diff options
| -rw-r--r-- | libm/sincos.c | 150 |
1 files changed, 134 insertions, 16 deletions
diff --git a/libm/sincos.c b/libm/sincos.c index e9f6dcc58..9bc432529 100644 --- a/libm/sincos.c +++ b/libm/sincos.c @@ -6,10 +6,10 @@ * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. + * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE @@ -26,29 +26,147 @@ */ #define _GNU_SOURCE 1 #include <math.h> +#define INLINE_KERNEL_COSDF +#define INLINE_KERNEL_SINDF +#include "src/math_private.h" +#include "src/k_cosf.c" +#include "src/k_sinf.c" -// Disable sincos optimization for all functions in this file, -// otherwise gcc would generate infinite calls. -// Refer to gcc PR46926. -// -fno-builtin-sin or -fno-builtin-cos can disable sincos optimization, -// but these two options do not work inside optimize pragma in-file. -// Thus we just enforce -O0 when compiling this file. -#pragma GCC optimize ("O0") +/* 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 */ +/* For implementation details, see src/s_sin.c, src/s_cos.c */ void sincos(double x, double *psin, double *pcos) { - *psin = sin(x); - *pcos = cos(x); + double y[2], z=0.0; + int32_t n, ix; + + /* High word of x. */ + GET_HIGH_WORD(ix, x); + + /* |x| ~< pi/4 */ + ix &= 0x7fffffff; + if(ix <= 0x3fe921fb) { + if(ix < 0x3e400000) { /* \x\ < 2**-27 */ + if((int)x==0) { /* generate inexact */ + *psin = x; + *pcos = 1.0; + return; + } + } + *psin = __kernel_sin(x, z, 0); + *pcos = __kernel_cos(x, z); + return; + } else if(ix>=0x7ff00000) { /* sin(Inf or NaN) and cos(Inf or NaN) is NaN */ + *psin = *pcos = x-x; + return; + } else { + n = __ieee754_rem_pio2(x, y); + switch(n&3) { + case 0: + *psin = __kernel_sin(y[0],y[1],1); + *pcos = __kernel_cos(y[0],y[1]); + return; + case 1: + *psin = __kernel_cos(y[0],y[1]); + *pcos = -__kernel_sin(y[0],y[1],1); + return; + case 2: + *psin = -__kernel_sin(y[0],y[1],1); + *pcos = -__kernel_cos(y[0],y[1]); + return; + default: + *psin = -__kernel_cos(y[0],y[1]); + *pcos = __kernel_sin(y[0],y[1],1); + return; + } + } } +/* For implementation details, see src/s_sinf.c, src/s_cosf.c */ void sincosf(float x, float *psin, float *pcos) { - *psin = sinf(x); - *pcos = cosf(x); + float y[2]; + int32_t n, hx, ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + + if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ + if(ix < 0x39800000) { /* |x| < 2**-12 */ + if(((int)x)==0) { /* x with inexact if x != 0 */ + *psin = x; + *pcos = 1.0; + return; + } + } + *psin = __kernel_sindf(x); + *pcos = __kernel_cosdf(x); + return; + } else if(ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */ + if(ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ + if(hx>0) { + *psin = __kernel_cosdf(x - s1pio2); + *pcos = __kernel_sindf(s1pio2 - x); + return; + } else { + *psin = -__kernel_cosdf(x + s1pio2); + *pcos = __kernel_sindf(x + s1pio2); + return; + } + } else { + *psin = __kernel_sindf((hx > 0 ? s2pio2 : -s2pio2) - x); + *pcos = -__kernel_cosdf(x + (hx > 0 ? -s2pio2 : s2pio2)); + return; + } + } else if(ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */ + if(ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ + if(hx>0) { + *psin = -__kernel_cosdf(x - s3pio2); + *pcos = __kernel_sindf(x - s3pio2); + return; + } else { + *psin = __kernel_cosdf(x + s3pio2); + *pcos = __kernel_sindf(-s3pio2 - x); + return; + } + } else { + *psin = __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2)); + *pcos = __kernel_cosdf(x + (hx > 0 ? -s4pio2 : s4pio2)); + return; + } + } else if(ix>=0x7f800000) { /* sin and cos (Inf or NaN) is NaN */ + *psin = *pcos = x-x; + return; + } else { + n = __ieee754_rem_pio2f(x,y); + switch(n&3) { + case 0: + *psin = __kernel_sindf((double)y[0]+y[1]); + *pcos = __kernel_cosdf((double)y[0]+y[1]); + return; + case 1: + *psin = __kernel_cosdf((double)y[0]+y[1]); + *pcos = __kernel_sindf(-(double)y[0]-y[1]); + return; + case 2: + *psin = __kernel_sindf(-(double)y[0]-y[1]); + *pcos = -__kernel_cosdf((double)y[0]+y[1]); + return; + default: + *psin = -__kernel_cosdf((double)y[0]+y[1]); + *pcos = __kernel_sindf((double)y[0]+y[1]); + return; + } + } } void sincosl(long double x, long double *psin, long double *pcos) { - *psin = sin(x); - *pcos = cos(x); + *psin = sin(x); + *pcos = cos(x); } |