cryb-to/lib/mpi/cryb_mpi_impl.h

/*
 * Copyright (c) 2014-2016 Dag-Erling Smørgrav
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* n rounded up to nearest multiple of p */
#define RUP(n, p) ((((n) + (p) - 1) / (p)) * (p))

/* one-based index of the most significant word of an mpi */
#define MPI_MSW(n) (((n)->msb + 31) / 32)

/*
 * Initialize an all-zeroes mpi.
 */
#define MPI_FAST_INIT(X)						\
	do {								\
		(X)->words = (X)->swords;				\
		(X)->size = CRYB_MPI_SWORDS;				\
	} while (0)
Big reorganization and cleanup 2016-09-04 12:56:39 +00:00			`/*`
Mechanically bump copyright dates to the date of the latest commit. 2017-02-19 19:07:43 +00:00			`* Copyright (c) 2014-2016 Dag-Erling Smørgrav`
sbuf-inspired managed string implementation which also supports wide strings. 2014-08-01 13:53:04 +00:00			`* All rights reserved.`
			`*`
			`* Redistribution and use in source and binary forms, with or without`
			`* modification, are permitted provided that the following conditions`
			`* are met:`
			`* 1. Redistributions of source code must retain the above copyright`
			`* notice, this list of conditions and the following disclaimer.`
			`* 2. Redistributions in binary form must reproduce the above copyright`
			`* notice, this list of conditions and the following disclaimer in the`
			`* documentation and/or other materials provided with the distribution.`
			`* 3. The name of the author may not be used to endorse or promote`
			`* products derived from this software without specific prior written`
			`* permission.`
			`*`
			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
			`* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE`
			`* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`* SUCH DAMAGE.`
			`*/`

Big reorganization and cleanup 2016-09-04 12:56:39 +00:00			`/* n rounded up to nearest multiple of p */`
			`#define RUP(n, p) ((((n) + (p) - 1) / (p)) * (p))`
sbuf-inspired managed string implementation which also supports wide strings. 2014-08-01 13:53:04 +00:00
Fix equality predicates. The count we passed to memcmp() in mpi_eq() and mpi_eq_abs() was actually the number of significant words in the MPI, rather than the number of bytes we wanted to compare. Multiply by 4 to get the correct value. To make the intent of the code more apparent, introduce a private MPI_MSW() macro which evaluates to the number of significant words (or 1-based index of the most significant word). This also comes in handy in mpi_{add,sub,mul}_abs(). Add a couple of test cases which not only demonstrate the bug we fixed here but also demonstrate why we must compare whole words: on a big-endian machine, we would be comparing the unused upper bytes of the first and only word instead of the lower bytes which actually hold a value... 2017-04-22 03:32:25 +00:00			`/* one-based index of the most significant word of an mpi */`
			`#define MPI_MSW(n) (((n)->msb + 31) / 32)`

Big reorganization and cleanup 2016-09-04 12:56:39 +00:00			`/*`
			`* Initialize an all-zeroes mpi.`
			`*/`
			`#define MPI_FAST_INIT(X) \`
			`do { \`
			`(X)->words = (X)->swords; \`
			`(X)->size = CRYB_MPI_SWORDS; \`
			`} while (0)`