madeeasy test series

Question

Answer 1

Register allocation improvement is the job of code optimization(Machine dependent)

Output of Intermediate code generation is Machine independent, ICG is the last module of front end/Machine-Independent part of compiler. Output of ICG is taken by code optimization module which marks the beginning of machine dependent/Back end part of compiler.

Leaf node of a tree will not always have inherited attributes.

Eg S--->T+S|T

T-->id.

The difference between ICG code and assembly code lies in number of registers used for computation--->TRUE

ICG (uses as many temp. registers it needs without considering efficient usage)--->3 address cod(say)--->code optimization(reduces the number of register aloocation to minimal)--->target code generation------->Assembly language.

Comments

 S--->T+S|T

T-->id. 

sorry if this sounds stupid but can you please explain what are the attributes here and how can we know decide if they are inherited or synthesized without the semantic rules?

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In option 2 ...i think they are talking about the syntax tree.

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I should have mentioned that : T--->id { T.value=id.value}

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Ya but T is not a leaf node.

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ICG (uses as many temp. registers it needs without considering efficient usage)--->3 address cod(say)--->code optimization(reduces the number of register aloocation to minimal)--->target code generation------->Assembly language.

Can u pls explain this ?