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      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
    146