Bug#572746: libm: sinf/cosf performance is awful on amd64
On 2010-03-21 20:55:01 +0100, Aurelien Jarno wrote:
> On Sun, Mar 21, 2010 at 04:30:36PM +0100, Vincent Lefevre wrote:
> > Actually the sincos() function uses the x87 FPU (fsincos instruction),
> > so that's not surprising that you get the same result.
>
> That just means that the precision is not an argument for switching to
> the x87 FPU version, contrary to what your first email suggested. Both
> are wrong.
My e-mail didn't suggest that. On the contrary, the glibc sincos()
implementation shouldn't use the x87 FPU version, but should use
the generic C implementation (like sin and cos) instead.
--
Vincent Lefèvre <vincent@vinc17.net> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)
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