To: Miles Bader <miles@cogsci.edinburgh.ac.uk>
Subject: Re: code-quality nit #297343 
Fcc: out-copy
In-reply-to: Your message of Fri, 22 Nov 91 19:23:28 +0000.
             <13999.9111221923@oliphant.cogsci.ed.ac.uk> 
--------

   The below looks like a really botched job of inlining something; is
   %primitive done at a really low level or something?

At a low enough level level that type inference doesn't really know what is
going on.  The problem here is that the compiler doesn't fully realize that
this %PRIMITIVE call always returns one value, so it is going though a
song-and-dance of computing the number of values and then seeing if it is
1.

If you wrap (truly-the t ...) around this call, then the code is much more
sensible.

In fact, for %PRIMITIVE to work in general, you *must* wrap a TRULY-THE
around the form to specify the result type.  Otherwise, obscure internal
errors in representation selection result when you try to return an
integer, float, or other value with a non-descriptor representation.

  Rob