Number of 1 address instructions

Question

How many maximum number of 1 address instructions supported?

Comments

Utkarsh Joshi

This is the original question https://gateoverflow.in/91676/gate1988-2-ii

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dude 1040 is not even nearby to 127. im so bad at co!! :(

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Utkarsh Joshi :'(

Answer 1

Total number of Instructions possible = 2^4=16

14 double Address instruction

Out of 16 Total instructions, if 14 Double instructions is used then we left with 2 unused instructions.

So, let x number of 1 address instructions , So we use unused instructions = 2*(2^6)-x

Now Zero number of instructions will be = 2^7(2^6-x)

60 zero number of instruction mentioned we substitute it  60 = 2^6(2^7-x)

x= (128*64 - 60)/64 =127

So maximum number of 1 address instruction = 2(2^6)-x=128-127=1.

Answer 2

See first you have to find total  no. of 2 address instructions which is 2^4= 16 now computer supports 14 1 address instructions so no. of unused instructions will be 16-14=2

Now get no. of take no. of 1 address instruction supported by computer as n so no. of unused instruction will be 2*(2^6)-n

Now no of zero address instructions will be (2*(2^6)-n)*2^6 which is = 60 so if we solve it we will get n as 127 ....

(60/64 will be 0.something but we take ceil of that as 1)