastInst &CI) {
+ Value *Op = CI.getOperand(0);
+ // If this is a cast from a 32-bit integer to a Long type, and the only uses
+ // of the case are GEP instructions, then the cast does not need to be
+ // generated explicitly, it will be folded into the GEP.
+ if (CI.getType() == Type::LongTy &&
+ (Op->getType() == Type::IntTy || Op->getType() == Type::UIntTy)) {
+ bool AllUsesAreGEPs = true;
+ for (Value::use_iterator I = CI.use_begin(), E = CI.use_end(); I != E; ++I)
+ if (!isa<GetElementPtrInst>(*I)) {
+ AllUsesAreGEPs = false;
+ break;
+ }
+
+ // No need to codegen this cast if all users are getelementptr instrs...
+ if (AllUsesAreGEPs) return;
+ }
+
+ unsigned DestReg = getReg(CI);
+ MachineBasicBlock::iterator MI = BB->end();
+ emitCastOperation(BB, MI, Op, CI.getType(), DestReg);
+ }
+
+ /// emitCastOperation - Common code shared between visitCastInst and constant
+ /// expression cast support.
+ ///
+ void ISel::emitCastOperation(MachineBasicBlock *BB,
+ MachineBasicBlock::iterator IP,
+ Value *Src, const Type *DestTy,
+ unsigned DestReg) {
+ unsigned SrcReg = getReg(Src, BB, IP);
+ const Type *SrcTy = Src->getType();
+ unsigned SrcClass = getClassB(SrcTy);
+ unsigned DestClass = getClassB(DestTy);
+
+ // Implement casts to bool by using compare on the operand followed by set if
+ // not zero on the result.
+ if (DestTy == Type::BoolTy) {
+ switch (SrcClass) {
+ case cByte:
+ BuildMI(*BB, IP, X86::TEST8rr, 2).addReg(SrcReg).addReg(SrcReg);
+ break;
+ case cShort:
+ BuildMI(*BB, IP, X86::TEST16rr, 2).addReg(SrcReg).addReg(SrcReg);
+ break;
+ case cInt:
+ BuildMI(*BB, IP, X86::TEST32rr, 2).addReg(SrcReg).addReg(SrcReg);
+ break;
+ case cLong: {
+ unsigned TmpReg = makeAnotherReg(Type::IntTy);
+ BuildMI(*BB, IP, X86::OR32rr, 2, TmpReg).addReg(SrcReg).addReg(SrcReg+1);
+ break;
+ }
+ case cFP:
+ BuildMI(*BB, IP, X86::FTST, 1).addReg(SrcReg);
+ BuildMI(*BB, IP, X86::FNSTSW8r, 0);
+ BuildMI(*BB, IP, X86::SAHF, 1);
+ break;
+ }
+
+ // If the zero flag is not set, then the value is true, set the byte to
+ // true.
+ BuildMI(*BB, IP, X86::SETNEr, 1, DestReg);
+ return;
+ }
+
+ static const unsigned RegRegMove[] = {
+ X86::MOV8rr, X86::MOV16rr, X86::MOV32rr, X86::FpMOV, X86::MOV32rr
+ };
+
+ // Implement casts between values of the same type class (as determined by
+ // getClass) by using a register-to-register move.
+ if (SrcClass == DestClass) {
+ if (SrcClass <= cInt || (SrcClass == cFP && SrcTy == DestTy)) {
+ BuildMI(*BB, IP, RegRegMove[SrcClass], 1, DestReg).addReg(SrcReg);
+ } else if (SrcClass == cFP) {
+ if (SrcTy == Type::FloatTy) { // double -> float
+ assert(DestTy == Type::DoubleTy && "Unknown cFP member!");
+ BuildMI(*BB, IP, X86::FpMOV, 1, DestReg).addReg(SrcReg);
+ } else { // float -> double
+ assert(SrcTy == Type::DoubleTy && DestTy == Type::FloatTy &&
+ "Unknown cFP member!");
+ // Truncate from double to float by storing to memory as short, then
+ // reading it back.
