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From: "David O'Brien" <obrien@freebsd.org>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
Subject: Re: optimization/10189: pentium4 breaks suns libm code for __ieee754_pow(double x, double y)
Date: Wed, 26 Mar 2003 18:06:00 -0000 [thread overview]
Message-ID: <20030326174600.26013.qmail@sources.redhat.com> (raw)
The following reply was made to PR optimization/10189; it has been noted by GNATS.
From: "David O'Brien" <obrien@freebsd.org>
To: ljrittle@gcc.gnu.org, freebsd-current@freebsd.org, gcc-bugs@gcc.gnu.org,
gcc-prs@gcc.gnu.org, nobody@gcc.gnu.org, till@f111.hadiko.de,
gcc-gnats@gcc.gnu.org
Cc:
Subject: Re: optimization/10189: pentium4 breaks suns libm code for __ieee754_pow(double x, double y)
Date: Wed, 26 Mar 2003 09:45:35 -0800
On Wed, Mar 26, 2003 at 01:01:18PM -0000, ljrittle@gcc.gnu.org wrote:
> Synopsis: pentium4 breaks suns libm code for __ieee754_pow(double x, double y)
Beautiful email!!
> Special secret #2: Although the FSF-side does want to improve all
> code generation (and I think proper PRs RE CPU switches will be
> looked at by someone given enough time) be aware that -O2 without
> special arch flags is probably the most stable for any given CPU
> for any given gcc release. Do you really want to trust a kernel
> built with optimization flags and arch flags that near zero or zero
> people have fully tested? Doubtful. However, inline with secret
> #1 and by virtual of being digital, if even one person tests it
> (i.e. yourself) and it appears OK, then it is probably safe to at
> least attempt to build a kernel and run it.
FreeBSD has for years recommended -O[1] vs. -O2. Do you think there is
value in having the GCC test suite runs you do at FreeBSD.org do runs
with both settings? To also do runs with the newer CPU types?
next reply other threads:[~2003-03-26 17:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-03-26 18:06 David O'Brien [this message]
-- strict thread matches above, loose matches on Subject: below --
2003-05-15 14:32 bangerth
2003-03-29 4:06 David O'Brien
2003-03-26 21:27 Alexander Leidinger
2003-03-26 14:02 ljrittle
2003-03-22 12:46 till
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