toolchain/gcc/newlib/libm/math/wf_gamma.c

   1 /* wf_gamma.c -- float version of w_gamma.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  *
  15  */
  16
  17 #include "fdlibm.h"
  18 #include <reent.h>
  19 #include <errno.h>
  20
  21 #ifdef __STDC__
  22         float gammaf(float x)
  23 #else
  24         float gammaf(x)
  25         float x;
  26 #endif
  27 {
  28 #ifdef _IEEE_LIBM
  29         return __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
  30 #else
  31         float y;
  32         struct exception exc;
  33         y = __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
  34         if(_LIB_VERSION == _IEEE_) return y;
  35         if(!finitef(y)&&finitef(x)) {
  36 #ifndef HUGE_VAL
  37 #define HUGE_VAL inf
  38             double inf = 0.0;
  39
  40             SET_HIGH_WORD(inf,0x7ff00000);      /* set inf to infinite */
  41 #endif
  42             if(floorf(x)==x&&x<=(float)0.0) {
  43                 /* gammaf(-integer) or gammaf(0) */
  44                 exc.type = SING;
  45                 exc.name = "gammaf";
  46                 exc.err = 0;
  47                 exc.arg1 = exc.arg2 = (double)x;
  48                 if (_LIB_VERSION == _SVID_)
  49                   exc.retval = HUGE;
  50                 else
  51                   exc.retval = HUGE_VAL;
  52                 if (_LIB_VERSION == _POSIX_)
  53                   errno = EDOM;
  54                 else if (!matherr(&exc)) {
  55                   errno = EDOM;
  56                 }
  57             } else {
  58                 /* gammaf(finite) overflow */
  59                 exc.type = OVERFLOW;
  60                 exc.name = "gammaf";
  61                 exc.err = 0;
  62                 exc.arg1 = exc.arg2 = (double)x;
  63                 if (_LIB_VERSION == _SVID_)
  64                   exc.retval = HUGE;
  65                 else
  66                   exc.retval = HUGE_VAL;
  67                 if (_LIB_VERSION == _POSIX_)
  68                   errno = ERANGE;
  69                 else if (!matherr(&exc)) {
  70                   errno = ERANGE;
  71                 }
  72             }
  73             if (exc.err != 0)
  74                errno = exc.err;
  75             return (float)exc.retval;
  76         } else
  77             return y;
  78 #endif
  79 }
  80
  81 #ifdef _DOUBLE_IS_32BITS
  82
  83 #ifdef __STDC__
  84         double gamma(double x)
  85 #else
  86         double gamma(x)
  87         double x;
  88 #endif
  89 {
  90         return (double) gammaf((float) x);
  91 }
  92
  93 #endif /* defined(_DOUBLE_IS_32BITS) */