Import the trace class from the reoptimizer

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12236 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/Trace.h

@@ -0,0 +1,106 @@
+//===- llvm/Analysis/Trace.h - Represent one trace of LLVM code -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and 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 <iosfwd>
+#include <vector>
+
+namespace llvm { 
+  class BasicBlock;
+  class Function;
+  class Module;
+
+class Trace {
+  typedef std::vector<BasicBlock *> BasicBlockListType;
+  BasicBlockListType BasicBlocks;
+
+public:
+  /// contains - Returns true if this trace contains the given basic
+  /// block.
+  ///
+  inline bool contains (const BasicBlock *X) {
+    for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
+      if (BasicBlocks[i] == X)
+        return true;
+    return false;
+  }
+
+  /// Trace ctor - Make a new trace from a vector of basic blocks,
+  /// residing in the function which is the parent of the first
+  /// basic block in the vector.
+  ///
+  Trace (const std::vector<BasicBlock *> &vBB) : BasicBlocks (vBB) {
+  }
+
+  /// getEntryBasicBlock - Return the entry basic block (first block)
+  /// of the trace.
+  ///
+  BasicBlock *getEntryBasicBlock () const { return BasicBlocks[0]; }
+
+  /// getFunction - Return this trace's parent function.
+  ///
+  Function *getFunction () const;
+
+  /// getModule - Return this Module that contains this trace's parent
+  /// function.
+  ///
+  Module *getModule () const;
+
+  /// print - Write trace to output stream.
+  ///
+  void print (std::ostream &O) const;
+
+  /// dump - Debugger convenience method; writes trace to standard error
+  /// output stream.
+  ///
+  void dump () const;
+
+  // 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(); }
+
+  BasicBlock *operator[] (unsigned i) const { return BasicBlocks[i]; }
+  BasicBlock *getBlock (unsigned i)   const { return BasicBlocks[i]; }
+
+  /// Returns true if B1 and B2 appear on a path from START to an exit
+  /// block => B1 appears before B2. If START is not provided, defaults
+  /// to 0, which means use getEntryBasicBlock().
+  ///
+  bool dominates (const BasicBlock *B1, const BasicBlock *B2,
+		  const BasicBlock *start = 0);
+};
+
+} // end namespace llvm
+
+#endif // TRACE_H

lib/Analysis/Trace.cpp

@@ -0,0 +1,50 @@
+//===- Trace.cpp - Implementation of Trace class --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/Trace.h"
+#include "llvm/Function.h"
+#include "llvm/Assembly/Writer.h"
+using namespace llvm;
+
+Function *Trace::getFunction() const {
+  return getEntryBasicBlock()->getParent();
+}
+
+
+Module *Trace::getModule() const {
+  return getFunction()->getParent();
+}
+
+/// print - Write trace to output stream.
+///
+void Trace::print (std::ostream &O) const {
+  Function *F = getFunction ();
+  O << "; Trace from function " << F->getName () << ", blocks:\n";
+  for (const_iterator i = begin (), e = end (); i != e; ++i) {
+    O << "; ";
+    WriteAsOperand (O, *i, true, true, getModule ());
+    O << "\n";
+  }
+  O << "; Trace parent function: \n" << *F;
+}
+
+/// dump - Debugger convenience method; writes trace to standard error
+/// output stream.
+///
+void Trace::dump () const {
+  print (std::cerr);
+}