From: Bernd Schmidt <bschmidt@redhat.com>
To: Eric Botcazou <ebotcazou@adacore.com>,
David Edelsohn <dje.gcc@gmail.com>
Cc: gcc-patches@gcc.gnu.org,
Richard Biener <richard.guenther@gmail.com>,
Jeffrey Law <law@redhat.com>,
Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: Enabling -frename-registers?
Date: Wed, 04 May 2016 10:11:00 -0000 [thread overview]
Message-ID: <5729CAB8.8040805@redhat.com> (raw)
In-Reply-To: <2317874.CXT2IFrHHt@polaris>
On 05/04/2016 12:03 PM, Eric Botcazou wrote:
>> The IBM LTC team has tested the benefit of -frename-registers at -O2
>> and sees no net benefit for PowerPC -- some benchmarks improve
>> slightly but others degrade slightly (a few percent). You mentioned
>> no overall benefit for x86. Although you mentioned benefit for
>> Itanium, it is not a primary nor secondary architecture target for GCC
>> and continues to have limited adoption. Andreas also reported a
>> bootstrap comparison failure for Itanium due to the change.
>
> ...which had nothing to do with -frename-registers but was a latent issue in
> the speculation support of the scheduler, see the audit trail.
Yeah, I'd forgotten to add this to the list of issues found. Also,
Alan's morestack representation issue.
Given how many latent bugs it has shown up I think that alone would make
it valuable to have enabled at -O2.
Bernd
next prev parent reply other threads:[~2016-05-04 10:11 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-29 13:02 David Edelsohn
2016-04-29 13:33 ` Bernd Schmidt
2016-04-29 13:42 ` David Edelsohn
2016-04-29 13:44 ` Bernd Schmidt
2016-04-29 13:48 ` David Edelsohn
2016-04-29 14:21 ` Richard Biener
2016-04-30 7:57 ` Andreas Schwab
2016-05-03 21:26 ` David Edelsohn
2016-05-03 22:53 ` Bernd Schmidt
2016-05-03 23:09 ` David Edelsohn
2016-05-04 8:39 ` Richard Biener
2016-05-04 9:05 ` Alan Modra
2016-05-04 9:08 ` Bernd Schmidt
2016-05-04 9:38 ` Alan Modra
2016-05-04 10:03 ` Eric Botcazou
2016-05-04 10:11 ` Bernd Schmidt [this message]
2016-05-04 10:26 ` Eric Botcazou
2016-05-04 13:25 ` Ramana Radhakrishnan
2016-05-04 13:37 ` Bernd Schmidt
2016-05-04 13:39 ` Ramana Radhakrishnan
2016-05-04 12:54 ` David Edelsohn
2016-05-04 17:50 ` Segher Boessenkool
2016-04-30 2:14 ` Segher Boessenkool
2016-05-02 13:32 ` Jeff Law
2016-05-11 4:07 ` Jeff Law
-- strict thread matches above, loose matches on Subject: below --
2016-05-04 15:20 Wilco Dijkstra
2016-05-04 19:06 ` Eric Botcazou
2016-05-04 22:55 ` Pat Haugen
2016-05-05 7:42 ` Ramana Radhakrishnan
2016-05-05 13:00 ` Wilco Dijkstra
2016-05-05 16:24 ` Mike Stump
2016-05-02 11:12 Uros Bizjak
2016-05-02 11:15 ` Bernd Schmidt
2016-05-02 11:21 ` Uros Bizjak
2016-05-02 11:58 ` Uros Bizjak
2016-05-02 13:20 ` Bernd Schmidt
2016-05-03 5:30 ` Uros Bizjak
[not found] <56AB9759.407@t-online.de>
2016-01-29 17:34 ` Bernd Schmidt
2016-01-29 18:50 ` Richard Biener
2016-04-17 21:24 ` Jeff Law
2016-04-26 12:44 ` Bernd Schmidt
2016-04-27 7:11 ` Eric Botcazou
2016-04-27 9:58 ` Bernd Schmidt
2016-04-27 10:36 ` Eric Botcazou
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