[llvm] r280280 - [LoopInfo] Add verification by recomputation.
Michael Zolotukhin via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 31 12:26:19 PDT 2016
Author: mzolotukhin
Date: Wed Aug 31 14:26:19 2016
New Revision: 280280
URL: http://llvm.org/viewvc/llvm-project?rev=280280&view=rev
Log:
[LoopInfo] Add verification by recomputation.
Summary:
Current implementation of LI verifier isn't ideal and fails to detect
some cases when LI is incorrect. For instance, it checks that all
recorded loops are in a correct form, but it has no way to check if
there are no more other (unrecorded in LI) loops in the function. This
patch adds a way to detect such bugs.
Reviewers: chandlerc, sanjoy, hfinkel
Subscribers: llvm-commits, silvas, mzolotukhin
Differential Revision: https://reviews.llvm.org/D23437
Modified:
llvm/trunk/include/llvm/Analysis/LoopInfo.h
llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h
llvm/trunk/lib/Analysis/LoopInfo.cpp
llvm/trunk/lib/Transforms/Scalar/LoopDistribute.cpp
Modified: llvm/trunk/include/llvm/Analysis/LoopInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfo.h?rev=280280&r1=280279&r2=280280&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfo.h Wed Aug 31 14:26:19 2016
@@ -635,7 +635,7 @@ public:
// Debugging
void print(raw_ostream &OS) const;
- void verify() const;
+ void verify(const DominatorTreeBase<BlockT> &DomTree) const;
};
// Implementation in LoopInfoImpl.h
Modified: llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h?rev=280280&r1=280279&r2=280280&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h Wed Aug 31 14:26:19 2016
@@ -17,6 +17,7 @@
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/Dominators.h"
@@ -514,8 +515,26 @@ void LoopInfoBase<BlockT, LoopT>::print(
#endif
}
-template<class BlockT, class LoopT>
-void LoopInfoBase<BlockT, LoopT>::verify() const {
+template <typename T>
+bool compareVectors(std::vector<T> &BB1, std::vector<T> &BB2) {
+ std::sort(BB1.begin(), BB1.end());
+ std::sort(BB2.begin(), BB2.end());
+ return BB1 == BB2;
+}
+
+template <class BlockT, class LoopT>
+static void
+addInnerLoopsToHeadersMap(DenseMap<BlockT *, const LoopT *> &LoopHeaders,
+ const LoopInfoBase<BlockT, LoopT> &LI,
+ const LoopT &L) {
+ LoopHeaders[L.getHeader()] = &L;
+ for (LoopT *SL : L)
+ addInnerLoopsToHeadersMap(LoopHeaders, LI, *SL);
+}
+
+template <class BlockT, class LoopT>
+void LoopInfoBase<BlockT, LoopT>::verify(
+ const DominatorTreeBase<BlockT> &DomTree) const {
DenseSet<const LoopT*> Loops;
for (iterator I = begin(), E = end(); I != E; ++I) {
assert(!(*I)->getParentLoop() && "Top-level loop has a parent!");
@@ -530,6 +549,48 @@ void LoopInfoBase<BlockT, LoopT>::verify
assert(Loops.count(L) && "orphaned loop");
assert(L->contains(BB) && "orphaned block");
}
+
+ // Recompute LoopInfo to verify loops structure.
+ LoopInfoBase<BlockT, LoopT> OtherLI;
+ OtherLI.analyze(DomTree);
+
+ DenseMap<BlockT *, const LoopT *> LoopHeaders1;
+ DenseMap<BlockT *, const LoopT *> LoopHeaders2;
+
+ for (LoopT *L : *this)
+ addInnerLoopsToHeadersMap(LoopHeaders1, *this, *L);
+ for (LoopT *L : OtherLI)
+ addInnerLoopsToHeadersMap(LoopHeaders2, OtherLI, *L);
+ assert(LoopHeaders1.size() == LoopHeaders2.size() &&
+ "LoopInfo is incorrect.");
+
+ auto compareLoops = [&](const LoopT *L1, const LoopT *L2) {
+ BlockT *H1 = L1->getHeader();
+ BlockT *H2 = L2->getHeader();
+ if (H1 != H2)
+ return false;
+ std::vector<BlockT *> BB1 = L1->getBlocks();
+ std::vector<BlockT *> BB2 = L2->getBlocks();
+ if (!compareVectors(BB1, BB2))
+ return false;
+
+ std::vector<BlockT *> SubLoopHeaders1;
+ std::vector<BlockT *> SubLoopHeaders2;
+ for (LoopT *L : *L1)
+ SubLoopHeaders1.push_back(L->getHeader());
+ for (LoopT *L : *L2)
+ SubLoopHeaders2.push_back(L->getHeader());
+
+ if (!compareVectors(SubLoopHeaders1, SubLoopHeaders2))
+ return false;
+ return true;
+ };
+
+ for (auto &I : LoopHeaders1) {
+ BlockT *H = I.first;
+ bool LoopsMatch = compareLoops(LoopHeaders1[H], LoopHeaders2[H]);
+ assert(LoopsMatch && "LoopInfo is incorrect.");
+ }
#endif
}
Modified: llvm/trunk/lib/Analysis/LoopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LoopInfo.cpp?rev=280280&r1=280279&r2=280280&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LoopInfo.cpp (original)
+++ llvm/trunk/lib/Analysis/LoopInfo.cpp Wed Aug 31 14:26:19 2016
@@ -703,8 +703,10 @@ void LoopInfoWrapperPass::verifyAnalysis
// -verify-loop-info option can enable this. In order to perform some
// checking by default, LoopPass has been taught to call verifyLoop manually
// during loop pass sequences.
- if (VerifyLoopInfo)
- LI.verify();
+ if (VerifyLoopInfo) {
+ auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+ LI.verify(DT);
+ }
}
void LoopInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
@@ -719,7 +721,8 @@ void LoopInfoWrapperPass::print(raw_ostr
PreservedAnalyses LoopVerifierPass::run(Function &F,
FunctionAnalysisManager &AM) {
LoopInfo &LI = AM.getResult<LoopAnalysis>(F);
- LI.verify();
+ auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
+ LI.verify(DT);
return PreservedAnalyses::all();
}
Modified: llvm/trunk/lib/Transforms/Scalar/LoopDistribute.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopDistribute.cpp?rev=280280&r1=280279&r2=280280&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopDistribute.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopDistribute.cpp Wed Aug 31 14:26:19 2016
@@ -742,7 +742,7 @@ public:
DEBUG(Partitions.printBlocks());
if (LDistVerify) {
- LI->verify();
+ LI->verify(*DT);
DT->verifyDomTree();
}
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