+ unsigned FltAlign = TM.getTargetData().getFloatAlignment();
+ int FrameIdx = F->getFrameInfo()->CreateStackObject(4, FltAlign);
+ addFrameReference(BuildMI(*BB, IP, X86::FST32m, 5), FrameIdx).addReg(SrcReg);
+ addFrameReference(BuildMI(*BB, IP, X86::FLD32m, 5, DestReg), FrameIdx);
+ }
+ } else if (SrcClass == cLong) {
+ BuildMI(*BB, IP, X86::MOV32rr, 1, DestReg).addReg(SrcReg);
+ BuildMI(*BB, IP, X86::MOV32rr, 1, DestReg+1).addReg(SrcReg+1);
+ } else {
+ assert(0 && "Cannot handle this type of cast instruction!");
+ abort();
+ }
+ return;
+ }
+
+ // Handle cast of SMALLER int to LARGER int using a move with sign extension
+ // or zero extension, depending on whether the source type was signed.
+ if (SrcClass <= cInt && (DestClass <= cInt || DestClass == cLong) &&
+ SrcClass < DestClass) {
+ bool isLong = DestClass == cLong;
+ if (isLong) DestClass = cInt;
+
+ static const unsigned Opc[][4] = {
+ { X86::MOVSX16rr8, X86::MOVSX32rr8, X86::MOVSX32rr16, X86::MOV32rr }, // s
+ { X86::MOVZX16rr8, X86::MOVZX32rr8, X86::MOVZX32rr16, X86::MOV32rr } // u
+ };
+
+ bool isUnsigned = SrcTy->isUnsigned();
+ BuildMI(*BB, IP, Opc[isUnsigned][SrcClass + DestClass - 1], 1,
+ DestReg).addReg(SrcReg);
+
+ if (isLong) { // Handle upper 32 bits as appropriate...
+ if (isUnsigned) // Zero out top bits...
+ BuildMI(*BB, IP, X86::MOV32ri, 1, DestReg+1).addImm(0);
+ else // Sign extend bottom half...
+ BuildMI(*BB, IP, X86::SAR32ri, 2, DestReg+1).addReg(DestReg).addImm(31);
+ }
+ return;
+ }
+
+ // Special case long -> int ...
+ if (SrcClass == cLong && DestClass == cInt) {
+ BuildMI(*BB, IP, X86::MOV32rr, 1, DestReg).addReg(SrcReg);
+ return;
+ }
+
+ // Handle cast of LARGER int to SMALLER int using a move to EAX followed by a
+ // move out of AX or AL.
+ if ((SrcClass <= cInt || SrcClass == cLong) && DestClass <= cInt
+ && SrcClass > DestClass) {
+ static const unsigned AReg[] = { X86::AL, X86::AX, X86::EAX, 0, X86::EAX };
+ BuildMI(*BB, IP, RegRegMove[SrcClass], 1, AReg[SrcClass]).addReg(SrcReg);
+ BuildMI(*BB, IP, RegRegMove[DestClass], 1, DestReg).addReg(AReg[DestClass]);
+ return;
+ }
+
+ // Handle casts from integer to floating point now...
+ if (DestClass == cFP) {
+ // Promote the integer to a type supported by FLD. We do this because there
+ // are no unsigned FLD instructions, so we must promote an unsigned value to
+ // a larger signed value, then use FLD on the larger value.
+ //
+ const Type *PromoteType = 0;
+ unsigned PromoteOpcode;
+ unsigned RealDestReg = DestReg;
+ switch (SrcTy->getPrimitiveID()) {
+ case Type::BoolTyID:
+ case Type::SByteTyID:
+ // We don't have the facilities for directly loading byte sized data from
+ // memory (even signed). Promote it to 16 bits.
+ PromoteType = Type::ShortTy;
+ PromoteOpcode = X86::MOVSX16rr8;
+ break;
+ case Type::UByteTyID:
+ PromoteType = Type::ShortTy;
+ PromoteOpcode = X86::MOVZX16rr8;
+ break;
+ case Type::UShortTyID:
+ PromoteType = Type::IntTy;
+ PromoteOpcode = X86::MOVZX32rr16;
+ break;
+ case Type::UIntTyID: {
+ // Make a 64 bit temporary... and zero out the top of it...
+ unsigned TmpReg = makeAnotherReg(Type::LongTy);
+ BuildMI(*BB, IP, X86::MOV32rr, 1, TmpReg).addReg(SrcReg);
+ BuildMI(*BB, IP, X86::MOV32ri, 1, TmpReg+1).addImm(0);
+ SrcTy = Type::LongTy;
+ SrcClass = cLong;
+ SrcReg = TmpReg;
+ break;
+ }
+ case Type::ULongTyID:
+ // Don't fild into the read destination.
