[444] | 1 | /* ef_sinh.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 "fdlibm.h" |
---|
| 17 | |
---|
| 18 | #ifdef __STDC__ |
---|
| 19 | static const float one = 1.0, shuge = 1.0e37; |
---|
| 20 | #else |
---|
| 21 | static float one = 1.0, shuge = 1.0e37; |
---|
| 22 | #endif |
---|
| 23 | |
---|
| 24 | #ifdef __STDC__ |
---|
| 25 | float __ieee754_sinhf(float x) |
---|
| 26 | #else |
---|
| 27 | float __ieee754_sinhf(x) |
---|
| 28 | float x; |
---|
| 29 | #endif |
---|
| 30 | { |
---|
| 31 | float t,w,h; |
---|
| 32 | __int32_t ix,jx; |
---|
| 33 | |
---|
| 34 | GET_FLOAT_WORD(jx,x); |
---|
| 35 | ix = jx&0x7fffffff; |
---|
| 36 | |
---|
| 37 | /* x is INF or NaN */ |
---|
| 38 | if(!FLT_UWORD_IS_FINITE(ix)) return x+x; |
---|
| 39 | |
---|
| 40 | h = 0.5; |
---|
| 41 | if (jx<0) h = -h; |
---|
| 42 | /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ |
---|
| 43 | if (ix < 0x41b00000) { /* |x|<22 */ |
---|
| 44 | if (ix<0x31800000) /* |x|<2**-28 */ |
---|
| 45 | if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ |
---|
| 46 | t = expm1f(fabsf(x)); |
---|
| 47 | if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); |
---|
| 48 | return h*(t+t/(t+one)); |
---|
| 49 | } |
---|
| 50 | |
---|
| 51 | /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ |
---|
| 52 | if (ix<=FLT_UWORD_LOG_MAX) return h*__ieee754_expf(fabsf(x)); |
---|
| 53 | |
---|
| 54 | /* |x| in [log(maxdouble), overflowthresold] */ |
---|
| 55 | if (ix<=FLT_UWORD_LOG_2MAX) { |
---|
| 56 | w = __ieee754_expf((float)0.5*fabsf(x)); |
---|
| 57 | t = h*w; |
---|
| 58 | return t*w; |
---|
| 59 | } |
---|
| 60 | |
---|
| 61 | /* |x| > overflowthresold, sinh(x) overflow */ |
---|
| 62 | return x*shuge; |
---|
| 63 | } |
---|