Use 1 byte per type/symbol tag #19735
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JukkaL
reviewed
Aug 26, 2025
mypyc/primitives/misc_ops.py
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| function_op( | ||
| name="native_internal.write_native_internal", |
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Should the name be ...write_tag, similar to the above ones?
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Oops, it looks like some Ctrl+R went wrong :-) Will fix it.
mypyc/primitives/misc_ops.py
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| name="native_internal.write_native_internal", | ||
| arg_types=[object_rprimitive, int_rprimitive], | ||
| return_type=none_rprimitive, | ||
| c_function_name="write_native_internal_internal", |
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Should this be write_tag_internal?
mypyc/primitives/misc_ops.py
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| ) | ||
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| function_op( | ||
| name="native_internal.read_native_internal", |
mypyc/primitives/misc_ops.py
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| name="native_internal.read_native_internal", | ||
| arg_types=[object_rprimitive], | ||
| return_type=int_rprimitive, | ||
| c_function_name="read_native_internal_internal", |
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According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
JukkaL
approved these changes
Aug 26, 2025
As discussed offline, I think that this is a good idea (if it doesn't cause any trouble). I think it's okay to do this in a follow-up PR, but it's up to you. |
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OK, I will make a separate PR for |
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This is a small incremental improvement for fixed format cache. I am adding a dedicated write/read functions for tags (i.e. integers in 0-255 range). I propose to exclusively use these functions for type tags (hence the name), and still use regular
write_int()/read_int()for integers that are "accidentally small" (like argument kinds etc). In a separate PR I will change regularintformat to be more progressive (e.g. only use 1 byte if an integer happens to be small). I also change the terminology from "marker" to "tag", as this is a more common name for this concept.Note we can probably use
mypy_extensions.u8for type tags. If there is a desire for this, I can switch to it (either in this or a separate PR).