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Re: [PATCH] Improves __ieee754_exp() performance by greater than 5x on sparc/x86.
On Mon, 23 Oct 2017, Patrick McGehearty wrote:
> Now I understand your point and researched the source of the comment and
> reason for the use of "small". By my reading of the ieee754 definition
> of "inexact", exp(x) for any x except 0.0 should set the inexact bit.
However, while that would apply for TS 18661-4 crexp (corresponding
directly to the IEEE 754 exp operation), glibc's accuracy goals for
functions not bound to IEEE operations are as documented in math.texi, and
those do not include correctness in whether "inexact" is raised. (There
is some existing code in glibc to set "inexact" in cases where it's not
necessary to do so. Removing such code would be reasonable cleanups, but
is independent of this exp patch.)
--
Joseph S. Myers
joseph@codesourcery.com