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

   1
   2 /* @(#)w_asin.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 /*
  16 FUNCTION
  17         <<asin>>, <<asinf>>---arc sine
  18
  19 INDEX
  20    asin
  21 INDEX
  22    asinf
  23
  24 ANSI_SYNOPSIS
  25         #include <math.h>
  26         double asin(double <[x]>);
  27         float asinf(float <[x]>);
  28
  29 TRAD_SYNOPSIS
  30         #include <math.h>
  31         double asin(<[x]>)
  32         double <[x]>;
  33
  34         float asinf(<[x]>)
  35         float <[x]>;
  36
  37
  38 DESCRIPTION
  39
  40 <<asin>> computes the inverse sine (arc sine) of the argument <[x]>.
  41 Arguments to <<asin>> must be in the range @minus{}1 to 1.
  42
  43 <<asinf>> is identical to <<asin>>, other than taking and
  44 returning floats.
  45
  46 You can modify error handling for these routines using <<matherr>>.
  47
  48 RETURNS
  49 @ifnottex
  50 <<asin>> returns values in radians, in the range of -pi/2 to pi/2.
  51 @end ifnottex
  52 @tex
  53 <<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$.
  54 @end tex
  55
  56 If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>>
  57 return NaN (not a number), set the global variable <<errno>> to
  58 <<EDOM>>, and issue a <<DOMAIN error>> message.
  59
  60 You can change this error treatment using <<matherr>>.
  61
  62 QUICKREF ANSI SVID POSIX RENTRANT
  63  asin    y,y,y,m
  64  asinf   n,n,n,m
  65
  66 MATHREF
  67  asin,  -1<=arg<=1, asin(arg),,,
  68  asin,  NAN,  arg,EDOM, DOMAIN
  69
  70 MATHREF
  71  asinf,  -1<=arg<=1, asin(arg),,,
  72  asinf,  NAN,  arg,EDOM, DOMAIN
  73
  74
  75 */
  76
  77 /*
  78  * wrapper asin(x)
  79  */
  80
  81
  82 #include "fdlibm.h"
  83 #include <errno.h>
  84
  85 #ifndef _DOUBLE_IS_32BITS
  86
  87 #ifdef __STDC__
  88         double asin(double x)           /* wrapper asin */
  89 #else
  90         double asin(x)                  /* wrapper asin */
  91         double x;
  92 #endif
  93 {
  94 #ifdef _IEEE_LIBM
  95         return __ieee754_asin(x);
  96 #else
  97         double z;
  98         struct exception exc;
  99         z = __ieee754_asin(x);
 100         if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
 101         if(fabs(x)>1.0) {
 102             /* asin(|x|>1) */
 103             exc.type = DOMAIN;
 104             exc.name = "asin";
 105             exc.err = 0;
 106             exc.arg1 = exc.arg2 = x;
 107             exc.retval = 0.0;
 108             if(_LIB_VERSION == _POSIX_)
 109               errno = EDOM;
 110             else if (!matherr(&exc)) {
 111               errno = EDOM;
 112             }
 113             if (exc.err != 0)
 114               errno = exc.err;
 115             return exc.retval;
 116         } else
 117             return z;
 118 #endif
 119 }
 120
 121 #endif /* defined(_DOUBLE_IS_32BITS) */