Files
RedBear-OS/recipes/libs/libgmp/source/mpn/cray/add_n.c
T
vasilito ff4ff35918 feat: track all source trees in git — full fork offline-first model
Red Bear OS is a full fork. All sources must be available from git clone
with zero network access. Removed gitignore rules that excluded fetched
source trees under recipes/*/source/, local/recipes/kde/*/source/,
local/recipes/qt/*/source/, and vendor source trees.

Build artifacts (target/, build/, source.tar, *.o, *.so) remain excluded.

127291 files added — kernel, relibc, base, bootloader, pkgar, all KDE/Qt
frameworks, mesa, wayland, DRM drivers, and every other recipe source.
2026-05-14 10:55:53 +01:00

91 lines
2.5 KiB
C

/* Cray PVP mpn_add_n -- add two limb vectors and store their sum in a third
limb vector.
Copyright 1996, 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 4 cycles/limb. It may be possible to bring it down
to 3 cycles/limb. */
#include "gmp-impl.h"
mp_limb_t
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;
int more_carries;
/* 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++)
{
a = up[i];
b = vp[i];
s0 = a + b;
rp[i] = s0;
c0 = ((a & b) | ((a | b) & ~s0)) >> 63;
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]. If this generates further carry, set
more_carries. */
more_carries = 0;
#pragma _CRI ivdep
for (i = 1; 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 = 1; 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 cyrec | cy[n - 1];
}
return cy[n - 1];
}