diff options
Diffstat (limited to 'libm/double/unity.c')
-rw-r--r-- | libm/double/unity.c | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/libm/double/unity.c b/libm/double/unity.c deleted file mode 100644 index 9223e0edf..000000000 --- a/libm/double/unity.c +++ /dev/null @@ -1,138 +0,0 @@ -/* unity.c - * - * Relative error approximations for function arguments near - * unity. - * - * log1p(x) = log(1+x) - * expm1(x) = exp(x) - 1 - * cosm1(x) = cos(x) - 1 - * - */ - -#include <math.h> - -#ifdef ANSIPROT -extern int isnan (double); -extern int isfinite (double); -extern double log ( double ); -extern double polevl ( double, void *, int ); -extern double p1evl ( double, void *, int ); -extern double exp ( double ); -extern double cos ( double ); -#else -double log(), polevl(), p1evl(), exp(), cos(); -int isnan(), isfinite(); -#endif -extern double INFINITY; - -/* log1p(x) = log(1 + x) */ - -/* Coefficients for log(1+x) = x - x**2/2 + x**3 P(x)/Q(x) - * 1/sqrt(2) <= x < sqrt(2) - * Theoretical peak relative error = 2.32e-20 - */ -static double LP[] = { - 4.5270000862445199635215E-5, - 4.9854102823193375972212E-1, - 6.5787325942061044846969E0, - 2.9911919328553073277375E1, - 6.0949667980987787057556E1, - 5.7112963590585538103336E1, - 2.0039553499201281259648E1, -}; -static double LQ[] = { -/* 1.0000000000000000000000E0,*/ - 1.5062909083469192043167E1, - 8.3047565967967209469434E1, - 2.2176239823732856465394E2, - 3.0909872225312059774938E2, - 2.1642788614495947685003E2, - 6.0118660497603843919306E1, -}; - -#define SQRTH 0.70710678118654752440 -#define SQRT2 1.41421356237309504880 - -double log1p(x) -double x; -{ -double z; - -z = 1.0 + x; -if( (z < SQRTH) || (z > SQRT2) ) - return( log(z) ); -z = x*x; -z = -0.5 * z + x * ( z * polevl( x, LP, 6 ) / p1evl( x, LQ, 6 ) ); -return (x + z); -} - - - -/* expm1(x) = exp(x) - 1 */ - -/* e^x = 1 + 2x P(x^2)/( Q(x^2) - P(x^2) ) - * -0.5 <= x <= 0.5 - */ - -static double EP[3] = { - 1.2617719307481059087798E-4, - 3.0299440770744196129956E-2, - 9.9999999999999999991025E-1, -}; -static double EQ[4] = { - 3.0019850513866445504159E-6, - 2.5244834034968410419224E-3, - 2.2726554820815502876593E-1, - 2.0000000000000000000897E0, -}; - -double expm1(x) -double x; -{ -double r, xx; - -#ifdef NANS -if( isnan(x) ) - return(x); -#endif -#ifdef INFINITIES -if( x == INFINITY ) - return(INFINITY); -if( x == -INFINITY ) - return(-1.0); -#endif -if( (x < -0.5) || (x > 0.5) ) - return( exp(x) - 1.0 ); -xx = x * x; -r = x * polevl( xx, EP, 2 ); -r = r/( polevl( xx, EQ, 3 ) - r ); -return (r + r); -} - - - -/* cosm1(x) = cos(x) - 1 */ - -static double coscof[7] = { - 4.7377507964246204691685E-14, --1.1470284843425359765671E-11, - 2.0876754287081521758361E-9, --2.7557319214999787979814E-7, - 2.4801587301570552304991E-5, --1.3888888888888872993737E-3, - 4.1666666666666666609054E-2, -}; - -extern double PIO4; - -double cosm1(x) -double x; -{ -double xx; - -if( (x < -PIO4) || (x > PIO4) ) - return( cos(x) - 1.0 ); -xx = x * x; -xx = -0.5*xx + xx * xx * polevl( xx, coscof, 6 ); -return xx; -} |