branch

Question

In case of conditional branch only PC is updated with the target address and there is no need to store the old PC value into the memory.

Why is it like that? if we dont save the old PC value how will it return back to continue executing after the completion of branch instruction ?

Comments

Why would we need to return to that address? Branch instruction is used to branch out from the current sequential flow of control, to some other location. If we want to go back we have to use another branch instruction which will be a backward jump.

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@rishabh

same case with unconditional branch too ?

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Yes. We do not save the address in branch instructions.

We save address when we call another procedure. Because in that case, we need to get back to the calling procedure after the called procedure is ended.