XCoreSelectionDAGInfo.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- XCoreSelectionDAGInfo.cpp - XCore 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 XCoreSelectionDAGInfo class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "XCoreTargetMachine.h"
15using namespace llvm;
16
17#define DEBUG_TYPE "xcore-selectiondag-info"
18
19XCoreSelectionDAGInfo::XCoreSelectionDAGInfo(const XCoreTargetMachine &TM)
20  : TargetSelectionDAGInfo(TM) {
21}
22
23XCoreSelectionDAGInfo::~XCoreSelectionDAGInfo() {
24}
25
26SDValue XCoreSelectionDAGInfo::
27EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl, SDValue Chain,
28                        SDValue Dst, SDValue Src, SDValue Size, unsigned Align,
29                        bool isVolatile, bool AlwaysInline,
30                        MachinePointerInfo DstPtrInfo,
31                        MachinePointerInfo SrcPtrInfo) const
32{
33  unsigned SizeBitWidth = Size.getValueType().getSizeInBits();
34  // Call __memcpy_4 if the src, dst and size are all 4 byte aligned.
35  if (!AlwaysInline && (Align & 3) == 0 &&
36      DAG.MaskedValueIsZero(Size, APInt(SizeBitWidth, 3))) {
37    const TargetLowering &TLI = *DAG.getTarget().getTargetLowering();
38    TargetLowering::ArgListTy Args;
39    TargetLowering::ArgListEntry Entry;
40    Entry.Ty = TLI.getDataLayout()->getIntPtrType(*DAG.getContext());
41    Entry.Node = Dst; Args.push_back(Entry);
42    Entry.Node = Src; Args.push_back(Entry);
43    Entry.Node = Size; Args.push_back(Entry);
44
45    TargetLowering::CallLoweringInfo CLI(DAG);
46    CLI.setDebugLoc(dl).setChain(Chain)
47      .setCallee(TLI.getLibcallCallingConv(RTLIB::MEMCPY),
48                 Type::getVoidTy(*DAG.getContext()),
49                 DAG.getExternalSymbol("__memcpy_4", TLI.getPointerTy()),
50                 &Args, 0)
51      .setDiscardResult();
52
53    std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(CLI);
54    return CallResult.second;
55  }
56
57  // Otherwise have the target-independent code call memcpy.
58  return SDValue();
59}
60