s_cosf.c revision 97409
1/* s_cosf.c -- float version of s_cos.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 */ 4 5/* 6 * ==================================================== 7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8 * 9 * Developed at SunPro, a Sun Microsystems, Inc. business. 10 * Permission to use, copy, modify, and distribute this 11 * software is freely granted, provided that this notice 12 * is preserved. 13 * ==================================================== 14 */ 15 16#ifndef lint 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_cosf.c 97409 2002-05-28 17:51:46Z alfred $"; 18#endif 19 20#include "math.h" 21#include "math_private.h" 22 23static const float one=1.0; 24 25 float cosf(float x) 26{ 27 float y[2],z=0.0; 28 int32_t n,ix; 29 30 GET_FLOAT_WORD(ix,x); 31 32 /* |x| ~< pi/4 */ 33 ix &= 0x7fffffff; 34 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z); 35 36 /* cos(Inf or NaN) is NaN */ 37 else if (ix>=0x7f800000) return x-x; 38 39 /* argument reduction needed */ 40 else { 41 n = __ieee754_rem_pio2f(x,y); 42 switch(n&3) { 43 case 0: return __kernel_cosf(y[0],y[1]); 44 case 1: return -__kernel_sinf(y[0],y[1],1); 45 case 2: return -__kernel_cosf(y[0],y[1]); 46 default: 47 return __kernel_sinf(y[0],y[1],1); 48 } 49 } 50} 51