/* ix87 specific implementation of arctanh function. Copyright (C) 1996-2015 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) /* Please note that we use double values for 0.5 and 1.0. These numbers have exact representations and so we don't get accuracy problems. The advantage is that the code is simpler. */ .type half,@object half: .double 0.5 ASM_SIZE_DIRECTIVE(half) .type one,@object one: .double 1.0 ASM_SIZE_DIRECTIVE(one) /* It is not important that this constant is precise. It is only a value which is known to be on the safe side for using the fyl2xp1 instruction. */ .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) #ifdef PIC #define MO(op) op##@GOTOFF(%edx) #else #define MO(op) op #endif .text ENTRY(__ieee754_atanhl) movl 12(%esp), %ecx movl %ecx, %eax andl $0x7fff, %eax cmpl $0x7fff, %eax je 5f cmpl $0x3fdf, %eax jge 7f // Exponent below -32; return x, with underflow if subnormal. fldt 4(%esp) cmpl $0, %eax jne 8f fld %st(0) fmul %st(0) fstp %st(0) 8: ret 7: #ifdef PIC LOAD_PIC_REG (dx) #endif andl $0x8000, %ecx // ECX == 0 iff X >= 0 fldt MO(ln2_2) // 0.5*ln2 xorl %ecx, 12(%esp) fldt 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 or �Inf 5: cmpl $0x80000000, 8(%esp) ja 6f cmpl $0, 4(%esp) je 7b 6: fldt 4(%esp) ret END(__ieee754_atanhl) strong_alias (__ieee754_atanhl, __atanhl_finite)