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 21 namespace 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. 29 class SimplifyCFGPass : public PassInfoMixin<SimplifyCFGPass> { 30 SimplifyCFGOptions Options; 31 32 public: 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