/* ix87 specific implementation of arctanh function.

   Copyright (C) 1996-2018 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>

#include <i386-math-asm.h>

	.section .rodata

	.align ALIGNARG(4)

	.type half,@object

half:	.double 0.5

	ASM_SIZE_DIRECTIVE(half)

	.type one,@object

one:	.double 1.0

	ASM_SIZE_DIRECTIVE(one)

	.type limit,@object

limit:	.double 0.29

	ASM_SIZE_DIRECTIVE(limit)

	.align ALIGNARG(4)

	.type ln2_2,@object

ln2_2:	.tfloat 0.3465735902799726547086160

	ASM_SIZE_DIRECTIVE(ln2_2)

DEFINE_FLT_MIN

#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|))

	FLT_CHECK_FORCE_UFLOW_NONNEG

	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)