Avoid redundant TokenValue drops in the lexer#25300
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Bizarrely, this does show a consistent 1-2% speed-up in the parser and lexer. |
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This is probably an instance where it's worth looking at the release assembly |
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Yeah, this branch includes an extra: Which lets us skip the drop, which is apparently not zero-cost even when the variant is in fact |
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thejchap
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May 23, 2026
## Summary If we avoid resetting the lexer value slot when it's already empty, this apparently improves performance by 1-2%. (In optimized builds, this keeps the common case to a discriminant branch instead of re-entering the `TokenValue` drop path.)
anishgirianish
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May 28, 2026
## Summary If we avoid resetting the lexer value slot when it's already empty, this apparently improves performance by 1-2%. (In optimized builds, this keeps the common case to a discriminant branch instead of re-entering the `TokenValue` drop path.)
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Summary
If we avoid resetting the lexer value slot when it's already empty, this apparently improves performance by 1-2%. (In optimized builds, this keeps the common case to a discriminant branch instead of re-entering the
TokenValuedrop path.)