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 #include "math.h" 17 #include "math_private.h" 18 19 float 20 cosf(float x) 21 { 22 float y[2],z=0.0; 23 int32_t n,ix; 24 25 GET_FLOAT_WORD(ix,x); 26 27 /* |x| ~< pi/4 */ 28 ix &= 0x7fffffff; 29 if(ix <= 0x3f490fd8) { 30 if(ix<0x39800000) /* if x < 2**-12 */ 31 if(((int)x)==0) return 1.0; /* generate inexact */ 32 return __kernel_cosf(x,z); 33 } 34 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 DEF_STD(cosf); 52