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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
//===--------- PolyhedralInfo.cpp - Create Scops from LLVM IR-------------===//
///
/// The LLVM Compiler Infrastructure
///
/// This file is distributed under the University of Illinois Open Source
/// License. See LICENSE.TXT for details.
///
//===----------------------------------------------------------------------===//
///
/// An interface to the Polyhedral analysis engine(Polly) of LLVM.
///
/// This pass provides an interface to the polyhedral analysis performed by
/// Polly.
///
/// This interface provides basic interface like isParallel, isVectorizable
/// that can be used in LLVM transformation passes.
///
/// Work in progress, this file is subject to change.
//===----------------------------------------------------------------------===//
#include "polly/PolyhedralInfo.h"
#include "polly/DependenceInfo.h"
#include "polly/LinkAllPasses.h"
#include "polly/Options.h"
#include "polly/ScopInfo.h"
#include "polly/Support/GICHelper.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Support/Debug.h"
#include <isl/map.h>
#include <isl/union_map.h>
using namespace llvm;
using namespace polly;
#define DEBUG_TYPE "polyhedral-info"
static cl::opt<bool> CheckParallel("polly-check-parallel",
cl::desc("Check for parallel loops"),
cl::Hidden, cl::init(false), cl::ZeroOrMore,
cl::cat(PollyCategory));
static cl::opt<bool> CheckVectorizable("polly-check-vectorizable",
cl::desc("Check for vectorizable loops"),
cl::Hidden, cl::init(false),
cl::ZeroOrMore, cl::cat(PollyCategory));
void PolyhedralInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequiredTransitive<DependenceInfoWrapperPass>();
AU.addRequired<LoopInfoWrapperPass>();
AU.addRequiredTransitive<ScopInfoWrapperPass>();
AU.setPreservesAll();
}
bool PolyhedralInfo::runOnFunction(Function &F) {
DI = &getAnalysis<DependenceInfoWrapperPass>();
SI = getAnalysis<ScopInfoWrapperPass>().getSI();
return false;
}
void PolyhedralInfo::print(raw_ostream &OS, const Module *) const {
auto &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
for (auto *TopLevelLoop : LI) {
for (auto *L : depth_first(TopLevelLoop)) {
OS.indent(2) << L->getHeader()->getName() << ":\t";
if (CheckParallel && isParallel(L))
OS << "Loop is parallel.\n";
else if (CheckParallel)
OS << "Loop is not parallel.\n";
}
}
}
bool PolyhedralInfo::checkParallel(Loop *L, isl_pw_aff **MinDepDistPtr) const {
bool IsParallel;
const Scop *S = getScopContainingLoop(L);
if (!S)
return false;
const Dependences &D =
DI->getDependences(const_cast<Scop *>(S), Dependences::AL_Access);
if (!D.hasValidDependences())
return false;
DEBUG(dbgs() << "Loop :\t" << L->getHeader()->getName() << ":\n");
isl_union_map *Deps =
D.getDependences(Dependences::TYPE_RAW | Dependences::TYPE_WAW |
Dependences::TYPE_WAR | Dependences::TYPE_RED);
DEBUG(dbgs() << "Dependences :\t" << stringFromIslObj(Deps) << "\n");
isl_union_map *Schedule = getScheduleForLoop(S, L);
DEBUG(dbgs() << "Schedule: \t" << stringFromIslObj(Schedule) << "\n");
IsParallel = D.isParallel(Schedule, Deps, MinDepDistPtr);
isl_union_map_free(Schedule);
return IsParallel;
}
bool PolyhedralInfo::isParallel(Loop *L) const { return checkParallel(L); }
const Scop *PolyhedralInfo::getScopContainingLoop(Loop *L) const {
assert((SI) && "ScopInfoWrapperPass is required by PolyhedralInfo pass!\n");
for (auto &It : *SI) {
Region *R = It.first;
if (R->contains(L))
return It.second.get();
}
return nullptr;
}
// Given a Loop and the containing SCoP, we compute the partial schedule
// by taking union of individual schedules of each ScopStmt within the loop
// and projecting out the inner dimensions from the range of the schedule.
// for (i = 0; i < n; i++)
// for (j = 0; j < n; j++)
// A[j] = 1; //Stmt
//
// The original schedule will be
// Stmt[i0, i1] -> [i0, i1]
// The schedule for the outer loop will be
// Stmt[i0, i1] -> [i0]
// The schedule for the inner loop will be
// Stmt[i0, i1] -> [i0, i1]
__isl_give isl_union_map *PolyhedralInfo::getScheduleForLoop(const Scop *S,
Loop *L) const {
isl_union_map *Schedule = isl_union_map_empty(S->getParamSpace().release());
int CurrDim = S->getRelativeLoopDepth(L);
DEBUG(dbgs() << "Relative loop depth:\t" << CurrDim << "\n");
assert(CurrDim >= 0 && "Loop in region should have at least depth one");
for (auto &SS : *S) {
if (L->contains(SS.getSurroundingLoop())) {
unsigned int MaxDim = SS.getNumIterators();
DEBUG(dbgs() << "Maximum depth of Stmt:\t" << MaxDim << "\n");
isl_map *ScheduleMap = SS.getSchedule().release();
assert(
ScheduleMap &&
"Schedules that contain extension nodes require special handling.");
ScheduleMap = isl_map_project_out(ScheduleMap, isl_dim_out, CurrDim + 1,
MaxDim - CurrDim - 1);
ScheduleMap = isl_map_set_tuple_id(ScheduleMap, isl_dim_in,
SS.getDomainId().release());
Schedule =
isl_union_map_union(Schedule, isl_union_map_from_map(ScheduleMap));
}
}
Schedule = isl_union_map_coalesce(Schedule);
return Schedule;
}
char PolyhedralInfo::ID = 0;
Pass *polly::createPolyhedralInfoPass() { return new PolyhedralInfo(); }
INITIALIZE_PASS_BEGIN(PolyhedralInfo, "polyhedral-info",
"Polly - Interface to polyhedral analysis engine", false,
false);
INITIALIZE_PASS_DEPENDENCY(DependenceInfoWrapperPass);
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass);
INITIALIZE_PASS_DEPENDENCY(ScopInfoWrapperPass);
INITIALIZE_PASS_END(PolyhedralInfo, "polyhedral-info",
"Polly - Interface to polyhedral analysis engine", false,
false)
|
