diff options
author | vlefevre <vlefevre@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-09-11 14:02:32 +0000 |
---|---|---|
committer | vlefevre <vlefevre@280ebfd0-de03-0410-8827-d642c229c3f4> | 2001-09-11 14:02:32 +0000 |
commit | be9487c8adbe928460d938b461a148dbfd474539 (patch) | |
tree | 68c38e603e19ba5c9d05ec47ce751a122f57ecdc /set_si.c | |
parent | 9912f005a86384a973cf56760ba51c0eb7b1964e (diff) | |
download | mpfr-be9487c8adbe928460d938b461a148dbfd474539.tar.gz |
Inexact ternary value for mpfr_set4, mpfr_set_ui and mpfr_set_si.
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1195 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'set_si.c')
-rw-r--r-- | set_si.c | 47 |
1 files changed, 30 insertions, 17 deletions
@@ -19,53 +19,66 @@ along with the MPFR 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 <stdio.h> #include "gmp.h" #include "gmp-impl.h" #include "longlong.h" #include "mpfr.h" #include "mpfr-impl.h" -void +int #if __STDC__ -mpfr_set_si (mpfr_ptr x, long int i, mp_rnd_t rnd_mode) +mpfr_set_si (mpfr_ptr x, long i, mp_rnd_t rnd_mode) #else mpfr_set_si (x, i, rnd_mode) mpfr_ptr x; - long int i; + long i; mp_rnd_t rnd_mode; #endif { + int inex; mp_size_t xn; - unsigned int cnt; + unsigned int cnt, nbits; mp_limb_t ai, *xp; MPFR_CLEAR_FLAGS(x); - if (i==0) { MPFR_SET_ZERO(x); return; } - xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB; - ai = (unsigned long) ABS(i); + if (i == 0) + { + MPFR_SET_ZERO(x); + if (MPFR_SIGN(x) < 0) MPFR_CHANGE_SIGN(x); + return 0; + } - count_leading_zeros(cnt, ai); + xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB; + ai = SAFE_ABS(long, i); + count_leading_zeros(cnt, ai); xp = MPFR_MANT(x); xp[xn] = ai << cnt; /* don't forget to put zero in lower limbs */ MPN_ZERO(xp, xn); - MPFR_EXP(x) = BITS_PER_MP_LIMB - cnt; + MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt; /* round if MPFR_PREC(x) smaller than length of i */ - if (MPFR_PREC(x) < BITS_PER_MP_LIMB-cnt) { - cnt = mpfr_round_raw(xp+xn, xp+xn, BITS_PER_MP_LIMB-cnt, (ai<0), - MPFR_PREC(x), rnd_mode, NULL); - if (cnt) { /* special case 1.000...000 */ + if (MPFR_PREC(x) < nbits) + { + int carry; + carry = mpfr_round_raw(xp+xn, xp+xn, nbits, (ai < 0), MPFR_PREC(x), + rnd_mode, &inex); + if (carry) + { + mp_exp_t exp = MPFR_EXP(x); + + if (exp == __mpfr_emax) + return mpfr_set_overflow(x, rnd_mode, (ai < 0 ? -1 : 1)); + MPFR_EXP(x)++; - xp[xn] = ((mp_limb_t) 1) << (BITS_PER_MP_LIMB-1); + xp[xn] = MP_LIMB_T_HIGHBIT; } } /* warning: don't change the precision of x! */ - if (i*MPFR_SIGN(x) < 0) MPFR_CHANGE_SIGN(x); + if ((i < 0) ^ (MPFR_SIGN(x) < 0)) MPFR_CHANGE_SIGN(x); - return; + MPFR_RET(inex); } |