winsup/cygwin/math/logbl.c

   1 /**
   2  * This file has no copyright assigned and is placed in the Public Domain.
   3  * This file is part of the mingw-w64 runtime package.
   4  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
   5  */
   6 /*
   7  * Written by J.T. Conklin <jtc@netbsd.org>.
   8  * Changes for long double by Ulrich Drepper <drepper@cygnus.com>
   9  * Public domain.
  10  */
  11
  12 #include <math.h>
  13
  14 long double
  15 logbl (long double x)
  16 {
  17   long double res = 0.0L;
  18
  19   asm volatile (
  20        "fxtract\n\t"
  21        "fstp    %%st" : "=t" (res) : "0" (x));
  22   return res;
  23 }