From: Alejandro Colomar <alx@kernel.org>
Date: Tue, 5 Mar 2024 01:01:34 +0000 (+0100)
Subject: cbrt.3: wfix: Cube roots are rarely representable
X-Git-Tag: man-pages-6.7~50
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c4744946cb45e1b49f3fe0069265fc7fef28be9b;p=thirdparty%2Fman-pages.git

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 cf9c41771..64fc3c072 100644
--- 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 .