diff options
Diffstat (limited to 'src/math/coshf.c')
| -rw-r--r-- | src/math/coshf.c | 49 |
1 files changed, 14 insertions, 35 deletions
diff --git a/src/math/coshf.c b/src/math/coshf.c index 2bed1258..b09f2ee5 100644 --- a/src/math/coshf.c +++ b/src/math/coshf.c @@ -1,54 +1,33 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/e_coshf.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 "libm.h" float coshf(float x) { union {float f; uint32_t i;} u = {.f = x}; - uint32_t ix; + uint32_t w; float t; /* |x| */ u.i &= 0x7fffffff; x = u.f; - ix = u.i; + w = u.i; - /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */ - if (ix < 0x3eb17218) { - t = expm1f(x); - if (ix < 0x39800000) + /* |x| < log(2) */ + if (w < 0x3f317217) { + if (w < 0x3f800000 - (12<<23)) { + FORCE_EVAL(x + 0x1p120f); return 1; + } + t = expm1f(x); return 1 + t*t/(2*(1+t)); } - /* |x| in [0.5*ln2,9], return (exp(|x|)+1/exp(|x|))/2; */ - if (ix < 0x41100000) { + /* |x| < log(FLT_MAX) */ + if (w < 0x42b17217) { t = expf(x); - return 0.5f*t + 0.5f/t; + return 0.5f*(t + 1/t); } - /* |x| in [9, log(maxfloat)] return 0.5f*exp(|x|) */ - if (ix < 0x42b17217) - return 0.5f*expf(x); - - /* |x| in [log(maxfloat), overflowthresold] */ - if (ix <= 0x42b2d4fc) - return __expo2f(x); - - /* |x| > overflowthresold or nan */ - x *= 0x1p127f; - return x; + /* |x| > log(FLT_MAX) or nan */ + t = __expo2f(x); + return t; } |