vasilito
ff4ff35918
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.
132 lines
3.5 KiB
C
132 lines
3.5 KiB
C
/* mpn_sec_div_qr, mpn_sec_div_r -- Compute Q = floor(U / V), U = U mod V.
|
|
Side-channel silent under the assumption that the used instructions are
|
|
side-channel silent.
|
|
|
|
Contributed to the GNU project by Torbjörn Granlund.
|
|
|
|
Copyright 2011-2015 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/. */
|
|
|
|
#include "gmp-impl.h"
|
|
#include "longlong.h"
|
|
|
|
#if OPERATION_sec_div_qr
|
|
#define FNAME mpn_sec_div_qr
|
|
#define FNAME_itch mpn_sec_div_qr_itch
|
|
#define Q(q) q,
|
|
#define RETTYPE mp_limb_t
|
|
#endif
|
|
#if OPERATION_sec_div_r
|
|
#define FNAME mpn_sec_div_r
|
|
#define FNAME_itch mpn_sec_div_r_itch
|
|
#define Q(q)
|
|
#define RETTYPE void
|
|
#endif
|
|
|
|
mp_size_t
|
|
FNAME_itch (mp_size_t nn, mp_size_t dn)
|
|
{
|
|
#if OPERATION_sec_div_qr
|
|
/* Needs (nn + dn + 1) + mpn_sec_pi1_div_qr's needs of (2nn' - dn + 1) for a
|
|
total of 3nn + 4 limbs at tp. Note that mpn_sec_pi1_div_qr's nn is one
|
|
greater than ours, therefore +4 and not just +2. */
|
|
return 3 * nn + 4;
|
|
#endif
|
|
#if OPERATION_sec_div_r
|
|
/* Needs (nn + dn + 1) + mpn_sec_pi1_div_r's needs of (dn + 1) for a total of
|
|
nn + 2dn + 2 limbs at tp. */
|
|
return nn + 2 * dn + 2;
|
|
#endif
|
|
}
|
|
|
|
RETTYPE
|
|
FNAME (Q(mp_ptr qp)
|
|
mp_ptr np, mp_size_t nn,
|
|
mp_srcptr dp, mp_size_t dn,
|
|
mp_ptr tp)
|
|
{
|
|
mp_limb_t d1, d0;
|
|
unsigned int cnt;
|
|
mp_limb_t inv32;
|
|
|
|
ASSERT (dn >= 1);
|
|
ASSERT (nn >= dn);
|
|
ASSERT (dp[dn - 1] != 0);
|
|
|
|
d1 = dp[dn - 1];
|
|
count_leading_zeros (cnt, d1);
|
|
|
|
if (cnt != 0)
|
|
{
|
|
mp_limb_t qh, cy;
|
|
mp_ptr np2, dp2;
|
|
dp2 = tp; /* dn limbs */
|
|
mpn_lshift (dp2, dp, dn, cnt);
|
|
|
|
np2 = tp + dn; /* (nn + 1) limbs */
|
|
cy = mpn_lshift (np2, np, nn, cnt);
|
|
np2[nn++] = cy;
|
|
|
|
d0 = dp2[dn - 1];
|
|
d0 += (~d0 != 0);
|
|
invert_limb (inv32, d0);
|
|
|
|
/* We add nn + dn to tp here, not nn + 1 + dn, as expected. This is
|
|
since nn here will have been incremented. */
|
|
#if OPERATION_sec_div_qr
|
|
qh = mpn_sec_pi1_div_qr (np2 + dn, np2, nn, dp2, dn, inv32, tp + nn + dn);
|
|
ASSERT (qh == 0); /* FIXME: this indicates inefficiency! */
|
|
MPN_COPY (qp, np2 + dn, nn - dn - 1);
|
|
qh = np2[nn - 1];
|
|
#else
|
|
mpn_sec_pi1_div_r (np2, nn, dp2, dn, inv32, tp + nn + dn);
|
|
#endif
|
|
|
|
mpn_rshift (np, np2, dn, cnt);
|
|
|
|
#if OPERATION_sec_div_qr
|
|
return qh;
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
/* FIXME: Consider copying np => np2 here, adding a 0-limb at the top.
|
|
That would simplify the underlying pi1 function, since then it could
|
|
assume nn > dn. */
|
|
d0 = dp[dn - 1];
|
|
d0 += (~d0 != 0);
|
|
invert_limb (inv32, d0);
|
|
|
|
#if OPERATION_sec_div_qr
|
|
return mpn_sec_pi1_div_qr (qp, np, nn, dp, dn, inv32, tp);
|
|
#else
|
|
mpn_sec_pi1_div_r (np, nn, dp, dn, inv32, tp);
|
|
#endif
|
|
}
|
|
}
|