1 /* sf_tan.c -- float version of s_tan.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 "fdlibm.h" 17 18 #ifdef __STDC__ tanf(float x)19 float tanf(float x) 20 #else 21 float tanf(x) 22 float x; 23 #endif 24 { 25 float y[2],z=0.0; 26 __int32_t n,ix; 27 28 GET_FLOAT_WORD(ix,x); 29 30 /* |x| ~< pi/4 */ 31 ix &= 0x7fffffff; 32 if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1); 33 34 /* tan(Inf or NaN) is NaN */ 35 else if (!FLT_UWORD_IS_FINITE(ix)) return x-x; /* NaN */ 36 37 /* argument reduction needed */ 38 else { 39 n = __ieee754_rem_pio2f(x,y); 40 return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even 41 -1 -- n odd */ 42 } 43 } 44 45 #ifdef _DOUBLE_IS_32BITS 46 47 #ifdef __STDC__ tan(double x)48 double tan(double x) 49 #else 50 double tan(x) 51 double x; 52 #endif 53 { 54 return (double) tanf((float) x); 55 } 56 57 #endif /* defined(_DOUBLE_IS_32BITS) */ 58