=================================================================== RCS file: /home/cvs/OpenXM_contrib/gmp/mpn/cray/Attic/add_n.c,v retrieving revision 1.1.1.1 retrieving revision 1.1.1.2 diff -u -p -r1.1.1.1 -r1.1.1.2 --- OpenXM_contrib/gmp/mpn/cray/Attic/add_n.c 2000/09/09 14:12:22 1.1.1.1 +++ OpenXM_contrib/gmp/mpn/cray/Attic/add_n.c 2003/08/25 16:06:18 1.1.1.2 @@ -1,96 +1,82 @@ -/* mpn_add_n -- Add two limb vectors of equal, non-zero length. - For Cray vector processors. +/* Cray PVP mpn_add_n -- add two limb vectors and store their sum in a third + limb vector. - Copyright (C) 1996, 2000 Free Software Foundation, Inc. +Copyright 1996, 2000, 2001 Free Software Foundation, Inc. - This file is part of the GNU MP Library. +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 the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or (at your - option) any later version. +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 2.1 of the License, or (at your +option) any later version. - 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 Lesser General Public - License for more details. +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 Lesser General Public +License for more details. - You should have received a copy of the GNU Lesser General Public License - along with the GNU MP Library; see the file COPYING.LIB. If not, write to - the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, - MA 02111-1307, USA. */ +You should have received a copy of the GNU Lesser General Public License +along with the GNU MP Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +MA 02111-1307, USA. */ +/* This code runs at 4 cycles/limb. It may be possible to bring it down + to 3 cycles/limb. */ + #include "gmp.h" #include "gmp-impl.h" mp_limb_t -mpn_add_n (c, a, b, n) - mp_ptr c; - mp_srcptr a, b; - mp_size_t n; +mpn_add_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n) { + mp_limb_t cy[n]; + mp_limb_t a, b, r, s0, c0, c1; mp_size_t i; - mp_size_t nm1 = n - 1; - int more_carries = 0; - int carry_out; + int more_carries; - /* For small operands the non-vector code is faster. */ - if (n < 16) - goto sequential; - - if (a == c || b == c) + /* Main add loop. Generate a raw output sum in rp[] and a carry vector + in cy[]. */ +#pragma _CRI ivdep + for (i = 0; i < n; i++) { - TMP_DECL (marker); - TMP_MARK (marker); - if (c == a) - { - /* allocate temp space for a */ - mp_ptr ax = (mp_ptr) TMP_ALLOC (n * BYTES_PER_MP_LIMB); - MPN_COPY (ax, a, n); - a = (mp_srcptr) ax; - } - if (c == b) - { - /* allocate temp space for b */ - mp_ptr bx = (mp_ptr) TMP_ALLOC (n * BYTES_PER_MP_LIMB); - MPN_COPY (bx, b, n); - b = (mp_srcptr) bx; - } - carry_out = mpn_add_n (c, a, b, n); - TMP_FREE (marker); - return carry_out; + a = up[i]; + b = vp[i]; + s0 = a + b; + rp[i] = s0; + c0 = ((a & b) | ((a | b) & ~s0)) >> 63; + cy[i] = c0; } - - carry_out = a[nm1] + b[nm1] < a[nm1]; - -#pragma _CRI ivdep /* Cray PVP systems */ - for (i = nm1; i > 0; i--) + /* Carry add loop. Add the carry vector cy[] to the raw sum rp[] and + store the new sum back to rp[0]. If this generates further carry, set + more_carries. */ + more_carries = 0; +#pragma _CRI ivdep + for (i = 1; i < n; i++) { - int cy_in; - cy_in = a[i - 1] + b[i - 1] < a[i - 1]; - c[i] = a[i] + b[i] + cy_in; - more_carries += c[i] < cy_in; + r = rp[i]; + c0 = cy[i - 1]; + s0 = r + c0; + rp[i] = s0; + c0 = (r & ~s0) >> 63; + more_carries += c0; } - c[0] = a[0] + b[0]; - + /* If that second loop generated carry, handle that in scalar loop. */ if (more_carries) { - /* This won't vectorize, but we should come here rarely. */ - int cy; - sequential: - cy = 0; - for (i = 0; i < n; i++) + mp_limb_t cyrec = 0; + /* Look for places where rp[k] is zero and cy[k-1] is non-zero. + These are where we got a recurrency carry. */ + for (i = 1; i < n; i++) { - mp_limb_t ai, ci, t; - ai = a[i]; - t = b[i] + cy; - cy = t < cy; - ci = ai + t; - cy += ci < ai; - c[i] = ci; + r = rp[i]; + c0 = (r == 0 && cy[i - 1] != 0); + s0 = r + cyrec; + rp[i] = s0; + c1 = (r & ~s0) >> 63; + cyrec = c0 | c1; } - carry_out = cy; + return cyrec | cy[n - 1]; } - return carry_out; + return cy[n - 1]; }