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
| //===- LoopAnalysisManager.cpp - Loop analysis management -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LoopAnalysisManager.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemorySSA.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
#include "llvm/IR/Dominators.h"
using namespace llvm;
namespace llvm {
// Explicit template instantiations and specialization definitions for core
// template typedefs.
template class AllAnalysesOn<Loop>;
template class AnalysisManager<Loop, LoopStandardAnalysisResults &>;
template class InnerAnalysisManagerProxy<LoopAnalysisManager, Function>;
template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop,
LoopStandardAnalysisResults &>;
bool LoopAnalysisManagerFunctionProxy::Result::invalidate(
Function &F, const PreservedAnalyses &PA,
FunctionAnalysisManager::Invalidator &Inv) {
// First compute the sequence of IR units covered by this proxy. We will want
// to visit this in postorder, but because this is a tree structure we can do
// this by building a preorder sequence and walking it backwards. We also
// want siblings in forward program order to match the LoopPassManager so we
// get the preorder with siblings reversed.
SmallVector<Loop *, 4> PreOrderLoops = LI->getLoopsInReverseSiblingPreorder();
// If this proxy or the loop info is going to be invalidated, we also need
// to clear all the keys coming from that analysis. We also completely blow
// away the loop analyses if any of the standard analyses provided by the
// loop pass manager go away so that loop analyses can freely use these
// without worrying about declaring dependencies on them etc.
// FIXME: It isn't clear if this is the right tradeoff. We could instead make
// loop analyses declare any dependencies on these and use the more general
// invalidation logic below to act on that.
auto PAC = PA.getChecker<LoopAnalysisManagerFunctionProxy>();
bool invalidateMemorySSAAnalysis = false;
if (MSSAUsed)
invalidateMemorySSAAnalysis = Inv.invalidate<MemorySSAAnalysis>(F, PA);
if (!(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>()) ||
Inv.invalidate<AAManager>(F, PA) ||
Inv.invalidate<AssumptionAnalysis>(F, PA) ||
Inv.invalidate<DominatorTreeAnalysis>(F, PA) ||
Inv.invalidate<LoopAnalysis>(F, PA) ||
Inv.invalidate<ScalarEvolutionAnalysis>(F, PA) ||
invalidateMemorySSAAnalysis) {
// Note that the LoopInfo may be stale at this point, however the loop
// objects themselves remain the only viable keys that could be in the
// analysis manager's cache. So we just walk the keys and forcibly clear
// those results. Note that the order doesn't matter here as this will just
// directly destroy the results without calling methods on them.
for (Loop *L : PreOrderLoops) {
// NB! `L` may not be in a good enough state to run Loop::getName.
InnerAM->clear(*L, "<possibly invalidated loop>");
}
// We also need to null out the inner AM so that when the object gets
// destroyed as invalid we don't try to clear the inner AM again. At that
// point we won't be able to reliably walk the loops for this function and
// only clear results associated with those loops the way we do here.
// FIXME: Making InnerAM null at this point isn't very nice. Most analyses
// try to remain valid during invalidation. Maybe we should add an
// `IsClean` flag?
InnerAM = nullptr;
// Now return true to indicate this *is* invalid and a fresh proxy result
// needs to be built. This is especially important given the null InnerAM.
return true;
}
// Directly check if the relevant set is preserved so we can short circuit
// invalidating loops.
bool AreLoopAnalysesPreserved =
PA.allAnalysesInSetPreserved<AllAnalysesOn<Loop>>();
// Since we have a valid LoopInfo we can actually leave the cached results in
// the analysis manager associated with the Loop keys, but we need to
// propagate any necessary invalidation logic into them. We'd like to
// invalidate things in roughly the same order as they were put into the
// cache and so we walk the preorder list in reverse to form a valid
// postorder.
for (Loop *L : reverse(PreOrderLoops)) {
Optional<PreservedAnalyses> InnerPA;
// Check to see whether the preserved set needs to be adjusted based on
// function-level analysis invalidation triggering deferred invalidation
// for this loop.
if (auto *OuterProxy =
InnerAM->getCachedResult<FunctionAnalysisManagerLoopProxy>(*L))
for (const auto &OuterInvalidationPair :
OuterProxy->getOuterInvalidations()) {
AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
if (Inv.invalidate(OuterAnalysisID, F, PA)) {
if (!InnerPA)
InnerPA = PA;
for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
InnerPA->abandon(InnerAnalysisID);
}
}
// Check if we needed a custom PA set. If so we'll need to run the inner
// invalidation.
if (InnerPA) {
InnerAM->invalidate(*L, *InnerPA);
continue;
}
// Otherwise we only need to do invalidation if the original PA set didn't
// preserve all Loop analyses.
if (!AreLoopAnalysesPreserved)
InnerAM->invalidate(*L, PA);
}
// Return false to indicate that this result is still a valid proxy.
return false;
}
template <>
LoopAnalysisManagerFunctionProxy::Result
LoopAnalysisManagerFunctionProxy::run(Function &F,
FunctionAnalysisManager &AM) {
return Result(*InnerAM, AM.getResult<LoopAnalysis>(F));
}
}
PreservedAnalyses llvm::getLoopPassPreservedAnalyses() {
PreservedAnalyses PA;
PA.preserve<DominatorTreeAnalysis>();
PA.preserve<LoopAnalysis>();
PA.preserve<LoopAnalysisManagerFunctionProxy>();
PA.preserve<ScalarEvolutionAnalysis>();
// FIXME: What we really want to do here is preserve an AA category, but that
// concept doesn't exist yet.
PA.preserve<AAManager>();
PA.preserve<BasicAA>();
PA.preserve<GlobalsAA>();
PA.preserve<SCEVAA>();
return PA;
}
|