[PATCH v2 3/3] manual: Cube roots are rarely representable
DJ Delorie
dj@redhat.com
Sat Mar 30 16:51:35 GMT 2024
Paul Zimmermann <Paul.Zimmermann@inria.fr> writes:
>> From: DJ Delorie <dj@redhat.com>
>> Cc: libc-alpha@sourceware.org
>> Date: Fri, 29 Mar 2024 20:27:44 -0400
>>
>> Alejandro Colomar <alx@kernel.org> writes:
>>
>> > -These functions return the cube root of @var{x}. They cannot
>> > -fail; every representable real value has a representable real cube root.
>>
>> > +These functions return the cube root of @var{x}. They cannot
>> > +fail; every representable real value has a real cube root,
>> > +and rounding it to a representable value
>> > +never causes overflow nor underflow.
>>
>> Wording is OK but the $subject says the exact opposite...
>
> It is fine to me. The subject says that the cube root of a floating-point
> number is rarely a floating-point number, which is true: for a p-bit format,
> only about 2^(p/3) numbers have an exact cube root.
Let me rephrase: The $subject does not convey the intent of the patch.
If the patch adds wording that "the result never errors" the subject
should reflect that change, not some other aspect of the issue.
Something like "Note why cube roots always give representable results."
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