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 #include "math.h" 18 #include "math_private.h" 19 20 static const float one = 1.0, shuge = 1.0e37; 21 22 float 23 sinhf(float x) 24 { 25 float t,h; 26 int32_t ix,jx; 27 28 GET_FLOAT_WORD(jx,x); 29 ix = jx&0x7fffffff; 30 31 /* x is INF or NaN */ 32 if(ix>=0x7f800000) return x+x; 33 34 h = 0.5; 35 if (jx<0) h = -h; 36 /* |x| in [0,9], return sign(x)*0.5*(E+E/(E+1))) */ 37 if (ix < 0x41100000) { /* |x|<9 */ 38 if (ix<0x39800000) /* |x|<2**-12 */ 39 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ 40 t = expm1f(fabsf(x)); 41 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); 42 return h*(t+t/(t+one)); 43 } 44 45 /* |x| in [9, logf(maxfloat)] return 0.5*exp(|x|) */ 46 if (ix < 0x42b17217) return h*expf(fabsf(x)); 47 48 /* |x| in [logf(maxfloat), overflowthresold] */ 49 if (ix<=0x42b2d4fc) 50 return h*2.0F*__ldexp_expf(fabsf(x), -1); 51 52 /* |x| > overflowthresold, sinh(x) overflow */ 53 return x*shuge; 54 } 55