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//===-- BPFSelectionDAGInfo.cpp - BPF SelectionDAG Info -------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file implements the BPFSelectionDAGInfo class.
#include "BPFTargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/IR/DerivedTypes.h"
using namespace llvm;
#define DEBUG_TYPE "bpf-selectiondag-info"
SDValue BPFSelectionDAGInfo::EmitTargetCodeForMemcpy(
SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
SDValue Size, Align Alignment, bool isVolatile, bool AlwaysInline,
MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
// Requires the copy size to be a constant.
ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
if (!ConstantSize)
return SDValue();
unsigned CopyLen = ConstantSize->getZExtValue();
unsigned StoresNumEstimate = alignTo(CopyLen, Alignment) >> Log2(Alignment);
// Impose the same copy length limit as MaxStoresPerMemcpy.
if (StoresNumEstimate > getCommonMaxStoresPerMemFunc())
return SDValue();
SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Glue);
Dst = DAG.getNode(BPFISD::MEMCPY, dl, VTs, Chain, Dst, Src,
DAG.getConstant(CopyLen, dl, MVT::i64),
DAG.getConstant(Alignment.value(), dl, MVT::i64));
return Dst.getValue(0);