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Twist for project 6 - Compact your assembler
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The twist for project 6 is to add support for the [ ] operator in your Assembler.
This operator has the same effect as @xxx (i.e., [xxx] stores xxx in the A register) but instead of being used in a seperate line, it can be joined with any assembly command that uses the value of the A register. This operator can only appear once in a line and should appear right after the first token that uses the value of the A register.
For example, instead of the following 2 lines (of our original assembly):
@xxx
D=M
One may write the following line, which should have the same effect:
D=M[xxx]
Please notice that:
- You should support this operator for all commands that use the value of the A register (and please notice that xxx can also be a label / variable name / reserved name / etc).
- You should submit one Assembler that includes the twist. The twist does not replace any part of the assembly - it's just an addition. (All programs which are valid in the original assembly are still valid and do the exact same thing!).
- You should describe in your README how you chose to implement this operator.
- You should check your own code - we will not supply tests for this operator.
- This operator will save a lot of assembly code (before, each assembly instruction line was exactly one HACK instruction and vice-versa). Can you think of other ways to do so?
Some other examples of uses of the [ ] operator:
- D=M[xxx]+1 (similar to the above).
- M[xxx]=M+1 (in this case the two "M"s refer to the same memory address - xxx).
- D=A[xxx] (this will result in both A and D having the value xxx).
- D;JGT[xxx] (this will cause a jump to xxx if D>0).
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