mirror of https://github.com/macssh/macssh.git
85 lines
2.6 KiB
C
Executable File
85 lines
2.6 KiB
C
Executable File
/* mpfr_mul_ui -- multiply a floating-point number by a machine integer
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Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
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This file is part of the MPFR Library.
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The MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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The MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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License for more details.
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You should have received a copy of the GNU Library General Public License
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along with the MPFR Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include <stdio.h>
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#include "gmp.h"
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#include "gmp-impl.h"
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#include "longlong.h"
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#include "mpfr.h"
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void
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#if __STDC__
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mpfr_mul_ui(mpfr_ptr y, mpfr_srcptr x, unsigned long u, unsigned char RND_MODE)
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#else
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mpfr_mul_ui(y, x, u, RND_MODE)
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mpfr_ptr y;
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mpfr_srcptr x;
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unsigned long u;
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unsigned char RND_MODE;
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#endif
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{
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mp_limb_t carry, *my, *old_my; unsigned long c;
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unsigned long xsize, ysize, cnt, dif;
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TMP_DECL(marker);
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TMP_MARK(marker);
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my = MANT(y);
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ysize = (PREC(y)-1)/BITS_PER_MP_LIMB + 1;
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xsize = (PREC(x)-1)/BITS_PER_MP_LIMB + 1;
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if (ysize < xsize) {
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old_my = my;
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my = (mp_ptr) TMP_ALLOC (xsize * BYTES_PER_MP_LIMB);
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dif=0;
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}
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else dif=ysize-xsize;
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carry = mpn_mul_1(my+dif, MANT(x), xsize, u);
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MPN_ZERO(my, dif);
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/* WARNING: count_leading_zeros is undefined for carry=0 */
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if (carry) count_leading_zeros(cnt, carry);
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else cnt=BITS_PER_MP_LIMB;
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c = mpfr_round_raw(my, my, PREC(x), (SIGN(x)<0),
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PREC(y)-BITS_PER_MP_LIMB+cnt, RND_MODE);
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/* If cnt = 1111111111111 and c = 1 we shall get depressed */
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if (c && (carry == (((mp_limb_t)1) << (BITS_PER_MP_LIMB - cnt)) - 1))
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{
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cnt--;
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mpn_rshift(my, my, ysize, BITS_PER_MP_LIMB - cnt);
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my[ysize - 1] |= ((mp_limb_t) 1) << (BITS_PER_MP_LIMB - 1);
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}
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else
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{
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/* Warning: mpn_rshift is undefined for shift=0 */
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if (cnt!=BITS_PER_MP_LIMB)
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mpn_rshift(my, my, ysize, BITS_PER_MP_LIMB - cnt);
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my[ysize - 1] |= (carry << cnt);
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}
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EXP(y) = EXP(x) + BITS_PER_MP_LIMB - cnt;
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if (ysize < xsize) MPN_COPY(old_my, my, ysize);
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/* set sign */
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if (SIGN(y) != SIGN(x)) CHANGE_SIGN(y);
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TMP_FREE(marker);
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}
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