//===-- X86ISelLowering.h - X86 DAG Lowering Interface ----------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file was developed by Chris Lattner and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines the interfaces that X86 uses to lower LLVM code into a // selection DAG. // //===----------------------------------------------------------------------===// #include "X86.h" #include "X86ISelLowering.h" #include "X86TargetMachine.h" #include "llvm/CallingConv.h" #include "llvm/Function.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/SelectionDAG.h" #include "llvm/CodeGen/SSARegMap.h" #include "llvm/Target/TargetOptions.h" using namespace llvm; // FIXME: temporary. #include "llvm/Support/CommandLine.h" static cl::opt EnableFastCC("enable-x86-fastcc", cl::Hidden, cl::desc("Enable fastcc on X86")); X86TargetLowering::X86TargetLowering(TargetMachine &TM) : TargetLowering(TM) { // Set up the TargetLowering object. // X86 is weird, it always uses i8 for shift amounts and setcc results. setShiftAmountType(MVT::i8); setSetCCResultType(MVT::i8); setSetCCResultContents(ZeroOrOneSetCCResult); setShiftAmountFlavor(Mask); // shl X, 32 == shl X, 0 // Set up the register classes. addRegisterClass(MVT::i8, X86::R8RegisterClass); addRegisterClass(MVT::i16, X86::R16RegisterClass); addRegisterClass(MVT::i32, X86::R32RegisterClass); // Promote all UINT_TO_FP to larger SINT_TO_FP's, as X86 doesn't have this // operation. setOperationAction(ISD::UINT_TO_FP , MVT::i1 , Promote); setOperationAction(ISD::UINT_TO_FP , MVT::i8 , Promote); setOperationAction(ISD::UINT_TO_FP , MVT::i16 , Promote); setOperationAction(ISD::UINT_TO_FP , MVT::i32 , Promote); // Promote i1/i8 SINT_TO_FP to larger SINT_TO_FP's, as X86 doesn't have // this operation. setOperationAction(ISD::SINT_TO_FP , MVT::i1 , Promote); setOperationAction(ISD::SINT_TO_FP , MVT::i8 , Promote); if (!X86ScalarSSE) { // We can handle SINT_TO_FP and FP_TO_SINT from/TO i64 even though i64 // isn't legal. setOperationAction(ISD::SINT_TO_FP , MVT::i64 , Custom); setOperationAction(ISD::FP_TO_SINT , MVT::i64 , Custom); setOperationAction(ISD::FP_TO_SINT , MVT::i32 , Custom); setOperationAction(ISD::FP_TO_SINT , MVT::i16 , Custom); } // Handle FP_TO_UINT by promoting the destination to a larger signed // conversion. setOperationAction(ISD::FP_TO_UINT , MVT::i1 , Promote); setOperationAction(ISD::FP_TO_UINT , MVT::i8 , Promote); setOperationAction(ISD::FP_TO_UINT , MVT::i16 , Promote); if (!X86ScalarSSE) setOperationAction(ISD::FP_TO_UINT , MVT::i32 , Promote); // Promote i1/i8 FP_TO_SINT to larger FP_TO_SINTS's, as X86 doesn't have // this operation. setOperationAction(ISD::FP_TO_SINT , MVT::i1 , Promote); setOperationAction(ISD::FP_TO_SINT , MVT::i8 , Promote); setOperationAction(ISD::FP_TO_SINT , MVT::i16 , Promote); setOperationAction(ISD::BIT_CONVERT, MVT::f32, Expand); setOperationAction(ISD::BIT_CONVERT, MVT::i32, Expand); if (X86DAGIsel) { setOperationAction(ISD::BRCOND , MVT::Other, Custom); } setOperationAction(ISD::BRCONDTWOWAY , MVT::Other, Expand); setOperationAction(ISD::BRTWOWAY_CC , MVT::Other, Expand); setOperationAction(ISD::MEMMOVE , MVT::Other, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16 , Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8 , Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand); setOperationAction(ISD::FP_ROUND_INREG , MVT::f32 , Expand); setOperationAction(ISD::SEXTLOAD , MVT::i1 , Expand); setOperationAction(ISD::FREM , MVT::f64 , Expand); setOperationAction(ISD::CTPOP , MVT::i8 , Expand); setOperationAction(ISD::CTTZ , MVT::i8 , Expand); setOperationAction(ISD::CTLZ , MVT::i8 , Expand); setOperationAction(ISD::CTPOP , MVT::i16 , Expand); setOperationAction(ISD::CTTZ , MVT::i16 , Expand); setOperationAction(ISD::CTLZ , MVT::i16 , Expand); setOperationAction(ISD::CTPOP , MVT::i32 , Expand); setOperationAction(ISD::CTTZ , MVT::i32 , Expand); setOperationAction(ISD::CTLZ , MVT::i32 , Expand); setOperationAction(ISD::READCYCLECOUNTER , MVT::i64 , Custom); setOperationAction(ISD::READIO , MVT::i1 , Expand); setOperationAction(ISD::READIO , MVT::i8 , Expand); setOperationAction(ISD::READIO , MVT::i16 , Expand); setOperationAction(ISD::READIO , MVT::i32 , Expand); setOperationAction(ISD::WRITEIO , MVT::i1 , Expand); setOperationAction(ISD::WRITEIO , MVT::i8 , Expand); setOperationAction(ISD::WRITEIO , MVT::i16 , Expand); setOperationAction(ISD::WRITEIO , MVT::i32 , Expand); // These should be promoted to a larger select which is supported. setOperationAction(ISD::SELECT , MVT::i1 , Promote); setOperationAction(ISD::SELECT , MVT::i8 , Promote); // X86 wants to expand cmov itself. if (X86DAGIsel) { setOperationAction(ISD::SELECT , MVT::i16 , Custom); setOperationAction(ISD::SELECT , MVT::i32 , Custom); setOperationAction(ISD::SETCC , MVT::i8 , Custom); setOperationAction(ISD::SETCC , MVT::i16 , Custom); setOperationAction(ISD::SETCC , MVT::i32 , Custom); setOperationAction(ISD::GlobalAddress , MVT::i32 , Custom); } // We don't have line number support yet. setOperationAction(ISD::LOCATION, MVT::Other, Expand); setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand); if (X86ScalarSSE) { // Set up the FP register classes. addRegisterClass(MVT::f32, X86::V4F4RegisterClass); addRegisterClass(MVT::f64, X86::V2F8RegisterClass); // SSE has no load+extend ops setOperationAction(ISD::EXTLOAD, MVT::f32, Expand); setOperationAction(ISD::ZEXTLOAD, MVT::f32, Expand); // SSE has no i16 to fp conversion, only i32 setOperationAction(ISD::SINT_TO_FP, MVT::i16, Promote); setOperationAction(ISD::FP_TO_SINT, MVT::i16, Promote); // Expand FP_TO_UINT into a select. // FIXME: We would like to use a Custom expander here eventually to do // the optimal thing for SSE vs. the default expansion in the legalizer. setOperationAction(ISD::FP_TO_UINT , MVT::i32 , Expand); // We don't support sin/cos/sqrt/fmod setOperationAction(ISD::FSIN , MVT::f64, Expand); setOperationAction(ISD::FCOS , MVT::f64, Expand); setOperationAction(ISD::FABS , MVT::f64, Expand); setOperationAction(ISD::FNEG , MVT::f64, Expand); setOperationAction(ISD::FREM , MVT::f64, Expand); setOperationAction(ISD::FSIN , MVT::f32, Expand); setOperationAction(ISD::FCOS , MVT::f32, Expand); setOperationAction(ISD::FABS , MVT::f32, Expand); setOperationAction(ISD::FNEG , MVT::f32, Expand); setOperationAction(ISD::FREM , MVT::f32, Expand); addLegalFPImmediate(+0.0); // xorps / xorpd } else { // Set up the FP register classes. addRegisterClass(MVT::f64, X86::RFPRegisterClass); if (!UnsafeFPMath) { setOperationAction(ISD::FSIN , MVT::f64 , Expand); setOperationAction(ISD::FCOS , MVT::f64 , Expand); } addLegalFPImmediate(+0.0); // FLD0 addLegalFPImmediate(+1.0); // FLD1 addLegalFPImmediate(-0.0); // FLD0/FCHS addLegalFPImmediate(-1.0); // FLD1/FCHS } computeRegisterProperties(); maxStoresPerMemSet = 8; // For %llvm.memset -> sequence of stores maxStoresPerMemCpy = 8; // For %llvm.memcpy -> sequence of stores maxStoresPerMemMove = 8; // For %llvm.memmove -> sequence of stores allowUnalignedMemoryAccesses = true; // x86 supports it! } std::vector X86TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) { if (F.getCallingConv() == CallingConv::Fast && EnableFastCC) return LowerFastCCArguments(F, DAG); return LowerCCCArguments(F, DAG); } std::pair X86TargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg, unsigned CallingConv, bool isTailCall, SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG) { assert((!isVarArg || CallingConv == CallingConv::C) && "Only C takes varargs!"); if (CallingConv == CallingConv::Fast && EnableFastCC) return LowerFastCCCallTo(Chain, RetTy, isTailCall, Callee, Args, DAG); return LowerCCCCallTo(Chain, RetTy, isVarArg, isTailCall, Callee, Args, DAG); } SDOperand X86TargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op, SelectionDAG &DAG) { if (!X86DAGIsel) return DAG.getNode(ISD::RET, MVT::Other, Chain, Op); SDOperand Copy; MVT::ValueType OpVT = Op.getValueType(); switch (OpVT) { default: assert(0 && "Unknown type to return!"); case MVT::i32: Copy = DAG.getCopyToReg(Chain, X86::EAX, Op, SDOperand()); break; case MVT::i64: { SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op, DAG.getConstant(1, MVT::i32)); SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op, DAG.getConstant(0, MVT::i32)); Copy = DAG.getCopyToReg(Chain, X86::EAX, Hi, SDOperand()); Copy = DAG.getCopyToReg(Copy, X86::EDX, Lo, Copy.getValue(1)); break; } case MVT::f32: case MVT::f64: if (!X86ScalarSSE) { std::vector Tys; Tys.push_back(MVT::Other); Tys.push_back(MVT::Flag); std::vector Ops; Ops.push_back(Chain); if (OpVT == MVT::f32) Op = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Op); Ops.push_back(Op); Copy = DAG.getNode(X86ISD::FP_SET_RESULT, Tys, Ops); } else { // Spill the value to memory and reload it into top of stack. unsigned Size = MVT::getSizeInBits(OpVT)/8; MachineFunction &MF = DAG.getMachineFunction(); int SSFI = MF.getFrameInfo()->CreateStackObject(Size, Size); SDOperand StackSlot = DAG.getFrameIndex(SSFI, getPointerTy()); Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain, Op, StackSlot, DAG.getSrcValue(NULL)); std::vector Tys; Tys.push_back(MVT::f64); Tys.push_back(MVT::Other); std::vector Ops; Ops.push_back(Chain); Ops.push_back(StackSlot); Ops.push_back(DAG.getValueType(OpVT)); Copy = DAG.getNode(X86ISD::FLD, Tys, Ops); Tys.clear(); Tys.push_back(MVT::Other); Tys.push_back(MVT::Flag); Ops.clear(); Ops.push_back(Copy.getValue(1)); Ops.push_back(Copy); Copy = DAG.getNode(X86ISD::FP_SET_RESULT, Tys, Ops); } break; } return DAG.getNode(X86ISD::RET_FLAG, MVT::Other, Copy, DAG.getConstant(getBytesToPopOnReturn(), MVT::i16), Copy.getValue(1)); } //===----------------------------------------------------------------------===// // C Calling Convention implementation //===----------------------------------------------------------------------===// std::vector X86TargetLowering::LowerCCCArguments(Function &F, SelectionDAG &DAG) { std::vector ArgValues; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); // Add DAG nodes 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 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) { MVT::ValueType ObjectVT = getValueType(I->getType()); unsigned ArgIncrement = 4; unsigned ObjSize; switch (ObjectVT) { default: assert(0 && "Unhandled argument type!"); case MVT::i1: case MVT::i8: ObjSize = 1; break; case MVT::i16: ObjSize = 2; break; case MVT::i32: ObjSize = 4; break; case MVT::i64: ObjSize = ArgIncrement = 8; break; case MVT::f32: ObjSize = 4; break; case MVT::f64: ObjSize = ArgIncrement = 8; break; } // Create the frame index object for this incoming parameter... int FI = MFI->CreateFixedObject(ObjSize, ArgOffset); // Create the SelectionDAG nodes corresponding to a load from this parameter SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32); // Don't codegen dead arguments. FIXME: remove this check when we can nuke // dead loads. SDOperand ArgValue; if (!I->use_empty()) ArgValue = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN, DAG.getSrcValue(NULL)); else { if (MVT::isInteger(ObjectVT)) ArgValue = DAG.getConstant(0, ObjectVT); else ArgValue = DAG.getConstantFP(0, ObjectVT); } ArgValues.push_back(ArgValue); ArgOffset += ArgIncrement; // Move on to the next argument... } // If the function takes variable number of arguments, make a frame index for // the start of the first vararg value... for expansion of llvm.va_start. if (F.isVarArg()) VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset); ReturnAddrIndex = 0; // No return address slot generated yet. BytesToPopOnReturn = 0; // Callee pops nothing. BytesCallerReserves = ArgOffset; // Finally, inform the code generator which regs we return values in. switch (getValueType(F.getReturnType())) { default: assert(0 && "Unknown type!"); case MVT::isVoid: break; case MVT::i1: case MVT::i8: case MVT::i16: case MVT::i32: MF.addLiveOut(X86::EAX); break; case MVT::i64: MF.addLiveOut(X86::EAX); MF.addLiveOut(X86::EDX); break; case MVT::f32: case MVT::f64: MF.addLiveOut(X86::ST0); break; } return ArgValues; } std::pair X86TargetLowering::LowerCCCCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg, bool isTailCall, SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG) { // Count how many bytes are to be pushed on the stack. unsigned NumBytes = 0; if (Args.empty()) { // Save zero bytes. Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain, DAG.getConstant(0, getPointerTy())); } else { for (unsigned i = 0, e = Args.size(); i != e; ++i) switch (getValueType(Args[i].second)) { default: assert(0 && "Unknown value type!"); case MVT::i1: case MVT::i8: case MVT::i16: case MVT::i32: case MVT::f32: NumBytes += 4; break; case MVT::i64: case MVT::f64: NumBytes += 8; break; } Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain, DAG.getConstant(NumBytes, getPointerTy())); // Arguments go on the stack in reverse order, as specified by the ABI. unsigned ArgOffset = 0; SDOperand StackPtr = DAG.getCopyFromReg(DAG.getEntryNode(), X86::ESP, MVT::i32); std::vector Stores; for (unsigned i = 0, e = Args.size(); i != e; ++i) { SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy()); PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff); switch (getValueType(Args[i].second)) { default: assert(0 && "Unexpected ValueType for argument!"); case MVT::i1: case MVT::i8: case MVT::i16: // Promote the integer to 32 bits. If the input type is signed use a // sign extend, otherwise use a zero extend. if (Args[i].second->isSigned()) Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first); else Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first); // FALL THROUGH case MVT::i32: case MVT::f32: Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, Args[i].first, PtrOff, DAG.getSrcValue(NULL))); ArgOffset += 4; break; case MVT::i64: case MVT::f64: Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, Args[i].first, PtrOff, DAG.getSrcValue(NULL))); ArgOffset += 8; break; } } Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Stores); } std::vector RetVals; MVT::ValueType RetTyVT = getValueType(RetTy); RetVals.push_back(MVT::Other); // The result values produced have to be legal. Promote the result. switch (RetTyVT) { case MVT::isVoid: break; default: RetVals.push_back(RetTyVT); break; case MVT::i1: case MVT::i8: case MVT::i16: RetVals.push_back(MVT::i32); break; case MVT::f32: if (X86ScalarSSE) RetVals.push_back(MVT::f32); else RetVals.push_back(MVT::f64); break; case MVT::i64: RetVals.push_back(MVT::i32); RetVals.push_back(MVT::i32); break; } std::vector Ops; Ops.push_back(Chain); Ops.push_back(Callee); Ops.push_back(DAG.getConstant(NumBytes, getPointerTy())); Ops.push_back(DAG.getConstant(0, getPointerTy())); SDOperand TheCall = DAG.getNode(isTailCall ? X86ISD::TAILCALL : X86ISD::CALL, RetVals, Ops); Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, TheCall); SDOperand ResultVal; switch (RetTyVT) { case MVT::isVoid: break; default: ResultVal = TheCall.getValue(1); break; case MVT::i1: case MVT::i8: case MVT::i16: ResultVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, TheCall.getValue(1)); break; case MVT::f32: // FIXME: we would really like to remember that this FP_ROUND operation is // okay to eliminate if we allow excess FP precision. ResultVal = DAG.getNode(ISD::FP_ROUND, MVT::f32, TheCall.getValue(1)); break; case MVT::i64: ResultVal = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, TheCall.getValue(1), TheCall.getValue(2)); break; } return std::make_pair(ResultVal, Chain); } SDOperand X86TargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP, Value *VAListV, SelectionDAG &DAG) { // vastart just stores the address of the VarArgsFrameIndex slot. SDOperand FR = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32); return DAG.getNode(ISD::STORE, MVT::Other, Chain, FR, VAListP, DAG.getSrcValue(VAListV)); } std::pair X86TargetLowering::LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV, const Type *ArgTy, SelectionDAG &DAG) { MVT::ValueType ArgVT = getValueType(ArgTy); SDOperand Val = DAG.getLoad(MVT::i32, Chain, VAListP, DAG.getSrcValue(VAListV)); SDOperand Result = DAG.getLoad(ArgVT, Chain, Val, DAG.getSrcValue(NULL)); unsigned Amt; if (ArgVT == MVT::i32) Amt = 4; else { assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) && "Other types should have been promoted for varargs!"); Amt = 8; } Val = DAG.getNode(ISD::ADD, Val.getValueType(), Val, DAG.getConstant(Amt, Val.getValueType())); Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain, Val, VAListP, DAG.getSrcValue(VAListV)); return std::make_pair(Result, Chain); } //===----------------------------------------------------------------------===// // Fast Calling Convention implementation //===----------------------------------------------------------------------===// // // The X86 'fast' calling convention passes up to two integer arguments in // registers (an appropriate portion of EAX/EDX), passes arguments in C order, // and requires that the callee pop its arguments off the stack (allowing proper // tail calls), and has the same return value conventions as C calling convs. // // This calling convention always arranges for the