| 1 | /* Compute maximum of two numbers, regarding NaN as missing argument. |
|---|
| 2 | Copyright (C) 1997-2022 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 |
|---|
| 23 | ENTRY(__fmax) |
|---|
| 24 | fldl 12(%esp) // y |
|---|
| 25 | fxam |
|---|
| 26 | fnstsw |
|---|
| 27 | fldl 4(%esp) // y : x |
|---|
| 28 | |
|---|
| 29 | andb $0x45, %ah |
|---|
| 30 | cmpb $0x01, %ah |
|---|
| 31 | je 1f // y == NaN |
|---|
| 32 | |
|---|
| 33 | fucom %st(1) |
|---|
| 34 | fnstsw |
|---|
| 35 | sahf |
|---|
| 36 | jnc 1f |
|---|
| 37 | |
|---|
| 38 | fxch %st(1) |
|---|
| 39 | 1: fstp %st(1) |
|---|
| 40 | |
|---|
| 41 | ret |
|---|
| 42 | END(__fmax) |
|---|
| 43 | libm_alias_double (__fmax, fmax) |
|---|
| 44 | |
|---|
