1 /* sf_cos.c -- float version of s_cos.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) 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 "fdlibm.h" 17 18 #ifdef __STDC__ 19 static const float one=1.0; 20 #else 21 static float one=1.0; 22 #endif 23 24 #ifdef __STDC__ 25 float cosf(float x) 26 #else 27 float cosf(x) 28 float x; 29 #endif 30 { 31 float y[2],z=0.0; 32 __int32_t n,ix; 33 34 GET_FLOAT_WORD(ix,x); 35 36 /* |x| ~< pi/4 */ 37 ix &= 0x7fffffff; 38 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z); 39 40 /* cos(Inf or NaN) is NaN */ 41 else if (!FLT_UWORD_IS_FINITE(ix)) return x-x; 42 43 /* argument reduction needed */ 44 else { 45 n = __ieee754_rem_pio2f(x,y); 46 switch(n&3) { 47 case 0: return __kernel_cosf(y[0],y[1]); 48 case 1: return -__kernel_sinf(y[0],y[1],1); 49 case 2: return -__kernel_cosf(y[0],y[1]); 50 default: 51 return __kernel_sinf(y[0],y[1],1); 52 } 53 } 54 } 55 56 #ifdef _DOUBLE_IS_32BITS 57 58 #ifdef __STDC__ 59 double cos(double x) 60 #else 61 double cos(x) 62 double x; 63 #endif 64 { 65 return (double) cosf((float) x); 66 } 67 68 #endif /* defined(_DOUBLE_IS_32BITS) */ 69
