- //===- ConstantMerge.h - Merge duplicate global constants -------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file defines the interface to a pass that merges duplicate global 
- // constants together into a single constant that is shared.  This is useful 
- // because some passes (ie TraceValues) insert a lot of string constants into 
- // the program, regardless of whether or not an existing string is available. 
- // 
- // Algorithm: ConstantMerge is designed to build up a map of available constants 
- // and eliminate duplicates when it is initialized. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 
- #define LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 
-   
- #include "llvm/IR/PassManager.h" 
-   
- namespace llvm { 
-   
- class Module; 
-   
- /// A pass that merges duplicate global constants into a single constant. 
- class ConstantMergePass : public PassInfoMixin<ConstantMergePass> { 
- public: 
-   PreservedAnalyses run(Module &M, ModuleAnalysisManager &); 
- }; 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_TRANSFORMS_IPO_CONSTANTMERGE_H 
-