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[/] [or1k/] [trunk/] [newlib/] [newlib/] [libm/] [mathfp/] [sf_sineh.c] - Blame information for rev 1765

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/* @(#)z_sinehf.c 1.0 98/08/13 */
/******************************************************************
 * The following routines are coded directly from the algorithms
 * and coefficients given in "Software Manual for the Elementary
 * Functions" by William J. Cody, Jr. and William Waite, Prentice
 * Hall, 1980.
 ******************************************************************/
/******************************************************************
 * Hyperbolic Sine
 *
 * Input:
 *   x - floating point value
 *
 * Output:
 *   hyperbolic sine of x
 *
 * Description:
 *   This routine calculates hyperbolic sines.
 *
 *****************************************************************/
 
#include <float.h>
#include "fdlibm.h"
#include "zmath.h"
 
static const float q[] = { -0.428277109e+2 };
static const float p[] = { -0.713793159e+1,
                           -0.190333399 };
static const float LNV = 0.6931610107;
static const float INV_V2 = 0.2499930850;
static const float V_OVER2_MINUS1 = 0.1383027787e-4;
 
float
_DEFUN (sinehf, (float, int),
        float x _AND
        int cosineh)
{
  float y, f, P, Q, R, res, z, w;
  int sgn = 1;
  float WBAR = 18.55;
 
  /* Check for special values. */
  switch (numtestf (x))
    {
      case NAN:
        errno = EDOM;
        return (x);
      case INF:
        errno = ERANGE;
        return (ispos (x) ? z_infinity_f.f : -z_infinity_f.f);
    }
 
  y = fabs (x);
 
  if (!cosineh && x < 0.0)
    sgn = -1;
 
  if ((y > 1.0 && !cosineh) || cosineh)
    {
      if (y > BIGX)
        {
          w = y - LNV;
 
          /* Check for w > maximum here. */
          if (w > BIGX)
            {
              errno = ERANGE;
              return (x);
            }
 
          z = exp (w);
 
          if (w > WBAR)
            res = z * (V_OVER2_MINUS1 + 1.0);
        }
 
      else
        {
          z = exp (y);
          if (cosineh)
            res = (z + 1 / z) / 2.0;
          else
            res = (z - 1 / z) / 2.0;
        }
 
      if (sgn < 0)
        res = -res;
    }
  else
    {
      /* Check for y being too small. */
      if (y < z_rooteps_f)
        {
          res = x;
        }
      /* Calculate the Taylor series. */
      else
        {
          f = x * x;
          Q = f + q[0];
          P = p[1] * f + p[0];
          R = f * (P / Q);
 
          res = x + x * R;
        }
    }
 
  return (res);
}

Line No.	Rev	Author	Line
1	56	joel
2			`/* @(#)z_sinehf.c 1.0 98/08/13 */`
3			`/******************************************************************`
4			`* The following routines are coded directly from the algorithms`
5			`* and coefficients given in "Software Manual for the Elementary`
6			`* Functions" by William J. Cody, Jr. and William Waite, Prentice`
7			`* Hall, 1980.`
8			`******************************************************************/`
9			`/******************************************************************`
10			`* Hyperbolic Sine`
11			`*`
12			`* Input:`
13			`* x - floating point value`
14			`*`
15			`* Output:`
16			`* hyperbolic sine of x`
17			`*`
18			`* Description:`
19			`* This routine calculates hyperbolic sines.`
20			`*`
21			`*****************************************************************/`
22
23			`#include <float.h>`
24			`#include "fdlibm.h"`
25			`#include "zmath.h"`
26
27			`static const float q[] = { -0.428277109e+2 };`
28			`static const float p[] = { -0.713793159e+1,`
29			`-0.190333399 };`
30			`static const float LNV = 0.6931610107;`
31			`static const float INV_V2 = 0.2499930850;`
32			`static const float V_OVER2_MINUS1 = 0.1383027787e-4;`
33
34			`float`
35			`_DEFUN (sinehf, (float, int),`
36			`float x _AND`
37			`int cosineh)`
38			`{`
39			`float y, f, P, Q, R, res, z, w;`
40			`int sgn = 1;`
41			`float WBAR = 18.55;`
42
43			`/* Check for special values. */`
44			`switch (numtestf (x))`
45			`{`
46			`case NAN:`
47			`errno = EDOM;`
48			`return (x);`
49			`case INF:`
50			`errno = ERANGE;`
51			`return (ispos (x) ? z_infinity_f.f : -z_infinity_f.f);`
52			`}`
53
54			`y = fabs (x);`
55
56			`if (!cosineh && x < 0.0)`
57			`sgn = -1;`
58
59			`if ((y > 1.0 && !cosineh) \|\| cosineh)`
60			`{`
61			`if (y > BIGX)`
62			`{`
63			`w = y - LNV;`
64
65			`/* Check for w > maximum here. */`
66			`if (w > BIGX)`
67			`{`
68			`errno = ERANGE;`
69			`return (x);`
70			`}`
71
72			`z = exp (w);`
73
74			`if (w > WBAR)`
75			`res = z * (V_OVER2_MINUS1 + 1.0);`
76			`}`
77
78			`else`
79			`{`
80			`z = exp (y);`
81			`if (cosineh)`
82			`res = (z + 1 / z) / 2.0;`
83			`else`
84			`res = (z - 1 / z) / 2.0;`
85			`}`
86
87			`if (sgn < 0)`
88			`res = -res;`
89			`}`
90			`else`
91			`{`
92			`/* Check for y being too small. */`
93			`if (y < z_rooteps_f)`
94			`{`
95			`res = x;`
96			`}`
97			`/* Calculate the Taylor series. */`
98			`else`
99			`{`
100			`f = x * x;`
101			`Q = f + q[0];`
102			`P = p[1] * f + p[0];`
103			`R = f * (P / Q);`
104
105			`res = x + x * R;`
106			`}`
107			`}`
108
109			`return (res);`
110			`}`

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