| Message ID | 20240305161213.14364-2-alx@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | manual/math.texi: logb(3) and cbrt(3) fixes | expand |
Hi DJ, On Fri, Mar 29, 2024 at 06:08:19PM -0400, DJ Delorie wrote: > Alejandro Colomar <alx@kernel.org> writes: > > -to @code{floor (log2 ( x ))}, except it's probably faster. > > +to @code{floor (log2 (fabs (x)))}, except it's probably faster. > > Confirmed that the only change here is the addition of fabs() > > Confirmed that logb() accepts negative numbers > > LGTM > Reviewed-by: DJ Delorie <dj@redhat.com> Thanks! Have a lovely night! Alex
diff --git a/manual/math.texi b/manual/math.texi index 2f6ee253b9..c54eaebb65 100644 --- a/manual/math.texi +++ b/manual/math.texi @@ -561,7 +561,7 @@ These functions return the base-2 logarithm of @var{x}. @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} These functions extract the exponent of @var{x} and return it as a floating-point value. If @code{FLT_RADIX} is two, @code{logb} is equal -to @code{floor (log2 (x))}, except it's probably faster. +to @code{floor (log2 (fabs (x)))}, except it's probably faster. If @var{x} is de-normalized, @code{logb} returns the exponent @var{x} would have if it were normalized. If @var{x} is infinity (positive or
log2(3) doesn't accept negative input, but it seems logb(3) does accept it. Link: <https://lore.kernel.org/linux-man/ZeYKUOKYS7G90SaV@debian/T/#u> Reported-by: Morten Welinder <mwelinder@gmail.com> Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> Cc: Vincent Lefevre <vincent@vinc17.net> Signed-off-by: Alejandro Colomar <alx@kernel.org> --- manual/math.texi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)