1 //===- InstSimplifyPass.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 /// \file 9 /// 10 /// Defines passes for running instruction simplification across chunks of IR. 11 /// 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_TRANSFORMS_SCALAR_INSTSIMPLIFYPASS_H 15 #define LLVM_TRANSFORMS_SCALAR_INSTSIMPLIFYPASS_H 16 17 #include "llvm/IR/PassManager.h" 18 19 namespace llvm { 20 21 /// Run instruction simplification across each instruction in the function. 22 /// 23 /// Instruction simplification has useful constraints in some contexts: 24 /// - It will never introduce *new* instructions. 25 /// - There is no need to iterate to a fixed point. 26 /// 27 /// Many passes use instruction simplification as a library facility, but it may 28 /// also be useful (in tests and other contexts) to have access to this very 29 /// restricted transform at a pass granularity. However, for a much more 30 /// powerful and comprehensive peephole optimization engine, see the 31 /// `instcombine` pass instead. 32 class InstSimplifyPass : public PassInfoMixin<InstSimplifyPass> { 33 public: 34 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); 35 }; 36 37 } // end namespace llvm 38 39 #endif // LLVM_TRANSFORMS_SCALAR_INSTSIMPLIFYPASS_H 40