Saving to 32 bits of GPRs in signal context

[Segher Boessenkool]

>  > We don't need another ABI change to powerpc32 (still recovering 
> from the
>  > -msecure-plt ABI change) and WE DONT NEED a 3rd ABI.
>  >
>  > ABI changes ripple everywhere (not just GCC/GLIBC) including all 
> debuggers
>  > and performance tools. Believe me you really don't want this.
>
> Fully agreed.  This may have gotten lost in the discussion thread, but 
> what
> Ben originally proposed was *not* an ABI change, for exactly that 
> reason.
> We simply want to allow strictly local use of 64-bit registers for
> performance optimization purposes, while still fully complying with
> the 32-bit ABI.

Some stuff gets added to the user version of the signal
frame; is that not an ABI change?  Quite possibly a
(supposedly) compatible change, but a change anyway.


Segher