Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /* mpi-sub-ui.c - Subtract an unsigned integer from an MPI.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Free Software Foundation, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * This file was based on the GNU MP Library source file:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * The GNU MP Library is free software; you can redistribute it and/or modify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * it under the terms of either:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  *   * the GNU Lesser General Public License as published by the Free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  *     Software Foundation; either version 3 of the License, or (at your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  *     option) any later version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  *   * the GNU General Public License as published by the Free Software
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  *     Foundation; either version 2 of the License, or (at your option) any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  *     later version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * or both in parallel, as here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * The GNU MP Library is distributed in the hope that it will be useful, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * You should have received copies of the GNU General Public License and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  * GNU Lesser General Public License along with the GNU MP Library.  If not,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  * see https://www.gnu.org/licenses/.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include "mpi-internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) int mpi_sub_ui(MPI w, MPI u, unsigned long vval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	if (u->nlimbs == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		if (mpi_resize(w, 1) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 			return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 		w->d[0] = vval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 		w->nlimbs = (vval != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		w->sign = (vval != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	/* If not space for W (and possible carry), increase space. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	if (mpi_resize(w, u->nlimbs + 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	if (u->sign) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		mpi_limb_t cy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 		w->d[u->nlimbs] = cy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 		w->nlimbs = u->nlimbs + cy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		w->sign = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 		/* The signs are different.  Need exact comparison to determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 		 * which operand to subtract from which.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 		if (u->nlimbs == 1 && u->d[0] < vval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 			w->d[0] = vval - u->d[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 			w->nlimbs = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 			w->sign = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 			mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 			/* Size can decrease with at most one limb. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 			w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 			w->sign = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	mpi_normalize(w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) EXPORT_SYMBOL_GPL(mpi_sub_ui);