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/* _PDCLIB_bigint_shl( _PDCLIB_bigint_t *, unsigned )
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>
#include <string.h>
_PDCLIB_bigint_t * _PDCLIB_bigint_shl( _PDCLIB_bigint_t * lhs, unsigned rhs )
{
unsigned word_shifts = rhs / 32;
unsigned bit_shifts = rhs - ( word_shifts * 32 );
uint_least64_t digit;
uint_least32_t carry = 0;
int i;
if ( lhs->size == 0 )
{
return lhs;
}
if ( word_shifts > 0 )
{
memmove( lhs->data + word_shifts, lhs->data, sizeof( uint_least32_t ) * lhs->size );
memset( lhs->data, 0, sizeof( uint_least32_t ) * word_shifts );
lhs->size += word_shifts;
}
for ( i = 0 + word_shifts; i < lhs->size; ++i )
{
digit = ( (uint_least64_t)lhs->data[i] << bit_shifts ) | carry;
carry = digit >> 32;
lhs->data[i] = digit & UINT32_C( 0xFFFFFFFF );
}
if ( carry > 0 )
{
lhs->data[ lhs->size++ ] = carry;
}
return lhs;
}
#endif
#ifdef TEST
#include "_PDCLIB_test.h"
int main( void )
{
#ifndef REGTEST
_PDCLIB_bigint_t lhs;
_PDCLIB_bigint32( &lhs, 12 );
_PDCLIB_bigint_shl( &lhs, 2 );
TESTCASE( lhs.size == 1 );
TESTCASE( lhs.data[0] == 48 );
_PDCLIB_bigint32( &lhs, UINT32_C( 0x80000001 ) );
_PDCLIB_bigint_shl( &lhs, 1 );
TESTCASE( lhs.size == 2 );
TESTCASE( lhs.data[0] == 2 );
TESTCASE( lhs.data[1] == 1 );
_PDCLIB_bigint_shl( &lhs, 65 );
TESTCASE( lhs.size == 4 );
TESTCASE( lhs.data[0] == 0 );
TESTCASE( lhs.data[1] == 0 );
TESTCASE( lhs.data[2] == 4 );
TESTCASE( lhs.data[3] == 2 );
#endif
return TEST_RESULTS;
}
#endif
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