llvm-6502/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp

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//===-- AArch64SelectionDAGInfo.cpp - AArch64 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 AArch64SelectionDAGInfo class.
//
//===----------------------------------------------------------------------===//
#include "AArch64TargetMachine.h"
using namespace llvm;
#define DEBUG_TYPE "aarch64-selectiondag-info"
AArch64SelectionDAGInfo::AArch64SelectionDAGInfo(const DataLayout *DL)
: TargetSelectionDAGInfo(DL) {}
AArch64SelectionDAGInfo::~AArch64SelectionDAGInfo() {}
SDValue AArch64SelectionDAGInfo::EmitTargetCodeForMemset(
SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src,
SDValue Size, unsigned Align, bool isVolatile,
MachinePointerInfo DstPtrInfo) const {
// Check to see if there is a specialized entry-point for memory zeroing.
ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src);
ConstantSDNode *SizeValue = dyn_cast<ConstantSDNode>(Size);
const AArch64Subtarget &STI =
DAG.getMachineFunction().getSubtarget<AArch64Subtarget>();
const char *bzeroEntry =
(V && V->isNullValue()) ? STI.getBZeroEntry() : nullptr;
// For small size (< 256), it is not beneficial to use bzero
// instead of memset.
if (bzeroEntry && (!SizeValue || SizeValue->getZExtValue() > 256)) {
const AArch64TargetLowering &TLI = *STI.getTargetLowering();
EVT IntPtr = TLI.getPointerTy();
Type *IntPtrTy = getDataLayout()->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);
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(dl).setChain(Chain)
.setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
DAG.getExternalSymbol(bzeroEntry, IntPtr), std::move(Args), 0)
.setDiscardResult();
std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
return CallResult.second;
}
return SDValue();
}