[llvm-commits] [llvm] r106872 - /llvm/trunk/lib/Analysis/ScalarEvolution.cpp

[Dan Gohman]

Author: djg
Date: Fri Jun 25 13:47:08 2010
New Revision: 106872

URL: http://llvm.org/viewvc/llvm-project?rev=106872&view=rev
Log:
Eliminate a redundant FoldingSet lookup.

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

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=106872&r1=106871&r2=106872&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Fri Jun 25 13:47:08 2010
@@ -845,9 +845,9 @@
     return getAddRecExpr(Operands, AddRec->getLoop());
   }
 
-  // The cast wasn't folded; create an explicit cast node.
-  // Recompute the insert position, as it may have been invalidated.
-  if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
+  // The cast wasn't folded; create an explicit cast node. We can reuse
+  // the existing insert position since if we get here, we won't have
+  // made any changes which would invalidate it.
   SCEV *S = new (SCEVAllocator) SCEVTruncateExpr(ID.Intern(SCEVAllocator),
                                                  Op, Ty);
   UniqueSCEVs.InsertNode(S, IP);