[llvm] r332781 - [MemDep] Fixed handling of invariant.group
Piotr Padlewski via llvm-commits
llvm-commits at lists.llvm.org
Fri May 18 15:40:34 PDT 2018
Author: prazek
Date: Fri May 18 15:40:34 2018
New Revision: 332781
URL: http://llvm.org/viewvc/llvm-project?rev=332781&view=rev
Log:
[MemDep] Fixed handling of invariant.group
Summary:
Memdep had funny bug related to invariant.groups - because it did not
invalidated cache, in some very rare cases it was possible to show memory
dependence of the instruction that was deleted, but because other
instruction took it's place it resulted in call to vtable!
Thanks @amharc for repro!.
Reviewers: dberlin, kuhar, amharc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45320
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny at gmail.com>
Added:
llvm/trunk/test/Analysis/MemoryDependenceAnalysis/invariant.group-bug.ll
Modified:
llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h
llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
Modified: llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h?rev=332781&r1=332780&r2=332781&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h (original)
+++ llvm/trunk/include/llvm/Analysis/MemoryDependenceAnalysis.h Fri May 18 15:40:34 2018
@@ -26,6 +26,7 @@
#include "llvm/IR/Metadata.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/PredIteratorCache.h"
+#include "llvm/IR/ValueHandle.h"
#include "llvm/Pass.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
@@ -314,7 +315,10 @@ private:
/// Cache storing single nonlocal def for the instruction.
/// It is set when nonlocal def would be found in function returning only
/// local dependencies.
- DenseMap<Instruction *, NonLocalDepResult> NonLocalDefsCache;
+ DenseMap<AssertingVH<const Value>, NonLocalDepResult> NonLocalDefsCache;
+ using ReverseNonLocalDefsCacheTy =
+ DenseMap<Instruction *, SmallPtrSet<const Value*, 4>>;
+ ReverseNonLocalDefsCacheTy ReverseNonLocalDefsCache;
/// This map stores the cached results of doing a pointer lookup at the
/// bottom of a block.
Modified: llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp?rev=332781&r1=332780&r2=332781&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp Fri May 18 15:40:34 2018
@@ -433,6 +433,7 @@ MemoryDependenceResults::getInvariantGro
NonLocalDefsCache.try_emplace(
LI, NonLocalDepResult(ClosestDependency->getParent(),
MemDepResult::getDef(ClosestDependency), nullptr));
+ ReverseNonLocalDefsCache[ClosestDependency].insert(LI);
return MemDepResult::getNonLocal();
}
@@ -919,12 +920,12 @@ void MemoryDependenceResults::getNonLoca
"Can't get pointer deps of a non-pointer!");
Result.clear();
{
- // Check if there is cached Def with invariant.group. FIXME: cache might be
- // invalid if cached instruction would be removed between call to
- // getPointerDependencyFrom and this function.
+ // Check if there is cached Def with invariant.group.
auto NonLocalDefIt = NonLocalDefsCache.find(QueryInst);
if (NonLocalDefIt != NonLocalDefsCache.end()) {
- Result.push_back(std::move(NonLocalDefIt->second));
+ Result.push_back(NonLocalDefIt->second);
+ ReverseNonLocalDefsCache[NonLocalDefIt->second.getResult().getInst()]
+ .erase(QueryInst);
NonLocalDefsCache.erase(NonLocalDefIt);
return;
}
@@ -1459,9 +1460,29 @@ bool MemoryDependenceResults::getNonLoca
return true;
}
-/// If P exists in CachedNonLocalPointerInfo, remove it.
+/// If P exists in CachedNonLocalPointerInfo or NonLocalDefsCache, remove it.
void MemoryDependenceResults::RemoveCachedNonLocalPointerDependencies(
ValueIsLoadPair P) {
+
+ // Most of the time this cache is empty.
+ if (!NonLocalDefsCache.empty()) {
+ auto it = NonLocalDefsCache.find(P.getPointer());
+ if (it != NonLocalDefsCache.end()) {
+ RemoveFromReverseMap(ReverseNonLocalDefsCache,
+ it->second.getResult().getInst(), P.getPointer());
+ NonLocalDefsCache.erase(it);
+ }
+
+ if (auto *I = dyn_cast<Instruction>(P.getPointer())) {
+ auto toRemoveIt = ReverseNonLocalDefsCache.find(I);
+ if (toRemoveIt != ReverseNonLocalDefsCache.end()) {
+ for (const auto &entry : toRemoveIt->second)
+ NonLocalDefsCache.erase(entry);
+ ReverseNonLocalDefsCache.erase(toRemoveIt);
+ }
+ }
+ }
+
CachedNonLocalPointerInfo::iterator It = NonLocalPointerDeps.find(P);
if (It == NonLocalPointerDeps.end())
return;
Added: llvm/trunk/test/Analysis/MemoryDependenceAnalysis/invariant.group-bug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/MemoryDependenceAnalysis/invariant.group-bug.ll?rev=332781&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/MemoryDependenceAnalysis/invariant.group-bug.ll (added)
+++ llvm/trunk/test/Analysis/MemoryDependenceAnalysis/invariant.group-bug.ll Fri May 18 15:40:34 2018
@@ -0,0 +1,111 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -gvn -S < %s | FileCheck %s
+
+; Memdep had funny bug related to invariant.groups - because it did not
+; invalidated cache, in some very rare cases it was possible to show memory
+; dependence of the instruction that was deleted, but because other instruction
+; took it's place it resulted in call to vtable! Removing any of the branch
+; hides the bug.
