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/* _PDCLIB_bigint_div32( _PDCLIB_bigint_t *, _PDCLIB_bigint_t const *, uint_least32_t )
This file is part of the Public Domain C Library (PDCLib).
Permission is granted to use, modify, and / or redistribute at will.
*/
#ifndef REGTEST
#include "pdclib/_PDCLIB_internal.h"
#include <stdint.h>
_PDCLIB_bigint_t * _PDCLIB_bigint_div32( _PDCLIB_bigint_t * _PDCLIB_restrict lhs, uint_least32_t rhs )
{
unsigned i;
uint_least32_t digit;
uint_least64_t carry = 0;
uint_least64_t base = UINT64_C(1)<<32;
for ( i = lhs->size; i > 0; --i )
{
digit = lhs->data[ i - 1 ];
lhs->data[ i - 1 ] = (uint_least32_t)( ( carry * base + digit ) / rhs );
carry = ( base + digit ) - lhs->data[ i - 1 ] * rhs;
}
while ( lhs->size > 0 && lhs->data[ lhs->size - 1 ] == 0 )
{
--lhs->size;
}
return lhs;
}
#endif
#ifdef TEST
#include "_PDCLIB_test.h"
int main( void )
{
#ifndef REGTEST
_PDCLIB_bigint_t lhs;
_PDCLIB_bigint32( &lhs, 1 );
_PDCLIB_bigint_div32( &lhs, 2 );
TESTCASE( lhs.size == 0 );
_PDCLIB_bigint32( &lhs, 2 );
_PDCLIB_bigint_div32( &lhs, 2 );
TESTCASE( lhs.size == 1 );
TESTCASE( lhs.data[0] == 1 );
_PDCLIB_bigint64( &lhs, UINT64_C( 0x0000000100000000 ) );
_PDCLIB_bigint_div32( &lhs, 2 );
TESTCASE( lhs.size == 1 );
TESTCASE( lhs.data[0] == UINT32_C( 0x80000000 ) );
_PDCLIB_bigint64( &lhs, UINT64_C( 0x0000000200000000 ) );
_PDCLIB_bigint_div32( &lhs, 2 );
TESTCASE( lhs.data[0] == 0 );
TESTCASE( lhs.data[1] == 1 );
TESTCASE( lhs.size == 2 );
#endif
return TEST_RESULTS;
}
#endif
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