[llvm] r278646 - [ScopedNoAliasAA] Only collect noalias nodes if we have alias.scope nodes

[David Majnemer via llvm-commits]

Author: majnemer
Date: Sun Aug 14 21:23:50 2016
New Revision: 278646

URL: http://llvm.org/viewvc/llvm-project?rev=278646&view=rev
Log:
[ScopedNoAliasAA] Only collect noalias nodes if we have alias.scope nodes

No functional change is intended.

Modified:
    llvm/trunk/lib/Analysis/ScopedNoAliasAA.cpp

Modified: llvm/trunk/lib/Analysis/ScopedNoAliasAA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScopedNoAliasAA.cpp?rev=278646&r1=278645&r2=278646&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScopedNoAliasAA.cpp (original)
+++ llvm/trunk/lib/Analysis/ScopedNoAliasAA.cpp Sun Aug 14 21:23:50 2016
@@ -151,12 +151,14 @@ bool ScopedNoAliasAAResult::mayAliasInSc
   // We alias unless, for some domain, the set of noalias scopes in that domain
   // is a superset of the set of alias scopes in that domain.
   for (const MDNode *Domain : Domains) {
-    SmallPtrSet<const MDNode *, 16> NANodes, ScopeNodes;
-    collectMDInDomain(NoAlias, Domain, NANodes);
+    SmallPtrSet<const MDNode *, 16> ScopeNodes;
     collectMDInDomain(Scopes, Domain, ScopeNodes);
     if (ScopeNodes.empty())
       continue;
 
+    SmallPtrSet<const MDNode *, 16> NANodes;
+    collectMDInDomain(NoAlias, Domain, NANodes);
+
     // To not alias, all of the nodes in ScopeNodes must be in NANodes.
     bool FoundAll = true;
     for (const MDNode *SMD : ScopeNodes)