//===-- X86SelectionDAGInfo.cpp - X86 SelectionDAG Info -------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the X86SelectionDAGInfo class. // //===----------------------------------------------------------------------===// #define DEBUG_TYPE "x86-selectiondag-info" #include "X86TargetMachine.h" #include "llvm/DerivedTypes.h" #include "llvm/CodeGen/SelectionDAG.h" using namespace llvm; X86SelectionDAGInfo::X86SelectionDAGInfo(const X86TargetMachine &TM) : TargetSelectionDAGInfo(TM), Subtarget(&TM.getSubtarget<X86Subtarget>()), TLI(*TM.getTargetLowering()) { } X86SelectionDAGInfo::~X86SelectionDAGInfo() { } SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(SelectionDAG &DAG, DebugLoc dl, SDValue Chain, SDValue Dst, SDValue Src, SDValue Size, unsigned Align, bool isVolatile, MachinePointerInfo DstPtrInfo) const { ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); // If to a segment-relative address space, use the default lowering. if (DstPtrInfo.getAddrSpace() >= 256) return SDValue(); // If not DWORD aligned or size is more than the threshold, call the library. // The libc version is likely to be faster for these cases. It can use the // address value and run time information about the CPU. if ((Align & 3) != 0 || !ConstantSize || ConstantSize->getZExtValue() > Subtarget->getMaxInlineSizeThreshold()) { SDValue InFlag(0, 0); // Check to see if there is a specialized entry-point for memory zeroing. ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src); if (const char *bzeroEntry = V && V->isNullValue() ? Subtarget->getBZeroEntry() : 0) { EVT IntPtr = TLI.getPointerTy(); Type *IntPtrTy = getTargetData()->getIntPtrType(*DAG.getContext()); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; Entry.Node = Dst; Entry.Ty = IntPtrTy; Args.push_back(Entry); Entry.Node = Size; Args.push_back(Entry); std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(Chain, Type::getVoidTy(*DAG.getContext()), false, false, false, false, 0, CallingConv::C, false, /*isReturnValueUsed=*/false, DAG.getExternalSymbol(bzeroEntry, IntPtr), Args, DAG, dl); return CallResult.second; } // Otherwise have the target-independent code call memset. return SDValue(); } uint64_t SizeVal = ConstantSize->getZExtValue(); SDValue InFlag(0, 0); EVT AVT; SDValue Count; ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Src); unsigned BytesLeft = 0; bool TwoRepStos = false; if (ValC) { unsigned ValReg; uint64_t Val = ValC->getZExtValue() & 255; // If the value is a constant, then we can potentially use larger sets. switch (Align & 3) { case 2: // WORD aligned AVT = MVT::i16; ValReg = X86::AX; Val = (Val << 8) | Val; break; case 0: // DWORD aligned AVT = MVT::i32; ValReg = X86::EAX; Val = (Val << 8) | Val; Val = (Val << 16) | Val; if (Subtarget->is64Bit() && ((Align & 0x7) == 0)) { // QWORD aligned AVT = MVT::i64; ValReg = X86::RAX; Val = (Val << 32) | Val; } break; default: // Byte aligned AVT = MVT::i8; ValReg = X86::AL; Count = DAG.getIntPtrConstant(SizeVal); break; } if (AVT.bitsGT(MVT::i8)) { unsigned UBytes = AVT.getSizeInBits() / 8; Count = DAG.getIntPtrConstant(SizeVal / UBytes); BytesLeft = SizeVal % UBytes; } Chain = DAG.getCopyToReg(Chain, dl, ValReg, DAG.getConstant(Val, AVT), InFlag); InFlag = Chain.getValue(1); } else { AVT = MVT::i8; Count = DAG.getIntPtrConstant(SizeVal); Chain = DAG.getCopyToReg(Chain, dl, X86::AL, Src, InFlag); InFlag = Chain.getValue(1); } Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RCX : X86::ECX, Count, InFlag); InFlag = Chain.