On 6/1/07, H. J. Lu <[EMAIL PROTECTED]> wrote:
On Fri, Jun 01, 2007 at 09:37:54AM -0700, H. J. Lu wrote:
> The predictive commoning patch:
>
> http://gcc.gnu.org/ml/gcc-patches/2007-05/msg01061.html
>
> miscompiles 482.sphinx3 in SPEC CPU 2006 with -O2 -ffast-math on
> Linux/x86-64. Zdenek, do you have any ideas?
>
Something is wrong. Predictive commoning is supposed to be turned
on at -O3. But it definitely afffects -O2. Why?
Because the patch had other effects like adding a DCE after Copyprop
in the loop optimizer section.
This actually speed up a couple of benchmarks in SPEC 2k too (mgrid
and apsi comes to mind).
Thanks,
Andrew Pinski
