int pvm_code_get_int32(struct pvm_code_handler *code)
{
pvm_code_check_bounds( code, code->IP+int_size()-1, "get_int32" );
int ret = pvm_code_do_get_int( code->code+code->IP );
code->IP += int_size();
return ret;
}
int positive_module ( int n)
{
unsigned int int_size ( void );
if ( n > 0)
return n % int_size ();
else
return -n % int_size ();
}
int bit_set(unsigned int x, int n)
{
int j = int_size();
unsigned int temp = 1 << (j - 1);
temp = temp >> n;
return (temp | x);
}
unsigned int bitpat_get(unsigned int source, int begin, int len)
{
unsigned int result = 0;
for (int i = 0; i < len; i++){
result <<= 1;
result += bit_test(source, int_size () - arg_size (source) + begin + i);
}
return result;
}
//function to calculate the min number of bits needed to represent a value
int numberOfBits(unsigned int x)
{
int sizeOfInt = int_size();
int counter = 0;
unsigned int temp = 1 << (sizeOfInt - 1);
while ( (temp | x) != x)
{
temp = temp >> 1;
counter++;
}
return sizeOfInt - counter;
}
int bitpat_search( unsigned int source, unsigned int pattern, int n )
{
unsigned int temp_pattern, temp_source, loc;
unsigned int int_size ( void );
int positive_module ( int n);
for ( loc = 0; loc <= int_size () - n; loc++ )
{
int j = 0, k = 0;
temp_source = source;
while ( j < n)
{
temp_source = bit_set ( temp_source, loc + j );
j++;
}
temp_pattern = pattern << ( int_size () - n - loc );
while ( k < loc )
{
temp_pattern = bit_set ( temp_pattern, k );
k++;
}
k = loc + n ;
while ( k < int_size () )
{
temp_pattern = bit_set ( temp_pattern, k );
k++;
}
printf ( "temp_pattern is %0x and temp_source is %0x and loc is %i\n", temp_pattern, temp_source, loc );
if ( ( temp_pattern & temp_source ) == source)
return loc;
}
return -1;
}
int bit_test ( unsigned int value, int n )
{
unsigned int i = 1, size;
unsigned int int_size ( void );
size = int_size ();
n %= size;
i = ~ ( i << (31 - n) );
if (value == ( value & i))
return 0;
else
return 1;
}
bool bit_test(unsigned int x, int n)
{
/*algorithm:
*1. j = int_size()
*2.temp = 1 << j (left shift 1 j times to place bit on the left)
*3.temp = temp >> n
*3.temp & x == temp if n bit is set
*/
int j = int_size();
unsigned int temp = 1 << (j - 1);
temp = temp >> n;
if ((temp & n) == temp) //nbit is set
return true;
else
return false;
}
//extracts a specified set of bits from source starting at start
int bitpat_get(unsigned int source, int start, int n)
{
unsigned int temp, nTempBits,nSourceBits,intSize, offset;
intSize = int_size();
nSourceBits = numberOfBits(source);
temp = ~0;
temp = temp >> (intSize - nSourceBits);
temp = temp >> start;
nTempBits = numberOfBits(temp);
temp = temp & source;
if (nTempBits >= n)
{
offset = nTempBits - n;
temp = temp >> offset;
}
int main (void)
{
unsigned int x, n;
printf("Number of bits for u int : %i\n", int_size());
printf("Enter int x and bit number to test: ");
scanf("%u %u", &x, &n);
if (bit_test(x,n))
printf("Bit %i is set on %i\n", n,x);
else {
printf("Bit %i is not set, setting...\n", n);
x = bit_set(x,n);
printf("New value of x: %i\n", x);
}
return 0;
}
int bitpat_search(unsigned int source, unsigned int pattern, int n)
{
unsigned int num1;
int m , count = 0;
int int_size(void);
m = int_size();
num1 = pattern << (m - n);
if(source == num1)
return 0;
while ((source & num1) != num1){
source <<= 1;
++count;
if(count > (m - n))
return -1;
}
return count;
}
unsigned int bit_set ( unsigned int value, int n )
{
unsigned int i = 1, size;
unsigned int int_size ( void );
size = int_size ();
n %= size;
i = ~ ( i << (31 - n) );
int bit_test ( unsigned int value, int n );
if ( bit_test ( value, n) )
{
return value;
}
else
{
return value + ~i;
}
}
