[llvm-commits] CVS: llvm/lib/Analysis/BasicAliasAnalysis.cpp

[Chris Lattner]

Changes in directory llvm/lib/Analysis:

BasicAliasAnalysis.cpp updated: 1.50 -> 1.51

---
Log message:

Fix test/Regression/Analysis/BasicAA/2004-07-28-MustAliasbug.llx

This also fixes the miscompilation of MallocBench/gs with dead store
elimination enabled.


---
Diffs of the changes:  (+9 -5)

Index: llvm/lib/Analysis/BasicAliasAnalysis.cpp
diff -u llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.50 llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.51
--- llvm/lib/Analysis/BasicAliasAnalysis.cpp:1.50	Mon Jul 26 21:18:52 2004
+++ llvm/lib/Analysis/BasicAliasAnalysis.cpp	Thu Jul 29 02:56:39 2004
@@ -322,11 +322,15 @@
       BasePtr1 = GetGEPOperands(V1, GEP1Ops);
       BasePtr2 = GetGEPOperands(V2, GEP2Ops);
 
-      AliasResult GAlias =
-        CheckGEPInstructions(BasePtr1->getType(), GEP1Ops, V1Size,
-                             BasePtr2->getType(), GEP2Ops, V2Size);
-      if (GAlias != MayAlias)
-        return GAlias;
+      // If GetGEPOperands were able to fold to the same must-aliased pointer,
+      // do the comparison.
+      if (BasePtr1 == BasePtr2) {
+        AliasResult GAlias =
+          CheckGEPInstructions(BasePtr1->getType(), GEP1Ops, V1Size,
+                               BasePtr2->getType(), GEP2Ops, V2Size);
+        if (GAlias != MayAlias)
+          return GAlias;
+      }
     }
   }