+ DestReg = makeAnotherReg(Type::DoubleTy);
+ break;
+ default: // No promotion needed...
+ break;
+ }
+
+ if (PromoteType) {
+ unsigned TmpReg = makeAnotherReg(PromoteType);
+ unsigned Opc = SrcTy->isSigned() ? X86::MOVSX16rr8 : X86::MOVZX16rr8;
+ BuildMI(*BB, IP, Opc, 1, TmpReg).addReg(SrcReg);
+ SrcTy = PromoteType;
+ SrcClass = getClass(PromoteType);
+ SrcReg = TmpReg;
+ }
+
+ // Spill the integer to memory and reload it from there...
+ int FrameIdx =
+ F->getFrameInfo()->CreateStackObject(SrcTy, TM.getTargetData());
+
+ if (SrcClass == cLong) {
+ addFrameReference(BuildMI(*BB, IP, X86::MOV32mr, 5),
+ FrameIdx).addReg(SrcReg);
+ addFrameReference(BuildMI(*BB, IP, X86::MOV32mr, 5),
+ FrameIdx, 4).addReg(SrcReg+1);
+ } else {
+ static const unsigned Op1[] = { X86::MOV8mr, X86::MOV16mr, X86::MOV32mr };
+ addFrameReference(BuildMI(*BB, IP, Op1[SrcClass], 5),
+ FrameIdx).addReg(SrcReg);
+ }
+
+ static const unsigned Op2[] =
+ { 0/*byte*/, X86::FILD16m, X86::FILD32m, 0/*FP*/, X86::FILD64m };
+ addFrameReference(BuildMI(*BB, IP, Op2[SrcClass], 5, DestReg), FrameIdx);
+
+ // We need special handling for unsigned 64-bit integer sources. If the
+ // input number has the "sign bit" set, then we loaded it incorrectly as a
+ // negative 64-bit number. In this case, add an offset value.
+ if (SrcTy == Type::ULongTy) {
+ // Emit a test instruction to see if the dynamic input value was signed.
+ BuildMI(*BB, IP, X86::TEST32rr, 2).addReg(SrcReg+1).addReg(SrcReg+1);
+
+ // If the sign bit is set, get a pointer to an offset, otherwise get a
+ // pointer to a zero.
+ MachineConstantPool *CP = F->getConstantPool();
+ unsigned Zero = makeAnotherReg(Type::IntTy);
+ Constant *Null = Constant::getNullValue(Type::UIntTy);
+ addConstantPoolReference(BuildMI(*BB, IP, X86::LEA32r, 5, Zero),
+ CP->getConstantPoolIndex(Null));
+ unsigned Offset = makeAnotherReg(Type::IntTy);
+ Constant *OffsetCst = ConstantUInt::get(Type::UIntTy, 0x5f800000);
+
+ addConstantPoolReference(BuildMI(*BB, IP, X86::LEA32r, 5, Offset),
+ CP->getConstantPoolIndex(OffsetCst));
+ unsigned Addr = makeAnotherReg(Type::IntTy);
+ BuildMI(*BB, IP, X86::CMOVS32rr, 2, Addr).addReg(Zero).addReg(Offset);
+
+ // Load the constant for an add. FIXME: this could make an 'fadd' that
+ // reads directly from memory, but we don't support these yet.
+ unsigned ConstReg = makeAnotherReg(Type::DoubleTy);
+ addDirectMem(BuildMI(*BB, IP, X86::FLD32m, 4, ConstReg), Addr);
+
+ BuildMI(*BB, IP, X86::FpADD, 2, RealDestReg)
+ .addReg(ConstReg).addReg(DestReg);
+ }
+
+ return;
+ }
+
+ // Handle casts from floating point to integer now...
+ if (SrcClass == cFP) {
+ // Change the floating point control register to use "round towards zero"
+ // mode when truncating to an integer value.
+ //
+ int CWFrameIdx = F->getFrameInfo()->CreateStackObject(2, 2);
+ addFrameReference(BuildMI(*BB, IP, X86::FNSTCW16m, 4), CWFrameIdx);
+
+ // Load the old value of the high byte of the control word...
+ unsigned HighPartOfCW = makeAnotherReg(Type::UByteTy);
+ addFrameReference(BuildMI(*BB, IP, X86::MOV8rm, 4, HighPartOfCW),
+ CWFrameIdx, 1);
+
+ // Set the high part to be round to zero...
