Convert hash API to use MP_UNARY_OP_HASH instead of ad-hoc function #1250
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Hashing is now done using mp_unary_op function with MP_UNARY_OP_HASH as the operator argument. Hashing for int, str and bytes still go via fast-path in mp_unary_op since they are the most common objects which need to be hashed. This lead to quite a bit of code cleanup, and should be more efficient if anything. It saves 176 bytes code space on Thumb2, and 360 bytes on x86. The only loss is that the error message "unhashable type" is now the more generic "unsupported type for __hash__".
| mp_obj_t val = mp_call_function_1(member[0], self_in); | ||
| // __hash__ must return a small int | ||
| if (op == MP_UNARY_OP_HASH) { | ||
| val = MP_OBJ_NEW_SMALL_INT(mp_obj_get_int(val)); |
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Actually, this should be mp_obj_get_int_truncated.
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Well, I imagined more localized refactor, where mp_obj_hash() stays the same for simple types and dispatches to ->unary_op for more complex ones, but if that's what allowed to get more code size savings, looks good, thanks for going for that! |
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It was natural to put small-int hash in unary op with all the other small-int unary ops there already. And then only str hashing was left as the most common one needing a fast path (and actually needed a better fast path than existing in mp_obj_hash, as per old comment in objstr.c). So mp_obj_hash became reduntant and everything worked out for the best. |
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Hashing is now done using mp_unary_op function with MP_UNARY_OP_HASH as
the operator argument. Hashing for int, str and bytes still go via
fast-path in mp_unary_op since they are the most common objects which
need to be hashed.
This lead to quite a bit of code cleanup, and should be more efficient
if anything. It saves 176 bytes code space on Thumb2, and 360 bytes on
x86.
The only loss is that the error message "unhashable type" is now the
more generic "unsupported type for hash".
To address issue #1246.
@pfalcon it turned out that I could save a significant number of bytes and at the same time (hopefully) cover all your points. Please take a critical look!