new register allocator and HARD_REGNO_CALL_PART_CLOBBERED

[Alexandre Oliva]

On May 15, 2003, Michael Matz <matz@suse.de> wrote:

> Sure.  But then I would explicitely add the necessary clobbers (of
> subregs) to the call instructions, explicitely stating what happens,
> namely that some register parts will be destroyed, instead of an
> abstraction like HARD_REGNO_CALL_PART_CLOBBERED.  At least for clobbers
> which can change per call.

Clobbering a subreg will still affects the entire register, if
BITS_PER_WORD is defined properly, so this is not an option.  Besides,
you don't want to pollute calls with clobbers, otherwise why would we
have CALL_USED_REGISTERS in the first place?

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
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CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
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