Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA
Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!think!harvard!seismo!brl-tgr!tgr!cottrell@nbs-vms.arpa
From: cottrell@nbs-vms.arpa (COTTRELL, JAMES)
Newsgroups: net.lang.c
Subject: Code Generation
Message-ID: <3457@brl-tgr.ARPA>
Date: Wed, 20-Nov-85 17:42:11 EST
Article-I.D.: brl-tgr.3457
Posted: Wed Nov 20 17:42:11 1985
Date-Received: Sat, 23-Nov-85 01:49:30 EST
Sender: news@brl-tgr.ARPA
Lines: 22

/* Key: >> Ron Natalie, > Chris Torek
> > It doesn't ignore register short definitions, it mearly does not put them
> > in registers because registers can only be applied to types int and long
> > on VAX.
> 
> You can indeed apply
> registers to `short's and `char's and even `float's and `double's;
> it is merely much more difficult to get the code generation right.

Why is that? For the moment lets forget about the floating types.
From the way I read my manual, using the byte & word flavors of
instruxions makes the registers appear to be 8 & 16 bits wide.
So what's so difficult about that.

To put it another way, write a fragment of code using ints, run it
thru `cc -S'. Then change the `ints' to `shorts'. Now I claim I should
be able to get equivalent (more efficient tho) code merely by changing
the flavors of the instruxions from `long' to `word'. Prove me wrong.

	jim		cottrell@nbs
*/
------