include/llvm/Transforms/IPO/ConstantMerge.h

   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