e_sinhf.c revision 97409
1/* e_sinhf.c -- float version of e_sinh.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 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/e_sinhf.c 97409 2002-05-28 17:51:46Z alfred $"; 18#endif 19 20#include "math.h" 21#include "math_private.h" 22 23static const float one = 1.0, shuge = 1.0e37; 24 25 float __ieee754_sinhf(float x) 26{ 27 float t,w,h; 28 int32_t ix,jx; 29 30 GET_FLOAT_WORD(jx,x); 31 ix = jx&0x7fffffff; 32 33 /* x is INF or NaN */ 34 if(ix>=0x7f800000) return x+x; 35 36 h = 0.5; 37 if (jx<0) h = -h; 38 /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ 39 if (ix < 0x41b00000) { /* |x|<22 */ 40 if (ix<0x31800000) /* |x|<2**-28 */ 41 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ 42 t = expm1f(fabsf(x)); 43 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); 44 return h*(t+t/(t+one)); 45 } 46 47 /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ 48 if (ix < 0x42b17180) return h*__ieee754_expf(fabsf(x)); 49 50 /* |x| in [log(maxdouble), overflowthresold] */ 51 if (ix<=0x42b2d4fc) { 52 w = __ieee754_expf((float)0.5*fabsf(x)); 53 t = h*w; 54 return t*w; 55 } 56 57 /* |x| > overflowthresold, sinh(x) overflow */ 58 return x*shuge; 59} 60