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 #include <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: e_sinhf.c,v 1.6 1999/07/02 15:37:41 simonb Exp $"); 19 #endif 20 21 #include "math.h" 22 #include "math_private.h" 23 24 #ifdef __STDC__ 25 static const float one = 1.0, shuge = 1.0e37; 26 #else 27 static float one = 1.0, shuge = 1.0e37; 28 #endif 29 30 #ifdef __STDC__ 31 float __ieee754_sinhf(float x) 32 #else 33 float __ieee754_sinhf(x) 34 float x; 35 #endif 36 { 37 float t,w,h; 38 int32_t ix,jx; 39 40 GET_FLOAT_WORD(jx,x); 41 ix = jx&0x7fffffff; 42 43 /* x is INF or NaN */ 44 if(ix>=0x7f800000) return x+x; 45 46 h = 0.5; 47 if (jx<0) h = -h; 48 /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ 49 if (ix < 0x41b00000) { /* |x|<22 */ 50 if (ix<0x31800000) /* |x|<2**-28 */ 51 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ 52 t = expm1f(fabsf(x)); 53 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); 54 return h*(t+t/(t+one)); 55 } 56 57 /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ 58 if (ix < 0x42b17180) return h*__ieee754_expf(fabsf(x)); 59 60 /* |x| in [log(maxdouble), overflowthresold] */ 61 if (ix<=0x42b2d4fc) { 62 w = __ieee754_expf((float)0.5*fabsf(x)); 63 t = h*w; 64 return t*w; 65 } 66 67 /* |x| > overflowthresold, sinh(x) overflow */ 68 return x*shuge; 69 } 70