[MemDep] Also remove load instructions from NonLocalDesCache.

Currently load instructions are added to the cache for invariant pointer
group dependencies, but only pointer values are removed currently. That
leads to dangling AssertingVHs in the test case below, where we delete a
load from an invariant pointer group. We should also remove the entries
from the cache.

Fixes PR46054.

Reviewers: efriedma, hfinkel, asbirlea

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D81726

1 files changed, 15 insertions, 5 deletions

diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index 142c7fe30523..566eba5c54af 100644
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -1518,15 +1518,25 @@ void MemoryDependenceResults::removeInstruction(Instruction *RemInst) {
     LocalDeps.erase(LocalDepEntry);
   }
 
-  // If we have any cached pointer dependencies on this instruction, remove
-  // them.  If the instruction has non-pointer type, then it can't be a pointer
-  // base.
+  // If we have any cached dependencies on this instruction, remove
+  // them.
 
-  // Remove it from both the load info and the store info.  The instruction
-  // can't be in either of these maps if it is non-pointer.
+  // If the instruction is a pointer, remove it from both the load info and the
+  // store info.
   if (RemInst->getType()->isPointerTy()) {
     RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
     RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
+  } else {
+    // Otherwise, if the instructions is in the map directly, it must be a load.
+    // Remove it.
+    auto toRemoveIt = NonLocalDefsCache.find(RemInst);
+    if (toRemoveIt != NonLocalDefsCache.end()) {
+      assert(isa<LoadInst>(RemInst) &&
+             "only load instructions should be added directly");
+      const Instruction *DepV = toRemoveIt->second.getResult().getInst();
+      ReverseNonLocalDefsCache.find(DepV)->second.erase(RemInst);
+      NonLocalDefsCache.erase(toRemoveIt);
+    }
   }
 
   // Loop over all of the things that depend on the instruction we're removing.