1//===- SimplifyCFG.h - Simplify and canonicalize the CFG --------*- 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/// This file provides the interface for the pass responsible for both 10/// simplifying and canonicalizing the CFG. 11/// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H 15#define LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H 16 17#include "llvm/Transforms/Utils/Local.h" 18#include "llvm/IR/Function.h" 19#include "llvm/IR/PassManager.h" 20 21namespace llvm { 22 23/// A pass to simplify and canonicalize the CFG of a function. 24/// 25/// This pass iteratively simplifies the entire CFG of a function. It may change 26/// or remove control flow to put the CFG into a canonical form expected by 27/// other passes of the mid-level optimizer. Depending on the specified options, 28/// it may further optimize control-flow to create non-canonical forms. 29class SimplifyCFGPass : public PassInfoMixin<SimplifyCFGPass> { 30 SimplifyCFGOptions Options; 31 32public: 33 /// The default constructor sets the pass options to create canonical IR, 34 /// rather than optimal IR. That is, by default we bypass transformations that 35 /// are likely to improve performance but make analysis for other passes more 36 /// difficult. 37 SimplifyCFGPass() 38 : SimplifyCFGPass(SimplifyCFGOptions() 39 .forwardSwitchCondToPhi(false) 40 .convertSwitchToLookupTable(false) 41 .needCanonicalLoops(true) 42 .sinkCommonInsts(false)) {} 43 44 45 /// Construct a pass with optional optimizations. 46 SimplifyCFGPass(const SimplifyCFGOptions &PassOptions); 47 48 /// Run the pass over the function. 49 PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); 50}; 51 52} 53 54#endif 55