From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001 From: Duncan Wilkie Date: Sat, 18 Nov 2023 06:11:09 -0600 Subject: Initial commit. --- gmp-6.3.0/mpn/cray/ieee/mul_1.c | 103 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 gmp-6.3.0/mpn/cray/ieee/mul_1.c (limited to 'gmp-6.3.0/mpn/cray/ieee/mul_1.c') diff --git a/gmp-6.3.0/mpn/cray/ieee/mul_1.c b/gmp-6.3.0/mpn/cray/ieee/mul_1.c new file mode 100644 index 0000000..40139fb --- /dev/null +++ b/gmp-6.3.0/mpn/cray/ieee/mul_1.c @@ -0,0 +1,103 @@ +/* Cray PVP/IEEE mpn_mul_1 -- multiply a limb vector with a limb and store the + result in a second limb vector. + +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/. */ + +/* This code runs at 5 cycles/limb on a T90. That would probably + be hard to improve upon, even with assembly code. */ + +#include +#include "gmp-impl.h" + +mp_limb_t +mpn_mul_1 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_limb_t vl) +{ + mp_limb_t cy[n]; + mp_limb_t a, b, r, s0, s1, c0, c1; + mp_size_t i; + int more_carries; + + if (up == rp) + { + /* The algorithm used below cannot handle overlap. Handle it here by + making a temporary copy of the source vector, then call ourselves. */ + mp_limb_t xp[n]; + MPN_COPY (xp, up, n); + return mpn_mul_1 (rp, xp, n, vl); + } + + a = up[0] * vl; + rp[0] = a; + cy[0] = 0; + + /* Main multiply loop. Generate a raw accumulated output product in rp[] + and a carry vector in cy[]. */ +#pragma _CRI ivdep + for (i = 1; i < n; i++) + { + a = up[i] * vl; + b = _int_mult_upper (up[i - 1], vl); + s0 = a + b; + c0 = ((a & b) | ((a | b) & ~s0)) >> 63; + rp[i] = s0; + cy[i] = c0; + } + /* Carry add loop. Add the carry vector cy[] to the raw sum rp[] and + store the new sum back to rp[0]. */ + more_carries = 0; +#pragma _CRI ivdep + for (i = 2; i < n; 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; + /* 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 = 2; i < n; i++) + { + r = rp[i]; + c0 = (r == 0 && cy[i - 1] != 0); + s0 = r + cyrec; + rp[i] = s0; + c1 = (r & ~s0) >> 63; + cyrec = c0 | c1; + } + return _int_mult_upper (up[n - 1], vl) + cyrec + cy[n - 1]; + } + + return _int_mult_upper (up[n - 1], vl) + cy[n - 1]; +} -- cgit v1.2.3