glibc/sysdeps/i386/fpu/e_atanhf.S
2012-02-09 23:18:22 +00:00

106 lines
2.9 KiB
ArmAsm

/* ix87 specific implementation of arctanh function.
Copyright (C) 1996, 1999, 2005, 2011-2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
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 <machine/asm.h>
.section .rodata
.align ALIGNARG(4)
ASM_TYPE_DIRECTIVE(half,@object)
half: .double 0.5
ASM_SIZE_DIRECTIVE(half)
ASM_TYPE_DIRECTIVE(one,@object)
one: .double 1.0
ASM_SIZE_DIRECTIVE(one)
ASM_TYPE_DIRECTIVE(limit,@object)
limit: .double 0.29
ASM_SIZE_DIRECTIVE(limit)
.align ALIGNARG(4)
ASM_TYPE_DIRECTIVE(ln2_2,@object)
ln2_2: .tfloat 0.3465735902799726547086160
ASM_SIZE_DIRECTIVE(ln2_2)
#ifdef PIC
#define MO(op) op##@GOTOFF(%edx)
#else
#define MO(op) op
#endif
.text
ENTRY(__ieee754_atanhf)
movl 4(%esp), %ecx
movl %ecx, %eax
andl $0x7fffffff, %eax
cmpl $0x7f800000, %eax
ja 5f
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
andl $0x80000000, %ecx // ECX == 0 iff X >= 0
fldt MO(ln2_2) // 0.5*ln2
xorl %ecx, 4(%esp)
flds 4(%esp) // |x| : 0.5*ln2
fcoml MO(half) // |x| : 0.5*ln2
fld %st(0) // |x| : |x| : 0.5*ln2
fnstsw // |x| : |x| : 0.5*ln2
sahf
jae 2f
fadd %st, %st(1) // |x| : 2*|x| : 0.5*ln2
fld %st // |x| : |x| : 2*|x| : 0.5*ln2
fsubrl MO(one) // 1-|x| : |x| : 2*|x| : 0.5*ln2
fxch // |x| : 1-|x| : 2*|x| : 0.5*ln2
fmul %st(2) // 2*|x|^2 : 1-|x| : 2*|x| : 0.5*ln2
fdivp // (2*|x|^2)/(1-|x|) : 2*|x| : 0.5*ln2
faddp // 2*|x|+(2*|x|^2)/(1-|x|) : 0.5*ln2
fcoml MO(limit) // 2*|x|+(2*|x|^2)/(1-|x|) : 0.5*ln2
fnstsw // 2*|x|+(2*|x|^2)/(1-|x|) : 0.5*ln2
sahf
jae 4f
fyl2xp1 // 0.5*ln2*ld(1+2*|x|+(2*|x|^2)/(1-|x|))
jecxz 3f
fchs // 0.5*ln2*ld(1+2*x+(2*x^2)/(1-x))
3: ret
.align ALIGNARG(4)
4: faddl MO(one) // 1+2*|x|+(2*|x|^2)/(1-|x|) : 0.5*ln2
fyl2x // 0.5*ln2*ld(1+2*|x|+(2*|x|^2)/(1-|x|))
jecxz 3f
fchs // 0.5*ln2*ld(1+2*x+(2*x^2)/(1-x))
3: ret
.align ALIGNARG(4)
2: faddl MO(one) // 1+|x| : |x| : 0.5*ln2
fxch // |x| : 1+|x| : 0.5*ln2
fsubrl MO(one) // 1-|x| : 1+|x| : 0.5*ln2
fdivrp // (1+|x|)/(1-|x|) : 0.5*ln2
fyl2x // 0.5*ln2*ld((1+|x|)/(1-|x|))
jecxz 3f
fchs // 0.5*ln2*ld((1+x)/(1-x))
3: ret
// x == NaN
5: flds 4(%esp)
ret
END(__ieee754_atanhf)
strong_alias (__ieee754_atanhf, __atanhf_finite)