URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libquadmath/] [math/] [acoshq.c] - Rev 743
Go to most recent revision | Compare with Previous | Blame | View Log
/* e_acoshl.c -- long double 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. * ==================================================== */ /* __ieee754_acoshl(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)); } }
Go to most recent revision | Compare with Previous | Blame | View Log