Monash University > School of Computer Science and Software Engineering > CSE1303 > Part B > Lectures > Lecture B05 notes

CSE1303 Computer Science
Semester 2, 2003
Part B
Lecture B05 notes: Words, bits and pieces

In this lecture

• Byte order
  • Little endian: least significant byte stored at lowest address
  • Big endian: most significant byte stored at lowest address
• Bitwise operations
  • Bitwise NOT (~)
  • Bitwise AND (&)
  • Bitwise OR (|)
  • Bitwise exclusive OR (XOR) (^)
• Masking
  • Use AND to extract bits
  • Use AND to clear bits to 0
  • Use OR to set bits to 1
  • Use XOR to toggle bit values
• Shifting
  • Shift left (<<)
  • Shift right (>>)
    • Arithmetic shift right for signed values (preserves MSB)
    • Logical shift right for unsigned/non-numeric values (sets MSB to 0)
  • Relationship to multiplication and division
    • Shift left: multiplication by powers of 2
    • Shift right: division by powers of 2

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Last modified 2002-12-04