glibc/sysdeps/x86_64/fpu/s_fmaxl.S

60 lines
1.5 KiB
ArmAsm

/* Compute maximum of two numbers, regarding NaN as missing argument.
Copyright (C) 1997-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <libm-alias-ldouble.h>
.text
ENTRY(__fmaxl)
fldt 8(%rsp) // x
fldt 24(%rsp) // x : y
fucomi %st(1), %st
jp 2f
fcmovb %st(1), %st
fstp %st(1)
ret
2: // Unordered.
fucomi %st(0), %st
jp 3f
// st(1) is a NaN; st(0) is not. Test if st(1) is signaling.
testb $0x40, 15(%rsp)
jz 4f
fstp %st(1)
ret
3: // st(0) is a NaN; st(1) may or may not be.
fxch
fucomi %st(0), %st
jp 4f
// st(1) is a NaN; st(0) is not. Test if st(1) is signaling.
testb $0x40, 31(%rsp)
jz 4f
fstp %st(1)
ret
4: // Both arguments are NaNs, or one is a signaling NaN.
faddp
ret
END(__fmaxl)
libm_alias_ldouble (__fmax, fmax)