git: 7764e9ca28a9 - main - fmax.3: Add caveat for going beyond C std requirements

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=7764e9ca28a9702aed4ba7391e055ec2fcf35c41

commit 7764e9ca28a9702aed4ba7391e055ec2fcf35c41
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2026-04-02 21:59:42 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2026-04-06 17:00:15 +0000

    fmax.3: Add caveat for going beyond C std requirements
    
    libm's fmax and fmin family of functions treat +0.0 as greater than
    -0.0.  This is not required by the C standard, so the user may not see
    this behaviour due to compiler optimization.
    
    PR:             294214
    Reviewed by:    fuz
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D56230
---
 lib/msun/man/fmax.3 | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/msun/man/fmax.3 b/lib/msun/man/fmax.3
index 25fc9b6d518a..873a19375ce5 100644
--- a/lib/msun/man/fmax.3
+++ b/lib/msun/man/fmax.3
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd June 29, 2004
+.Dd April 6, 2026
 .Dt FMAX 3
 .Os
 .Sh NAME
@@ -68,10 +68,6 @@ functions return the smaller of
 .Fa x
 and
 .Fa y .
-They treat
-.Li +0.0
-as being larger than
-.Li -0.0 .
 If one argument is an \*(Na, then the other argument is returned.
 If both arguments are \*(Nas, then the result is an \*(Na.
 These routines do not raise any floating-point exceptions.
@@ -90,6 +86,13 @@ and
 .Fn fminl
 functions conform to
 .St -isoC-99 .
+.Sh CAVEATS
+The library implementations of these functions treat
+.Li +0.0
+as being larger than
+.Li -0.0 .
+This behavior is not specified by the C standard, is not portable,
+and may not occur in light of compiler optimizations.
 .Sh HISTORY
 These routines first appeared in
 .Fx 5.3 .