diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -9564,8 +9564,8 @@
 
   ASTContext::BuiltinVectorTypeInfo Info = Context.getBuiltinVectorTypeInfo(Ty);
 
-  unsigned EltSize = Context.getTypeSize(Info.ElementType);
-  unsigned MinElts = Info.EC.getKnownMinValue();
+  uint64_t EltSize = Context.getTypeSize(Info.ElementType);
+  uint64_t MinElts = Info.EC.getKnownMinValue();
   return VScale->first * MinElts * EltSize;
 }