1 //===- EarlyCSE.h - Simple and fast CSE pass --------------------*- 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 /// \file
10 /// This file provides the interface for a simple, fast CSE pass.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
15 #define LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
16 
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/PassManager.h"
19 
20 namespace llvm {
21 
22 /// \brief A simple and fast domtree-based CSE pass.
23 ///
24 /// This pass does a simple depth-first walk over the dominator tree,
25 /// eliminating trivially redundant instructions and using instsimplify to
26 /// canonicalize things as it goes. It is intended to be fast and catch obvious
27 /// cases so that instcombine and other passes are more effective. It is
28 /// expected that a later pass of GVN will catch the interesting/hard cases.
29 class EarlyCSEPass {
30 public:
name()31   static StringRef name() { return "EarlyCSEPass"; }
32 
33   /// \brief Run the pass over the function.
34   PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);
35 };
36 
37 }
38 
39 #endif
40