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_archive/rhai_engine/rhaibook/engine/optimize/passes.md

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+Optimization Passes
+===================
+
+{{#include ../../links.md}}
+
+[Script optimization] is performed via multiple _passes_.
+Each pass does a specific optimization.
+
+The optimization is completed when no passes can simplify the [`AST`] any further.
+
+
+Built-in Optimization Passes
+----------------------------
+
+| Pass                                       | Description                                       |
+| ------------------------------------------ | ------------------------------------------------- |
+| [Dead code elimination](dead-code.md)      | Eliminates code that cannot be reached            |
+| [Constants propagation](constants.md)      | Replaces [constants] with values                  |
+| [Compound assignments rewrite](rewrite.md) | Rewrites assignments into compound assignments    |
+| [Eager operator evaluation](op-eval.md)    | Eagerly calls operators with [constant] arguments |
+| [Eager function evaluation](eager.md)      | Eagerly calls functions with [constant] arguments |