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Diffstat (limited to 'newlib/libm/mathfp/s_sineh.c')
| -rw-r--r-- | newlib/libm/mathfp/s_sineh.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/newlib/libm/mathfp/s_sineh.c b/newlib/libm/mathfp/s_sineh.c new file mode 100644 index 0000000..6b3480d --- /dev/null +++ b/newlib/libm/mathfp/s_sineh.c @@ -0,0 +1,185 @@ + +/* @(#)z_sineh.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. + ******************************************************************/ + +/* +FUNCTION + <<sinh>>, <<sinhf>>, <<cosh>>, <<coshf>>, <<sineh>>---hyperbolic sine or cosine + +INDEX + sinh +INDEX + sinhf +INDEX + cosh +INDEX + coshf + +ANSI_SYNOPSIS + #include <math.h> + double sinh(double <[x]>); + float sinhf(float <[x]>); + double cosh(double <[x]>); + float coshf(float <[x]>); +TRAD_SYNOPSIS + #include <math.h> + double sinh(<[x]>) + double <[x]>; + + float sinhf(<[x]>) + float <[x]>; + + double cosh(<[x]>) + double <[x]>; + + float coshf(<[x]>) + float <[x]>; + +DESCRIPTION + <<sinh>> and <<cosh>> compute the hyperbolic sine or cosine + of the argument <[x]>. + Angles are specified in radians. <<sinh>>(<[x]>) is defined as + @ifinfo + . (exp(<[x]>) - exp(-<[x]>))/2 + @end ifinfo + @tex + $${e^x - e^{-x}}\over 2$$ + @end tex + <<cosh>> is defined as + @ifinfo + . (exp(<[x]>) - exp(-<[x]>))/2 + @end ifinfo + @tex + $${e^x + e^{-x}}\over 2$$ + @end tex + + <<sinhf>> and <<coshf>> are identical, save that they take + and returns <<float>> values. + +RETURNS + The hyperbolic sine or cosine of <[x]> is returned. + + When the correct result is too large to be representable (an + overflow), the functions return <<HUGE_VAL>> with the + appropriate sign, and sets the global value <<errno>> to + <<ERANGE>>. + +PORTABILITY + <<sinh>> is ANSI C. + <<sinhf>> is an extension. + <<cosh>> is ANSI C. + <<coshf>> is an extension. + +*/ + +/****************************************************************** + * 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 double q[] = { -0.21108770058106271242e+7, + 0.36162723109421836460e+5, + -0.27773523119650701667e+3 }; +static const double p[] = { -0.35181283430177117881e+6, + -0.11563521196851768270e+5, + -0.16375798202630751372e+3, + -0.78966127417357099479 }; +static const double LNV = 0.6931610107421875000; +static const double INV_V2 = 0.24999308500451499336; +static const double V_OVER2_MINUS1 = 0.13830277879601902638e-4; + +double +_DEFUN (sineh, (double, int), + double x _AND + int cosineh) +{ + double y, f, P, Q, R, res, z, w; + int sgn = 1; + double WBAR = 18.55; + + /* Check for special values. */ + switch (numtest (x)) + { + case NAN: + errno = EDOM; + return (x); + case INF: + errno = ERANGE; + return (ispos (x) ? z_infinity.d : -z_infinity.d); + } + + 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) + { + res = x; + } + /* Calculate the Taylor series. */ + else + { + f = x * x; + Q = ((f + q[2]) * f + q[1]) * f + q[0]; + P = ((p[3] * f + p[2]) * f + p[1]) * f + p[0]; + R = f * (P / Q); + + res = x + x * R; + } + } + + return (res); +} |