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 17 static char rcsid[] = "$FreeBSD$"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 #ifdef __STDC__ 24 static const float one=1.0; 25 #else 26 static float one=1.0; 27 #endif 28 29 #ifdef __STDC__ 30 float cosf(float x) 31 #else 32 float cosf(x) 33 float x; 34 #endif 35 { 36 float y[2],z=0.0; 37 int32_t n,ix; 38 39 GET_FLOAT_WORD(ix,x); 40 41 /* |x| ~< pi/4 */ 42 ix &= 0x7fffffff; 43 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z); 44 45 /* cos(Inf or NaN) is NaN */ 46 else if (ix>=0x7f800000) return x-x; 47 48 /* argument reduction needed */ 49 else { 50 n = __ieee754_rem_pio2f(x,y); 51 switch(n&3) { 52 case 0: return __kernel_cosf(y[0],y[1]); 53 case 1: return -__kernel_sinf(y[0],y[1],1); 54 case 2: return -__kernel_cosf(y[0],y[1]); 55 default: 56 return __kernel_sinf(y[0],y[1],1); 57 } 58 } 59 } 60