1 //===- EarlyCSE.h - Simple and fast CSE pass --------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 /// This file provides the interface for a simple, fast CSE pass.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
15 #define LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/PassManager.h"
22 /// \brief A simple and fast domtree-based CSE pass.
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.
31 static StringRef name() { return "EarlyCSEPass"; }
33 /// \brief Run the pass over the function.
35 /// This will lower all of th expect intrinsic calls in this function into
36 /// branch weight metadata. That metadata will subsequently feed the analysis
37 /// of the probabilities and frequencies of the CFG. After running this pass,
38 /// no more expect intrinsics remain, allowing the rest of the optimizer to
40 PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);