1//===-- HexagonSelectionDAGInfo.cpp - Hexagon 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 HexagonSelectionDAGInfo class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "HexagonTargetMachine.h"
15#include "llvm/CodeGen/SelectionDAG.h"
16using namespace llvm;
17
18#define DEBUG_TYPE "hexagon-selectiondag-info"
19
20SDValue HexagonSelectionDAGInfo::EmitTargetCodeForMemcpy(
21    SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
22    SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,
23    MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
24  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
25  if (AlwaysInline || (Align & 0x3) != 0 || !ConstantSize)
26    return SDValue();
27
28  uint64_t SizeVal = ConstantSize->getZExtValue();
29  if (SizeVal < 32 || (SizeVal % 8) != 0)
30    return SDValue();
31
32  // Special case aligned memcpys with size >= 32 bytes and a multiple of 8.
33  //
34  const TargetLowering &TLI = *DAG.getSubtarget().getTargetLowering();
35  TargetLowering::ArgListTy Args;
36  TargetLowering::ArgListEntry Entry;
37  Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
38  Entry.Node = Dst;
39  Args.push_back(Entry);
40  Entry.Node = Src;
41  Args.push_back(Entry);
42  Entry.Node = Size;
43  Args.push_back(Entry);
44
45  const char *SpecialMemcpyName =
46      "__hexagon_memcpy_likely_aligned_min32bytes_mult8bytes";
47
48  TargetLowering::CallLoweringInfo CLI(DAG);
49  CLI.setDebugLoc(dl)
50      .setChain(Chain)
51      .setCallee(TLI.getLibcallCallingConv(RTLIB::MEMCPY),
52                 Type::getVoidTy(*DAG.getContext()),
53                 DAG.getTargetExternalSymbol(
54                     SpecialMemcpyName, TLI.getPointerTy(DAG.getDataLayout())),
55                 std::move(Args))
56      .setDiscardResult();
57
58  std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
59  return CallResult.second;
60}
61