glibc/sysdeps/i386/fpu/e_atanh.S
Ulrich Drepper 0ac5ae2335 Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
2011-10-12 11:27:51 -04:00

118 lines
3.1 KiB
ArmAsm
Raw Blame History

/* ix87 specific implementation of arctanh function.
Copyright (C) 1996, 1999, 2005, 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <machine/asm.h>
#ifdef __ELF__
.section .rodata
#else
.text
#endif
.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)
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_atanh)
movl 8(%esp), %ecx
movl %ecx, %eax
andl $0x7fffffff, %eax
cmpl $0x7ff00000, %eax
jae 5f
7:
#ifdef PIC
call 1f
cfi_adjust_cfa_offset (4)
1: popl %edx
cfi_adjust_cfa_offset (-4)
addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %edx
#endif
andl $0x80000000, %ecx // ECX == 0 iff X >= 0
fldt MO(ln2_2) // 0.5*ln2
xorl %ecx, 8(%esp)
fldl 4(%esp) // |x| : 0.5*ln2
fcoml MO(half) // |x| : 0.5*ln2
fld %st // |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 or <EFBFBD>Inf
5: ja 6f
cmpl $0, 4(%esp)
je 7b
6: fldl 4(%esp)
ret
END(__ieee754_atanh)
strong_alias (__ieee754_atanh, __atanh_finite)