+ addFrameReference(BuildMI(*BB, IP, X86::MOV8mi, 5),
+ CWFrameIdx, 1).addImm(12);
+
+ // Reload the modified control word now...
+ addFrameReference(BuildMI(*BB, IP, X86::FLDCW16m, 4), CWFrameIdx);
+
+ // Restore the memory image of control word to original value
+ addFrameReference(BuildMI(*BB, IP, X86::MOV8mr, 5),
+ CWFrameIdx, 1).addReg(HighPartOfCW);
+
+ // We don't have the facilities for directly storing byte sized data to
+ // memory. Promote it to 16 bits. We also must promote unsigned values to
+ // larger classes because we only have signed FP stores.
+ unsigned StoreClass = DestClass;
+ const Type *StoreTy = DestTy;
+ if (StoreClass == cByte || DestTy->isUnsigned())
+ switch (StoreClass) {
+ case cByte: StoreTy = Type::ShortTy; StoreClass = cShort; break;
+ case cShort: StoreTy = Type::IntTy; StoreClass = cInt; break;
+ case cInt: StoreTy = Type::LongTy; StoreClass = cLong; break;
+ // The following treatment of cLong may not be perfectly right,
+ // but it survives chains of casts of the form
+ // double->ulong->double.
+ case cLong: StoreTy = Type::LongTy; StoreClass = cLong; break;
+ default: assert(0 && "Unknown store class!");
+ }
+
+ // Spill the integer to memory and reload it from there...
+ int FrameIdx =
+ F->getFrameInfo()->CreateStackObject(StoreTy, TM.getTargetData());
+
+ static const unsigned Op1[] =
+ { 0, X86::FIST16m, X86::FIST32m, 0, X86::FISTP64m };
+ addFrameReference(BuildMI(*BB, IP, Op1[StoreClass], 5),
+ FrameIdx).addReg(SrcReg);
+
+ if (DestClass == cLong) {
+ addFrameReference(BuildMI(*BB, IP, X86::MOV32rm, 4, DestReg), FrameIdx);
+ addFrameReference(BuildMI(*BB, IP, X86::MOV32rm, 4, DestReg+1),
+ FrameIdx, 4);
+ } else {
+ static const unsigned Op2[] = { X86::MOV8rm, X86::MOV16rm, X86::MOV32rm };
+ addFrameReference(BuildMI(*BB, IP, Op2[DestClass], 4, DestReg), FrameIdx);
+ }
+
+ // Reload the original control word now...
+ addFrameReference(BuildMI(*BB, IP, X86::FLDCW16m, 4), CWFrameIdx);
+ return;
+ }
+
+ // Anything we haven't handled already, we can't (yet) handle at all.
+ assert(0 && "Unhandled cast instruction!");
+ abort();
+ }
+
+ /// visitVANextInst - Implement the va_next instruction...
+ ///
+ void ISel::visitVANextInst(VANextInst &I) {
+ unsigned VAList = getReg(I.getOperand(0));
+ unsigned DestReg = getReg(I);
+
+ unsigned Size;
+ switch (I.getArgType()->getPrimitiveID()) {
+ default:
+ std::cerr << I;
+ assert(0 && "Error: bad type for va_next instruction!");
+ return;
+ case Type::PointerTyID:
+ case Type::UIntTyID:
+ case Type::IntTyID:
+ Size = 4;
+ break;
+ case Type::ULongTyID:
+ case Type::LongTyID:
+ case Type::DoubleTyID:
+ Size = 8;
+ break;
+ }
+
+ // Increment the VAList pointer...
+ BuildMI(BB, X86::ADD32ri, 2, DestReg).addReg(VAList).addImm(Size);
+ }
+
+ void ISel::visitVAArgInst(VAArgInst &I) {
+ unsigned VAList = getReg(I.getOperand(0));
+ unsigned DestReg = getReg(I);
+
+ switch (I.getType()->getPrimitiveID()) {
+ default:
+ std::cerr << I;
+ assert(0 && "Error: bad type for va_next instruction!");
+ return;
+ case Type::PointerTyID:
+ case Type::UIntTyID:
+ case Type::IntTyID:
+ addDirectMem(BuildMI(BB, X86::MOV32rm, 4, DestReg), VAList);
+ break;
+ case Type::ULongTyID:
+ case Type::LongTyID:
+ addDirectMem(BuildMI(BB, X86::MOV32rm, 4, DestReg), VAList);
+ addRegOffset(BuildMI(BB, X86::MOV32rm, 4, DestReg+1), VAList, 4);
+ break;
+ case Type::DoubleTyID:
+ addDirectMem(BuildMI(BB, X86::FLD64m, 4, DestReg), VAList);
+ break;
+ }
+ }
+
+ /// visitGetElementPtrInst - instruction-select GEP instructions
+ ///
+ void ISel::visitGetElementPtrInst(GetElementPtrInst &I) {
+ // If this GEP instruction will be folded into all of its users, we don't need
+ // to explicitly calculate it!
