Re: PATCH][RFC][resend] CC_OPTIMIZE_FOR_SIZE should default to N

Andi Kleen
2011-03-23T17:47:22Z

Linus Torvalds <torvalds@linux-foundation.org> writes:

> On Tue, Mar 22, 2011 at 3:27 AM, Ingo Molnar <mingo@elte.hu> wrote:
>>
>> If that situation has changed - if GCC has regressed in this area then a commit
>> changing the default IMHO gains a lot of credibility if it is backed by careful
>> measurements using perf stat --repeat or similar tools.
>
> Also, please don't back up any numbers for the "-O2 is faster than
> -Os" case with some benchmark that is hot in the caches.

Haven't done it recently, but some time last year -O2 vs -Os
made a measurable difference in large OLTP benchmarks.

(-Os being worse of course -- friends don't let friends use -Os)

-Andi
--
ak@linux.intel.com -- Speaking for myself only