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 <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: s_cosf.c,v 1.5 1997/10/09 11:31:32 lukem Exp $"); 19 #endif 20 21 #include "math.h" 22 #include "math_private.h" 23 24 #ifdef __STDC__ 25 static const float one=1.0; 26 #else 27 static float one=1.0; 28 #endif 29 30 #ifdef __STDC__ 31 float cosf(float x) 32 #else 33 float cosf(x) 34 float x; 35 #endif 36 { 37 float y[2],z=0.0; 38 int32_t n,ix; 39 40 GET_FLOAT_WORD(ix,x); 41 42 /* |x| ~< pi/4 */ 43 ix &= 0x7fffffff; 44 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z); 45 46 /* cos(Inf or NaN) is NaN */ 47 else if (ix>=0x7f800000) return x-x; 48 49 /* argument reduction needed */ 50 else { 51 n = __ieee754_rem_pio2f(x,y); 52 switch(n&3) { 53 case 0: return __kernel_cosf(y[0],y[1]); 54 case 1: return -__kernel_sinf(y[0],y[1],1); 55 case 2: return -__kernel_cosf(y[0],y[1]); 56 default: 57 return __kernel_sinf(y[0],y[1],1); 58 } 59 } 60 } 61