/* Compute maximum of two numbers, regarding NaN as missing argument. Copyright (C) 1997-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include #include .text ENTRY(__fmaxl) fldt 16(%esp) // y fxam fnstsw fldt 4(%esp) // y : x andb $0x45, %ah cmpb $0x01, %ah je 2f // y == NaN fxam fnstsw andb $0x45, %ah cmpb $0x01, %ah je 3f // x == NaN fucom %st(1) fnstsw sahf jnc 1f fxch %st(1) 1: fstp %st(1) ret 2: // st(1) is a NaN; st(0) may or may not be. fxam fnstsw andb $0x45, %ah cmpb $0x01, %ah je 4f // st(1) is a NaN; st(0) is not. Test if st(1) is signaling. testb $0x40, 23(%esp) jz 4f fstp %st(1) ret 3: // st(0) is a NaN; st(1) is not. Test if st(0) is signaling. testb $0x40, 11(%esp) jz 4f fstp %st(0) ret 4: // Both arguments are NaNs, or one is a signaling NaN. faddp ret END(__fmaxl) libm_alias_ldouble (__fmax, fmax)