math/w_lgamma_main.c

   1 /* @(#)w_lgamma.c 5.1 93/09/24 */
   2 /*
   3  * ====================================================
   4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   5  *
   6  * Developed at SunPro, a Sun Microsystems, Inc. business.
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 /* double lgamma(double x)
  14  * Return the logarithm of the Gamma function of x.
  15  *
  16  * Method: call __ieee754_lgamma_r
  17  */
  18
  19 #include <math.h>
  20 #include <math_private.h>
  21
  22 #include <lgamma-compat.h>
  23
  24 #if BUILD_LGAMMA
  25 double
  26 LGFUNC (__lgamma) (double x)
  27 {
  28         double y = CALL_LGAMMA (double, __ieee754_lgamma_r, x);
  29         if(__builtin_expect(!isfinite(y), 0)
  30            && isfinite(x) && _LIB_VERSION != _IEEE_)
  31                 return __kernel_standard(x, x,
  32                                          __floor(x)==x&&x<=0.0
  33                                          ? 15 /* lgamma pole */
  34                                          : 14); /* lgamma overflow */
  35
  36         return y;
  37 }
  38 # if USE_AS_COMPAT
  39 compat_symbol (libm, __lgamma_compat, lgamma, LGAMMA_OLD_VER);
  40 #  ifdef NO_LONG_DOUBLE
  41 strong_alias (__lgamma_compat, __lgammal_compat)
  42 compat_symbol (libm, __lgammal_compat, lgammal, LGAMMA_OLD_VER);
  43 #  endif
  44 # else
  45 versioned_symbol (libm, __lgamma, lgamma, LGAMMA_NEW_VER);
  46 #  ifdef NO_LONG_DOUBLE
  47 strong_alias (__lgamma, __lgammal)
  48 versioned_symbol (libm, __lgammal, lgammal, LGAMMA_NEW_VER);
  49 #  endif
  50 # endif
  51 # if GAMMA_ALIAS
  52 strong_alias (LGFUNC (__lgamma), __gamma)
  53 weak_alias (__gamma, gamma)
  54 #  ifdef NO_LONG_DOUBLE
  55 strong_alias (__gamma, __gammal)
  56 weak_alias (__gamma, gammal)
  57 #  endif
  58 # endif
  59 #endif