+ unsigned A, B, C, D;
+ if (isGEPFoldable(0, I.getOperand(0), I.op_begin()+1, I.op_end(), A,B,C,D)) {
+ // Check all of the users of the instruction to see if they are loads and
+ // stores.
+ bool AllWillFold = true;
+ for (Value::use_iterator UI = I.use_begin(), E = I.use_end(); UI != E; ++UI)
+ if (cast<Instruction>(*UI)->getOpcode() != Instruction::Load)
+ if (cast<Instruction>(*UI)->getOpcode() != Instruction::Store ||
+ cast<Instruction>(*UI)->getOperand(0) == &I) {
+ AllWillFold = false;
+ break;
+ }
+
+ // If the instruction is foldable, and will be folded into all users, don't
+ // emit it!
+ if (AllWillFold) return;
+ }
+
+ unsigned outputReg = getReg(I);
+ emitGEPOperation(BB, BB->end(), I.getOperand(0),
+ I.op_begin()+1, I.op_end(), outputReg);
+ }
+
+ /// getGEPIndex - Inspect the getelementptr operands specified with GEPOps and
+ /// GEPTypes (the derived types being stepped through at each level). On return
+ /// from this function, if some indexes of the instruction are representable as
+ /// an X86 lea instruction, the machine operands are put into the Ops
+ /// instruction and the consumed indexes are poped from the GEPOps/GEPTypes
+ /// lists. Otherwise, GEPOps.size() is returned. If this returns a an
+ /// addressing mode that only partially consumes the input, the BaseReg input of
+ /// the addressing mode must be left free.
+ ///
+ /// Note that there is one fewer entry in GEPTypes than there is in GEPOps.
+ ///
+ void ISel::getGEPIndex(MachineBasicBlock *MBB, MachineBasicBlock::iterator IP,
+ std::vector<Value*> &GEPOps,
+ std::vector<const Type*> &GEPTypes, unsigned &BaseReg,
+ unsigned &Scale, unsigned &IndexReg, unsigned &Disp) {
+ const TargetData &TD = TM.getTargetData();
+
+ // Clear out the state we are working with...
+ BaseReg = 0; // No base register
+ Scale = 1; // Unit scale
+ IndexReg = 0; // No index register
+ Disp = 0; // No displacement
+
+ // While there are GEP indexes that can be folded into the current address,
+ // keep processing them.
+ while (!GEPTypes.empty()) {
+ if (const StructType *StTy = dyn_cast<StructType>(GEPTypes.back())) {
+ // It's a struct access. CUI is the index into the structure,
+ // which names the field. This index must have unsigned type.
+ const ConstantUInt *CUI = cast<ConstantUInt>(GEPOps.back());
+
+ // Use the TargetData structure to pick out what the layout of the
+ // structure is in memory. Since the structure index must be constant, we
+ // can get its value and use it to find the right byte offset from the
+ // StructLayout class's list of structure member offsets.
+ Disp += TD.getStructLayout(StTy)->MemberOffsets[CUI->getValue()];
+ GEPOps.pop_back(); // Consume a GEP operand
+ GEPTypes.pop_back();
+ } else {
+ // It's an array or pointer access: [ArraySize x ElementType].
+ const SequentialType *SqTy = cast<SequentialType>(GEPTypes.back());
+ Value *idx = GEPOps.back();
+
+ // idx is the index into the array. Unlike with structure
+ // indices, we may not know its actual value at code-generation
+ // time.
+ assert(idx->getType() == Type::LongTy && "Bad GEP array index!");
+
+ // If idx is a constant, fold it into the offset.
+ unsigned TypeSize = TD.getTypeSize(SqTy->getElementType());
+ if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(idx)) {
+ Disp += TypeSize*CSI->getValue();
+ } else {
+ // If the index reg is already taken, we can't handle this index.
+ if (IndexReg) return;
+
+ // If this is a size that we can handle, then add the index as
+ switch (TypeSize) {
+ case 1: case 2: case 4: case 8:
+ // These are all acceptable scales on X86.