callee pop value to be 8n+4 // bytes, which is needed for tail recursion elimination and stack alignment // reasons. // // Note that this can be enhanced in the future to pass fp vals in registers // (when we have a global fp allocator) and do other tricks. // /// AddLiveIn - This helper function adds the specified physical register to the /// MachineFunction as a live in value. It also creates a corresponding virtual /// register for it. static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg, TargetRegisterClass *RC) { assert(RC->contains(PReg) && "Not the correct regclass!"); unsigned VReg = MF.getSSARegMap()->createVirtualRegister(RC); MF.addLiveIn(PReg, VReg); return VReg; } std::vector X86TargetLowering::LowerFastCCArguments(Function &F, SelectionDAG &DAG) { std::vector ArgValues; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); // Add DAG nodes to load the arguments... On entry to a function the stack // frame looks like this: // // [ESP] -- return address // [ESP + 4] -- first nonreg argument (leftmost lexically) // [ESP + 8] -- second nonreg argument, if first argument is 4 bytes in size // ... unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot // Keep track of the number of integer regs passed so far. This can be either // 0 (neither EAX or EDX used), 1 (EAX is used) or 2 (EAX and EDX are both // used). unsigned NumIntRegs = 0; for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) { MVT::ValueType ObjectVT = getValueType(I->getType()); unsigned ArgIncrement = 4; unsigned ObjSize = 0; SDOperand ArgValue; switch (ObjectVT) { default: assert(0 && "Unhandled argument type!"); case MVT::i1: case MVT::i8: if (NumIntRegs < 2) { if (!I->use_empty()) { unsigned VReg = AddLiveIn(MF, NumIntRegs ? X86::DL : X86::AL, X86::R8RegisterClass); ArgValue = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i8); DAG.setRoot(ArgValue.getValue(1)); if (ObjectVT == MVT::i1) // FIXME: Should insert a assertzext here. ArgValue = DAG.getNode(ISD::TRUNCATE, MVT::i1, ArgValue); } ++NumIntRegs; break; } ObjSize = 1; break; case MVT::i16: if (NumIntRegs < 2) { if (!I->use_empty()) { unsigned VReg = AddLiveIn(MF, NumIntRegs ? X86::DX : X86::AX, X86::R16RegisterClass); ArgValue = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i16); DAG.setRoot(ArgValue.getValue(1)); } ++NumIntRegs; break; } ObjSize = 2; break; case MVT::i32: if (NumIntRegs < 2) { if (!I->use_empty()) { unsigned VReg = AddLiveIn(MF,NumIntRegs ? X86::EDX : X86::EAX, X86::R32RegisterClass); ArgValue = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32); DAG.setRoot(ArgValue.getValue(1)); } ++NumIntRegs; break; } ObjSize = 4; break; case MVT::i64: if (NumIntRegs == 0) { if (!I->use_empty()) { unsigned BotReg = AddLiveIn(MF, X86::EAX, X86::R32RegisterClass); unsigned TopReg = AddLiveIn(MF, X86::EDX, X86::R32RegisterClass); SDOperand Low = DAG.getCopyFromReg(DAG.getRoot(), BotReg, MVT::i32); SDOperand Hi = DAG.getCopyFromReg(Low.getValue(1), TopReg, MVT::i32); DAG.setRoot(Hi.getValue(1)); ArgValue = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Low, Hi); } NumIntRegs = 2; break; } else if (NumIntRegs == 1) { if (!I->use_empty()) { unsigned BotReg = AddLiveIn(MF, X86::EDX, X86::R32RegisterClass); SDOperand Low = DAG.getCopyFromReg(DAG.getRoot(), BotReg, MVT::i32); DAG.setRoot(Low.getValue(1)); // Load the high part from memory. // Create the frame index object for this incoming parameter... int FI = MFI->CreateFixedObject(4, ArgOffset); SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32); SDOperand Hi = DAG.getLoad(MVT::i32, DAG.getEntryNode(), FIN, DAG.getSrcValue(NULL)); ArgValue = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Low, Hi); } ArgOffset += 4; NumIntRegs = 2; break; } ObjSize = ArgIncrement = 8; break; case MVT::f32: ObjSize = 4; break; case MVT::f64: ObjSize = ArgIncrement = 8; break; } // Don't codegen dead arguments. FIXME: remove this check when we can nuke // dead loads. if (ObjSize && !I->use_empty()) { // Create the frame index object for this incoming parameter... int FI = MFI->CreateFixedObject(ObjSize, ArgOffset); // Create the SelectionDAG nodes corresponding to a load from this // parameter. SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32); ArgValue = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN, DAG.getSrcValue(NULL)); } else