Trace.h

//===- llvm/Analysis/Trace.h - Represent one trace of LLVM code -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class represents a single trace of LLVM basic blocks.  A trace is a
// single entry, multiple exit, region of code that is often hot.  Trace-based
// optimizations treat traces almost like they are a large, strange, basic
// block: because the trace path is assumed to be hot, optimizations for the
// fall-through path are made at the expense of the non-fall-through paths.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_TRACE_H
#define LLVM_ANALYSIS_TRACE_H

#include <vector>
#include <cassert>

namespace llvm {
  class BasicBlock;
  class Function;
  class Module;
  class raw_ostream;

class Trace {
  typedef std::vector<BasicBlock *> BasicBlockListType;
  BasicBlockListType BasicBlocks;

public:
  Trace(const std::vector<BasicBlock *> &vBB) : BasicBlocks (vBB) {}

  BasicBlock *getEntryBasicBlock () const { return BasicBlocks[0]; }

  BasicBlock *operator[](unsigned i) const { return BasicBlocks[i]; }
  BasicBlock *getBlock(unsigned i)   const { return BasicBlocks[i]; }

  Function *getFunction () const;

  Module *getModule () const;

  int getBlockIndex(const BasicBlock *X) const {
    for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
      if (BasicBlocks[i] == X)
        return i;
    return -1;
  }

  bool contains(const BasicBlock *X) const {
    return getBlockIndex(X) != -1;
  }

  bool dominates(const BasicBlock *B1, const BasicBlock *B2) const {
    int B1Idx = getBlockIndex(B1), B2Idx = getBlockIndex(B2);
    assert(B1Idx != -1 && B2Idx != -1 && "Block is not in the trace!");
    return B1Idx <= B2Idx;
  }

  // BasicBlock iterators...
  typedef BasicBlockListType::iterator iterator;
  typedef BasicBlockListType::const_iterator const_iterator;
  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
  typedef std::reverse_iterator<iterator> reverse_iterator;

  iterator                begin()       { return BasicBlocks.begin(); }
  const_iterator          begin() const { return BasicBlocks.begin(); }
  iterator                end  ()       { return BasicBlocks.end();   }
  const_iterator          end  () const { return BasicBlocks.end();   }

  reverse_iterator       rbegin()       { return BasicBlocks.rbegin(); }
  const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
  reverse_iterator       rend  ()       { return BasicBlocks.rend();   }
  const_reverse_iterator rend  () const { return BasicBlocks.rend();   }

  unsigned                 size() const { return BasicBlocks.size(); }
  bool                    empty() const { return BasicBlocks.empty(); }

  iterator erase(iterator q)               { return BasicBlocks.erase (q); }
  iterator erase(iterator q1, iterator q2) { return BasicBlocks.erase (q1, q2); }

  void print(raw_ostream &O) const;

  void dump() const;
};

} // end namespace llvm

#endif // TRACE_H

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