/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/lib/Target/Hexagon/RDFDeadCode.h
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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 | | |
26 | | #include "RDFGraph.h" |
27 | | #include "RDFLiveness.h" |
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 | 3.34k | : Trace(false), DFG(dfg), MRI(mri), LV(mri, dfg) {} |
37 | | |
38 | | bool collect(); |
39 | | bool erase(const SetVector<NodeId> &Nodes); |
40 | 3.34k | void trace(bool On) { Trace = On; } |
41 | 20.9k | bool trace() const { return Trace; } |
42 | | |
43 | 419 | SetVector<NodeId> getDeadNodes() { return DeadNodes; } |
44 | 410 | SetVector<NodeId> getDeadInstrs() { return DeadInstrs; } |
45 | 477 | 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 | | |
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 |
65 | | |
66 | | #endif |