|
150
|
1 //===--- RDFDeadCode.h ----------------------------------------------------===//
|
|
|
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 // RDF-based generic dead code elimination.
|
|
|
10 //
|
|
|
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.
|
|
|
22
|
|
|
23 #ifndef RDF_DEADCODE_H
|
|
|
24 #define RDF_DEADCODE_H
|
|
|
25
|
|
173
|
26 #include "llvm/CodeGen/RDFGraph.h"
|
|
|
27 #include "llvm/CodeGen/RDFLiveness.h"
|
|
150
|
28 #include "llvm/ADT/SetVector.h"
|
|
|
29
|
|
|
30 namespace llvm {
|
|
|
31 class MachineRegisterInfo;
|
|
|
32
|
|
|
33 namespace rdf {
|
|
|
34 struct DeadCodeElimination {
|
|
|
35 DeadCodeElimination(DataFlowGraph &dfg, MachineRegisterInfo &mri)
|
|
|
36 : Trace(false), DFG(dfg), MRI(mri), LV(mri, dfg) {}
|
|
|
37
|
|
|
38 bool collect();
|
|
|
39 bool erase(const SetVector<NodeId> &Nodes);
|
|
|
40 void trace(bool On) { Trace = On; }
|
|
|
41 bool trace() const { return Trace; }
|
|
|
42
|
|
|
43 SetVector<NodeId> getDeadNodes() { return DeadNodes; }
|
|
|
44 SetVector<NodeId> getDeadInstrs() { return DeadInstrs; }
|
|
|
45 DataFlowGraph &getDFG() { return DFG; }
|
|
|
46
|
|
|
47 private:
|
|
|
48 bool Trace;
|
|
|
49 SetVector<NodeId> LiveNodes;
|
|
|
50 SetVector<NodeId> DeadNodes;
|
|
|
51 SetVector<NodeId> DeadInstrs;
|
|
|
52 DataFlowGraph &DFG;
|
|
|
53 MachineRegisterInfo &MRI;
|
|
|
54 Liveness LV;
|
|
|
55
|
|
|
56 template<typename T> struct SetQueue;
|
|
|
57
|
|
252
|
58 bool isLiveInstr(NodeAddr<StmtNode*> S) const;
|
|
150
|
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
|
|
|
65
|
|
|
66 #endif
|
