source/libs/gmp/gmp-src/mpn/generic/addmul_1.c

   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 Free Software Foundation, Inc.
   7
   8 This file is part of the GNU MP Library.
   9
  10 The GNU MP Library is free software; you can redistribute it and/or modify
  11 it under the terms of either:
  12
  13   * the GNU Lesser General Public License as published by the Free
  14     Software Foundation; either version 3 of the License, or (at your
  15     option) any later version.
  16
  17 or
  18
  19   * the GNU General Public License as published by the Free Software
  20     Foundation; either version 2 of the License, or (at your option) any
  21     later version.
  22
  23 or both in parallel, as here.
  24
  25 The GNU MP Library is distributed in the hope that it will be useful, but
  26 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  27 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  28 for more details.
  29
  30 You should have received copies of the GNU General Public License and the
  31 GNU Lesser General Public License along with the GNU MP Library.  If not,
  32 see https://www.gnu.org/licenses/.  */
  33
  34 #include "gmp.h"
  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 vl)
  43 {
  44   mp_limb_t ul, cl, hpl, lpl, rl;
  45
  46   ASSERT (n >= 1);
  47   ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
  48
  49   cl = 0;
  50   do
  51     {
  52       ul = *up++;
  53       umul_ppmm (hpl, lpl, ul, vl);
  54
  55       lpl += cl;
  56       cl = (lpl < cl) + hpl;
  57
  58       rl = *rp;
  59       lpl = rl + lpl;
  60       cl += lpl < rl;
  61       *rp++ = lpl;
  62     }
  63   while (--n != 0);
  64
  65   return cl;
  66 }
  67
  68 #endif
  69
  70 #if GMP_NAIL_BITS == 1
  71
  72 mp_limb_t
  73 mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl)
  74 {
  75   mp_limb_t shifted_vl, ul, rl, lpl, hpl, prev_hpl, cl, xl, c1, c2, c3;
  76
  77   ASSERT (n >= 1);
  78   ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
  79   ASSERT_MPN (rp, n);
  80   ASSERT_MPN (up, n);
  81   ASSERT_LIMB (vl);
  82
  83   shifted_vl = vl << GMP_NAIL_BITS;
  84   cl = 0;
  85   prev_hpl = 0;
  86   do
  87     {
  88       ul = *up++;
  89       rl = *rp;
  90       umul_ppmm (hpl, lpl, ul, shifted_vl);
  91       lpl >>= GMP_NAIL_BITS;
  92       ADDC_LIMB (c1, xl, prev_hpl, lpl);
  93       ADDC_LIMB (c2, xl, xl, rl);
  94       ADDC_LIMB (c3, xl, xl, cl);
  95       cl = c1 + c2 + c3;
  96       *rp++ = xl;
  97       prev_hpl = hpl;
  98     }
  99   while (--n != 0);
 100
 101   return prev_hpl + cl;
 102 }
 103
 104 #endif
 105
 106 #if GMP_NAIL_BITS >= 2
 107
 108 mp_limb_t
 109 mpn_addmul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl)
 110 {
 111   mp_limb_t shifted_vl, ul, rl, lpl, hpl, prev_hpl, xw, cl, xl;
 112
 113   ASSERT (n >= 1);
 114   ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
 115   ASSERT_MPN (rp, n);
 116   ASSERT_MPN (up, n);
 117   ASSERT_LIMB (vl);
 118
 119   shifted_vl = vl << GMP_NAIL_BITS;
 120   cl = 0;
 121   prev_hpl = 0;
 122   do
 123     {
 124       ul = *up++;
 125       rl = *rp;
 126       umul_ppmm (hpl, lpl, ul, shifted_vl);
 127       lpl >>= GMP_NAIL_BITS;
 128       xw = prev_hpl + lpl + rl + cl;
 129       cl = xw >> GMP_NUMB_BITS;
 130       xl = xw & GMP_NUMB_MASK;
 131       *rp++ = xl;
 132       prev_hpl = hpl;
 133     }
 134   while (--n != 0);
 135
 136   return prev_hpl + cl;
 137 }
 138
 139 #endif