From: Segher Boessenkool <segher@kernel.crashing.org>
To: Richard Biener <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] CSE negated multiplications and divisions
Date: Fri, 18 Sep 2020 18:43:52 -0500 [thread overview]
Message-ID: <20200918234352.GY28786@gate.crashing.org> (raw)
In-Reply-To: <nycvar.YFH.7.76.2009171320180.3323@elmra>
Hi!
On Thu, Sep 17, 2020 at 01:20:35PM +0200, Richard Biener wrote:
> This adds the capability to look for available negated multiplications
> and divisions, replacing them with cheaper negates.
It is longer latency than the original insns. Combine will try to undo
this, because of that (it depends on the insn costs if that can
succeed). On gimple it is always cheaper, of course.
Segher
next prev parent reply other threads:[~2020-09-18 23:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-17 11:20 Richard Biener
2020-09-18 12:39 ` Christophe Lyon
2020-09-18 23:43 ` Segher Boessenkool [this message]
2020-09-21 7:16 ` Richard Biener
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