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Re: large peephole2 speedup.
- To: Zack Weinberg <zack at wolery dot cumb dot org>
- Subject: Re: large peephole2 speedup.
- From: Richard Henderson <rth at cygnus dot com>
- Date: Tue, 11 Apr 2000 16:00:06 -0700
- Cc: gcc-patches at gcc dot gnu dot org
- References: <20000409102545.E9400@wolery.cumb.org>
On Sun, Apr 09, 2000 at 10:25:45AM -0700, Zack Weinberg wrote:
> This patch changes the peephole2 optimizer so that it uses flow.c
> routines to determine live registers, rather than resource.c.
Whee.
> Note that find_free_register no longer has
> the ability to determine if a register remains available till later;
> no existing peephole needed that.
Bad, and not entirely true. You can see one such example in
the D30V on condexec-branch. We do still need the ability to
ask live/dead questions at any point in the matched sequence.
r~