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"
15 using namespace llvm;
16 
17 #define DEBUG_TYPE "xcore-selectiondag-info"
18 
19 SDValue XCoreSelectionDAGInfo::
EmitTargetCodeForMemcpy(SelectionDAG & DAG,SDLoc dl,SDValue Chain,SDValue Dst,SDValue Src,SDValue Size,unsigned Align,bool isVolatile,bool AlwaysInline,MachinePointerInfo DstPtrInfo,MachinePointerInfo SrcPtrInfo) const20 EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl, SDValue Chain,
21                         SDValue Dst, SDValue Src, SDValue Size, unsigned Align,
22                         bool isVolatile, bool AlwaysInline,
23                         MachinePointerInfo DstPtrInfo,
24                         MachinePointerInfo SrcPtrInfo) const
25 {
26   unsigned SizeBitWidth = Size.getValueType().getSizeInBits();
27   // Call __memcpy_4 if the src, dst and size are all 4 byte aligned.
28   if (!AlwaysInline && (Align & 3) == 0 &&
29       DAG.MaskedValueIsZero(Size, APInt(SizeBitWidth, 3))) {
30     const TargetLowering &TLI = *DAG.getSubtarget().getTargetLowering();
31     TargetLowering::ArgListTy Args;
32     TargetLowering::ArgListEntry Entry;
33     Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
34     Entry.Node = Dst; Args.push_back(Entry);
35     Entry.Node = Src; Args.push_back(Entry);
36     Entry.Node = Size; Args.push_back(Entry);
37 
38     TargetLowering::CallLoweringInfo CLI(DAG);
39     CLI.setDebugLoc(dl)
40         .setChain(Chain)
41         .setCallee(TLI.getLibcallCallingConv(RTLIB::MEMCPY),
42                    Type::getVoidTy(*DAG.getContext()),
43                    DAG.getExternalSymbol("__memcpy_4",
44                                          TLI.getPointerTy(DAG.getDataLayout())),
45                    std::move(Args), 0)
46         .setDiscardResult();
47 
48     std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(CLI);
49     return CallResult.second;
50   }
51 
52   // Otherwise have the target-independent code call memcpy.
53   return SDValue();
54 }
55