Date: Wed, 26 Mar 2003 09:45:35 -0800 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 Subject: Re: optimization/10189: pentium4 breaks suns libm code for __ieee754_pow(double x, double y) Message-ID: <20030326174535.GA83816@dragon.nuxi.com> In-Reply-To: <20030326130118.8374.qmail@sources.redhat.com> References: <20030326130118.8374.qmail@sources.redhat.com>
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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?
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