[llvm-commits] [llvm] r90507 - /llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp

[Chris Lattner]

Author: lattner
Date: Thu Dec  3 19:03:32 2009
New Revision: 90507

URL: http://llvm.org/viewvc/llvm-project?rev=90507&view=rev
Log:
add an assert to make it really clear what this is doing.  Return singularval as
a compile time perf optimization to avoid a load.

Modified:
    llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp

Modified: llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp?rev=90507&r1=90506&r2=90507&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SSAUpdater.cpp Thu Dec  3 19:03:32 2009
@@ -295,10 +295,14 @@
       InsertedVal = SingularValue;
     }
 
+    // Either path through the 'if' should have set insertedVal -> SingularVal.
+    assert((InsertedVal == SingularValue || isa<UndefValue>(InsertedVal)) &&
+           "RAUW didn't change InsertedVal to be SingularVal");
+
     // Drop the entries we added in IncomingPredInfo to restore the stack.
     IncomingPredInfo.erase(IncomingPredInfo.begin()+FirstPredInfoEntry,
                            IncomingPredInfo.end());
-    return InsertedVal;
+    return SingularValue;
   }
 
   // Otherwise, we do need a PHI: insert one now if we don't already have one.