Re: sparc64 changes and generic backend patches

[Richard Henderson <rth at cygnus dot com>]

On Fri, May 22, 1998 at 01:16:33AM -0600, Jeffrey A Law wrote:
> I'd kind of prefer Jim Wilson and David Edelsohn review this and
> test it a little.  Jim understands the irix issues and probably
> understands the code.  David understands the structure passing
> problems for AIX, I don't know if he understands the group load
> code.

This code went around to them and Kenner back in January, iirc,
Unfortunately, I seem to have lost whatever mail was exchanged,
but I don't recall that much was said.

If I remember the Irix6 and AIX problems correctly, they use a 
subset of the structure promotion rules that Sparc64 does.  It
is complicated by the fact that I think we currently get the
Irix6 rules wrong.

> We've made several attempts to fix these structure passing problems
> over the years, many of them we've found out later were incorrect.

Yes, it the bits involved are rather fragile, unfortunately.

>   > (2) Attachment 2 disables a check in reload not applicable to Sparc's
>   >     32-bit FP regs when considered with a 64-bit word size.
> Ouch.  I thought Joern has some concerns about this patch, have you
> addressed any of them?

Just now I asked for clarification.

>   > (3) Attachment 3 contains a few unidentified fixes I found in my tree.
>   >     Most of it consists of propogating a change made by Jeff
>   > 
>   >     Wed Dec 31 01:28:37 1997  Jeff Law  <law@cygnus.com>
>   > 
>   > 	* expr.c (expand_expr): For {BITFIELD,COMPONENT,ARRAY}_REF, if the
>   > 	offset's mode is not ptr_mode, convert it.
> I *vaguely* remember this change.  Wow. I can't remember if I was
> trying to solve an Alpha/VMS or some weird mn10200 problem.
> 
> These changes look reasonable to me.

I'll go ahead and commit these, then.


r~