diff options
Diffstat (limited to 'lib/msun/src/e_coshf.c')
-rw-r--r-- | lib/msun/src/e_coshf.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/msun/src/e_coshf.c b/lib/msun/src/e_coshf.c new file mode 100644 index 0000000..95a0d6e --- /dev/null +++ b/lib/msun/src/e_coshf.c @@ -0,0 +1,59 @@ +/* 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. + * ==================================================== + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "math.h" +#include "math_private.h" + +static const float one = 1.0, half=0.5, huge = 1.0e30; + +float +__ieee754_coshf(float x) +{ + 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<0x39800000) return one; /* cosh(tiny) = 1 */ + return one+(t*t)/(w+w); + } + + /* |x| in [0.5*ln2,9], return (exp(|x|)+1/exp(|x|))/2; */ + if (ix < 0x41100000) { + t = __ieee754_expf(fabsf(x)); + return half*t+half/t; + } + + /* |x| in [9, log(maxfloat)] return half*exp(|x|) */ + if (ix < 0x42b17217) return half*__ieee754_expf(fabsf(x)); + + /* |x| in [log(maxfloat), overflowthresold] */ + if (ix<=0x42b2d4fc) + return __ldexp_expf(fabsf(x), -1); + + /* |x| > overflowthresold, cosh(x) overflow */ + return huge*huge; +} |