From: Ian Lance Taylor <iant@google.com>
To: Anatoly Sokolov <aesok@post.ru>
Cc: gcc-patches@gcc.gnu.org, rth@redhat.com, chertykov@gmail.com
Subject: Re: Add more restriction in 'peep2_find_free_register'
Date: Wed, 18 Jun 2008 14:47:00 -0000 [thread overview]
Message-ID: <m3r6au245m.fsf@google.com> (raw)
In-Reply-To: <113229086.20080618021412@post.ru> (Anatoly Sokolov's message of "Wed\, 18 Jun 2008 02\:14\:12 +0400")
Anatoly Sokolov <aesok@post.ru> writes:
> This patch add two more check in 'peep2_find_free_register' function, which
> find free hard registers for use as scratch registers in peephole2.
>
> * It is not allowed to use register that are being declared as global, as
> scratch register.
>
> * For an interrupt function it is safety to use only call-used registers
> which are saved in prologue. In 'rename_registers' optimization pass this
> check is done in HARD_REGNO_RENAME_OK macro. This patch add
> HARD_REGNO_SCRATCH_OK macro for 'peephole2' pass. The
> HARD_REGNO_SCRATCH_OK macro sould be difined for target which use interrupt
> and 'match_scratch' in peephole2 (avr, m68k).
Please make a new target hook instead (I know that the existing
HARD_REGNO_RENAME_OK is still a macro). Thanks.
Ian
next prev parent reply other threads:[~2008-06-18 14:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-17 22:26 Anatoly Sokolov
2008-06-18 14:47 ` Ian Lance Taylor [this message]
2008-06-19 15:36 ` Anatoly Sokolov
2008-06-30 21:02 ` Ian Lance Taylor
2008-06-18 22:10 Anatoly Sokolov
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