0.8.1.34:

[sbcl.git] / src / compiler / generic / vm-type.lisp

diff --git a/src/compiler/generic/vm-type.lisp b/src/compiler/generic/vm-type.lisp
index cde035f..f432393 100644 (file)
--- a/src/compiler/generic/vm-type.lisp
+++ b/src/compiler/generic/vm-type.lisp
@@ -124,6 +124,16 @@
                    (return stype))))))
     type))
 
+(defun sb!xc:upgraded-array-element-type (spec &optional environment)
+  #!+sb-doc
+  "Return the element type that will actually be used to implement an array
+   with the specifier :ELEMENT-TYPE Spec."
+  (declare (ignore environment))
+  (if (unknown-type-p (specifier-type spec))
+      (error "undefined type: ~S" spec)
+      (type-specifier (array-type-specialized-element-type
+                      (specifier-type `(array ,spec))))))
+
 ;;; Return the most specific integer type that can be quickly checked that
 ;;; includes the given type.
 (defun containing-integer-type (subtype)