[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371752 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/AliasSetTracker.cpp b/lib/Analysis/AliasSetTracker.cpp
index a6e5b9fab558d09b6fd3d3da0530443e72ca3c5f..79fbcd464c1b5bda80e2807d7b9fd3829be3ab6a 100644 (file)
--- a/lib/Analysis/AliasSetTracker.cpp
+++ b/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";

diff --git a/test/Transforms/LICM/pr38513.ll b/test/Transforms/LICM/pr38513.ll
new file mode 100644 (file)
index 0000000..ebc2751
--- /dev/null
+++ b/test/Transforms/LICM/pr38513.ll
@@ -0,0 +1,27 @@
+; RUN: opt -enable-mssa-loop-dependency=false -disable-basicaa -alias-set-saturation-threshold=2 -licm -S < %s | FileCheck %s
+; REQUIRES: asserts
+
+; CHECK-LABEL: @f1()
+define void @f1() {
+  %lc1.10 = alloca [3 x i16]
+  br label %bb1
+
+bb1:                                              ; preds = %bb6, %0
+  store i16 undef, i16* undef
+  br label %bb2
+
+bb2:                                              ; preds = %bb8, %bb1
+  %_tmp18.fca.0.gep = getelementptr inbounds [3 x i16], [3 x i16]* %lc1.10, i32 0, i32 0
+  %_tmp18.fca.0.load = load i16, i16* %_tmp18.fca.0.gep
+  %_tmp18.fca.1.gep = getelementptr inbounds [3 x i16], [3 x i16]* %lc1.10, i32 0, i32 1
+  %_tmp18.fca.1.load = load i16, i16* %_tmp18.fca.1.gep
+  %_tmp18.fca.2.gep = getelementptr inbounds [3 x i16], [3 x i16]* %lc1.10, i32 0, i32 2
+  %_tmp18.fca.2.load = load i16, i16* %_tmp18.fca.2.gep
+  br label %bb8
+
+bb8:                                              ; preds = %bb2
+  br i1 undef, label %bb2, label %bb6
+
+bb6:                                              ; preds = %bb8
+  br label %bb1
+}