[llvm-commits] [llvm] r130271 - /llvm/trunk/lib/Analysis/ScalarEvolution.cpp

[Andrew Trick]

Author: atrick
Date: Tue Apr 26 20:21:25 2011
New Revision: 130271

URL: http://llvm.org/viewvc/llvm-project?rev=130271&view=rev
Log:
Fix for PR9633 [indvars] Assertion `isa<X>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

Added a type check in ScalarEvolution::computeSCEVAtScope to handle the case in which operands of an
AddRecExpr in the current scope are folded.

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=130271&r1=130270&r2=130271&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Tue Apr 26 20:21:25 2011
@@ -4701,9 +4701,14 @@
       for (++i; i != e; ++i)
         NewOps.push_back(getSCEVAtScope(AddRec->getOperand(i), L));
 
-      AddRec = cast<SCEVAddRecExpr>(
+      const SCEV *FoldedRec =
         getAddRecExpr(NewOps, AddRec->getLoop(),
-                      AddRec->getNoWrapFlags(SCEV::FlagNW)));
+                      AddRec->getNoWrapFlags(SCEV::FlagNW));
+      AddRec = dyn_cast<SCEVAddRecExpr>(FoldedRec);
+      // In cases with "undef" values, a loop's own recurrence may
+      // fold into a constant. Go ahead and return the optimistic value.
+      if (!AddRec)
+        return FoldedRec;
       break;
     }