Coverage Report

Created: 2023-02-22 06:39

/src/gmp-6.2.1/mpn/redc_2.c
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/* mpn_redc_2.  Set rp[] <- up[]/R^n mod mp[].  Clobber up[].
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   mp[] is n limbs; up[] is 2n limbs.
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   THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE.  IT IS ONLY
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   SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
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Copyright (C) 2000-2002, 2004, 2008, 2012 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 either:
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  * the GNU Lesser General Public License as published by the Free
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    Software Foundation; either version 3 of the License, or (at your
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    option) any later version.
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or
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  * the GNU General Public License as published by the Free Software
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    Foundation; either version 2 of the License, or (at your option) any
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    later version.
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or both in parallel, as here.
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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 General Public License
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for more details.
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You should have received copies of the GNU General Public License and the
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GNU Lesser General Public License along with the GNU MP Library.  If not,
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see https://www.gnu.org/licenses/.  */
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#include "gmp-impl.h"
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#include "longlong.h"
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#if GMP_NAIL_BITS != 0
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you lose
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#endif
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/* For testing purposes, define our own mpn_addmul_2 if there is none already
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   available.  */
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#ifndef HAVE_NATIVE_mpn_addmul_2
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#undef mpn_addmul_2
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static mp_limb_t
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mpn_addmul_2 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_srcptr vp)
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{
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  rp[n] = mpn_addmul_1 (rp, up, n, vp[0]);
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  return mpn_addmul_1 (rp + 1, up, n, vp[1]);
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}
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#endif
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#if defined (__GNUC__) && ! defined (NO_ASM) \
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  && defined (__ia64) && W_TYPE_SIZE == 64
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#define umul2low(ph, pl, uh, ul, vh, vl) \
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  do {                  \
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    mp_limb_t _ph, _pl;             \
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    __asm__ ("xma.hu %0 = %3, %5, f0\n\t"       \
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       "xma.l %1 = %3, %5, f0\n\t"        \
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       ";;\n\t"             \
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       "xma.l %0 = %3, %4, %0\n\t"        \
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       ";;\n\t"             \
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       "xma.l %0 = %2, %5, %0"          \
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       : "=&f" (ph), "=&f" (pl)         \
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       : "f" (uh), "f" (ul), "f" (vh), "f" (vl));     \
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  } while (0)
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#endif
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#ifndef umul2low
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#define umul2low(ph, pl, uh, ul, vh, vl) \
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0
  do {                 \
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    mp_limb_t _ph, _pl;             \
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    umul_ppmm (_ph, _pl, ul, vl);          \
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    (ph) = _ph + (ul) * (vh) + (uh) * (vl);       \
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    (pl) = _pl;               \
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  } while (0)
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#endif
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mp_limb_t
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mpn_redc_2 (mp_ptr rp, mp_ptr up, mp_srcptr mp, mp_size_t n, mp_srcptr mip)
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{
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  mp_limb_t q[2];
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  mp_size_t j;
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  mp_limb_t upn;
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  mp_limb_t cy;
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  ASSERT (n > 0);
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  ASSERT_MPN (up, 2*n);
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  if ((n & 1) != 0)
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    {
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      up[0] = mpn_addmul_1 (up, mp, n, (up[0] * mip[0]) & GMP_NUMB_MASK);
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      up++;
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    }
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  for (j = n - 2; j >= 0; j -= 2)
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    {
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      umul2low (q[1], q[0], mip[1], mip[0], up[1], up[0]);
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      upn = up[n];    /* mpn_addmul_2 overwrites this */
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      up[1] = mpn_addmul_2 (up, mp, n, q);
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      up[0] = up[n];
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      up[n] = upn;
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      up += 2;
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    }
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  cy = mpn_add_n (rp, up, up - n, n);
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  return cy;
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}