1 //===- ConstantMerge.h - Merge duplicate global constants -------*- 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 // 9 // This file defines the interface to a pass that merges duplicate global 10 // constants together into a single constant that is shared. This is useful 11 // because some passes (ie TraceValues) insert a lot of string constants into 12 // the program, regardless of whether or not an existing string is available. 13 // 14 // Algorithm: ConstantMerge is designed to build up a map of available constants 15 // and eliminate duplicates when it is initialized. 16 // 17 //===----------------------------------------------------------------------===// 18 19 #ifndef LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 20 #define LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 21 22 #include "llvm/IR/PassManager.h" 23 24 namespace llvm { 25 26 class Module; 27 28 /// A pass that merges duplicate global constants into a single constant. 29 class ConstantMergePass : public PassInfoMixin<ConstantMergePass> { 30 public: 31 PreservedAnalyses run(Module &M, ModuleAnalysisManager &); 32 }; 33 34 } // end namespace llvm 35 36 #endif // LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 37