| //===- InstCombine.h - InstCombine pass -------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file |
| /// |
| /// This file provides the primary interface to the instcombine pass. This pass |
| /// is suitable for use in the new pass manager. For a pass that works with the |
| /// legacy pass manager, use \c createInstructionCombiningPass(). |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINE_H |
| #define LLVM_TRANSFORMS_INSTCOMBINE_INSTCOMBINE_H |
| |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/PassManager.h" |
| #include "llvm/Pass.h" |
| |
| #define DEBUG_TYPE "instcombine" |
| #include "llvm/Transforms/Utils/InstructionWorklist.h" |
| |
| namespace llvm { |
| |
| class InstCombinePass : public PassInfoMixin<InstCombinePass> { |
| InstructionWorklist Worklist; |
| const unsigned MaxIterations; |
| |
| public: |
| explicit InstCombinePass(); |
| explicit InstCombinePass(unsigned MaxIterations); |
| |
| PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); |
| }; |
| |
| /// The legacy pass manager's instcombine pass. |
| /// |
| /// This is a basic whole-function wrapper around the instcombine utility. It |
| /// will try to combine all instructions in the function. |
| class InstructionCombiningPass : public FunctionPass { |
| InstructionWorklist Worklist; |
| const unsigned MaxIterations; |
| |
| public: |
| static char ID; // Pass identification, replacement for typeid |
| |
| explicit InstructionCombiningPass(); |
| explicit InstructionCombiningPass(unsigned MaxIterations); |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const override; |
| bool runOnFunction(Function &F) override; |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| // |
| // InstructionCombining - Combine instructions to form fewer, simple |
| // instructions. This pass does not modify the CFG, and has a tendency to make |
| // instructions dead, so a subsequent DCE pass is useful. |
| // |
| // This pass combines things like: |
| // %Y = add int 1, %X |
| // %Z = add int 1, %Y |
| // into: |
| // %Z = add int 2, %X |
| // |
| FunctionPass *createInstructionCombiningPass(); |
| FunctionPass *createInstructionCombiningPass(unsigned MaxIterations); |
| } |
| |
| #undef DEBUG_TYPE |
| |
| #endif |