llvm-project/llvm/lib/Target/Hexagon/HexagonSelectionDAGInfo.cpp

65 lines
2.3 KiB
C++

//===-- HexagonSelectionDAGInfo.cpp - Hexagon 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 HexagonSelectionDAGInfo class.
//
//===----------------------------------------------------------------------===//
#include "HexagonTargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"
using namespace llvm;
#define DEBUG_TYPE "hexagon-selectiondag-info"
SDValue HexagonSelectionDAGInfo::EmitTargetCodeForMemcpy(
SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,
MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
if (AlwaysInline || (Align & 0x3) != 0 || !ConstantSize)
return SDValue();
uint64_t SizeVal = ConstantSize->getZExtValue();
if (SizeVal < 32 || (SizeVal % 8) != 0)
return SDValue();
// Special case aligned memcpys with size >= 32 bytes and a multiple of 8.
//
const TargetLowering &TLI = *DAG.getSubtarget().getTargetLowering();
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
Entry.Node = Dst;
Args.push_back(Entry);
Entry.Node = Src;
Args.push_back(Entry);
Entry.Node = Size;
Args.push_back(Entry);
const char *SpecialMemcpyName =
"__hexagon_memcpy_likely_aligned_min32bytes_mult8bytes";
const MachineFunction &MF = DAG.getMachineFunction();
bool LongCalls = MF.getSubtarget<HexagonSubtarget>().useLongCalls();
unsigned Flags = LongCalls ? HexagonII::HMOTF_ConstExtended : 0;
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(dl)
.setChain(Chain)
.setLibCallee(
TLI.getLibcallCallingConv(RTLIB::MEMCPY),
Type::getVoidTy(*DAG.getContext()),
DAG.getTargetExternalSymbol(
SpecialMemcpyName, TLI.getPointerTy(DAG.getDataLayout()), Flags),
std::move(Args))
.setDiscardResult();
std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
return CallResult.second;
}