GATE | GATE-CS-2017 (Set 1) | Question 38
Consider the expression (a-1) * ((( b + c ) / 3 )) + d)). Let X be the minimum number of registers required by an optimal code generation (without any register spill) algorithm for a load/store architecture, in which
(i) only load and store instructions can have memory operands and
(ii) arithmetic instructions can have only register or immediate operands
The value of X is ________.
Note : This questions appeared as Numerical Answer Type.
Explanation: The assembly code using the load/store architecture can be written as follows:
Load R1, b
Load R2, c
ADD R1, R2
Div R1, 3
Load R2, d
Add R1, R2
Load R2, a
Sub R2, 1
Mul R2, R1
Hence minimum 2 registers required.
This explanation is contributed by Sonal Kukreja.
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