cbrt.3: wfix: Cube roots are rarely representable

On Thu, Feb 29, 2024 at 07:28:10PM -0500, Morten Welinder wrote:
> The phrase "every representable real value has a representable real
> cube root" is wrong.  In fact, a representable cube root is quite
> rare.

Link: <https://lore.kernel.org/linux-man/ZeYKUOKYS7G90SaV@debian/T/#mff0ab388000c6afdb5e5162804d4a0073de481de>
Reported-by: Morten Welinder <mwelinder@gmail.com>
Cowritten-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>

diff --git a/man3/cbrt.3 b/man3/cbrt.3
index cf9c41771c09bd530bd1c1fbc452237da484964c..64fc3c0725fc20163c2bb689b5f63e1593494b98 100644 (file)
--- a/man3/cbrt.3
+++ b/man3/cbrt.3
@@ -47,8 +47,11 @@ Feature Test Macro Requirements for glibc (see
 .SH DESCRIPTION
 These functions return the (real) cube root of
 .IR x .
-This function cannot fail; every representable real value has a
-representable real cube root.
+This function cannot fail;
+every representable real value
+has a real cube root,
+and rounding it to a representable value
+never causes overflow nor underflow.
 .SH RETURN VALUE
 These functions return the cube root of
 .IR x .