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RDI : X86::EDI, Dst, InFlag); InFlag = Chain.getValue(1); SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag }; Chain = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops, array_lengthof(Ops)); if (TwoRepStos) { InFlag = Chain.getValue(1); Count = Size; EVT CVT = Count.getValueType(); SDValue Left = DAG.getNode(ISD::AND, dl, CVT, Count, DAG.getConstant((AVT == MVT::i64) ? 7 : 3, CVT)); Chain = DAG.getCopyToReg(Chain, dl, (CVT == MVT::i64) ? X86::RCX : X86::ECX, Left, InFlag); InFlag = Chain.getValue(1); Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(MVT::i8), InFlag }; Chain = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops, array_lengthof(Ops)); } else if (BytesLeft) { // Handle the last 1 - 7 bytes. unsigned Offset = SizeVal - BytesLeft; EVT AddrVT = Dst.getValueType(); EVT SizeVT = Size.getValueType(); Chain = DAG.getMemset(Chain, dl, DAG.getNode(ISD::ADD, dl, AddrVT, Dst, DAG.getConstant(Offset, AddrVT)), Src, DAG.getConstant(BytesLeft, SizeVT), Align, isVolatile, DstPtrInfo.getWithOffset(Offset)); } // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain. return Chain; } SDValue X86SelectionDAGInfo::EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl, SDValue Chain, SDValue Dst, SDValue Src, SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline, MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const { // This requires the copy size to be a constant, preferably // within a subtarget-specific limit. ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); if (!ConstantSize) return SDValue(); uint64_t SizeVal = ConstantSize->getZExtValue(); if (!AlwaysInline && SizeVal > Subtarget->getMaxInlineSizeThreshold()) return SDValue(); /// If not DWORD aligned, it is more efficient to call the library. However /// if calling the library is not allowed (AlwaysInline), then soldier on as /// the code generated here is better than the long load-store sequence we /// would otherwise get. if (!AlwaysInline && (Align & 3) != 0) return SDValue(); // If to a segment-relative address space, use the default lowering. if (DstPtrInfo.getAddrSpace() >= 256 || SrcPtrInfo.getAddrSpace() >= 256) return SDValue(); MVT AVT; if (Align & 1) AVT = MVT::i8; else if (Align & 2) AVT = MVT::i16; else if (Align & 4) // DWORD aligned AVT = MVT::i32; else // QWORD aligned AVT = Subtarget->is64Bit() ? MVT::i64 : MVT::i32; unsigned UBytes = AVT.getSizeInBits() / 8; unsigned CountVal = SizeVal / UBytes; SDValue Count = DAG.getIntPtrConstant(CountVal); unsigned BytesLeft = SizeVal % UBytes; SDValue InFlag(0, 0); Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RCX : X86::ECX, Count, InFlag); InFlag = Chain.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RDI : X86::EDI, Dst, InFlag); InFlag = Chain.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RSI : X86::ESI, Src, InFlag); InFlag = Chain.getValue(1); SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag }; SDValue RepMovs = DAG.getNode(X86ISD::REP_MOVS, dl, Tys, Ops, array_lengthof(Ops)); SmallVector<SDValue, 4> Results; Results.push_back(RepMovs); if (BytesLeft) { // Handle the last 1 - 7 bytes. unsigned Offset = SizeVal - BytesLeft; EVT DstVT = Dst.getValueType(); EVT SrcVT = Src.getValueType(); EVT SizeVT = Size.getValueType(); Results.push_back(DAG.getMemcpy(Chain, dl, DAG.getNode(ISD::ADD, dl, DstVT, Dst, DAG.getConstant(Offset, DstVT)), DAG.getNode(ISD::ADD, dl, SrcVT, Src, DAG.getConstant(Offset, SrcVT)), DAG.getConstant(BytesLeft, SizeVT), Align, isVolatile, AlwaysInline, DstPtrInfo.getWithOffset(Offset), SrcPtrInfo.getWithOffset(Offset))); } return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &Results[0], Results.size()); }