+ Scale = TypeSize;
+ break;
+ default:
+ // Otherwise, we can't handle this scale
+ return;
+ }
+
+ if (CastInst *CI = dyn_cast<CastInst>(idx))
+ if (CI->getOperand(0)->getType() == Type::IntTy ||
+ CI->getOperand(0)->getType() == Type::UIntTy)
+ idx = CI->getOperand(0);
+
+ IndexReg = MBB ? getReg(idx, MBB, IP) : 1;
+ }
+
+ GEPOps.pop_back(); // Consume a GEP operand
+ GEPTypes.pop_back();
+ }
+ }
+
+ // GEPTypes is empty, which means we have a single operand left. See if we
+ // can set it as the base register.
+ //
+ // FIXME: When addressing modes are more powerful/correct, we could load
+ // global addresses directly as 32-bit immediates.
+ assert(BaseReg == 0);
+ BaseReg = MBB ? getReg(GEPOps[0], MBB, IP) : 1;
+ GEPOps.pop_back(); // Consume the last GEP operand
+ }
+
+
+ /// isGEPFoldable - Return true if the specified GEP can be completely
+ /// folded into the addressing mode of a load/store or lea instruction.
+ bool ISel::isGEPFoldable(MachineBasicBlock *MBB,
+ Value *Src, User::op_iterator IdxBegin,
+ User::op_iterator IdxEnd, unsigned &BaseReg,
+ unsigned &Scale, unsigned &IndexReg, unsigned &Disp) {
+ if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(Src))
+ Src = CPR->getValue();
+
+ std::vector<Value*> GEPOps;
+ GEPOps.resize(IdxEnd-IdxBegin+1);
+ GEPOps[0] = Src;
+ std::copy(IdxBegin, IdxEnd, GEPOps.begin()+1);
+
+ std::vector<const Type*> GEPTypes;
+ GEPTypes.assign(gep_type_begin(Src->getType(), IdxBegin, IdxEnd),
+ gep_type_end(Src->getType(), IdxBegin, IdxEnd));
+
+ MachineBasicBlock::iterator IP;
+ if (MBB) IP = MBB->end();
+ getGEPIndex(MBB, IP, GEPOps, GEPTypes, BaseReg, Scale, IndexReg, Disp);
+
+ // We can fold it away iff the getGEPIndex call eliminated all operands.
+ return GEPOps.empty();
+ }
+
+ void ISel::emitGEPOperation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator IP,
+ Value *Src, User::op_iterator IdxBegin,
+ User::op_iterator IdxEnd, unsigned TargetReg) {
+ const TargetData &TD = TM.getTargetData();
+ if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(Src))
+ Src = CPR->getValue();
+
+ std::vector<Value*> GEPOps;
+ GEPOps.resize(IdxEnd-IdxBegin+1);
+ GEPOps[0] = Src;
+ std::copy(IdxBegin, IdxEnd, GEPOps.begin()+1);
+
+ std::vector<const Type*> GEPTypes;
+ GEPTypes.assign(gep_type_begin(Src->getType(), IdxBegin, IdxEnd),
+ gep_type_end(Src->getType(), IdxBegin, IdxEnd));
+
+ // Keep emitting instructions until we consume the entire GEP instruction.
+ while (!GEPOps.empty()) {
+ unsigned OldSize = GEPOps.size();
+ unsigned BaseReg, Scale, IndexReg, Disp;
+ getGEPIndex(MBB, IP, GEPOps, GEPTypes, BaseReg, Scale, IndexReg, Disp);
+
+ if (GEPOps.size() != OldSize) {
+ // getGEPIndex consumed some of the input. Build an LEA instruction here.
+ unsigned NextTarget = 0;
+ if (!GEPOps.empty()) {
+ assert(BaseReg == 0 &&
+ "getGEPIndex should have left the base register open for chaining!");
+ NextTarget = BaseReg = makeAnotherReg(Type::UIntTy);
+ }
+
+ if (IndexReg == 0 && Disp == 0)
+ BuildMI(*MBB, IP, X86::MOV32rr, 1, TargetReg).addReg(BaseReg);
+ else
+ addFullAddress(BuildMI(*MBB, IP, X86::LEA32r, 5, TargetReg),
+ BaseReg, Scale, IndexReg, Disp);
+ --IP;
+ TargetReg = NextTarget;
+ } else if (GEPTypes.empty()) {
+ // The getGEPIndex operation didn't want to build an LEA. Check to see if
+ // all operands are consumed but the base pointer. If so, just load it
+ // into the register.
