/* Cray PVP/IEEE mpn_mul_basecase.

Copyright 2000, 2001 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify

it under the terms of either:

  * the GNU Lesser General Public License as published by the Free

    Software Foundation; either version 3 of the License, or (at your

    option) any later version.

or

  * the GNU General Public License as published by the Free Software

    Foundation; either version 2 of the License, or (at your option) any

    later version.

or both in parallel, as here.

The GNU MP Library is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

You should have received copies of the GNU General Public License and the

GNU Lesser General Public License along with the GNU MP Library.  If not,

see https://www.gnu.org/licenses/.  */

/* The most critical loop of this code runs at about 5 cycles/limb on a T90.

   That is not perfect, mainly due to vector register shortage.  */

#include <intrinsics.h>

#include "gmp.h"

#include "gmp-impl.h"

void

mpn_mul_basecase (mp_ptr rp,

		  mp_srcptr up, mp_size_t un,

		  mp_srcptr vp, mp_size_t vn)

{

  mp_limb_t cy[un + vn];

  mp_limb_t vl;

  mp_limb_t a, b, r, s0, s1, c0, c1;

  mp_size_t i, j;

  int more_carries;

  for (i = 0; i < un + vn; i++)

    {

      rp[i] = 0;

      cy[i] = 0;

    }

#pragma _CRI novector

  for (j = 0; j < vn; j++)

    {

      vl = vp[j];

      a = up[0] * vl;

      r = rp[j];

      s0 = a + r;

      rp[j] = s0;

      c0 = ((a & r) | ((a | r) & ~s0)) >> 63;

      cy[j] += c0;

#pragma _CRI ivdep

      for (i = 1; i < un; i++)

	{

	  a = up[i] * vl;

	  b = _int_mult_upper (up[i - 1], vl);

	  s0 = a + b;

	  c0 = ((a & b) | ((a | b) & ~s0)) >> 63;

	  r = rp[j + i];

	  s1 = s0 + r;

	  rp[j + i] = s1;

	  c1 = ((s0 & r) | ((s0 | r) & ~s1)) >> 63;

	  cy[j + i] += c0 + c1;

	}

      rp[j + un] = _int_mult_upper (up[un - 1], vl);

    }

  more_carries = 0;

#pragma _CRI ivdep

  for (i = 1; i < un + vn; i++)

    {

      r = rp[i];

      c0 = cy[i - 1];

      s0 = r + c0;

      rp[i] = s0;

      c0 = (r & ~s0) >> 63;

      more_carries += c0;

    }

  /* If that second loop generated carry, handle that in scalar loop.  */

  if (more_carries)

    {

      mp_limb_t cyrec = 0;

      for (i = 1; i < un + vn; i++)

	{

	  r = rp[i];

	  c0 = (r < cy[i - 1]);

	  s0 = r + cyrec;

	  rp[i] = s0;

	  c1 = (r & ~s0) >> 63;

	  cyrec = c0 | c1;

	}

    }

}