From: nsz Date: Thu, 15 Mar 2012 07:17:28 +0000 (+0100) Subject: efficient sincos based on sin and cos X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=0144b45b71c0b78055b311fe3e7408fee71eb0c1 efficient sincos based on sin and cos --- diff --git a/include/math.h b/include/math.h index f320b8e9..b9139b02 100644 --- a/include/math.h +++ b/include/math.h @@ -382,6 +382,10 @@ long double ynl(int, long double); double scalb(double, double); float scalbf(float, float); long double scalbl(long double, long double); + +void sincos(double, double*, double*); +void sincosf(float, float*, float*); +void sincosl(long double, long double*, long double*); #endif #ifdef __cplusplus diff --git a/src/linux/sincos.c b/src/linux/sincos.c deleted file mode 100644 index b69ffce9..00000000 --- a/src/linux/sincos.c +++ /dev/null @@ -1,8 +0,0 @@ -#define _GNU_SOURCE -#include - -void sincos(double t, double *y, double *x) -{ - *y = sin(t); - *x = cos(t); -} 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; + } +} diff --git a/src/math/sincosf.c b/src/math/sincosf.c new file mode 100644 index 00000000..fede5f23 --- /dev/null +++ b/src/math/sincosf.c @@ -0,0 +1,113 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + * Optimized by Bruce D. Evans. + */ +/* + * ==================================================== + * 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" + +/* Small multiples of pi/2 rounded to double precision. */ +static const double +s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ +s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ +s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ +s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ + +void sincosf(float x, float *sin, float *cos) +{ + double y, s, c; + uint32_t n, hx, ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + + /* |x| ~<= pi/4 */ + if (ix <= 0x3f490fda) { + /* |x| < 2**-12 */ + if (ix < 0x39800000) { + /* raise inexact if x != 0 */ + if((int)x == 0) { + *sin = x; + *cos = 1.0f; + } + return; + } + *sin = __sindf(x); + *cos = __cosdf(x); + return; + } + + /* |x| ~<= 5*pi/4 */ + if (ix <= 0x407b53d1) { + if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ + if (hx < 0x80000000) { + *sin = __cosdf(x - s1pio2); + *cos = __sindf(s1pio2 - x); + } else { + *sin = -__cosdf(x + s1pio2); + *cos = __sindf(x + s1pio2); + } + return; + } + *sin = __sindf(hx < 0x80000000 ? s2pio2 - x : -s2pio2 - x); + *cos = -__cosdf(hx < 0x80000000 ? x - s2pio2 : x + s2pio2); + return; + } + + /* |x| ~<= 9*pi/4 */ + if (ix <= 0x40e231d5) { + if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ + if (hx < 0x80000000) { + *sin = -__cosdf(x - s3pio2); + *cos = __sindf(x - s3pio2); + } else { + *sin = __cosdf(x + s3pio2); + *cos = __sindf(-s3pio2 - x); + } + return; + } + *sin = __sindf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2); + *cos = __cosdf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2); + return; + } + + /* sin(Inf or NaN) is NaN */ + if (ix >= 0x7f800000) { + *sin = *cos = x - x; + return; + } + + /* general argument reduction needed */ + n = __rem_pio2f(x, &y); + s = __sindf(y); + c = __cosdf(y); + 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; + } +} diff --git a/src/math/sincosl.c b/src/math/sincosl.c new file mode 100644 index 00000000..378dc979 --- /dev/null +++ b/src/math/sincosl.c @@ -0,0 +1,66 @@ +#include "libm.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +void sincosl(long double x, long double *sin, long double *cos) +{ + double s, c; + sincos(x, &s, &c); + *sin = s; + *cos = c; +} +#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 +#include "__rem_pio2l.h" + +void sincosl(long double x, long double *sin, long double *cos) +{ + union IEEEl2bits u; + int n; + long double y[2], s, c; + + u.e = x; + u.bits.sign = 0; + + /* x = +-0 or subnormal */ + if (!u.bits.exp) { + *sin = x; + *cos = 1.0; + return; + } + + /* x = nan or inf */ + if (u.bits.exp == 0x7fff) { + *sin = *cos = x - x; + return; + } + + /* |x| < pi/4 */ + if (u.e < M_PI_4) { + *sin = __sinl(x, 0, 0); + *cos = __cosl(x, 0); + return; + } + + n = __rem_pio2l(x, y); + s = __sinl(y[0], y[1], 1); + c = __cosl(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; + } +} +#endif