Fix PR2358 by resolving calls with undef arguments to overdefined.

llvm-svn: 51535

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 79cda33f793..da715acd29b 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1370,6 +1370,12 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
         else
           markOverdefined(LV, I);
         return true;
+      case Instruction::Call:
+        // If a call has an undef result, it is because it is constant foldable
+        // but one of the inputs was undef.  Just force the result to
+        // overdefined.
+        markOverdefined(LV, I);
+        return true;
       }
     }