Index: llvm/include/llvm/CodeGen/BasicTTIImpl.h
===================================================================
--- llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -1204,7 +1204,7 @@
         // In practice it's not currently possible to have a change in lane
         // length for extending loads or truncating stores so both types should
         // have the same scalable property.
-        TypeSize::isKnownLT(Src->getPrimitiveSizeInBits(),
+        TypeSize::isKnownLT(DL.getTypeStoreSizeInBits(Src),
                             LT.second.getSizeInBits())) {
       // This is a vector load that legalizes to a larger type than the vector
       // itself. Unless the corresponding extending load or truncating store is