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+/* ix87 specific implementation of arcsinh.
+ Copyright (C) 1996 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. 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(one,@object)
+one: .double 1.0
+ ASM_SIZE_DIRECTIVE(one)
+ ASM_TYPE_DIRECTIVE(limit,@object)
+limit: .double 0.29
+ ASM_SIZE_DIRECTIVE(limit)
+
+#ifdef PIC
+#define MO(op) op##@GOTOFF(%edx)
+#else
+#define MO(op) op
+#endif
+
+ .text
+ENTRY(__ieee754_acosh)
+ movl 8(%esp), %ecx
+ cmpl $0x3ff00000, %ecx
+ jl 5f // < 1 => invalid
+ fldln2 // log(2)
+ fldl 4(%esp) // x : log(2)
+ cmpl $0x41b00000, %ecx
+ ja 3f // x > 2^28
+#ifdef PIC
+ call 1f
+1: popl %edx
+ addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %edx
+#endif
+ cmpl $0x40000000, %ecx
+ ja 4f // x > 2
+
+ // 1 <= x <= 2 => y = log1p(x-1+sqrt(2*(x-1)+(x-1)^2))
+ fsubl MO(one) // x-1 : log(2)
+ fld %st // x-1 : x-1 : log(2)
+ fmul %st(1) // (x-1)^2 : x-1 : log(2)
+ fadd %st(1) // x-1+(x-1)^2 : x-1 : log(2)
+ fadd %st(1) // 2*(x-1)+(x-1)^2 : x-1 : log(2)
+ fsqrt // sqrt(2*(x-1)+(x-1)^2) : x-1 : log(2)
+ faddp // x-1+sqrt(2*(x-1)+(x-1)^2) : log(2)
+ fcoml MO(limit)
+ fnstsw
+ sahf
+ ja 2f
+ fyl2xp1 // log1p(x-1+sqrt(2*(x-1)+(x-1)^2))
+ ret
+
+2: faddl MO(one) // x+sqrt(2*(x-1)+(x-1)^2) : log(2)
+ fyl2x // log(x+sqrt(2*(x-1)+(x-1)^2))
+ ret
+
+ // x > 2^28 => y = log(x) + log(2)
+ .align ALIGNARG(4)
+3: fyl2x // log(x)
+ fldln2 // log(2) : log(x)
+ faddp // log(x)+log(2)
+ ret
+
+ // 2^28 > x > 2 => y = log(2*x - 1/(x+sqrt(x*x-1)))
+ .align ALIGNARG(4)
+4: fld %st // x : x : log(2)
+ fadd %st, %st(1) // x : 2*x : log(2)
+ fld %st // x : x : 2*x : log(2)
+ fmul %st(1) // x^2 : x : 2*x : log(2)
+ fsubl MO(one) // x^2-1 : x : 2*x : log(2)
+ fsqrt // sqrt(x^2-1) : x : 2*x : log(2)
+ faddp // x+sqrt(x^2-1) : 2*x : log(2)
+ fdivrl MO(one) // 1/(x+sqrt(x^2-1)) : 2*x : log(2)
+ fsubrp // 2*x+1/(x+sqrt(x^2)-1) : log(2)
+ fyl2x // log(2*x+1/(x+sqrt(x^2-1)))
+ ret
+
+ // x < 1 => NaN
+ .align ALIGNARG(4)
+5: fldz
+ fdiv %st, %st(0)
+ ret
+END(__ieee754_acosh)