Demonstrate bitwise left shift
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
#include <iomanip>
using std::setw;
void displayBits( unsigned ); // prototype
int main()
{
unsigned number1 = 960;
cout << "The result of left shifting\n";
displayBits( number1 );
cout << "8 bit positions using the left-shift operator is\n";
displayBits( number1 << 8 );
return 0;
}
//Quote from
//C++ How to Program (5th Edition) (How to Program) (Paperback)
//by Harvey & Paul) Deitel & Associates
//Publisher: Prentice Hall; 5 edition (January 5, 2005)
//Language: English
//ISBN-10: 0131857576
//ISBN-13: 978-0131857575
void displayBits( unsigned value ) {
const int SHIFT = 8 * sizeof( unsigned ) - 1;
const unsigned MASK = 1 << SHIFT;
cout << setw( 10 ) << value << " = ";
for ( unsigned i = 1; i <= SHIFT + 1; i++ )
{
cout << ( value & MASK ? "1" : "0" );
value <<= 1;
if ( i 8 == 0 )
cout << " ";
}
cout << endl;
}The result of left shifting
960 = 00000000 00000000 00000011 11000000
8 bit positions using the left-shift operator is
245760 = 00000000 00000011 11000000 00000000
Demonstrate bitwise right shift
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
#include <iomanip>
using std::setw;
void displayBits( unsigned ); // prototype
int main()
{
unsigned number1 = 960;
cout << "\nThe result of right shifting\n";
displayBits( number1 );
cout << "8 bit positions using the right-shift operator is\n";
displayBits( number1 >> 8 );
return 0;
}
//Quote from
//C++ How to Program (5th Edition) (How to Program) (Paperback)
//by Harvey & Paul) Deitel & Associates
//Publisher: Prentice Hall; 5 edition (January 5, 2005)
//Language: English
//ISBN-10: 0131857576
//ISBN-13: 978-0131857575
void displayBits( unsigned value ) {
const int SHIFT = 8 * sizeof( unsigned ) - 1;
const unsigned MASK = 1 << SHIFT;
cout << setw( 10 ) << value << " = ";
for ( unsigned i = 1; i <= SHIFT + 1; i++ )
{
cout << ( value & MASK ? "1" : "0" );
value <<= 1;
if ( i 8 == 0 )
cout << " ";
}
cout << endl;
}The result of right shifting
960 = 00000000 00000000 00000011 11000000
8 bit positions using the right-shift operator is
3 = 00000000 00000000 00000000 00000011
Left rotate functions for byte values
/*
Quote from: C++: A Beginner"s Guide, Second Edition
# Publisher: McGraw-Hill Osborne Media; 2 edition (December 3, 2003)
# Language: English
# ISBN-10: 0072232153
# ISBN-13: 978-0072232158
*/
#include <iostream>
using namespace std;
unsigned char lrotate(unsigned char val, int n);
void show_binary(unsigned int u);
int main()
{
char ch = "A";
cout << "Original value in binary:\n";
show_binary(ch);
cout << "Rotating left 8 times:\n";
for(int i=0; i < 8; i++) {
ch = lrotate(ch, 1);
show_binary(ch);
}
return 0;
}
unsigned char lrotate(unsigned char val, int n)
{
unsigned int t;
t = val;
for(int i=0; i < n; i++) {
t = t << 1;
/* If a bit shifts out, it will be in bit 8
of the integer t. If this is the case,
put that bit on the right side. */
if(t & 256)
t = t | 1; // put a 1 on the right end
}
return t; // return the lower 8 bits.
}
// Display the bits within a byte.
void show_binary(unsigned int u)
{
int t;
for(t=128; t>0; t = t/2)
if(u & t) cout << "1 ";
else cout << "0 ";
cout << "\n";
}Original value in binary:
0 1 0 0 0 0 0 1
Rotating left 8 times:
1 0 0 0 0 0 1 0
0 0 0 0 0 1 0 1
0 0 0 0 1 0 1 0
0 0 0 1 0 1 0 0
0 0 1 0 1 0 0 0
0 1 0 1 0 0 0 0
1 0 1 0 0 0 0 0
0 1 0 0 0 0 0 1
Right rotate functions for byte values
/*
Quote from: C++: A Beginner"s Guide, Second Edition
# Publisher: McGraw-Hill Osborne Media; 2 edition (December 3, 2003)
# Language: English
# ISBN-10: 0072232153
# ISBN-13: 978-0072232158
*/
#include <iostream>
using namespace std;
unsigned char rrotate(unsigned char val, int n);
void show_binary(unsigned int u);
int main()
{
char ch = "T";
cout << "Original value in binary:\n";
show_binary(ch);
cout << "Rotating right 8 times:\n";
for(int i=0; i < 8; i++) {
ch = rrotate(ch, 1);
show_binary(ch);
}
return 0;
}
// Right-rotate a byte n places.
unsigned char rrotate(unsigned char val, int n)
{
unsigned int t;
t = val;
// First, move the value 8 bits higher.
t = t << 8;
for(int i=0; i < n; i++) {
t = t >> 1;
/* If a bit shifts out, it will be in bit 7
of the integer t. If this is the case,
put that bit on the left side. */
if(t & 128)
t = t | 32768; // put a 1 on left end
}
/* Finally, move the result back to the
lower 8 bits of t. */
t = t >> 8;
return t;
}
// Display the bits within a byte.
void show_binary(unsigned int u)
{
int t;
for(t=128; t>0; t = t/2)
if(u & t) cout << "1 ";
else cout << "0 ";
cout << "\n";
}Original value in binary:
0 1 0 1 0 1 0 0
Rotating right 8 times:
0 0 1 0 1 0 1 0
0 0 0 1 0 1 0 1
1 0 0 0 1 0 1 0
0 1 0 0 0 1 0 1
1 0 1 0 0 0 1 0
0 1 0 1 0 0 0 1
1 0 1 0 1 0 0 0
0 1 0 1 0 1 0 0
Shift left
#include <iostream>
using namespace std;
void show_binary(unsigned int u);
int main()
{
int i=1, t;
for(t=0; t < 8; t++) {
show_binary(i);
i = i << 1 ;
}
return 0;
}
// Display the bits within a byte.
void show_binary(unsigned int u)
{
int t;
for(t=128; t>0; t=t/2)
if(u & t) cout << "1 ";
else cout << "0 ";
cout << "\n";
}0 0 0 0 0 0 0 1
0 0 0 0 0 0 1 0
0 0 0 0 0 1 0 0
0 0 0 0 1 0 0 0
0 0 0 1 0 0 0 0
0 0 1 0 0 0 0 0
0 1 0 0 0 0 0 0
1 0 0 0 0 0 0 0
Shift right
#include <iostream>
using namespace std;
void show_binary(unsigned int u);
int main()
{
int i=1, t;
for(t=0; t < 8; t++) {
i = i >> 1;
show_binary(i);
}
return 0;
}
// Display the bits within a byte.
void show_binary(unsigned int u)
{
int t;
for(t=128; t>0; t=t/2)
if(u & t) cout << "1 ";
else cout << "0 ";
cout << "\n";
}0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
