diff options
Diffstat (limited to 'src/math/sincos.c')
| -rw-r--r-- | src/math/sincos.c | 68 | 
1 files changed, 68 insertions, 0 deletions
| diff --git a/src/math/sincos.c b/src/math/sincos.c new file mode 100644 index 00000000..442e285e --- /dev/null +++ b/src/math/sincos.c @@ -0,0 +1,68 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_sin.c */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "libm.h" + +void sincos(double x, double *sin, double *cos) +{ +	double y[2], s, c; +	uint32_t n, ix; + +	GET_HIGH_WORD(ix, x); +	ix &= 0x7fffffff; + +	/* |x| ~< pi/4 */ +	if (ix <= 0x3fe921fb) { +		/* if |x| < 2**-27 * sqrt(2) */ +		if (ix < 0x3e46a09e) { +			/* raise inexact if x != 0 */ +			if ((int)x == 0) { +				*sin = x; +				*cos = 1.0; +			} +			return; +		} +		*sin = __sin(x, 0.0, 0); +		*cos = __cos(x, 0.0); +		return; +	} + +	/* sincos(Inf or NaN) is NaN */ +	if (ix >= 0x7ff00000) { +		*sin = *cos = x - x; +		return; +	} + +	/* argument reduction needed */ +	n = __rem_pio2(x, y); +	s = __sin(y[0], y[1], 1); +	c = __cos(y[0], y[1]); +	switch (n&3) { +	case 0: +		*sin = s; +		*cos = c; +		break; +	case 1: +		*sin = c; +		*cos = -s; +		break; +	case 2: +		*sin = -s; +		*cos = -c; +		break; +	case 3: +	default: +		*sin = -c; +		*cos = s; +		break; +	} +} | 
