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/* s_cosf.c -- float version of s_cos.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
#ifndef lint
static char rcsid[] = "$FreeBSD$";
#endif
#include "math.h"
#define INLINE_KERNEL_COSF
#define INLINE_KERNEL_SINF
#include "math_private.h"
#include "k_cosf.c"
#include "k_sinf.c"
/* Small multiples of pi/2 rounded to double precision. */
static const double
c1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
c2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
c3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
c4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
static inline float
__kernel_cosdf(double x)
{
return __kernel_cosf((float)x, x - (float)x);
}
static inline float
__kernel_sindf(double x)
{
return __kernel_sinf((float)x, x - (float)x, 1);
}
float
cosf(float x)
{
float y[2];
int32_t n,ix;
x = fabsf(x);
GET_FLOAT_WORD(ix,x);
if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
if(ix<0x39800000) /* |x| < 2**-12 */
if(((int)x)==0) return 1.0; /* 1 with inexact if x != 0 */
return __kernel_cosf(x,0.0);
}
if(ix<=0x407b53d1) { /* |x| <= ~5*pi/4 */
if(ix<=0x4016cbe3) /* |x| <= ~3pi/4 */
return -__kernel_sindf(x - c1pio2);
else
return -__kernel_cosdf(x - c2pio2);
}
if(ix<=0x40e231d5) { /* |x| <= ~9*pi/4 */
if(ix<=0x40afeddf) /* |x| <= ~7*pi/4 */
return __kernel_sindf(x - c3pio2);
else
return __kernel_cosdf(x - c4pio2);
}
/* cos(Inf or NaN) is NaN */
else if (ix>=0x7f800000) return x-x;
/* general argument reduction needed */
else {
n = __ieee754_rem_pio2f(x,y);
switch(n&3) {
case 0: return __kernel_cosf(y[0],y[1]);
case 1: return -__kernel_sinf(y[0],y[1],1);
case 2: return -__kernel_cosf(y[0],y[1]);
default:
return __kernel_sinf(y[0],y[1],1);
}
}
}
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