From: Chris Lattner <sabre@nondot.org>
Date: Thu, 26 Nov 2009 16:52:32 +0000 (+0000)
Subject: resolve a fixme.  I haven't figured out how to write a testcase
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5369250b73e172efe886b20bfcdab74e5b251a71;p=oota-llvm.git

resolve a fixme.  I haven't figured out how to write a testcase
to exercise this though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89954 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index f8d8873c4f6..c038b207058 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -400,7 +400,7 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset,
         V = GetLinearExpression(BOp->getOperand(0), Scale, Offset, TD);
         Offset += RHSC->getValue();
         return V;
-      // TODO: SHL, MUL, OR.
+      // TODO: SHL, MUL.
       }
     }
   }
@@ -610,10 +610,9 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, unsigned V1Size,
     // Check to see if these two pointers are related by the getelementptr
     // instruction.  If one pointer is a GEP with a non-zero index of the other
     // pointer, we know they cannot alias.
-    //
-    // FIXME: The check below only looks at the size of one of the pointers, not
-    // both, this may cause us to miss things.
-    if (V1Size == ~0U || V2Size == ~0U)
+
+    // If both accesses are unknown size, we can't do anything useful here.
+    if (V1Size == ~0U && V2Size == ~0U)
       return MayAlias;
 
     AliasResult R = aliasCheck(UnderlyingV1, ~0U, V2, V2Size);