This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: contribution
- From: Alexey Starovoytov <starlex at eng dot sun dot com>
- To: Andi Kleen <ak at suse dot de>
- Cc: <gcc at gcc dot gnu dot org>
- Date: Fri, 12 Apr 2002 10:54:44 -0700 (PDT)
- Subject: Re: contribution
- Reply-to: Alexey Starovoytov <stork at sun dot com>
On 12 Apr 2002, Andi Kleen wrote:
> Alexey Starovoytov <starlex@eng.sun.com> writes:
>
> > For example SPECfp benchmark 172.mgrid showed 48% improvement
> > compiled with "-O2 -Ws,-O2,-fno-strict-aliasing" vs plain GCC with "-O2"
>
> You could compiled 172.mgrid with gcc twice this way and it showed 48%
> improvement ? Or did you use a different compiler as backend?
It was gcc3.0.4 as a backend.
Environment:
US2 450Mhz Solaris 2.8
gcc_3.0.4 -O2:
Success 172.mgrid ratio=59.73, runtime=3013.766979
GCC_3.0.4 -> C -> GCC_3.0.4 -O2 -Ws,-O2,-fno-strict-aliasing
Success 172.mgrid ratio=88.55, runtime=2032.768725
GCC_3.1 -> C -> GCC_3.0.4 -O2 -Ws,-O2,-fno-strict-aliasing
Success 172.mgrid ratio=98.22, runtime=1832.557732
> If you used gcc - is it known where that huge difference comes from?
I didn't have time to check.
Best regards,
Alexey.