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Diffstat (limited to 'gcc-4.9/libquadmath/math/acoshq.c')
| -rw-r--r-- | gcc-4.9/libquadmath/math/acoshq.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/gcc-4.9/libquadmath/math/acoshq.c b/gcc-4.9/libquadmath/math/acoshq.c new file mode 100644 index 000000000..9845a8e36 --- /dev/null +++ b/gcc-4.9/libquadmath/math/acoshq.c @@ -0,0 +1,59 @@ +/* acoshq.c -- __float128 version of e_acosh.c. + * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz. + */ + +/* + * ==================================================== + * 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. + * ==================================================== + */ + +/* acoshq(x) + * Method : + * Based on + * acoshl(x) = logl [ x + sqrtl(x*x-1) ] + * we have + * acoshl(x) := logl(x)+ln2, if x is large; else + * acoshl(x) := logl(2x-1/(sqrtl(x*x-1)+x)) if x>2; else + * acoshl(x) := log1pl(t+sqrtl(2.0*t+t*t)); where t=x-1. + * + * Special cases: + * acoshl(x) is NaN with signal if x<1. + * acoshl(NaN) is NaN without signal. + */ + +#include "quadmath-imp.h" + +static const __float128 +one = 1.0Q, +ln2 = 0.6931471805599453094172321214581766Q; + +__float128 +acoshq (__float128 x) +{ + __float128 t; + uint64_t lx; + int64_t hx; + GET_FLT128_WORDS64(hx,lx,x); + if(hx<0x3fff000000000000LL) { /* x < 1 */ + return (x-x)/(x-x); + } else if(hx >=0x4035000000000000LL) { /* x > 2**54 */ + if(hx >=0x7fff000000000000LL) { /* x is inf of NaN */ + return x+x; + } else + return logq(x)+ln2; /* acoshl(huge)=logl(2x) */ + } else if(((hx-0x3fff000000000000LL)|lx)==0) { + return 0.0Q; /* acosh(1) = 0 */ + } else if (hx > 0x4000000000000000LL) { /* 2**28 > x > 2 */ + t=x*x; + return logq(2.0Q*x-one/(x+sqrtq(t-one))); + } else { /* 1<x<2 */ + t = x-one; + return log1pq(t+sqrtq(2.0Q*t+t*t)); + } +} |