/* Math functions for i387. Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by John C. Bowman , 1995. 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 double exp (double __x); double exp (double __x) { #ifdef __GNUC__ register double __value, __exponent; __asm __volatile__ ("fldl2e # e^x = 2^(x * log2(e))\n\t" "fmul %%st(1) # x * log2(e)\n\t" "fst %%st(1)\n\t" "frndint # int(x * log2(e))\n\t" "fxch\n\t" "fsub %%st(1) # fract(x * log2(e))\n\t" "f2xm1 # 2^(fract(x * log2(e))) - 1\n\t" : "=t" (__value), "=u" (__exponent) : "0" (__x)); __value += 1.0; __asm __volatile__ ("fscale" : "=t" (__value) : "0" (__value), "u" (__exponent)); return __value; #else return linkme_exp(__x); #endif /*__GNUC__*/ }