s_asinhf.c (1428B)
1 /* s_asinhf.c -- float version of s_asinh.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: src/lib/msun/src/s_asinhf.c,v 1.8 2002/05/28 18:15:04 alfred Exp $"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 static const float 24 one = 1.0000000000e+00, /* 0x3F800000 */ 25 ln2 = 6.9314718246e-01, /* 0x3f317218 */ 26 huge= 1.0000000000e+30; 27 28 float 29 asinhf(float x) 30 { 31 float t,w; 32 int32_t hx,ix; 33 GET_FLOAT_WORD(hx,x); 34 ix = hx&0x7fffffff; 35 if(ix>=0x7f800000) return x+x; /* x is inf or NaN */ 36 if(ix< 0x31800000) { /* |x|<2**-28 */ 37 if(huge+x>one) return x; /* return x inexact except 0 */ 38 } 39 if(ix>0x4d800000) { /* |x| > 2**28 */ 40 w = __ieee754_logf(fabsf(x))+ln2; 41 } else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */ 42 t = fabsf(x); 43 w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t)); 44 } else { /* 2.0 > |x| > 2**-28 */ 45 t = x*x; 46 w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t))); 47 } 48 if(hx>0) return w; else return -w; 49 }