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(GEPOps[0])) {
+ BuildMI(*MBB, IP, X86::MOV32ri, 1, TargetReg).addGlobalAddress(GV);
+ } else {
+ unsigned BaseReg = getReg(GEPOps[0], MBB, IP);
+ BuildMI(*MBB, IP, X86::MOV32rr, 1, TargetReg).addReg(BaseReg);
+ }
+ break; // we are now done
+
+ } else {
+ // It's an array or pointer access: [ArraySize x ElementType].
+ const SequentialType *SqTy = cast<SequentialType>(GEPTypes.back());
+ Value *idx = GEPOps.back();
+ GEPOps.pop_back(); // Consume a GEP operand
+ GEPTypes.pop_back();
+
+ // idx is the index into the array. Unlike with structure
+ // indices, we may not know its actual value at code-generation
+ // time.
+ assert(idx->getType() == Type::LongTy && "Bad GEP array index!");
+
+ // Most GEP instructions use a [cast (int/uint) to LongTy] as their
+ // operand on X86. Handle this case directly now...
+ if (CastInst *CI = dyn_cast<CastInst>(idx))
+ if (CI->getOperand(0)->getType() == Type::IntTy ||
+ CI->getOperand(0)->getType() == Type::UIntTy)
+ idx = CI->getOperand(0);
+
+ // We want to add BaseReg to(idxReg * sizeof ElementType). First, we
+ // must find the size of the pointed-to type (Not coincidentally, the next
+ // type is the type of the elements in the array).
+ const Type *ElTy = SqTy->getElementType();
+ unsigned elementSize = TD.getTypeSize(ElTy);
+
+ // If idxReg is a constant, we don't need to perform the multiply!
+ if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(idx)) {
+ if (!CSI->isNullValue()) {
+ unsigned Offset = elementSize*CSI->getValue();
+ unsigned Reg = makeAnotherReg(Type::UIntTy);
+ BuildMI(*MBB, IP, X86::ADD32ri, 2, TargetReg)
+ .addReg(Reg).addImm(Offset);
+ --IP; // Insert the next instruction before this one.
+ TargetReg = Reg; // Codegen the rest of the GEP into this
+ }
+ } else if (elementSize == 1) {
+ // If the element size is 1, we don't have to multiply, just add
+ unsigned idxReg = getReg(idx, MBB, IP);
+ unsigned Reg = makeAnotherReg(Type::UIntTy);
+ BuildMI(*MBB, IP, X86::ADD32rr, 2,TargetReg).addReg(Reg).addReg(idxReg);
+ --IP; // Insert the next instruction before this one.
+ TargetReg = Reg; // Codegen the rest of the GEP into this
+ } else {
+ unsigned idxReg = getReg(idx, MBB, IP);
+ unsigned OffsetReg = makeAnotherReg(Type::UIntTy);
+
+ // Make sure we can back the iterator up to point to the first
+ // instruction emitted.
+ MachineBasicBlock::iterator BeforeIt = IP;
+ if (IP == MBB->begin())
+ BeforeIt = MBB->end();
+ else
+ --BeforeIt;
+ doMultiplyConst(MBB, IP, OffsetReg, Type::IntTy, idxReg, elementSize);
+
+ // Emit an ADD to add OffsetReg to the basePtr.
+ unsigned Reg = makeAnotherReg(Type::UIntTy);
+ BuildMI(*MBB, IP, X86::ADD32rr, 2, TargetReg)
+ .addReg(Reg).addReg(OffsetReg);
+
+ // Step to the first instruction of the multiply.
+ if (BeforeIt == MBB->end())
+ IP = MBB->begin();
+ else
+ IP = ++BeforeIt;
+
+ TargetReg = Reg; // Codegen the rest of the GEP into this
+ }
+ }
+ }
+ }
+
+
+ /// visitAllocaInst - If this is a fixed size alloca, allocate space from the
+ /// frame manager, otherwise do it the hard way.
+ ///
+ void ISel::visitAllocaInst(AllocaInst &I) {
+ // Find the data size of the alloca inst's getAllocatedType.
+ const Type *Ty = I.getAllocatedType();
+ unsigned TySize = TM.getTargetData().getTypeSize(Ty);
+
+ // If this is a fixed size alloca in the entry block for the function,
+ // statically stack allocate the space.
