1 //===- SCCP.cpp - Sparse Conditional Constant Propagation -------*- 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 // \file
10 // This file implements sparse conditional constant propagation and merging:
11 //
12 // Specifically, this:
13 //   * Assumes values are constant unless proven otherwise
14 //   * Assumes BasicBlocks are dead unless proven otherwise
15 //   * Proves values to be constant, and replaces them with constants
16 //   * Proves conditional branches to be unconditional
17 //
18 //===----------------------------------------------------------------------===//
19 
20 #ifndef LLVM_TRANSFORMS_SCALAR_SCCP_H
21 #define LLVM_TRANSFORMS_SCALAR_SCCP_H
22 
23 #include "llvm/ADT/STLExtras.h"
24 #include "llvm/Analysis/TargetLibraryInfo.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/IR/Module.h"
28 #include "llvm/IR/PassManager.h"
29 #include "llvm/Transforms/Utils/PredicateInfo.h"
30 
31 namespace llvm {
32 
33 class PostDominatorTree;
34 
35 /// This pass performs function-level constant propagation and merging.
36 class SCCPPass : public PassInfoMixin<SCCPPass> {
37 public:
38   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
39 };
40 
41 /// Helper struct for bundling up the analysis results per function for IPSCCP.
42 struct AnalysisResultsForFn {
43   std::unique_ptr<PredicateInfo> PredInfo;
44   DominatorTree *DT;
45   PostDominatorTree *PDT;
46 };
47 
48 bool runIPSCCP(Module &M, const DataLayout &DL,
49                std::function<const TargetLibraryInfo &(Function &)> GetTLI,
50                function_ref<AnalysisResultsForFn(Function &)> getAnalysis);
51 } // end namespace llvm
52 
53 #endif // LLVM_TRANSFORMS_SCALAR_SCCP_H
54