diff options
author | Thomas Voss <mail@thomasvoss.com> | 2024-06-21 23:36:36 +0200 |
---|---|---|
committer | Thomas Voss <mail@thomasvoss.com> | 2024-06-21 23:42:26 +0200 |
commit | a89a14ef5da44684a16b204e7a70460cc8c4922a (patch) | |
tree | b23b4c6b155977909ef508fdae2f48d33d802813 /vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c | |
parent | 1db63fcedab0b288820d66e100b1877b1a5a8851 (diff) |
Basic constant folding implementation
Diffstat (limited to 'vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c')
-rw-r--r-- | vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c b/vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c new file mode 100644 index 0000000..70e617b --- /dev/null +++ b/vendor/gmp-6.3.0/mpn/generic/div_qr_2u_pi1.c @@ -0,0 +1,76 @@ +/* mpn_div_qr_2u_pi1 + + Contributed to the GNU project by Niels Möller + + THIS FILE CONTAINS INTERNAL FUNCTIONS WITH MUTABLE INTERFACES. IT IS ONLY + SAFE TO REACH THEM THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST + GUARANTEED THAT THEY'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE. + + +Copyright 2011 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" + + +/* 3/2 loop, for unnormalized divisor. Caller must pass shifted d1 and + d0, while {np,nn} is shifted on the fly. */ +mp_limb_t +mpn_div_qr_2u_pi1 (mp_ptr qp, mp_ptr rp, mp_srcptr np, mp_size_t nn, + mp_limb_t d1, mp_limb_t d0, int shift, mp_limb_t di) +{ + mp_limb_t qh; + mp_limb_t r2, r1, r0; + mp_size_t i; + + ASSERT (nn >= 2); + ASSERT (d1 & GMP_NUMB_HIGHBIT); + ASSERT (shift > 0); + + r2 = np[nn-1] >> (GMP_LIMB_BITS - shift); + r1 = (np[nn-1] << shift) | (np[nn-2] >> (GMP_LIMB_BITS - shift)); + r0 = np[nn-2] << shift; + + udiv_qr_3by2 (qh, r2, r1, r2, r1, r0, d1, d0, di); + + for (i = nn - 2 - 1; i >= 0; i--) + { + mp_limb_t q; + r0 = np[i]; + r1 |= r0 >> (GMP_LIMB_BITS - shift); + r0 <<= shift; + udiv_qr_3by2 (q, r2, r1, r2, r1, r0, d1, d0, di); + qp[i] = q; + } + + rp[0] = (r1 >> shift) | (r2 << (GMP_LIMB_BITS - shift)); + rp[1] = r2 >> shift; + + return qh; +} |