SMALL_REGISTER_CLASSES

[Geoffrey KEATING]

> Date: Sun, 25 Jan 1998 22:20:11 -0700
> From: Jeffrey A Law <law@hurl.cygnus.com>

>   In message < 199801260508.QAA01591@discus.anu.edu.au >you write:
>   > Unfortunately, the user can mention regs explicitly in 'asm'
>   > statements, too.  This causes problems on rs6000, where there are
>   > no small register classes mentioned in the RTL, but users can write
>   > things like
>   > 
>   > asm ("" : : : "cr0");
>   > 
>   > and get 'forbidden register spilled' if a pseudo (in this case, most
>   > likely derived from a "CC" in the RTL) needs a register of that class.
> This is a separate and distinct problem from whether or not a machine
> description should mention registers explicitly in RTL.

I mean,  you still have to define SMALL_REGISTER_CLASSES (or equivalent)
if you have small register classes, whether or not you mention
registers in those classes in the RTL.

--
Geoff Keating <Geoff.Keating@anu.edu.au>