[LICM/AST] Check if the AliasAny set is removed from the tracker.

Summary:
Resolves PR38513.
Credit to @bjope for debugging this.

Reviewers: hfinkel, uabelho, bjope

Subscribers: sanjoy.google, bjope, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67417

llvm-svn: 371752

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/AliasSetTracker.cpp b/llvm/lib/Analysis/AliasSetTracker.cpp
index a6e5b9fab55..79fbcd464c1 100644
--- a/llvm/lib/Analysis/AliasSetTracker.cpp
+++ b/llvm/lib/Analysis/AliasSetTracker.cpp
@@ -119,6 +119,12 @@ void AliasSetTracker::removeAliasSet(AliasSet *AS) {
         TotalMayAliasSetSize -= AS->size();
 
   AliasSets.erase(AS);
+  // If we've removed the saturated alias set, set saturated marker back to
+  // nullptr and ensure this tracker is empty.
+  if (AS == AliasAnyAS) {
+    AliasAnyAS = nullptr;
+    assert(AliasSets.empty() && "Tracker not empty");
+  }
 }
 
 void AliasSet::removeFromTracker(AliasSetTracker &AST) {
@@ -690,8 +696,10 @@ void AliasSet::print(raw_ostream &OS) const {
 }
 
 void AliasSetTracker::print(raw_ostream &OS) const {
-  OS << "Alias Set Tracker: " << AliasSets.size() << " alias sets for "
-     << PointerMap.size() << " pointer values.\n";
+  OS << "Alias Set Tracker: " << AliasSets.size();
+  if (AliasAnyAS)
+    OS << " (Saturated)";
+  OS << " alias sets for " << PointerMap.size() << " pointer values.\n";
   for (const AliasSet &AS : *this)
     AS.print(OS);
   OS << "\n";