Annotation of OpenXM_contrib/gmp/mpz/ui_sub.c, Revision 1.1
1.1 ! ohara 1: /* mpz_ui_sub -- Subtract an unsigned one-word integer and an mpz_t.
! 2:
! 3: Copyright 2002 Free Software Foundation, Inc.
! 4:
! 5: This file is part of the GNU MP Library.
! 6:
! 7: The GNU MP Library is free software; you can redistribute it and/or modify
! 8: it under the terms of the GNU Lesser General Public License as published by
! 9: the Free Software Foundation; either version 2.1 of the License, or (at your
! 10: option) any later version.
! 11:
! 12: The GNU MP Library is distributed in the hope that it will be useful, but
! 13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! 14: or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
! 15: License for more details.
! 16:
! 17: You should have received a copy of the GNU Lesser General Public License
! 18: along with the GNU MP Library; see the file COPYING.LIB. If not, write to
! 19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
! 20: MA 02111-1307, USA. */
! 21:
! 22: #include "gmp.h"
! 23: #include "gmp-impl.h"
! 24:
! 25: void
! 26: mpz_ui_sub (mpz_ptr w, unsigned long int uval, mpz_srcptr v)
! 27: {
! 28: mp_ptr vp, wp;
! 29: mp_size_t vn, wn;
! 30: mp_limb_t cy;
! 31:
! 32: #if GMP_NAIL_BITS != 0
! 33: if (uval > GMP_NUMB_MAX)
! 34: {
! 35: mpz_t u;
! 36: mp_limb_t ul[2];
! 37: PTR(u) = ul;
! 38: ul[0] = uval & GMP_NUMB_MASK;
! 39: ul[1] = uval >> GMP_NUMB_BITS;
! 40: SIZ(u) = 2;
! 41: mpz_sub (w, u, v);
! 42: return;
! 43: }
! 44: #endif
! 45:
! 46: vp = PTR(v);
! 47: vn = SIZ(v);
! 48:
! 49: wp = PTR(w);
! 50:
! 51: if (vn > 1)
! 52: {
! 53: wp = MPZ_REALLOC (w, vn);
! 54: vp = PTR(v);
! 55: mpn_sub_1 (wp, vp, vn, (mp_limb_t) uval);
! 56: wn = -(vn - (wp[vn - 1] == 0));
! 57: }
! 58: else if (vn == 1)
! 59: {
! 60: if (uval >= vp[0])
! 61: {
! 62: wp[0] = uval - vp[0];
! 63: wn = wp[0] != 0;
! 64: }
! 65: else
! 66: {
! 67: wp[0] = vp[0] - uval;
! 68: wn = -1;
! 69: }
! 70: }
! 71: else if (vn == 0)
! 72: {
! 73: wp[0] = uval;
! 74: wn = uval != 0;
! 75: }
! 76: else /* (vn < 0) */
! 77: {
! 78: vn = -vn;
! 79: wp = MPZ_REALLOC (w, vn + 1);
! 80: vp = PTR(v);
! 81: cy = mpn_add_1 (wp, vp, vn, (mp_limb_t) uval);
! 82: wp[vn] = cy;
! 83: wn = vn + (cy != 0);
! 84: }
! 85:
! 86: SIZ(w) = wn;
! 87: }
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