| /* e_coshf.c -- float version of e_cosh.c. |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| * Optimizations by Ulrich Drepper <drepper@gmail.com>, 2011 |
| */ |
| |
| /* |
| * ==================================================== |
| * 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. |
| * ==================================================== |
| */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| |
| static const float huge = 1.0e30; |
| static const float one = 1.0, half=0.5; |
| |
| float |
| __ieee754_coshf (float x) |
| { |
| float t,w; |
| int32_t ix; |
| |
| GET_FLOAT_WORD(ix,x); |
| ix &= 0x7fffffff; |
| |
| /* |x| in [0,22] */ |
| if (ix < 0x41b00000) { |
| /* |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; */ |
| 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 is INF or NaN */ |
| if(ix>=0x7f800000) return x*x; |
| |
| /* |x| > overflowthresold, cosh(x) overflow */ |
| return huge*huge; |
| } |
| strong_alias (__ieee754_coshf, __coshf_finite) |
