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 | |