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Jean Boussier
7da70f1773
Instead of iterating over the bytes of the ar_table hints
one by one, we can use a little bit of SWAR code to match them
all at once and return the first matching byte index.
In theory we could even re-use the mask to extract all matching
position, however we can't do that because since `ar_equal` calls
back into Ruby, the hints may change after every iteration.
```
compare-ruby: ruby 4.1.0dev (2026-08-06T14:05:57Z master 9658933451) +YJIT +PRISM [arm64-darwin25]
built-ruby: ruby 4.1.0dev (2026-08-06T16:42:50Z ar-find-entry-swar-2 723ff01514) +YJIT +PRISM [arm64-darwin25]
```
| |compare-ruby|built-ruby|
|:-----------|-----------:|---------:|
|hit_first | 13.891M| 15.085M|
| | -| 1.09x|
|hit_third | 13.322M| 15.065M|
| | -| 1.13x|
|hit_fourth | 12.759M| 14.410M|
| | -| 1.13x|
|hit_last | 11.545M| 15.275M|
| | -| 1.32x|
|miss | 10.872M| 16.286M|
| | -| 1.50x|
18 lines
603 B
YAML
18 lines
603 B
YAML
prelude: |
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h = {a:1, b:2, c:3, d:4, e:5, f:6, g:7, h:8}
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e = {}
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benchmark:
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miss_empty: |
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e[:a]; e[:a]; e[:a]; e[:a]; e[:a]; e[:a]; e[:a]; e[:a]; e[:a]; e[:a]
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hit_first: |
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h[:a]; h[:a]; h[:a]; h[:a]; h[:a]; h[:a]; h[:a]; h[:a]; h[:a]; h[:a]
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hit_third: |
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h[:c]; h[:c]; h[:c]; h[:c]; h[:c]; h[:c]; h[:c]; h[:c]; h[:c]; h[:c]
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hit_fourth: |
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h[:d]; h[:d]; h[:d]; h[:d]; h[:d]; h[:d]; h[:d]; h[:d]; h[:d]; h[:d]
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hit_last: |
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h[:h]; h[:h]; h[:h]; h[:h]; h[:h]; h[:h]; h[:h]; h[:h]; h[:h]; h[:h]
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miss: |
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h[:_]; h[:_]; h[:_]; h[:_]; h[:_]; h[:_]; h[:_]; h[:_]; h[:_]; h[:_]
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