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 "math.h" 17 #include "math_private.h" 18 19 static const float one = 1.0, shuge = 1.0e37; 20 21 float 22 sinhf(float x) 23 { 24 float t,h; 25 int32_t ix,jx; 26 27 GET_FLOAT_WORD(jx,x); 28 ix = jx&0x7fffffff; 29 30 /* x is INF or NaN */ 31 if(ix>=0x7f800000) return x+x; 32 33 h = 0.5; 34 if (jx<0) h = -h; 35 /* |x| in [0,9], return sign(x)*0.5*(E+E/(E+1))) */ 36 if (ix < 0x41100000) { /* |x|<9 */ 37 if (ix<0x39800000) /* |x|<2**-12 */ 38 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ 39 t = expm1f(fabsf(x)); 40 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); 41 return h*(t+t/(t+one)); 42 } 43 44 /* |x| in [9, logf(maxfloat)] return 0.5*exp(|x|) */ 45 if (ix < 0x42b17217) return h*expf(fabsf(x)); 46 47 /* |x| in [logf(maxfloat), overflowthresold] */ 48 if (ix<=0x42b2d4fc) 49 return h*2.0F*__ldexp_expf(fabsf(x), -1); 50 51 /* |x| > overflowthresold, sinh(x) overflow */ 52 return x*shuge; 53 } 54