LLVM  10.0.0svn
CombinerHelper.h
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1 //===-- llvm/CodeGen/GlobalISel/CombinerHelper.h --------------*- C++ -*-===//
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 /// This contains common combine transformations that may be used in a combine
10 /// pass,or by the target elsewhere.
11 /// Targets can pick individual opcode transformations from the helper or use
12 /// tryCombine which invokes all transformations. All of the transformations
13 /// return true if the MachineInstruction changed and false otherwise.
14 //
15 //===--------------------------------------------------------------------===//
16 
17 #ifndef LLVM_CODEGEN_GLOBALISEL_COMBINER_HELPER_H
18 #define LLVM_CODEGEN_GLOBALISEL_COMBINER_HELPER_H
19 
21 #include "llvm/CodeGen/Register.h"
22 
23 namespace llvm {
24 
25 class GISelChangeObserver;
26 class MachineIRBuilder;
27 class MachineRegisterInfo;
28 class MachineInstr;
29 class MachineOperand;
30 
32  LLT Ty; // The result type of the extend.
33  unsigned ExtendOpcode; // G_ANYEXT/G_SEXT/G_ZEXT
35 };
36 
38  MachineIRBuilder &Builder;
40  GISelChangeObserver &Observer;
41 
42 public:
44 
45  /// MachineRegisterInfo::replaceRegWith() and inform the observer of the changes
46  void replaceRegWith(MachineRegisterInfo &MRI, Register FromReg, Register ToReg) const;
47 
48  /// Replace a single register operand with a new register and inform the
49  /// observer of the changes.
50  void replaceRegOpWith(MachineRegisterInfo &MRI, MachineOperand &FromRegOp,
51  Register ToReg) const;
52 
53  /// If \p MI is COPY, try to combine it.
54  /// Returns true if MI changed.
55  bool tryCombineCopy(MachineInstr &MI);
56  bool matchCombineCopy(MachineInstr &MI);
57  void applyCombineCopy(MachineInstr &MI);
58 
59  /// If \p MI is extend that consumes the result of a load, try to combine it.
60  /// Returns true if MI changed.
61  bool tryCombineExtendingLoads(MachineInstr &MI);
62  bool matchCombineExtendingLoads(MachineInstr &MI, PreferredTuple &MatchInfo);
63  void applyCombineExtendingLoads(MachineInstr &MI, PreferredTuple &MatchInfo);
64 
65  bool matchCombineBr(MachineInstr &MI);
66  bool tryCombineBr(MachineInstr &MI);
67 
68  /// Try to transform \p MI by using all of the above
69  /// combine functions. Returns true if changed.
70  bool tryCombine(MachineInstr &MI);
71 };
72 } // namespace llvm
73 
74 #endif
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Abstract class that contains various methods for clients to notify about changes. ...
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
unsigned const MachineRegisterInfo * MRI
Helper class to build MachineInstr.
MachineOperand class - Representation of each machine instruction operand.
MachineInstr * MI
MachineRegisterInfo - Keep track of information for virtual and physical registers, including vreg register classes, use/def chains for registers, etc.
Representation of each machine instruction.
Definition: MachineInstr.h:64
Wrapper class representing virtual and physical registers.
Definition: Register.h:18