mirror of
https://github.com/cryb-to/cryb-to.git
synced 2024-11-30 17:45:42 +00:00
55 lines
1.9 KiB
C
55 lines
1.9 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2017 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "cryb/impl.h"
|
||
|
|
|
||
|
|
#include <stddef.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
#include <cryb/mpi.h>
|
||
|
|
|
||
|
|
#include "cryb_mpi_impl.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the 1-based index of the least significant bit of X
|
||
|
|
*/
|
||
|
|
unsigned int
|
||
|
|
mpi_lsb(const cryb_mpi *X)
|
||
|
|
{
|
||
|
|
unsigned int lsw, lsb;
|
||
|
|
|
||
|
|
if (X->msb == 0)
|
||
|
|
return (0);
|
||
|
|
for (lsw = 0; X->words[lsw] == 0; ++lsw)
|
||
|
|
/* nothing */ ;
|
||
|
|
for (lsb = 0; (X->words[lsw] & (1 << lsb)) == 0; ++lsb)
|
||
|
|
/* nothing */ ;
|
||
|
|
return (lsw * 32 + lsb + 1);
|
||
|
|
}
|