diff options
Diffstat (limited to 'newlib/libm/mathfp/sf_sineh.c')
-rw-r--r-- | newlib/libm/mathfp/sf_sineh.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/newlib/libm/mathfp/sf_sineh.c b/newlib/libm/mathfp/sf_sineh.c new file mode 100644 index 0000000..4eee2c9 --- /dev/null +++ b/newlib/libm/mathfp/sf_sineh.c @@ -0,0 +1,110 @@ + +/* @(#)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); +} |