Issue: ARRAY-TYPE-ELEMENT-TYPE-SEMANTICS (Version 9)

[Glenn S. Burke <gsb@ALDERAAN.SCRC.Symbolics.COM>]

    Date: Wed, 11 Jan 89 17:48:32 PST
    From: Jon L White <jonl@lucid.com>

    re: As I think about it, I'm not sure why we rule out the possibility that the
	upgrading of arrays might happen differently for different arrays: for
	example, I might have an algorithm that "upgraded" all simple
	non-adjustable arrays with ARRAY-TOTAL-SIZE less than 2 to ELEMENT-TYPE T,
	but be more strict about larger arrays. 

    Lucid would certainly oppose that change.  Our compiler optimizations
    work on simple-arrays of known element type; and good reasons exist
    as to why the simple/non-simple distinction and the element-type
    distinctions are important (other "stock hardware" implmentations 
    have similar open-coding techniques).  I see no benefit to further 
    discrimination based on rank or array total size.


    -- JonL --

Right.  If you can't determine the upgraded type from a declaration, the
declaration is next to useless.  (It just is not reasonable to have to,
for instance, know the size of an array in order to be able to determine
how to access it.)