LLVM  4.0.0
Analysis/Trace.h
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1 //===- llvm/Analysis/Trace.h - Represent one trace of LLVM code -*- 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 // This class represents a single trace of LLVM basic blocks. A trace is a
11 // single entry, multiple exit, region of code that is often hot. Trace-based
12 // optimizations treat traces almost like they are a large, strange, basic
13 // block: because the trace path is assumed to be hot, optimizations for the
14 // fall-through path are made at the expense of the non-fall-through paths.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_ANALYSIS_TRACE_H
19 #define LLVM_ANALYSIS_TRACE_H
20 
21 #include <cassert>
22 #include <vector>
23 
24 namespace llvm {
25  class BasicBlock;
26  class Function;
27  class Module;
28  class raw_ostream;
29 
30 class Trace {
31  typedef std::vector<BasicBlock *> BasicBlockListType;
32  BasicBlockListType BasicBlocks;
33 
34 public:
35  /// Trace ctor - Make a new trace from a vector of basic blocks,
36  /// residing in the function which is the parent of the first
37  /// basic block in the vector.
38  ///
39  Trace(const std::vector<BasicBlock *> &vBB) : BasicBlocks (vBB) {}
40 
41  /// getEntryBasicBlock - Return the entry basic block (first block)
42  /// of the trace.
43  ///
44  BasicBlock *getEntryBasicBlock () const { return BasicBlocks[0]; }
45 
46  /// operator[]/getBlock - Return basic block N in the trace.
47  ///
48  BasicBlock *operator[](unsigned i) const { return BasicBlocks[i]; }
49  BasicBlock *getBlock(unsigned i) const { return BasicBlocks[i]; }
50 
51  /// getFunction - Return this trace's parent function.
52  ///
53  Function *getFunction () const;
54 
55  /// getModule - Return this Module that contains this trace's parent
56  /// function.
57  ///
58  Module *getModule () const;
59 
60  /// getBlockIndex - Return the index of the specified basic block in the
61  /// trace, or -1 if it is not in the trace.
62  int getBlockIndex(const BasicBlock *X) const {
63  for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
64  if (BasicBlocks[i] == X)
65  return i;
66  return -1;
67  }
68 
69  /// contains - Returns true if this trace contains the given basic
70  /// block.
71  ///
72  bool contains(const BasicBlock *X) const {
73  return getBlockIndex(X) != -1;
74  }
75 
76  /// Returns true if B1 occurs before B2 in the trace, or if it is the same
77  /// block as B2.. Both blocks must be in the trace.
78  ///
79  bool dominates(const BasicBlock *B1, const BasicBlock *B2) const {
80  int B1Idx = getBlockIndex(B1), B2Idx = getBlockIndex(B2);
81  assert(B1Idx != -1 && B2Idx != -1 && "Block is not in the trace!");
82  return B1Idx <= B2Idx;
83  }
84 
85  // BasicBlock iterators...
86  typedef BasicBlockListType::iterator iterator;
87  typedef BasicBlockListType::const_iterator const_iterator;
88  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
89  typedef std::reverse_iterator<iterator> reverse_iterator;
90 
91  iterator begin() { return BasicBlocks.begin(); }
92  const_iterator begin() const { return BasicBlocks.begin(); }
93  iterator end () { return BasicBlocks.end(); }
94  const_iterator end () const { return BasicBlocks.end(); }
95 
96  reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
97  const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
98  reverse_iterator rend () { return BasicBlocks.rend(); }
99  const_reverse_iterator rend () const { return BasicBlocks.rend(); }
100 
101  unsigned size() const { return BasicBlocks.size(); }
102  bool empty() const { return BasicBlocks.empty(); }
103 
104  iterator erase(iterator q) { return BasicBlocks.erase (q); }
105  iterator erase(iterator q1, iterator q2) { return BasicBlocks.erase (q1, q2); }
106 
107  /// print - Write trace to output stream.
108  ///
109  void print(raw_ostream &O) const;
110 
111  /// dump - Debugger convenience method; writes trace to standard error
112  /// output stream.
113  ///
114  void dump() const;
115 };
116 
117 } // end namespace llvm
118 
119 #endif // LLVM_ANALYSIS_TRACE_H
BasicBlock * operator[](unsigned i) const
operator[]/getBlock - Return basic block N in the trace.
size_t i
Various leaf nodes.
Definition: ISDOpcodes.h:60
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:52
std::reverse_iterator< const_iterator > const_reverse_iterator
int getBlockIndex(const BasicBlock *X) const
getBlockIndex - Return the index of the specified basic block in the trace, or -1 if it is not in the...
bool empty() const
const_reverse_iterator rend() const
void dump() const
dump - Debugger convenience method; writes trace to standard error output stream. ...
iterator erase(iterator q)
const_reverse_iterator rbegin() const
bool contains(const BasicBlock *X) const
contains - Returns true if this trace contains the given basic block.
iterator begin()
iterator erase(iterator q1, iterator q2)
Trace(const std::vector< BasicBlock * > &vBB)
Trace ctor - Make a new trace from a vector of basic blocks, residing in the function which is the pa...
iterator end()
LLVM Basic Block Representation.
Definition: BasicBlock.h:51
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang","erlang-compatible garbage collector")
std::reverse_iterator< iterator > reverse_iterator
void print(raw_ostream &O) const
print - Write trace to output stream.
bool dominates(const BasicBlock *B1, const BasicBlock *B2) const
Returns true if B1 occurs before B2 in the trace, or if it is the same block as B2.
BasicBlock * getEntryBasicBlock() const
getEntryBasicBlock - Return the entry basic block (first block) of the trace.
reverse_iterator rbegin()
reverse_iterator rend()
BasicBlock * getBlock(unsigned i) const
Function * getFunction() const
getFunction - Return this trace's parent function.
Module * getModule() const
getModule - Return this Module that contains this trace's parent function.
BasicBlockListType::iterator iterator
const_iterator begin() const
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
unsigned size() const
const_iterator end() const
BasicBlockListType::const_iterator const_iterator