43 lines
1.4 KiB
Markdown
43 lines
1.4 KiB
Markdown
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# Future
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This document introduces some ideas for future improvements.
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## Basic Optimizations
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Implement basic optimizations such as common subexpression elimination and
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loop invariant code motion.
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Importantly, common subexpression elimination could be used to avoid
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redundant type checks.
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## Operation-specific Optimizations
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Some operations or combinations of successive operations can be
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replaced with more efficient operations. Examples:
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* If `s` is a string, `s[i] == 'x'` doesn't need to construct the
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intermediate single-character string object `s[i]` but just compare
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the character value to `ord('x')`.
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* `a + ':' + b` (two string concetenations) can be implemented as
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single three-operand concatenation that doesn't construct an
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intermediate object.
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* `x in {1, 3}` can be translated into `x == 1 or x == 3` (more
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generally we need to evaluate all right-hand-side items).
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## Integer Range Analysis
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Implement integer range analysis. This can be used in various ways:
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* Use untagged representations for some registers.
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* Use faster integer arithmetic operations for operations that
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only deal with short integers or that can't overflow.
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* Remove redundant list and string index checks.
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## Always Defined Attributes
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Somehow make it possible to enforce that attributes in a class are always
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defined. This makes attribute access faster since we don't need to explicitly
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check if the attribute is defined.
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