| 0,0 → 1,72 |
|---|
| /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| /* e_coshf.c -- float version of e_cosh.c. |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| */ |
| |
| /* |
| * ==================================================== |
| * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| * |
| * Developed at SunPro, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| */ |
| |
| #if defined(LIBM_SCCS) && !defined(lint) |
| static char rcsid[] = "$Id: e_coshf.c,v 1.2 1994/08/18 23:05:17 jtc Exp $"; |
| #endif |
| |
| #include "math.h" |
| #include "math_private.h" |
| |
| #ifdef __STDC__ |
| static const float one = 1.0, half=0.5, huge = 1.0e30; |
| #else |
| static float one = 1.0, half=0.5, huge = 1.0e30; |
| #endif |
| |
| #ifdef __STDC__ |
| float __ieee754_coshf(float x) |
| #else |
| float __ieee754_coshf(x) |
| float x; |
| #endif |
| { |
| float t,w; |
| int32_t ix; |
| |
| GET_FLOAT_WORD(ix,x); |
| ix &= 0x7fffffff; |
| |
| /* x is INF or NaN */ |
| if(ix>=0x7f800000) return x*x; |
| |
| /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */ |
| if(ix<0x3eb17218) { |
| t = expm1f(fabsf(x)); |
| w = one+t; |
| if (ix<0x24000000) return w; /* cosh(tiny) = 1 */ |
| return one+(t*t)/(w+w); |
| } |
| |
| /* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */ |
| if (ix < 0x41b00000) { |
| t = __ieee754_expf(fabsf(x)); |
| return half*t+half/t; |
| } |
| |
| /* |x| in [22, log(maxdouble)] return half*exp(|x|) */ |
| if (ix < 0x42b17180) return half*__ieee754_expf(fabsf(x)); |
| |
| /* |x| in [log(maxdouble), overflowthresold] */ |
| if (ix<=0x42b2d4fc) { |
| w = __ieee754_expf(half*fabsf(x)); |
| t = half*w; |
| return t*w; |
| } |
| |
| /* |x| > overflowthresold, cosh(x) overflow */ |
| return huge*huge; |
| } |
| Property changes: |
|---|
| Added: svn:executable |
|---|
| +* |
|---|
| \ No newline at end of property |
|---|