1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
//===- llvm/Analysis/LoopDependenceAnalysis.h --------------- -*- C++ -*---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// LoopDependenceAnalysis is an LLVM pass that analyses dependences in memory
// accesses in loops.
//
// Please note that this is work in progress and the interface is subject to
// change.
//
// TODO: adapt as interface progresses
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H
#define LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H
#include "llvm/ADT/FoldingSet.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Support/Allocator.h"
#include <iosfwd>
namespace llvm {
class AliasAnalysis;
class AnalysisUsage;
class ScalarEvolution;
class Value;
class raw_ostream;
class LoopDependenceAnalysis : public LoopPass {
AliasAnalysis *AA;
ScalarEvolution *SE;
/// L - The loop we are currently analysing.
Loop *L;
/// TODO: doc
enum DependenceResult { Independent = 0, Dependent = 1, Unknown = 2 };
/// DependencePair - Represents a data dependence relation between to memory
/// reference instructions.
///
/// TODO: add subscripts vector
struct DependencePair : public FastFoldingSetNode {
Value *A;
Value *B;
DependenceResult Result;
DependencePair(const FoldingSetNodeID &ID, Value *a, Value *b) :
FastFoldingSetNode(ID), A(a), B(b), Result(Unknown) {}
};
/// findOrInsertDependencePair - Return true if a DependencePair for the
/// given Values already exists, false if a new DependencePair had to be
/// created. The third argument is set to the pair found or created.
bool findOrInsertDependencePair(Value*, Value*, DependencePair*&);
/// TODO: doc
void analysePair(DependencePair *P) const;
public:
static char ID; // Class identification, replacement for typeinfo
LoopDependenceAnalysis() : LoopPass(&ID) {}
/// isDependencePair - Check wether two values can possibly give rise to a
/// data dependence: that is the case if both are instructions accessing
/// memory and at least one of those accesses is a write.
bool isDependencePair(const Value*, const Value*) const;
/// depends - Return a boolean indicating if there is a data dependence
/// between two instructions.
bool depends(Value*, Value*);
bool runOnLoop(Loop*, LPPassManager&);
virtual void releaseMemory();
virtual void getAnalysisUsage(AnalysisUsage&) const;
void print(raw_ostream&, const Module* = 0) const;
virtual void print(std::ostream&, const Module* = 0) const;
private:
FoldingSet<DependencePair> Pairs;
BumpPtrAllocator PairAllocator;
}; // class LoopDependenceAnalysis
// createLoopDependenceAnalysisPass - This creates an instance of the
// LoopDependenceAnalysis pass.
//
LoopPass *createLoopDependenceAnalysisPass();
} // namespace llvm
#endif /* LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H */
|
