1//===-- AArch64SelectionDAGInfo.cpp - AArch64 SelectionDAG Info -----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AArch64SelectionDAGInfo class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "AArch64TargetMachine.h"
15using namespace llvm;
16
17#define DEBUG_TYPE "aarch64-selectiondag-info"
18
19AArch64SelectionDAGInfo::AArch64SelectionDAGInfo(const DataLayout *DL)
20    : TargetSelectionDAGInfo(DL) {}
21
22AArch64SelectionDAGInfo::~AArch64SelectionDAGInfo() {}
23
24SDValue AArch64SelectionDAGInfo::EmitTargetCodeForMemset(
25    SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src,
26    SDValue Size, unsigned Align, bool isVolatile,
27    MachinePointerInfo DstPtrInfo) const {
28  // Check to see if there is a specialized entry-point for memory zeroing.
29  ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src);
30  ConstantSDNode *SizeValue = dyn_cast<ConstantSDNode>(Size);
31  const char *bzeroEntry =
32      (V && V->isNullValue())
33          ? DAG.getTarget().getSubtarget<AArch64Subtarget>().getBZeroEntry()
34          : nullptr;
35  // For small size (< 256), it is not beneficial to use bzero
36  // instead of memset.
37  if (bzeroEntry && (!SizeValue || SizeValue->getZExtValue() > 256)) {
38    const AArch64TargetLowering &TLI =
39        *static_cast<const AArch64TargetLowering *>(
40            DAG.getTarget().getTargetLowering());
41
42    EVT IntPtr = TLI.getPointerTy();
43    Type *IntPtrTy = getDataLayout()->getIntPtrType(*DAG.getContext());
44    TargetLowering::ArgListTy Args;
45    TargetLowering::ArgListEntry Entry;
46    Entry.Node = Dst;
47    Entry.Ty = IntPtrTy;
48    Args.push_back(Entry);
49    Entry.Node = Size;
50    Args.push_back(Entry);
51    TargetLowering::CallLoweringInfo CLI(DAG);
52    CLI.setDebugLoc(dl).setChain(Chain)
53      .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
54                 DAG.getExternalSymbol(bzeroEntry, IntPtr), std::move(Args), 0)
55      .setDiscardResult();
56    std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
57    return CallResult.second;
58  }
59  return SDValue();
60}
61