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From: Richard Sandiford <rdsandiford@googlemail.com>
To: Robert Suchanek <Robert.Suchanek@imgtec.com>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>,
	 "Catherine_Moore\@mentor.com"	<Catherine_Moore@mentor.com>,
	 "gcc-patches\@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] Disable -mbranch-likely for -Os when targetting generic architecture
Date: Thu, 20 Aug 2015 20:15:00 -0000	[thread overview]
Message-ID: <87y4h5iuwd.fsf@googlemail.com> (raw)
In-Reply-To: <B5E67142681B53468FAF6B7C31356562441B05F4@hhmail02.hh.imgtec.org>	(Robert Suchanek's message of "Fri, 14 Aug 2015 12:21:01 +0000")

Robert Suchanek <Robert.Suchanek@imgtec.com> writes:
> The patch below disables generation of the branch likely instructions for -Os
> but only for generic architecture.  The branch likely may result in some
> code size reduction but the cost of running the code on R6 core is significant.

How about instead splitting PTF_AVOID_BRANCHLIKELY into
PTF_AVOID_BRANCHLIKELY_SPEED and PTF_AVOID_BRANCHLIKELY_SIZE?
We could have PTF_AVOID_BRANCHLIKELY_ALWAYS as an OR of the two.

Anything that does string ops on the architecture is suspicious :-)

Thanks,
Richard

  reply	other threads:[~2015-08-20 20:10 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-14 13:14 Robert Suchanek
2015-08-20 20:15 ` Richard Sandiford [this message]
2015-08-20 21:52   ` Matthew Fortune
2015-09-04 14:29     ` Robert Suchanek
2015-10-22 19:09       ` Moore, Catherine
2016-05-24 15:35         ` Robert Suchanek
2016-09-21 13:32           ` Matthew Fortune
2016-10-11  8:00             ` Robert Suchanek

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