Two's Complement Operations
Negating a two's complement number: invert all bits and add 1
- remember: “negate” and “invert” are quite different!
Converting n bit numbers into numbers with more than n bits:
- MIPS 16 bit immediate gets converted to 32 bits for arithmetic
- copy the most significant bit (the sign bit) into the other bits 0010 -> 0000 0010 1010 -> 1111 1010
- "sign extension"