toolchain/gcc/libjava/java/lang/w_acos.c

   1
   2 /* @(#)w_acos.c 5.1 93/09/24 */
   3 /*
   4  * ====================================================
   5  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   6  *
   7  * Developed at SunPro, a Sun Microsystems, Inc. business.
   8  * Permission to use, copy, modify, and distribute this
   9  * software is freely granted, provided that this notice
  10  * is preserved.
  11  * ====================================================
  12  */
  13
  14 /*
  15 FUNCTION
  16         <<acos>>, <<acosf>>---arc cosine
  17
  18 INDEX
  19         acos
  20 INDEX
  21         acosf
  22
  23 ANSI_SYNOPSIS
  24         #include <math.h>
  25         double acos(double <[x]>);
  26         float acosf(float <[x]>);
  27
  28 TRAD_SYNOPSIS
  29         #include <math.h>
  30         double acos(<[x]>)
  31         double <[x]>;
  32
  33         float acosf(<[x]>)
  34         float <[x]>;
  35
  36
  37
  38 DESCRIPTION
  39
  40         <<acos>> computes the inverse cosine (arc cosine) of the input value.
  41         Arguments to <<acos>> must be in the range @minus{}1 to 1.
  42
  43         <<acosf>> is identical to <<acos>>, except that it performs
  44         its calculations on <<floats>>.
  45
  46 RETURNS
  47         @ifinfo
  48         <<acos>> and <<acosf>> return values in radians, in the range of 0 to pi.
  49         @end ifinfo
  50         @tex
  51         <<acos>> and <<acosf>> return values in radians, in the range of <<0>> to $\pi$.
  52         @end tex
  53
  54         If <[x]> is not between @minus{}1 and 1, the returned value is NaN
  55         (not a number) the global variable <<errno>> is set to <<EDOM>>, and a
  56         <<DOMAIN error>> message is sent as standard error output.
  57
  58         You can modify error handling for these functions using <<matherr>>.
  59
  60
  61 QUICKREF ANSI SVID POSIX RENTRANT
  62  acos    y,y,y,m
  63  acosf   n,n,n,m
  64
  65 MATHREF
  66  acos, [-1,1], acos(arg),,,
  67  acos, NAN,    arg,DOMAIN,EDOM
  68
  69 MATHREF
  70  acosf, [-1,1], acosf(arg),,,
  71  acosf, NAN,    argf,DOMAIN,EDOM
  72
  73 */
  74
  75 /*
  76  * wrap_acos(x)
  77  */
  78
  79 #include "fdlibm.h"
  80 #include <errno.h>
  81
  82 #ifndef _DOUBLE_IS_32BITS
  83
  84 #ifdef __STDC__
  85         double acos(double x)           /* wrapper acos */
  86 #else
  87         double acos(x)                  /* wrapper acos */
  88         double x;
  89 #endif
  90 {
  91 #ifdef _IEEE_LIBM
  92         return __ieee754_acos(x);
  93 #else
  94         double z;
  95         struct exception exc;
  96         z = __ieee754_acos(x);
  97         if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
  98         if(fabs(x)>1.0) {
  99             /* acos(|x|>1) */
 100             exc.type = DOMAIN;
 101             exc.name = "acos";
 102             exc.err = 0;
 103             exc.arg1 = exc.arg2 = x;
 104             exc.retval = 0.0;
 105             if (_LIB_VERSION == _POSIX_)
 106                errno = EDOM;
 107             else if (!matherr(&exc)) {
 108                errno = EDOM;
 109             }
 110             if (exc.err != 0)
 111                errno = exc.err;
 112             return exc.retval;
 113         } else
 114             return z;
 115 #endif
 116 }
 117
 118 #endif /* defined(_DOUBLE_IS_32BITS) */