if (ArgValue.Val == 0) { if (MVT::isInteger(ObjectVT)) ArgValue = DAG.getConstant(0, ObjectVT); else ArgValue = DAG.getConstantFP(0, ObjectVT); } ArgValues.push_back(ArgValue); if (ObjSize) ArgOffset += ArgIncrement; // Move on to the next argument. } // Make sure the instruction takes 8n+4 bytes to make sure the start of the // arguments and the arguments after the retaddr has been pushed are aligned. if ((ArgOffset & 7) == 0) ArgOffset += 4; VarArgsFrameIndex = 0xAAAAAAA; // fastcc functions can't have varargs. ReturnAddrIndex = 0; // No return address slot generated yet. BytesToPopOnReturn = ArgOffset; // Callee pops all stack arguments. BytesCallerReserves = 0; // Finally, inform the code generator which regs we return values in. switch (getValueType(F.getReturnType())) { default: assert(0 && "Unknown type!"); case MVT::isVoid: break; case MVT::i1: case MVT::i8: case MVT::i16: case MVT::i32: MF.addLiveOut(X86::EAX); break; case MVT::i64: MF.addLiveOut(X86::EAX); MF.addLiveOut(X86::EDX); break; case MVT::f32: case MVT::f64: MF.addLiveOut(X86::ST0); break; } return ArgValues; } std::pair X86TargetLowering::LowerFastCCCallTo(SDOperand Chain, const Type *RetTy, bool isTailCall, SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG) { // Count how many bytes are to be pushed on the stack. unsigned NumBytes = 0; // Keep track of the number of integer regs passed so far. This can be either // 0 (neither EAX or EDX used), 1 (EAX is used) or 2 (EAX and EDX are both // used). unsigned NumIntRegs = 0; for (unsigned i = 0, e = Args.size(); i != e; ++i) switch (getValueType(Args[i].second)) { default: assert(0 && "Unknown value type!"); case MVT::i1: case MVT::i8: case MVT::i16: case MVT::i32: if (NumIntRegs < 2) { ++NumIntRegs; break; } // fall through case MVT::f32: NumBytes += 4; break; case MVT::i64: if (NumIntRegs == 0) { NumIntRegs = 2; break; } else if (NumIntRegs == 1) { NumIntRegs = 2; NumBytes += 4; break; } // fall through case MVT::f64: NumBytes += 8; break; } // Make sure the instruction takes 8n+4 bytes to make sure the start of the // arguments and the arguments after the retaddr has been pushed are aligned. if ((NumBytes & 7) == 0) NumBytes += 4; Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain, DAG.getConstant(NumBytes, getPointerTy())); // Arguments go on the stack in reverse order, as specified by the ABI. unsigned ArgOffset = 0; SDOperand StackPtr = DAG.getCopyFromReg(DAG.getEntryNode(), X86::ESP, MVT::i32); NumIntRegs = 0; std::vector Stores; std::vector RegValuesToPass; for (unsigned i = 0, e = Args.size(); i != e; ++i) { switch (getValueType(Args[i].second)) { default: assert(0 && "Unexpected ValueType for argument!"); case MVT::i1: Args[i].first = DAG.getNode(ISD::ANY_EXTEND, MVT::i8, Args[i].first); // Fall through. case MVT::i8: case MVT::i16: case MVT::i32: if (NumIntRegs < 2) { RegValuesToPass.push_back(Args[i].first); ++NumIntRegs; break; } // Fall through case MVT::f32: { SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy()); PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff); Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, Args[i].first, PtrOff, DAG.getSrcValue(NULL))); ArgOffset += 4; break; } case MVT::i64: if (NumIntRegs < 2) { // Can pass part of it in regs? SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Args[i].first, DAG.getConstant(1, MVT::i32)); SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Args[i].first, DAG.getConstant(0, MVT::i32)); RegValuesToPass.push_back(Lo); ++NumIntRegs; if (NumIntRegs < 2) { // Pass both parts in regs? RegValuesToPass.push_back(Hi); ++NumIntRegs; } else { // Pass the high part in memory. SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy()); PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff); Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, Hi, PtrOff, DAG.getSrcValue(NULL))); ArgOffset += 4; } break; } // Fall through case MVT::f64: SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy()); PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff); Stores.