RE: [Patch,AVR] Fix PR46278, Take #3

["Weddington, Eric" <Eric dot Weddington at atmel dot com>]

> -----Original Message-----
> From: Georg-Johann Lay [mailto:avr@gjlay.de]
> Sent: Thursday, October 13, 2011 8:32 AM
> To: gcc-patches@gcc.gnu.org
> Cc: Anatoly Sokolov; Denis Chertykov; Weddington, Eric
> Subject: [Patch,AVR] Fix PR46278, Take #3
> 
> This is yet another attempt to fix PR46278 (fake X addressing).
> 
> After the previous clean-ups it is just a small change.
> 
> caller-saves.c tries to eliminate call-clobbered hard-regs allocated
to
> pseudos
> around function calls and that leads to situations that reload is no
more
> capable to perform all requested spills because of the very few AVR's
> address
> registers.
> 
> Thus, the patch adds a new target option -mstrict-X so that the user
can
> turn
> that option if he like to do so, and then -fcaller-save is disabled.
> 
> The patch passes the testsuite without regressions. Moreover, the
> testsuite
> passes without regressions if all test cases are run with -mstrict-X
and
> all
> libraries (libgcc, avr-libc) are built with the new option turned on.

Hi Johann,

Sorry, I haven't been keeping up with the discussion on this PR.

But if all test cases pass with running -mstrict-X and everything built
with that option on, then why is this even an option? Is it because that
it may not always reduce code size?...

Thanks,
Eric