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