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain, Args[i].first, PtrOff, DAG.getSrcValue(NULL))); ArgOffset += 8; break; } } if (!Stores.empty()) Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Stores); // Make sure the instruction takes 8n+4 bytes to make sure the start of the // arguments and the arguments after the retaddr has been pushed are aligned. if ((ArgOffset & 7) == 0) ArgOffset += 4; std::vector RetVals; MVT::ValueType RetTyVT = getValueType(RetTy); RetVals.push_back(MVT::Other); // The result values produced have to be legal. Promote the result. switch (RetTyVT) { case MVT::isVoid: break; default: RetVals.push_back(RetTyVT); break; case MVT::i1: case MVT::i8: case MVT::i16: RetVals.push_back(MVT::i32); break; case MVT::f32: if (X86ScalarSSE) RetVals.push_back(MVT::f32); else RetVals.push_back(MVT::f64); break; case MVT::i64: RetVals.push_back(MVT::i32); RetVals.push_back(MVT::i32); break; } std::vector Ops; Ops.push_back(Chain); Ops.push_back(Callee); Ops.push_back(DAG.getConstant(ArgOffset, getPointerTy())); // Callee pops all arg values on the stack. Ops.push_back(DAG.getConstant(ArgOffset, getPointerTy())); // Pass register arguments as needed. Ops.insert(Ops.end(), RegValuesToPass.begin(), RegValuesToPass.end()); SDOperand TheCall = DAG.getNode(isTailCall ? X86ISD::TAILCALL : X86ISD::CALL, RetVals, Ops); Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, TheCall); SDOperand ResultVal; switch (RetTyVT) { case MVT::isVoid: break; default: ResultVal = TheCall.getValue(1); break; case MVT::i1: case MVT::i8: case MVT::i16: ResultVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, TheCall.getValue(1)); break; case MVT::f32: // FIXME: we would really like to remember that this FP_ROUND operation is // okay to eliminate if we allow excess FP precision. ResultVal = DAG.getNode(ISD::FP_ROUND, MVT::f32, TheCall.getValue(1)); break; case MVT::i64: ResultVal = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, TheCall.getValue(1), TheCall.getValue(2)); break; } return std::make_pair(ResultVal, Chain); } SDOperand X86TargetLowering::getReturnAddressFrameIndex(SelectionDAG &DAG) { if (ReturnAddrIndex == 0) { // Set up a frame object for the return address. MachineFunction &MF = DAG.getMachineFunction(); ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(4, -4); } return DAG.getFrameIndex(ReturnAddrIndex, MVT::i32); } std::pair X86TargetLowering:: LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth, SelectionDAG &DAG) { SDOperand Result; if (Depth) // Depths > 0 not supported yet! Result = DAG.getConstant(0, getPointerTy()); else { SDOperand RetAddrFI = getReturnAddressFrameIndex(DAG); if (!isFrameAddress) // Just load the return address Result = DAG.getLoad(MVT::i32, DAG.getEntryNode(), RetAddrFI, DAG.getSrcValue(NULL)); else Result = DAG.getNode(ISD::SUB, MVT::i32, RetAddrFI, DAG.getConstant(4, MVT::i32)); } return std::make_pair(Result, Chain); } //===----------------------------------------------------------------------===// // X86 Custom Lowering Hooks //===----------------------------------------------------------------------===// /// LowerOperation - Provide custom lowering hooks for some operations. /// SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) { switch (Op.getOpcode()) { default: assert(0 && "Should not custom lower this!"); case ISD::SINT_TO_FP: { assert(Op.getValueType() == MVT::f64 && Op.getOperand(0).getValueType() == MVT::i64 && "Unknown SINT_TO_FP to lower!"); // We lower sint64->FP into a store to a temporary stack slot, followed by a // FILD64m node. MachineFunction &MF = DAG.getMachineFunction(); int SSFI = MF.getFrameInfo()->CreateStackObject(8, 8); SDOperand StackSlot = DAG.getFrameIndex(SSFI, getPointerTy()); SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, DAG.getEntryNode(), Op.getOperand(0), StackSlot, DAG.getSrcValue(NULL)); std::vector RTs; RTs.push_back(MVT::f64); RTs.push_back(MVT::Other); std::vector Ops; Ops.push_back(Store); Ops.push_back(StackSlot); return DAG.getNode(X86ISD::FILD64m, RTs, Ops); } case ISD::FP_TO_SINT: { assert(Op.getValueType() <= MVT::i64 && Op.getValueType() >= MVT::i16 && Op.getOperand(0).getValueType() == MVT::f64 && "Unknown FP_TO_SINT to lower!"); // We lower FP->sint64 into FISTP64, followed by a load, all to a temporary // stack slot. MachineFunction &MF = DAG.getMachineFunction(); unsigned MemSize = MVT::getSizeInBits(Op.getValueType())/8; int SSFI = MF.getFrameInfo()->CreateStackObject(MemSize, MemSize); SDOperand