e_sinhf.c revision 2117
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[] = "$Id: e_sinhf.c,v 1.2 1994/08/18 23:06:04 jtc Exp $"; 18#endif 19 20#include "math.h" 21#include "math_private.h" 22 23#ifdef __STDC__ 24static const float one = 1.0, shuge = 1.0e37; 25#else 26static float one = 1.0, shuge = 1.0e37; 27#endif 28 29#ifdef __STDC__ 30 float __ieee754_sinhf(float x) 31#else 32 float __ieee754_sinhf(x) 33 float x; 34#endif 35{ 36 float t,w,h; 37 int32_t ix,jx; 38 39 GET_FLOAT_WORD(jx,x); 40 ix = jx&0x7fffffff; 41 42 /* x is INF or NaN */ 43 if(ix>=0x7f800000) return x+x; 44 45 h = 0.5; 46 if (jx<0) h = -h; 47 /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ 48 if (ix < 0x41b00000) { /* |x|<22 */ 49 if (ix<0x31800000) /* |x|<2**-28 */ 50 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ 51 t = expm1f(fabsf(x)); 52 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); 53 return h*(t+t/(t+one)); 54 } 55 56 /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ 57 if (ix < 0x42b17180) return h*__ieee754_expf(fabsf(x)); 58 59 /* |x| in [log(maxdouble), overflowthresold] */ 60 if (ix<=0x42b2d4fc) { 61 w = __ieee754_expf((float)0.5*fabsf(x)); 62 t = h*w; 63 return t*w; 64 } 65 66 /* |x| > overflowthresold, sinh(x) overflow */ 67 return x*shuge; 68} 69