[proxmark3-svn] / client / reveng / bmpbit.c

/* bmpbit.c
 * Greg Cook, 27/Jun/2016
 */

/* CRC RevEng: arbitrary-precision CRC calculator and algorithm finder
 * Copyright (C) 2010, 2011, 2012, 2013, 2014, 2015, 2016  Gregory Cook
 *
 * This file is part of CRC RevEng.
 *
 * CRC RevEng is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * CRC RevEng 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 a copy of the GNU General Public License
 * along with CRC RevEng.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifdef BMPTST
#  include <stdio.h>
#  include <stdlib.h>
#else
#  define FILE void
#endif
#include "reveng.h"

#if (defined BMPTST) || (BMP_BIT < 32)
/* Size in bits of a bmp_t.  Not necessarily a power of two. */
int bmpbit;

/* The highest power of two that is strictly less than BMP_BIT.
 * Initialises the index of a binary search for set bits in a bmp_t.
 * (Computed correctly for BMP_BIT >= 2)
 */
int bmpsub;

void
setbmp(void) {
	/* Initialise BMP_BIT and BMP_SUB for the local architecture. */
	bmp_t bmpmax = ~(bmp_t) 0;

	bmpbit = 0; bmpsub = 1;

	while(bmpmax) {
		bmpmax <<= 1;
		++bmpbit;
	}

	while((bmpsub | (bmpsub - 1)) < bmpbit - 1)
		bmpsub <<= 1;
}
#endif

#ifdef BMPTST
int
main(int argc, char *argv[]) {
	/* check the compile-time bitmap width is correct, otherwise
	 * searches run forever. */
#  if BMP_BIT > 0
	setbmp();
	if(BMP_BIT != bmpbit || BMP_SUB != bmpsub) {
		fprintf(stderr,"reveng: configuration fault.  Update "
			"config.h with these definitions and "
			"recompile:\n"
			"\t#define BMP_BIT   %d\n"
			"\t#define BMP_SUB   %d\n",
			bmpbit, bmpsub);
		exit(EXIT_FAILURE);
	}
#  endif /* BMP_BIT > 0 */
	/* check the bitmap constant macro */
	if(~(bmp_t) 0 != ~BMP_C(0)) {
		fprintf(stderr, "reveng: configuration fault.  Edit "
			"the definition of BMP_C() in config.h to "
			"match BMP_T and recompile.\n");
		exit(EXIT_FAILURE);
	}
	exit(EXIT_SUCCESS);
}

#endif /* BMPTST */
Commit	Line	Data
a71ece51	1	/* bmpbit.c
2c9e3090	2	* Greg Cook, 27/Jun/2016
a71ece51	3	*/
a71ece51	4
2c9e3090	5	/* CRC RevEng: arbitrary-precision CRC calculator and algorithm finder
ca98f30c	6	* Copyright (C) 2010, 2011, 2012, 2013, 2014, 2015, 2016 Gregory Cook
a71ece51	7	*
	8	* This file is part of CRC RevEng.
	9	*
	10	* CRC RevEng is free software: you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation, either version 3 of the License, or
	13	* (at your option) any later version.
	14	*
	15	* CRC RevEng is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
2c9e3090	21	* along with CRC RevEng. If not, see <https://www.gnu.org/licenses/>.
a71ece51	22	*/
	23
	24	#ifdef BMPTST
	25	# include <stdio.h>
	26	# include <stdlib.h>
	27	#else
	28	# define FILE void
	29	#endif
	30	#include "reveng.h"
	31
	32	#if (defined BMPTST) \|\| (BMP_BIT < 32)
	33	/* Size in bits of a bmp_t. Not necessarily a power of two. */
	34	int bmpbit;
	35
	36	/* The highest power of two that is strictly less than BMP_BIT.
	37	* Initialises the index of a binary search for set bits in a bmp_t.
	38	* (Computed correctly for BMP_BIT >= 2)
	39	*/
	40	int bmpsub;
	41
	42	void
	43	setbmp(void) {
	44	/* Initialise BMP_BIT and BMP_SUB for the local architecture. */
	45	bmp_t bmpmax = ~(bmp_t) 0;
	46
	47	bmpbit = 0; bmpsub = 1;
	48
	49	while(bmpmax) {
	50	bmpmax <<= 1;
	51	++bmpbit;
	52	}
	53
	54	while((bmpsub \| (bmpsub - 1)) < bmpbit - 1)
	55	bmpsub <<= 1;
	56	}
	57	#endif
	58
	59	#ifdef BMPTST
	60	int
	61	main(int argc, char *argv[]) {
	62	/* check the compile-time bitmap width is correct, otherwise
	63	* searches run forever. */
	64	# if BMP_BIT > 0
	65	setbmp();
	66	if(BMP_BIT != bmpbit \|\| BMP_SUB != bmpsub) {
	67	fprintf(stderr,"reveng: configuration fault. Update "
	68	"config.h with these definitions and "
	69	"recompile:\n"
	70	"\t#define BMP_BIT %d\n"
	71	"\t#define BMP_SUB %d\n",
	72	bmpbit, bmpsub);
	73	exit(EXIT_FAILURE);
	74	}
	75	# endif /* BMP_BIT > 0 */
	76	/* check the bitmap constant macro */
	77	if(~(bmp_t) 0 != ~BMP_C(0)) {
	78	fprintf(stderr, "reveng: configuration fault. Edit "
	79	"the definition of BMP_C() in config.h to "
	80	"match BMP_T and recompile.\n");
	81	exit(EXIT_FAILURE);
	82	}
	83	exit(EXIT_SUCCESS);
	84	}
	85
86	#endif /* BMPTST */