[llvm] r330698 - [LoopInfo] Verify BBMap tracks innermost loops for BBs.

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Tue Apr 24 02:10:05 2018
New Revision: 330698

URL: http://llvm.org/viewvc/llvm-project?rev=330698&view=rev
Log:
[LoopInfo] Verify BBMap tracks innermost loops for BBs.

By checking that none of the child loops contain a BB we make sure BBMap
contains the innermost loop defining BB. This invariant was violated in
LoopInterchange and got caught by this assertion.

Reviewers: chandlerc, mzolotukhin, sanjoy, mehdi_amini, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D45971

Modified:
    llvm/trunk/include/llvm/Analysis/LoopInfo.h
    llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h

Modified: llvm/trunk/include/llvm/Analysis/LoopInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfo.h?rev=330698&r1=330697&r2=330698&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfo.h Tue Apr 24 02:10:05 2018
@@ -178,6 +178,12 @@ public:
     return DenseBlockSet;
   }
 
+  /// Return a direct, immutable handle to the blocks set.
+  const SmallPtrSetImpl<const BlockT *> &getBlocksSet() const {
+    assert(!isInvalid() && "Loop not in a valid state!");
+    return DenseBlockSet;
+  }
+
   /// Return true if this loop is no longer valid.  The only valid use of this
   /// helper is "assert(L.isInvalid())" or equivalent, since IsInvalid is set to
   /// true by the destructor.  In other words, if this accessor returns true,

Modified: llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h?rev=330698&r1=330697&r2=330698&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfoImpl.h Tue Apr 24 02:10:05 2018
@@ -617,6 +617,15 @@ static void compareLoops(const LoopT *L,
   std::vector<BlockT *> OtherBBs = OtherL->getBlocks();
   assert(compareVectors(BBs, OtherBBs) &&
          "Mismatched basic blocks in the loops!");
+
+  const SmallPtrSetImpl<const BlockT *> &BlocksSet = L->getBlocksSet();
+  const SmallPtrSetImpl<const BlockT *> &OtherBlocksSet = L->getBlocksSet();
+  assert(BlocksSet.size() == OtherBlocksSet.size() &&
+         std::all_of(BlocksSet.begin(), BlocksSet.end(),
+                     [&OtherBlocksSet](const BlockT *BB) {
+                       return OtherBlocksSet.count(BB);
+                     }) &&
+         "Mismatched basic blocks in BlocksSets!");
 }
 #endif
 
@@ -636,6 +645,9 @@ void LoopInfoBase<BlockT, LoopT>::verify
     LoopT *L = Entry.second;
     assert(Loops.count(L) && "orphaned loop");
     assert(L->contains(BB) && "orphaned block");
+    for (LoopT *ChildLoop : *L)
+      assert(!ChildLoop->contains(BB) &&
+             "BBMap should point to the innermost loop containing BB");
   }
 
   // Recompute LoopInfo to verify loops structure.