1  /* mpn_addmul_1 -- multiply the N long limb vector pointed to by UP by VL,
       2     add the N least significant limbs of the product to the limb vector
       3     pointed to by RP.  Return the most significant limb of the product,
       4     adjusted for carry-out from the addition.
       5  
       6  Copyright 1992-1994, 1996, 2000, 2002, 2004, 2016 Free Software Foundation,
       7  Inc.
       8  
       9  This file is part of the GNU MP Library.
      10  
      11  The GNU MP Library is free software; you can redistribute it and/or modify
      12  it under the terms of either:
      13  
      14    * the GNU Lesser General Public License as published by the Free
      15      Software Foundation; either version 3 of the License, or (at your
      16      option) any later version.
      17  
      18  or
      19  
      20    * the GNU General Public License as published by the Free Software
      21      Foundation; either version 2 of the License, or (at your option) any
      22      later version.
      23  
      24  or both in parallel, as here.
      25  
      26  The GNU MP Library is distributed in the hope that it will be useful, but
      27  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      28  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      29  for more details.
      30  
      31  You should have received copies of the GNU General Public License and the
      32  GNU Lesser General Public License along with the GNU MP Library.  If not,
      33  see https://www.gnu.org/licenses/.  */
      34  
      35  #include "gmp-impl.h"
      36  #include "longlong.h"
      37  
      38  
      39  #if GMP_NAIL_BITS == 0
      40  
      41  mp_limb_t
      42  mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t v0)
      43  {
      44    mp_limb_t u0, crec, c, p1, p0, r0;
      45  
      46    ASSERT (n >= 1);
      47    ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
      48  
      49    crec = 0;
      50    do
      51      {
      52        u0 = *up++;
      53        umul_ppmm (p1, p0, u0, v0);
      54  
      55        r0 = *rp;
      56  
      57        p0 = r0 + p0;
      58        c = r0 > p0;
      59  
      60        p1 = p1 + c;
      61  
      62        r0 = p0 + crec;		/* cycle 0, 3, ... */
      63        c = p0 > r0;		/* cycle 1, 4, ... */
      64  
      65        crec = p1 + c;		/* cycle 2, 5, ... */
      66  
      67        *rp++ = r0;
      68      }
      69    while (--n != 0);
      70  
      71    return crec;
      72  }
      73  
      74  #endif
      75  
      76  #if GMP_NAIL_BITS == 1
      77  
      78  mp_limb_t
      79  mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t v0)
      80  {
      81    mp_limb_t shifted_v0, u0, r0, p0, p1, prev_p1, crec, xl, c1, c2, c3;
      82  
      83    ASSERT (n >= 1);
      84    ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
      85    ASSERT_MPN (rp, n);
      86    ASSERT_MPN (up, n);
      87    ASSERT_LIMB (v0);
      88  
      89    shifted_v0 = v0 << GMP_NAIL_BITS;
      90    crec = 0;
      91    prev_p1 = 0;
      92    do
      93      {
      94        u0 = *up++;
      95        r0 = *rp;
      96        umul_ppmm (p1, p0, u0, shifted_v0);
      97        p0 >>= GMP_NAIL_BITS;
      98        ADDC_LIMB (c1, xl, prev_p1, p0);
      99        ADDC_LIMB (c2, xl, xl, r0);
     100        ADDC_LIMB (c3, xl, xl, crec);
     101        crec = c1 + c2 + c3;
     102        *rp++ = xl;
     103        prev_p1 = p1;
     104      }
     105    while (--n != 0);
     106  
     107    return prev_p1 + crec;
     108  }
     109  
     110  #endif
     111  
     112  #if GMP_NAIL_BITS >= 2
     113  
     114  mp_limb_t
     115  mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t v0)
     116  {
     117    mp_limb_t shifted_v0, u0, r0, p0, p1, prev_p1, xw, crec, xl;
     118  
     119    ASSERT (n >= 1);
     120    ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
     121    ASSERT_MPN (rp, n);
     122    ASSERT_MPN (up, n);
     123    ASSERT_LIMB (v0);
     124  
     125    shifted_v0 = v0 << GMP_NAIL_BITS;
     126    crec = 0;
     127    prev_p1 = 0;
     128    do
     129      {
     130        u0 = *up++;
     131        r0 = *rp;
     132        umul_ppmm (p1, p0, u0, shifted_v0);
     133        p0 >>= GMP_NAIL_BITS;
     134        xw = prev_p1 + p0 + r0 + crec;
     135        crec = xw >> GMP_NUMB_BITS;
     136        xl = xw & GMP_NUMB_MASK;
     137        *rp++ = xl;
     138        prev_p1 = p1;
     139      }
     140    while (--n != 0);
     141  
     142    return prev_p1 + crec;
     143  }
     144  
     145  #endif