+ //
+ if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(I.getArraySize())) {
+ if (I.getParent() == I.getParent()->getParent()->begin()) {
+ TySize *= CUI->getValue(); // Get total allocated size...
+ unsigned Alignment = TM.getTargetData().getTypeAlignment(Ty);
+
+ // Create a new stack object using the frame manager...
+ int FrameIdx = F->getFrameInfo()->CreateStackObject(TySize, Alignment);
+ addFrameReference(BuildMI(BB, X86::LEA32r, 5, getReg(I)), FrameIdx);
+ return;
+ }
+ }
+
+ // Create a register to hold the temporary result of multiplying the type size
+ // constant by the variable amount.
+ unsigned TotalSizeReg = makeAnotherReg(Type::UIntTy);
+ unsigned SrcReg1 = getReg(I.getArraySize());
+
+ // TotalSizeReg = mul <numelements>, <TypeSize>
+ MachineBasicBlock::iterator MBBI = BB->end();
+ doMultiplyConst(BB, MBBI, TotalSizeReg, Type::UIntTy, SrcReg1, TySize);
+
+ // AddedSize = add <TotalSizeReg>, 15
+ unsigned AddedSizeReg = makeAnotherReg(Type::UIntTy);
+ BuildMI(BB, X86::ADD32ri, 2, AddedSizeReg).addReg(TotalSizeReg).addImm(15);
+
+ // AlignedSize = and <AddedSize>, ~15
+ unsigned AlignedSize = makeAnotherReg(Type::UIntTy);
+ BuildMI(BB, X86::AND32ri, 2, AlignedSize).addReg(AddedSizeReg).addImm(~15);
+
+ // Subtract size from stack pointer, thereby allocating some space.
+ BuildMI(BB, X86::SUB32rr, 2, X86::ESP).addReg(X86::ESP).addReg(AlignedSize);
+
+ // Put a pointer to the space into the result register, by copying
+ // the stack pointer.
+ BuildMI(BB, X86::MOV32rr, 1, getReg(I)).addReg(X86::ESP);
+
+ // Inform the Frame Information that we have just allocated a variable-sized
+ // object.
+ F->getFrameInfo()->CreateVariableSizedObject();
+ }
+
+ /// visitMallocInst - Malloc instructions are code generated into direct calls
+ /// to the library malloc.
+ ///
+ void ISel::visitMallocInst(MallocInst &I) {
+ unsigned AllocSize = TM.getTargetData().getTypeSize(I.getAllocatedType());
+ unsigned Arg;
+
+ if (ConstantUInt *C = dyn_cast<ConstantUInt>(I.getOperand(0))) {
+ Arg = getReg(ConstantUInt::get(Type::UIntTy, C->getValue() * AllocSize));
+ } else {
+ Arg = makeAnotherReg(Type::UIntTy);
+ unsigned Op0Reg = getReg(I.getOperand(0));
+ MachineBasicBlock::iterator MBBI = BB->end();
+ doMultiplyConst(BB, MBBI, Arg, Type::UIntTy, Op0Reg, AllocSize);
+ }
+
+ std::vector<ValueRecord> Args;
+ Args.push_back(ValueRecord(Arg, Type::UIntTy));
+ MachineInstr *TheCall = BuildMI(X86::CALLpcrel32,
+ 1).addExternalSymbol("malloc", true);
+ doCall(ValueRecord(getReg(I), I.getType()), TheCall, Args);
+ }
+
+
+ /// visitFreeInst - Free instructions are code gen'd to call the free libc
+ /// function.
+ ///
+ void ISel::visitFreeInst(FreeInst &I) {
+ std::vector<ValueRecord> Args;
+ Args.push_back(ValueRecord(I.getOperand(0)));
+ MachineInstr *TheCall = BuildMI(X86::CALLpcrel32,
+ 1).addExternalSymbol("free", true);
+ doCall(ValueRecord(0, Type::VoidTy), TheCall, Args);
+ }
+
+ /// createX86SimpleInstructionSelector - This pass converts an LLVM function
+ /// into a machine code representation is a very simple peep-hole fashion. The
+ /// generated code sucks but the implementation is nice and simple.
+ ///
+ FunctionPass *llvm::createX86ReallySimpleInstructionSelector(TargetMachine &TM) {
+ return new ISel(TM);
+ }
+
+ #include "X86GenSimpInstrSelector.inc"
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