CODEWITHSUNDEEP
mips
aneena
aneena

Reputation: 197

signed bit extension of offset in MIPS

In MIPS instructions like LW $1, 2($2) I know that why do we need to extend the offset from 16 bits to 32 bits but my question is that why do we extend the sign it like 11111111111111111111111111111000 for -8 why not simply 00000000000000000000000000001000

Upvotes: 2

Views: 469

Answers (1)

Stack Player
Stack Player

Reputation: 1490

In MIPS we use signed 2's complement, check this it will make it all clear:

http://en.wikipedia.org/wiki/Two's_complement

Nevertheless to answer your question, the sign of a number in 2's complement is dictated by its most significant bit, 0 for positive, 1 for negative, if you have a negative number therefore you extend with 1's, if positive with 0's

Hope this helps =)

Upvotes: 1

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