1 //===-- HexagonSelectionDAGInfo.cpp - Hexagon SelectionDAG Info -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the HexagonSelectionDAGInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "HexagonTargetMachine.h"
14 #include "llvm/CodeGen/SelectionDAG.h"
15 using namespace llvm;
16
17 #define DEBUG_TYPE "hexagon-selectiondag-info"
18
EmitTargetCodeForMemcpy(SelectionDAG & DAG,const SDLoc & dl,SDValue Chain,SDValue Dst,SDValue Src,SDValue Size,Align Alignment,bool isVolatile,bool AlwaysInline,MachinePointerInfo DstPtrInfo,MachinePointerInfo SrcPtrInfo) const19 SDValue HexagonSelectionDAGInfo::EmitTargetCodeForMemcpy(
20 SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
21 SDValue Size, Align Alignment, bool isVolatile, bool AlwaysInline,
22 MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
23 ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
24 if (AlwaysInline || Alignment < Align(4) || !ConstantSize)
25 return SDValue();
26
27 uint64_t SizeVal = ConstantSize->getZExtValue();
28 if (SizeVal < 32 || (SizeVal % 8) != 0)
29 return SDValue();
30
31 // Special case aligned memcpys with size >= 32 bytes and a multiple of 8.
32 //
33 const TargetLowering &TLI = *DAG.getSubtarget().getTargetLowering();
34 TargetLowering::ArgListTy Args;
35 TargetLowering::ArgListEntry Entry;
36 Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
37 Entry.Node = Dst;
38 Args.push_back(Entry);
39 Entry.Node = Src;
40 Args.push_back(Entry);
41 Entry.Node = Size;
42 Args.push_back(Entry);
43
44 const char *SpecialMemcpyName =
45 "__hexagon_memcpy_likely_aligned_min32bytes_mult8bytes";
46 const MachineFunction &MF = DAG.getMachineFunction();
47 bool LongCalls = MF.getSubtarget<HexagonSubtarget>().useLongCalls();
48 unsigned Flags = LongCalls ? HexagonII::HMOTF_ConstExtended : 0;
49
50 TargetLowering::CallLoweringInfo CLI(DAG);
51 CLI.setDebugLoc(dl)
52 .setChain(Chain)
53 .setLibCallee(
54 TLI.getLibcallCallingConv(RTLIB::MEMCPY),
55 Type::getVoidTy(*DAG.getContext()),
56 DAG.getTargetExternalSymbol(
57 SpecialMemcpyName, TLI.getPointerTy(DAG.getDataLayout()), Flags),
58 std::move(Args))
59 .setDiscardResult();
60
61 std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
62 return CallResult.second;
63 }
64