Macros
#define	PRECISION 9

#define	M_PI 3.141592653589793238462643

Functions
double	sin (double x)

Variables
static double	sin_off_tbl [] = {0.0, -M_PI/2., 0, -M_PI/2.}

static double	sin_sign_tbl [] = {1,-1,-1,1}

Macro Definition Documentation

◆ M_PI

#define M_PI 3.141592653589793238462643

Definition at line 15 of file sin.c.

◆ PRECISION

#define PRECISION 9

Definition at line 14 of file sin.c.

Function Documentation

◆ sin()

double sin ( double x )

Definition at line 21 of file sin.c.

{
    int quadrant;
    double x2, result;
 
    /* Calculate the quadrant */
    quadrant = (int)(x * (2./M_PI));
 
    /* Get offset inside quadrant */
    x = x - quadrant * (M_PI/2.);
 
    /* Normalize quadrant to [0..3] */
    quadrant = (quadrant - 1) & 0x3;
 
    /* Fixup value for the generic function */
    x += sin_off_tbl[quadrant];
 
    /* Calculate the negative of the square of x */
    x2 = - (x * x);
 
    /* This is an unrolled taylor series using <PRECISION> iterations
     * Example with 4 iterations:
     * result = 1 - x^2/2! + x^4/4! - x^6/6! + x^8/8!
     * To save multiplications and to keep the precision high, it's performed
     * like this:
     * result = 1 - x^2 * (1/2! - x^2 * (1/4! - x^2 * (1/6! - x^2 * (1/8!))))
     */
 
    /* Start with 0, compiler will optimize this away */
    result = 0;
 
#if (PRECISION >= 10)
    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18*19*20);
    result *= x2;
#endif
#if (PRECISION >= 9)
    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18);
    result *= x2;
#endif
#if (PRECISION >= 8)
    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16);
    result *= x2;
#endif
#if (PRECISION >= 7)
    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12*13*14);
    result *= x2;
#endif
#if (PRECISION >= 6)
    result += 1./(1.*2*3*4*5*6*7*8*9*10*11*12);
    result *= x2;
#endif
#if (PRECISION >= 5)
    result += 1./(1.*2*3*4*5*6*7*8*9*10);
    result *= x2;
#endif
    result += 1./(1.*2*3*4*5*6*7*8);
    result *= x2;
 
    result += 1./(1.*2*3*4*5*6);
    result *= x2;
 
    result += 1./(1.*2*3*4);
    result *= x2;
 
    result += 1./(1.*2);
    result *= x2;
 
    result += 1;
 
    /* Apply correct sign */
    result *= sin_sign_tbl[quadrant];
 
    return result;
}

Referenced by __libm_sse2_sin(), __libm_sse2_sinf(), __rpc_get_time_offset(), __rpc_sockisbound(), __rpc_taddr2uaddr_af(), __rpc_uaddr2taddr_af(), __sincos(), _CIsin(), _libm_sse2_sin_precise(), add_arc_part(), bindresvport(), bindresvport_sa(), compute_sincos_table(), D3DRMQuaternionFromRotation(), D3DRMQuaternionSlerp(), D3DRMVectorRotate(), draw_cap(), draw_graphics(), DrawGLScene(), EMFDRV_ArcChordPie(), expT(), GdipRotateMatrix(), get_server(), CAppScrnshotPreview::GetFrameDotShift(), gl_rotation_matrix(), Global_Sin(), gluPerspective(), init_layer3(), IntGdiAngleArc(), IntGdiWidenPath(), main(), Math_sin(), NetBTCall(), NetBTSendNameQuery(), netfinger(), CDrvDefExt::PaintStaticControls(), PATH_DoArcPart(), polar(), powT(), pres_sin(), RotatePoint(), rpc_broadcast_exp(), rpcrt4_ip_tcp_get_top_of_tower(), rpn_sin(), shorten_line_percent(), sincos(), sinf(), sinl(), Test_sin_approx(), Test_sin_exact(), TestKs(), ValarrayTest::transcendentals(), uaddr_to_sockaddr(), unstretch_angle(), wave_generate_la(), and wave_generate_tone().

Variable Documentation

◆ sin_off_tbl

double sin_off_tbl[] = {0.0, -M_PI/2., 0, -M_PI/2.}

static

Definition at line 17 of file sin.c.

Referenced by sin().

◆ sin_sign_tbl

double sin_sign_tbl[] = {1,-1,-1,1}