From: Jeff Law <law@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>,
Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>, nd <nd@arm.com>
Subject: Re: [PATCH] Change default optimization level to -Og
Date: Fri, 27 Oct 2017 15:13:00 -0000 [thread overview]
Message-ID: <b436ec91-dd58-5ed1-9d2a-3702f3193995@redhat.com> (raw)
In-Reply-To: <20171026195026.GW14653@tucnak>
On 10/26/2017 01:50 PM, Jakub Jelinek wrote:
> On Thu, Oct 26, 2017 at 05:12:40PM +0000, Wilco Dijkstra wrote:
>> GCC's default optimization level is -O0. Unfortunately unlike other compilers,
>> GCC generates extremely inefficient code with -O0. It is almost unusable for
>> low-level debugging or manual inspection of generated code. So a -O option is
>> always required for compilation. -Og not only allows for fast compilation, but
>> also produces code that is efficient, readable as well as debuggable.
>> Therefore -Og makes for a much better default setting.
>>
>> Any comments?
>>
>> 2017-10-26 Wilco Dijkstra <wdijkstr@arm.com>
>>
>> * opts.c (default_options_optimization): Set default to -Og.
>>
>> doc/
>> * invoke.texi (-O0) Remove default mention.
>> (-Og): Add mention of default setting.
>
> This would only severely confuse users. -Og has lots of unresolved issues
> for debugging experience, and changing the default this way is IMHO
> extremely undesirable.
And changing a default that has been in place for 30 years just seems
unwise at this point.
jeff
next prev parent reply other threads:[~2017-10-27 15:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-26 17:13 Wilco Dijkstra
2017-10-26 18:20 ` Eric Gallager
2017-10-30 19:23 ` Eric Gallager
2017-10-26 19:50 ` Eric Botcazou
2017-10-26 19:57 ` Jakub Jelinek
2017-10-27 15:13 ` Jeff Law [this message]
2017-10-27 6:50 ` Andrew Pinski
2017-10-27 13:04 ` Wilco Dijkstra
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