StackSlot = DAG.getFrameIndex(SSFI, getPointerTy()); unsigned Opc; switch (Op.getValueType()) { default: assert(0 && "Invalid FP_TO_SINT to lower!"); case MVT::i16: Opc = X86ISD::FP_TO_INT16_IN_MEM; break; case MVT::i32: Opc = X86ISD::FP_TO_INT32_IN_MEM; break; case MVT::i64: Opc = X86ISD::FP_TO_INT64_IN_MEM; break; } // Build the FP_TO_INT*_IN_MEM std::vector Ops; Ops.push_back(DAG.getEntryNode()); Ops.push_back(Op.getOperand(0)); Ops.push_back(StackSlot); SDOperand FIST = DAG.getNode(Opc, MVT::Other, Ops); // Load the result. return DAG.getLoad(Op.getValueType(), FIST, StackSlot, DAG.getSrcValue(NULL)); } case ISD::READCYCLECOUNTER: { std::vector Tys; Tys.push_back(MVT::Other); Tys.push_back(MVT::Flag); std::vector Ops; Ops.push_back(Op.getOperand(0)); SDOperand rd = DAG.getNode(X86ISD::RDTSC_DAG, Tys, Ops); Ops.clear(); Ops.push_back(DAG.getCopyFromReg(rd, X86::EAX, MVT::i32, rd.getValue(1))); Ops.push_back(DAG.getCopyFromReg(Ops[0].getValue(1), X86::EDX, MVT::i32, Ops[0].getValue(2))); Ops.push_back(Ops[1].getValue(1)); Tys[0] = Tys[1] = MVT::i32; Tys.push_back(MVT::Other); return DAG.getNode(ISD::MERGE_VALUES, Tys, Ops); } case ISD::SETCC: { assert(Op.getValueType() == MVT::i8 && "SetCC type must be 8-bit integer"); SDOperand CC = Op.getOperand(2); SDOperand Cond = DAG.getNode(X86ISD::CMP, MVT::Flag, Op.getOperand(0), Op.getOperand(1)); return DAG.getNode(X86ISD::SETCC, MVT::i8, CC, Cond); } case ISD::SELECT: { SDOperand Cond = Op.getOperand(0); SDOperand CC; if (Cond.getOpcode() == X86ISD::SETCC) { CC = Cond.getOperand(0); Cond = Cond.getOperand(1); } else if (Cond.getOpcode() == ISD::SETCC) { CC = Cond.getOperand(2); Cond = DAG.getNode(X86ISD::CMP, MVT::Flag, Cond.getOperand(0), Cond.getOperand(1)); } else { CC = DAG.getCondCode(ISD::SETEQ); Cond = DAG.getNode(X86ISD::TEST, MVT::Flag, Cond, Cond); } return DAG.getNode(X86ISD::CMOV, Op.getValueType(), Op.getOperand(1), Op.getOperand(2), CC, Cond); } case ISD::BRCOND: { SDOperand Cond = Op.getOperand(1); SDOperand Dest = Op.getOperand(2); SDOperand CC; // TODO: handle Cond == OR / AND / XOR if (Cond.getOpcode() == X86ISD::SETCC) { CC = Cond.getOperand(0); Cond = Cond.getOperand(1); } else if (Cond.getOpcode() == ISD::SETCC) { CC = Cond.getOperand(2); Cond = DAG.getNode(X86ISD::CMP, MVT::Flag, Cond.getOperand(0), Cond.getOperand(1)); } else { CC = DAG.getCondCode(ISD::SETNE); Cond = DAG.getNode(X86ISD::TEST, MVT::Flag, Cond, Cond); } return DAG.getNode(X86ISD::BRCOND, Op.getValueType(), Op.getOperand(0), Op.getOperand(2), CC, Cond); } case ISD::GlobalAddress: { GlobalValue *GV = cast(Op)->getGlobal(); SDOperand GVOp = DAG.getTargetGlobalAddress(GV, getPointerTy()); // For Darwin, external and weak symbols are indirect, so we want to load // the value at address GV, not the value of GV itself. This means that // the GlobalAddress must be in the base or index register of the address, // not the GV offset field. if (getTargetMachine(). getSubtarget().getIndirectExternAndWeakGlobals() && (GV->hasWeakLinkage() || GV->isExternal())) return DAG.getLoad(MVT::i32, DAG.getEntryNode(), GVOp, DAG.getSrcValue(NULL)); else return GVOp; break; } } } const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { default: return NULL; case X86ISD::FILD64m: return "X86ISD::FILD64m"; case X86ISD::FP_TO_INT16_IN_MEM: return "X86ISD::FP_TO_INT16_IN_MEM"; case X86ISD::FP_TO_INT32_IN_MEM: return "X86ISD::FP_TO_INT32_IN_MEM"; case X86ISD::FP_TO_INT64_IN_MEM: return "X86ISD::FP_TO_INT64_IN_MEM"; case X86ISD::FLD: return "X86ISD::FLD"; case X86ISD::FP_SET_RESULT: return "X86ISD::FP_SET_RESULT"; case X86ISD::CALL: return "X86ISD::CALL"; case X86ISD::TAILCALL: return "X86ISD::TAILCALL"; case X86ISD::RDTSC_DAG: return "X86ISD::RDTSC_DAG"; case X86ISD::CMP: return "X86ISD::CMP"; case X86ISD::TEST: return "X86ISD::TEST"; case X86ISD::SETCC: return "X86ISD::SETCC"; case X86ISD::CMOV: return "X86ISD::CMOV"; case X86ISD::BRCOND: return "X86ISD::BRCOND"; case X86ISD::RET_FLAG: return "X86ISD::RET_FLAG"; } } bool X86TargetLowering::isMaskedValueZeroForTargetNode(const SDOperand &Op, uint64_t Mask) const { unsigned Opc = Op.getOpcode(); switch (Opc) { default: assert(Opc >= ISD::BUILTIN_OP_END && "Expected a target specific node"); break; case X86ISD::SETCC: return (Mask & 1) == 0; } return false; }