glibc/sysdeps/x86_64/fpu/s_fmax.S
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54 lines
1.6 KiB
ArmAsm

/* Compute maximum of two numbers, regarding NaN as missing argument.
Copyright (C) 2002-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 2002.
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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <libm-alias-double.h>
.text
ENTRY(__fmax)
ucomisd %xmm0, %xmm1
jp 1f // jump if unordered
maxsd %xmm1, %xmm0
jmp 2f
1: ucomisd %xmm1, %xmm1 // Is xmm1 a NaN?
jp 3f
// xmm0 is a NaN; xmm1 is not. Test if xmm0 is signaling.
movsd %xmm0, -8(%rsp)
testb $0x8, -2(%rsp)
jz 4f
movsd %xmm1, %xmm0 // otherwise return xmm1
ret
3: // xmm1 is a NaN; xmm0 may or may not be.
ucomisd %xmm0, %xmm0
jp 4f
// xmm1 is a NaN; xmm0 is not. Test if xmm1 is signaling.
movsd %xmm1, -8(%rsp)
testb $0x8, -2(%rsp)
jz 4f
ret
4: // Both arguments are NaNs, or one is a signaling NaN.
addsd %xmm1, %xmm0
2: ret
END(__fmax)
libm_alias_double (__fmax, fmax)