diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp
--- a/llvm/lib/IR/IntrinsicInst.cpp
+++ b/llvm/lib/IR/IntrinsicInst.cpp
@@ -299,7 +299,8 @@
   };
 
   Value *VPMask = getMaskParam();
-  assert(VPMask && "No mask param?");
+  if (!VPMask)
+    return GetVectorLengthOfType(getType());
   return GetVectorLengthOfType(VPMask->getType());
 }