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20 lines
866 B
20 lines
866 B
2 years ago
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Exercise 5.32: Using the preserving
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mechanism, the compiler will avoid saving and restoring env around the
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evaluation of the operator of a combination in the case where the operator is a
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symbol. We could also build such optimizations into the evaluator. Indeed,
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the explicit-control evaluator of 5.4 already performs a similar
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optimization, by treating combinations with no operands as a special case.
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Extend the explicit-control evaluator to recognize as a separate class of
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expressions combinations whose operator is a symbol, and to take advantage of
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this fact in evaluating such expressions.
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Alyssa P. Hacker suggests that by extending the evaluator to recognize more and
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more special cases we could incorporate all the compiler’s optimizations, and
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that this would eliminate the advantage of compilation altogether. What do you
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think of this idea?
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