LLVM 17.0.0git
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1//===-- BPFSelectionDAGInfo.cpp - BPF SelectionDAG Info -------------------===//
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
9// This file implements the BPFSelectionDAGInfo class.
13#include "BPFTargetMachine.h"
16using namespace llvm;
18#define DEBUG_TYPE "bpf-selectiondag-info"
21 SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
22 SDValue Size, Align Alignment, bool isVolatile, bool AlwaysInline,
23 MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
24 // Requires the copy size to be a constant.
25 ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
26 if (!ConstantSize)
27 return SDValue();
29 unsigned CopyLen = ConstantSize->getZExtValue();
30 unsigned StoresNumEstimate = alignTo(CopyLen, Alignment) >> Log2(Alignment);
31 // Impose the same copy length limit as MaxStoresPerMemcpy.
32 if (StoresNumEstimate > getCommonMaxStoresPerMemFunc())
33 return SDValue();
35 SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Glue);
37 Dst = DAG.getNode(BPFISD::MEMCPY, dl, VTs, Chain, Dst, Src,
38 DAG.getConstant(CopyLen, dl, MVT::i64),
39 DAG.getConstant(Alignment.value(), dl, MVT::i64));
41 return Dst.getValue(0);
uint64_t Size
SDValue 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 override
Emit target-specific code that performs a memcpy.
unsigned getCommonMaxStoresPerMemFunc() const
uint64_t getZExtValue() const
Wrapper class for IR location info (IR ordering and DebugLoc) to be passed into SDNode creation funct...
Unlike LLVM values, Selection DAG nodes may return multiple values as the result of a computation.
This is used to represent a portion of an LLVM function in a low-level Data Dependence DAG representa...
Definition: SelectionDAG.h:225
SDVTList getVTList(EVT VT)
Return an SDVTList that represents the list of values specified.
SDValue getConstant(uint64_t Val, const SDLoc &DL, EVT VT, bool isTarget=false, bool isOpaque=false)
Create a ConstantSDNode wrapping a constant value.
SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, ArrayRef< SDUse > Ops)
Gets or creates the specified node.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
uint64_t alignTo(uint64_t Size, Align A)
Returns a multiple of A needed to store Size bytes.
Definition: Alignment.h:155
unsigned Log2(Align A)
Returns the log2 of the alignment.
Definition: Alignment.h:208
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
uint64_t value() const
This is a hole in the type system and should not be abused.
Definition: Alignment.h:85
This class contains a discriminated union of information about pointers in memory operands,...
This represents a list of ValueType's that has been intern'd by a SelectionDAG.