[PATCH] Add VSX fmaxf/fminf optimization on rs6000

[David Edelsohn]

On Fri, Oct 22, 2010 at 4:26 PM, Michael Meissner
<meissner@linux.vnet.ibm.com> wrote:
> I've carried the following patch in my sandbox for the next round of floating
> point conversion fixes for some time, and I'm submitting it as a stand alone
> patch.  On VSX power systems, scalar single precision floating point values are
> kept internally as double precision.  For min/max, there is no need to do a
> rounding step, since the compiler believes both values are single precision, so
> we can use the double precision min/max instructions instead of doing a
> floating point compare and select.
>
> I've done a bootstrap and make check with no regressions.  Is it ok to install
> this patch?
>
> [gcc]
> 2010-10-22  Michael Meissner  <meissner@linux.vnet.ibm.com>
>
>        * config/rs6000/rs6000.c (rs6000_emit_minmax): Add support to use
>        xsmindp/xsmaxdp on VSX for single precision min/max.
>        * config/rs6000/vsx.md (vsx_smaxsf3): Ditto.
>        (vsx_sminsf3): Ditto.
>
> [gcc/testsuite]
> 2010-10-22  Michael Meissner  <meissner@linux.vnet.ibm.com>
>
>        * gcc.target/powerpc/vsx-sfminmax.c: New test for using double
>        precision min/max for single precision on VSX.

Okay.

Thanks, David