mirror of https://github.com/macssh/macssh.git
97 lines
2.4 KiB
C
Executable File
97 lines
2.4 KiB
C
Executable File
/* mpn_add_n -- Add two limb vectors of equal, non-zero length.
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For Cray vector processors.
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Copyright (C) 1996, 2000 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version.
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The GNU MP 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 Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MP 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 "gmp.h"
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#include "gmp-impl.h"
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mp_limb_t
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mpn_add_n (c, a, b, n)
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mp_ptr c;
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mp_srcptr a, b;
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mp_size_t n;
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{
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mp_size_t i;
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mp_size_t nm1 = n - 1;
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int more_carries = 0;
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int carry_out;
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/* For small operands the non-vector code is faster. */
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if (n < 16)
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goto sequential;
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if (a == c || b == c)
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{
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TMP_DECL (marker);
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TMP_MARK (marker);
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if (c == a)
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{
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/* allocate temp space for a */
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mp_ptr ax = (mp_ptr) TMP_ALLOC (n * BYTES_PER_MP_LIMB);
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MPN_COPY (ax, a, n);
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a = (mp_srcptr) ax;
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}
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if (c == b)
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{
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/* allocate temp space for b */
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mp_ptr bx = (mp_ptr) TMP_ALLOC (n * BYTES_PER_MP_LIMB);
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MPN_COPY (bx, b, n);
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b = (mp_srcptr) bx;
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}
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carry_out = mpn_add_n (c, a, b, n);
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TMP_FREE (marker);
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return carry_out;
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}
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carry_out = a[nm1] + b[nm1] < a[nm1];
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#pragma _CRI ivdep /* Cray PVP systems */
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for (i = nm1; i > 0; i--)
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{
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int cy_in;
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cy_in = a[i - 1] + b[i - 1] < a[i - 1];
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c[i] = a[i] + b[i] + cy_in;
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more_carries += c[i] < cy_in;
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}
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c[0] = a[0] + b[0];
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if (more_carries)
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{
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/* This won't vectorize, but we should come here rarely. */
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int cy;
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sequential:
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cy = 0;
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for (i = 0; i < n; i++)
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{
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mp_limb_t ai, ci, t;
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ai = a[i];
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t = b[i] + cy;
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cy = t < cy;
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ci = ai + t;
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cy += ci < ai;
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c[i] = ci;
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}
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carry_out = cy;
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}
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return carry_out;
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}
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