1/* Compute maximum of two numbers, regarding NaN as missing argument.
2 Copyright (C) 1997-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <sysdep.h>
21#include <libm-alias-ldouble.h>
22
23 .text
24ENTRY(__fmaxl)
25 fldt 8(%rsp) // x
26 fldt 24(%rsp) // x : y
27
28 fucomi %st(1), %st
29 jp 2f
30 fcmovb %st(1), %st
31
32 fstp %st(1)
33
34 ret
35
362: // Unordered.
37 fucomi %st(0), %st
38 jp 3f
39 // st(1) is a NaN; st(0) is not. Test if st(1) is signaling.
40 testb $0x40, 15(%rsp)
41 jz 4f
42 fstp %st(1)
43 ret
44
453: // st(0) is a NaN; st(1) may or may not be.
46 fxch
47 fucomi %st(0), %st
48 jp 4f
49 // st(1) is a NaN; st(0) is not. Test if st(1) is signaling.
50 testb $0x40, 31(%rsp)
51 jz 4f
52 fstp %st(1)
53 ret
54
554: // Both arguments are NaNs, or one is a signaling NaN.
56 faddp
57 ret
58END(__fmaxl)
59libm_alias_ldouble (__fmax, fmax)
60