X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=mpfr%2Fset_ui_2exp.c;fp=mpfr%2Fset_ui_2exp.c;h=c16c9a761935bb8affd8ab30ba28ff63e1a3a3da;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/mpfr/set_ui_2exp.c b/mpfr/set_ui_2exp.c new file mode 100644 index 00000000..c16c9a76 --- /dev/null +++ b/mpfr/set_ui_2exp.c @@ -0,0 +1,73 @@ +/* mpfr_set_ui_2exp -- set a MPFR number from a machine unsigned integer with + a shift + +Copyright 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +Contributed by the Arenaire and Cacao projects, INRIA. + +This file is part of the GNU MPFR Library. + +The GNU MPFR Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 2.1 of the License, or (at your +option) any later version. + +The GNU MPFR 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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, +MA 02110-1301, USA. */ + +#define MPFR_NEED_LONGLONG_H +#include "mpfr-impl.h" + +int +mpfr_set_ui_2exp (mpfr_ptr x, unsigned long i, mp_exp_t e, mp_rnd_t rnd_mode) +{ + MPFR_SET_POS (x); + + if (i == 0) + { + MPFR_SET_ZERO (x); + MPFR_RET (0); + } + else + { + mp_size_t xn; + unsigned int cnt, nbits; + mp_limb_t *xp; + int inex = 0; + + /* FIXME: support int limbs (e.g. 16-bit limbs on 16-bit proc) */ + MPFR_ASSERTD (i == (mp_limb_t) i); + + /* Position of the highest limb */ + xn = (MPFR_PREC (x) - 1) / BITS_PER_MP_LIMB; + count_leading_zeros (cnt, (mp_limb_t) i); + MPFR_ASSERTD (cnt < BITS_PER_MP_LIMB); /* OK since i != 0 */ + + xp = MPFR_MANT(x); + xp[xn] = ((mp_limb_t) i) << cnt; + /* Zero the xn lower limbs. */ + MPN_ZERO(xp, xn); + + nbits = BITS_PER_MP_LIMB - cnt; + e += nbits; /* exponent _before_ the rounding */ + + /* round if MPFR_PREC(x) smaller than length of i */ + if (MPFR_UNLIKELY (MPFR_PREC (x) < nbits) && + MPFR_UNLIKELY (mpfr_round_raw (xp + xn, xp + xn, nbits, 0, + MPFR_PREC (x), rnd_mode, &inex))) + { + e++; + xp[xn] = MPFR_LIMB_HIGHBIT; + } + + MPFR_CLEAR_FLAGS (x); + MPFR_EXP (x) = e; + return mpfr_check_range (x, inex, rnd_mode); + } +}