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-grtev4-linux-gnu"
+
+%0 = type { i32 (...)**, %1 }
+%1 = type { %2 }
+%2 = type { %3 }
+%3 = type { %4, i64, %5 }
+%4 = type { i8* }
+%5 = type { i64, [8 x i8] }
+
+define void @fail(i1* noalias sret, %0*, %1*, i8*) local_unnamed_addr #0 {
+; CHECK-LABEL: @fail(
+; CHECK-NEXT: [[TMP5:%.*]] = bitcast %0* [[TMP1:%.*]] to i64 (%0*)***
+; CHECK-NEXT: [[TMP6:%.*]] = load i64 (%0*)**, i64 (%0*)*** [[TMP5]], align 8, !invariant.group !6
+; CHECK-NEXT: [[TMP7:%.*]] = getelementptr inbounds i64 (%0*)*, i64 (%0*)** [[TMP6]], i64 6
+; CHECK-NEXT: [[TMP8:%.*]] = load i64 (%0*)*, i64 (%0*)** [[TMP7]], align 8, !invariant.load !6
+; CHECK-NEXT: [[TMP9:%.*]] = tail call i64 [[TMP8]](%0* [[TMP1]]) #1
+; CHECK-NEXT: [[TMP10:%.*]] = getelementptr inbounds [[TMP1]], %1* [[TMP2:%.*]], i64 0, i32 0, i32 0, i32 0, i32 0
+; CHECK-NEXT: [[TMP11:%.*]] = load i8*, i8** [[TMP10]], align 8
+; CHECK-NEXT: store i8 0, i8* [[TMP11]], align 1
+; CHECK-NEXT: [[TMP12:%.*]] = bitcast i64 (%0*)** [[TMP6]] to i64 (%0*, i8*, i64)**
+; CHECK-NEXT: br i1 undef
+; CHECK: [[TMP14:%.*]] = bitcast %0* [[TMP1]] to i64 (%0*, i8*, i64)***
+; CHECK-NEXT: [[DOTPHI_TRANS_INSERT:%.*]] = getelementptr inbounds i64 (%0*, i8*, i64)*, i64 (%0*, i8*, i64)** [[TMP12]], i64 22
+; CHECK-NEXT: [[DOTPRE:%.*]] = load i64 (%0*, i8*, i64)*, i64 (%0*, i8*, i64)** [[DOTPHI_TRANS_INSERT]], align 8, !invariant.load !6
+; CHECK-NEXT: br label [[TMP15:%.*]]
+; CHECK: [[TMP16:%.*]] = call i64 [[DOTPRE]](%0* nonnull [[TMP1]], i8* null, i64 0) #1
+
+ %5 = bitcast %0* %1 to i64 (%0*)***
+ %6 = load i64 (%0*)**, i64 (%0*)*** %5, align 8, !invariant.group !6
+ %7 = getelementptr inbounds i64 (%0*)*, i64 (%0*)** %6, i64 6
+ %8 = load i64 (%0*)*, i64 (%0*)** %7, align 8, !invariant.load !6
+ %9 = tail call i64 %8(%0* %1) #1
+ %10 = getelementptr inbounds %1, %1* %2, i64 0, i32 0, i32 0, i32 0, i32 0
+ %11 = load i8*, i8** %10, align 8
+ store i8 0, i8* %11, align 1
+ br i1 undef, label %12, label %31
+
+; <label>:12: ; preds = %4
+ %13 = bitcast %0* %1 to i64 (%0*, i8*, i64)***
+ br label %14
+
+; <label>:14: ; preds = %30, %12
+ %15 = load i64 (%0*, i8*, i64)**, i64 (%0*, i8*, i64)*** %13, align 8, !invariant.group !6
+ %16 = getelementptr inbounds i64 (%0*, i8*, i64)*, i64 (%0*, i8*, i64)** %15, i64 22
+ %17 = load i64 (%0*, i8*, i64)*, i64 (%0*, i8*, i64)** %16, align 8, !invariant.load !6
+ %18 = call i64 %17(%0* nonnull %1, i8* null, i64 0) #1
+ br i1 undef, label %30, label %19
+
+; <label>:19: ; preds = %14
+ br i1 undef, label %20, label %23
+
+; <label>:20: ; preds = %19
+ br label %21
+
+; <label>:21: ; preds = %20
+ br label %22
+
+; <label>:22: ; preds = %21
+ br label %30
+
+; <label>:23: ; preds = %19
+ br label %24
+
+; <label>:24: ; preds = %23
+ br label %25
+
+; <label>:25: ; preds = %24
+ br label %26
+
+; <label>:26: ; preds = %25
+ br i1 undef, label %27, label %28
+
+; <label>:27: ; preds = %26
+ br label %30
+
+; <label>:28: ; preds = %26
+ br label %29
+
+; <label>:29: ; preds = %28
+ br label %30
+
+; <label>:30: ; preds = %29, %27, %22, %14
+ br i1 undef, label %14, label %31
+
+; <label>:31: ; preds = %30, %4
+ ret void
+}
+
+attributes #0 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.linker.options = !{}
+!llvm.module.flags = !{!0, !1, !3, !4, !5}
+
+!0 = !{i32 1, !"StrictVTablePointers", i32 1}
+!1 = !{i32 3, !"StrictVTablePointersRequirement", !2}
+!2 = !{!"StrictVTablePointers", i32 1}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 7, !"PIC Level", i32 2}
+!5 = !{i32 7, !"PIE Level", i32 2}
+!6 = !{}
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