LLVM 17.0.0git
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1//===--- RDFDeadCode.h ----------------------------------------------------===//
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// RDF-based generic dead code elimination.
11// The main interface of this class are functions "collect" and "erase".
12// This allows custom processing of the function being optimized by a
13// particular consumer. The simplest way to use this class would be to
14// instantiate an object, and then simply call "collect" and "erase",
15// passing the result of "getDeadInstrs()" to it.
16// A more complex scenario would be to call "collect" first, then visit
17// all post-increment instructions to see if the address update is dead
18// or not, and if it is, convert the instruction to a non-updating form.
19// After that "erase" can be called with the set of nodes including both,
20// dead defs from the updating instructions and the nodes corresponding
21// to the dead instructions.
23#ifndef RDF_DEADCODE_H
24#define RDF_DEADCODE_H
28#include "llvm/ADT/SetVector.h"
30namespace llvm {
31 class MachineRegisterInfo;
33namespace rdf {
36 : Trace(false), DFG(dfg), MRI(mri), LV(mri, dfg) {}
38 bool collect();
39 bool erase(const SetVector<NodeId> &Nodes);
40 void trace(bool On) { Trace = On; }
41 bool trace() const { return Trace; }
43 SetVector<NodeId> getDeadNodes() { return DeadNodes; }
44 SetVector<NodeId> getDeadInstrs() { return DeadInstrs; }
45 DataFlowGraph &getDFG() { return DFG; }
47 private:
48 bool Trace;
49 SetVector<NodeId> LiveNodes;
50 SetVector<NodeId> DeadNodes;
51 SetVector<NodeId> DeadInstrs;
52 DataFlowGraph &DFG;
54 Liveness LV;
56 template<typename T> struct SetQueue;
58 bool isLiveInstr(const MachineInstr *MI) const;
59 void scanInstr(NodeAddr<InstrNode*> IA, SetQueue<NodeId> &WorkQ);
60 void processDef(NodeAddr<DefNode*> DA, SetQueue<NodeId> &WorkQ);
61 void processUse(NodeAddr<UseNode*> UA, SetQueue<NodeId> &WorkQ);
62 };
63} // namespace rdf
64} // namespace llvm
static bool processUse(CallInst *CI, bool IsV5OrAbove)
IRTranslator LLVM IR MI
This file implements a set that has insertion order iteration characteristics.
Representation of each machine instruction.
Definition: MachineInstr.h:68
MachineRegisterInfo - Keep track of information for virtual and physical registers,...
A vector that has set insertion semantics.
Definition: SetVector.h:40
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
SetVector< NodeId > getDeadNodes()
Definition: RDFDeadCode.h:43
DataFlowGraph & getDFG()
Definition: RDFDeadCode.h:45
DeadCodeElimination(DataFlowGraph &dfg, MachineRegisterInfo &mri)
Definition: RDFDeadCode.h:35
SetVector< NodeId > getDeadInstrs()
Definition: RDFDeadCode.h:44
bool erase(const SetVector< NodeId > &Nodes)