freebsd-dev/contrib/libgmp/mpf/add_ui.c
Mark Murray aa9bc17601 Clean import of libgmp 2.0.2, with only the non-x86 bits removed.
BMakefiles and other bits will follow.

Requested by:	Andrey Chernov
Made world by:	Chuck Robey
1996-10-20 08:49:26 +00:00

152 lines
3.6 KiB
C

/* mpf_add_ui -- Add a float and an unsigned integer.
Copyright (C) 1993, 1994, 1996 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the GNU MP Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "gmp.h"
#include "gmp-impl.h"
void
#if __STDC__
mpf_add_ui (mpf_ptr sum, mpf_srcptr u, unsigned long int v)
#else
mpf_add_ui (sum, u, v)
mpf_ptr sum;
mpf_srcptr u;
unsigned long int v;
#endif
{
mp_srcptr up = u->_mp_d;
mp_ptr sump = sum->_mp_d;
mp_size_t usize, sumsize;
mp_size_t prec = sum->_mp_prec;
mp_exp_t uexp = u->_mp_exp;
usize = u->_mp_size;
if (usize <= 0)
{
if (usize == 0)
{
mpf_set_ui (sum, v);
return;
}
else
{
__mpf_struct u_negated;
u_negated._mp_size = -usize;
u_negated._mp_exp = u->_mp_exp;
u_negated._mp_d = u->_mp_d;
mpf_sub_ui (sum, &u_negated, v);
sum->_mp_size = -(sum->_mp_size);
return;
}
}
if (v == 0)
{
sum_is_u:
if (u != sum)
{
sumsize = MIN (usize, prec + 1);
MPN_COPY (sum->_mp_d, up + usize - sumsize, sumsize);
sum->_mp_size = sumsize;
sum->_mp_exp = u->_mp_exp;
}
return;
}
if (uexp > 0)
{
/* U >= 1. */
if (uexp > prec)
{
/* U >> V, V is not part of final result. */
goto sum_is_u;
}
else
{
/* U's "limb point" is somewhere between the first limb
and the PREC:th limb.
Both U and V are part of the final result. */
if (uexp > usize)
{
/* uuuuuu0000. */
/* + v. */
/* We begin with moving U to the top of SUM, to handle
samevar(U,SUM). */
MPN_COPY_DECR (sump + uexp - usize, up, usize);
sump[0] = v;
MPN_ZERO (sump + 1, uexp - usize - 1);
#if 0 /* What is this??? */
if (sum == u)
MPN_COPY (sum->_mp_d, sump, uexp);
#endif
sum->_mp_size = uexp;
sum->_mp_exp = uexp;
}
else
{
/* uuuuuu.uuuu */
/* + v. */
mp_limb_t cy_limb;
if (usize > prec)
{
/* Ignore excess limbs in U. */
up += usize - prec;
usize -= usize - prec; /* Eq. usize = prec */
}
if (sump != up)
MPN_COPY (sump, up, usize - uexp);
cy_limb = mpn_add_1 (sump + usize - uexp, up + usize - uexp,
uexp, (mp_limb_t) v);
sump[usize] = cy_limb;
sum->_mp_size = usize + cy_limb;
sum->_mp_exp = uexp + cy_limb;
}
}
}
else
{
/* U < 1, so V > U for sure. */
/* v. */
/* .0000uuuu */
if ((-uexp) >= prec)
{
sump[0] = v;
sum->_mp_size = 1;
sum->_mp_exp = 1;
}
else
{
if (usize + (-uexp) + 1 > prec)
{
/* Ignore excess limbs in U. */
up += usize + (-uexp) + 1 - prec;
usize -= usize + (-uexp) + 1 - prec;
}
if (sump != up)
MPN_COPY (sump, up, usize);
MPN_ZERO (sump + usize, -uexp);
sump[usize + (-uexp)] = v;
sum->_mp_size = usize + (-uexp) + 1;
sum->_mp_exp = 1;
}
}
}