1 //===- ConstantMerge.h - Merge duplicate global constants -------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the interface to a pass that merges duplicate global 11 // constants together into a single constant that is shared. This is useful 12 // because some passes (ie TraceValues) insert a lot of string constants into 13 // the program, regardless of whether or not an existing string is available. 14 // 15 // Algorithm: ConstantMerge is designed to build up a map of available constants 16 // and eliminate duplicates when it is initialized. 17 // 18 //===----------------------------------------------------------------------===// 19 20 #ifndef LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 21 #define LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 22 23 #include "llvm/IR/Module.h" 24 #include "llvm/IR/PassManager.h" 25 26 namespace llvm { 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 35 #endif // LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 36