LLVM  14.0.0git
InstCombine.h
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1 //===- InstCombine.h - InstCombine pass -------------------------*- 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 /// \file
9 ///
10 /// This file provides the primary interface to the instcombine pass. This pass
11 /// is suitable for use in the new pass manager. For a pass that works with the
12 /// legacy pass manager, use \c createInstructionCombiningPass().
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINE_H
17 #define LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINE_H
18 
19 #include "llvm/IR/Function.h"
20 #include "llvm/IR/PassManager.h"
21 
22 #define DEBUG_TYPE "instcombine"
24 
25 namespace llvm {
26 
27 class InstCombinePass : public PassInfoMixin<InstCombinePass> {
28  InstructionWorklist Worklist;
29  const unsigned MaxIterations;
30 
31 public:
32  explicit InstCombinePass();
33  explicit InstCombinePass(unsigned MaxIterations);
34 
36 };
37 
38 /// The legacy pass manager's instcombine pass.
39 ///
40 /// This is a basic whole-function wrapper around the instcombine utility. It
41 /// will try to combine all instructions in the function.
43  InstructionWorklist Worklist;
44  const unsigned MaxIterations;
45 
46 public:
47  static char ID; // Pass identification, replacement for typeid
48 
49  explicit InstructionCombiningPass();
50  explicit InstructionCombiningPass(unsigned MaxIterations);
51 
52  void getAnalysisUsage(AnalysisUsage &AU) const override;
53  bool runOnFunction(Function &F) override;
54 };
55 
56 //===----------------------------------------------------------------------===//
57 //
58 // InstructionCombining - Combine instructions to form fewer, simple
59 // instructions. This pass does not modify the CFG, and has a tendency to make
60 // instructions dead, so a subsequent DCE pass is useful.
61 //
62 // This pass combines things like:
63 // %Y = add int 1, %X
64 // %Z = add int 1, %Y
65 // into:
66 // %Z = add int 2, %X
67 //
69 FunctionPass *createInstructionCombiningPass(unsigned MaxIterations);
70 }
71 
72 #undef DEBUG_TYPE
73 
74 #endif
llvm::PreservedAnalyses
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:155
llvm
This file implements support for optimizing divisions by a constant.
Definition: AllocatorList.h:23
llvm::InstructionCombiningPass::getAnalysisUsage
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - This function should be overriden by passes that need analysis information to do t...
Definition: InstructionCombining.cpp:4238
llvm::PassInfoMixin
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:374
llvm::Function
Definition: Function.h:62
llvm::InstructionCombiningPass::InstructionCombiningPass
InstructionCombiningPass()
Definition: InstructionCombining.cpp:4282
llvm::InstCombinePass::InstCombinePass
InstCombinePass()
Definition: InstructionCombining.cpp:4205
F
#define F(x, y, z)
Definition: MD5.cpp:56
InstructionWorklist.h
llvm::AnalysisUsage
Represent the analysis usage information of a pass.
Definition: PassAnalysisSupport.h:47
llvm::InstructionCombiningPass::ID
static char ID
Definition: InstCombine.h:47
llvm::InstCombinePass
Definition: InstCombine.h:27
llvm::InstructionCombiningPass::runOnFunction
bool runOnFunction(Function &F) override
runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.
Definition: InstructionCombining.cpp:4254
Function.h
PassManager.h
llvm::InstructionWorklist
InstructionWorklist - This is the worklist management logic for InstCombine and other simplification ...
Definition: InstructionWorklist.h:25
llvm::createInstructionCombiningPass
FunctionPass * createInstructionCombiningPass()
Definition: InstructionCombining.cpp:4315
llvm::AnalysisManager
A container for analyses that lazily runs them and caches their results.
Definition: InstructionSimplify.h:44
llvm::FunctionPass
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:298
llvm::InstCombinePass::run
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Definition: InstructionCombining.cpp:4210
llvm::InstructionCombiningPass
The legacy pass manager's instcombine pass.
Definition: InstCombine.h:42