1/* Compute maximum of two numbers, regarding NaN as missing argument.
2 Copyright (C) 1997-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <sysdep.h>
20#include <libm-alias-double.h>
21
22 .text
23ENTRY(__fmax)
24 fldl 4(%esp) // x
25 fldl 12(%esp) // x : y
26
27 fucomi %st(0), %st
28 fcmovu %st(1), %st // now %st contains y if not NaN, x otherwise
29
30 fxch
31
32 fucomi %st(1), %st
33 fcmovb %st(1), %st
34
35 fstp %st(1)
36
37 ret
38END(__fmax)
39libm_alias_double (__fmax, fmax)
40

source code of glibc/sysdeps/i386/i686/fpu/s_fmax.S