source/libs/gmp/gmp-src/mpn/cray/ieee/sqr_basecase.c

   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 }