github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/cray/ieee/sqr_basecase.c (about)

     1  /* Cray PVP/IEEE mpn_sqr_basecase.
     2  
     3  Copyright 2000, 2001 Free Software Foundation, Inc.
     4  
     5  This file is part of the GNU MP Library.
     6  
     7  The GNU MP Library is free software; you can redistribute it and/or modify
     8  it under the terms of either:
     9  
    10    * the GNU Lesser General Public License as published by the Free
    11      Software Foundation; either version 3 of the License, or (at your
    12      option) any later version.
    13  
    14  or
    15  
    16    * the GNU General Public License as published by the Free Software
    17      Foundation; either version 2 of the License, or (at your option) any
    18      later version.
    19  
    20  or both in parallel, as here.
    21  
    22  The GNU MP Library is distributed in the hope that it will be useful, but
    23  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    24  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    25  for more details.
    26  
    27  You should have received copies of the GNU General Public License and the
    28  GNU Lesser General Public License along with the GNU MP Library.  If not,
    29  see https://www.gnu.org/licenses/.  */
    30  
    31  /* This is just mpn_mul_basecase with trivial modifications.  */
    32  
    33  #include <intrinsics.h>
    34  #include "gmp.h"
    35  #include "gmp-impl.h"
    36  
    37  void
    38  mpn_sqr_basecase (mp_ptr rp,
    39  		  mp_srcptr up, mp_size_t un)
    40  {
    41    mp_limb_t cy[un + un];
    42    mp_limb_t ul;
    43    mp_limb_t a, b, r, s0, s1, c0, c1;
    44    mp_size_t i, j;
    45    int more_carries;
    46  
    47    for (i = 0; i < un + un; i++)
    48      {
    49        rp[i] = 0;
    50        cy[i] = 0;
    51      }
    52  
    53  #pragma _CRI novector
    54    for (j = 0; j < un; j++)
    55      {
    56        ul = up[j];
    57  
    58        a = up[0] * ul;
    59        r = rp[j];
    60        s0 = a + r;
    61        rp[j] = s0;
    62        c0 = ((a & r) | ((a | r) & ~s0)) >> 63;
    63        cy[j] += c0;
    64  
    65  #pragma _CRI ivdep
    66        for (i = 1; i < un; i++)
    67  	{
    68  	  a = up[i] * ul;
    69  	  b = _int_mult_upper (up[i - 1], ul);
    70  	  s0 = a + b;
    71  	  c0 = ((a & b) | ((a | b) & ~s0)) >> 63;
    72  	  r = rp[j + i];
    73  	  s1 = s0 + r;
    74  	  rp[j + i] = s1;
    75  	  c1 = ((s0 & r) | ((s0 | r) & ~s1)) >> 63;
    76  	  cy[j + i] += c0 + c1;
    77  	}
    78        rp[j + un] = _int_mult_upper (up[un - 1], ul);
    79      }
    80  
    81    more_carries = 0;
    82  #pragma _CRI ivdep
    83    for (i = 1; i < un + un; i++)
    84      {
    85        r = rp[i];
    86        c0 = cy[i - 1];
    87        s0 = r + c0;
    88        rp[i] = s0;
    89        c0 = (r & ~s0) >> 63;
    90        more_carries += c0;
    91      }
    92    /* If that second loop generated carry, handle that in scalar loop.  */
    93    if (more_carries)
    94      {
    95        mp_limb_t cyrec = 0;
    96        for (i = 1; i < un + un; i++)
    97  	{
    98  	  r = rp[i];
    99  	  c0 = (r < cy[i - 1]);
   100  	  s0 = r + cyrec;
   101  	  rp[i] = s0;
   102  	  c1 = (r & ~s0) >> 63;
   103  	  cyrec = c0 | c1;
   104  	}
   105      }
   106  }