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Bytecode parity #7504

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Merged
youknowone merged 15 commits into from
Mar 25, 2026
Merged

Bytecode parity #7504

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a6aab76
Match CPython LOAD_SPECIAL stack semantics for with/async-with
youknowone Mar 23, 2026
d015f02
Normalize LOAD_FAST_CHECK and JUMP_BACKWARD_NO_INTERRUPT
youknowone Mar 23, 2026
37d1e03
Add EXTENDED_ARG to SKIP_OPS, normalize LOAD_FAST_CHECK and JUMP_BACK…
youknowone Mar 23, 2026
b559a6e
Remove duplicate return-None when block already has return
youknowone Mar 23, 2026
6b200d9
Improve __static_attributes__ collection accuracy
youknowone Mar 23, 2026
122f76a
Use method mode for function-local import attribute calls
youknowone Mar 25, 2026
d1641dd
Optimize constant iterable before GET_ITER to LOAD_CONST tuple
youknowone Mar 25, 2026
5b19b70
Fix cell variable ordering: parameters first, then alphabetical
youknowone Mar 25, 2026
5b32c68
Emit COPY_FREE_VARS before MAKE_CELL matching CPython order
youknowone Mar 25, 2026
96462fa
Fix RESUME AfterYield encoding to match CPython 3.14 (value 5)
youknowone Mar 25, 2026
296eaa1
Address code review feedback from #7481
youknowone Mar 25, 2026
b2eaa71
Fold constant list/set/tuple literals in compiler
youknowone Mar 23, 2026
c7f505d
Use BUILD_MAP 0 + MAP_ADD for large dicts (>= 16 pairs)
youknowone Mar 23, 2026
a23315a
Fix clippy warnings and cargo fmt
youknowone Mar 25, 2026
cab59e7
fix surrogate
youknowone Mar 25, 2026
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Optimize constant iterable before GET_ITER to LOAD_CONST tuple 
Convert BUILD_LIST/SET 0 + LOAD_CONST + LIST_EXTEND/SET_UPDATE + GET_ITER
to just LOAD_CONST (tuple) + GET_ITER, matching CPython's optimization
for constant list/set literals in for-loop iterables.

Also fix is_name_imported to use method mode for function-local imports,
and improve __static_attributes__ accuracy (skip @classmethod/@staticmethod,
handle tuple/list unpacking targets).
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@youknowone
youknowone committed Mar 25, 2026
commit d1641dd9c7d4f3134ae55ca39c540d3f135ba50a
45 changes: 45 additions & 0 deletions crates/codegen/src/ir.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,8 @@ impl CodeInfo {
self.fold_tuple_constants();
self.fold_list_constants();
self.fold_set_constants();
self.remove_nops(); // remove NOPs from folding before iterable optimization
self.fold_const_iterable_for_iter();
self.convert_to_load_small_int();
self.remove_unused_consts();
self.remove_nops();
Expand Down Expand Up @@ -878,6 +880,49 @@ impl CodeInfo {
}
}

/// Convert constant list/set construction before GET_ITER to just LOAD_CONST tuple.
/// BUILD_LIST 0 + LOAD_CONST (tuple) + LIST_EXTEND 1 + GET_ITER
/// → LOAD_CONST (tuple) + GET_ITER
/// Also handles BUILD_SET 0 + LOAD_CONST + SET_UPDATE 1 + GET_ITER.
fn fold_const_iterable_for_iter(&mut self) {
for block in &mut self.blocks {
let mut i = 0;
while i + 3 < block.instructions.len() {
let is_build = matches!(
block.instructions[i].instr.real(),
Some(Instruction::BuildList { .. } | Instruction::BuildSet { .. })
) && u32::from(block.instructions[i].arg) == 0;

let is_const = matches!(
block.instructions[i + 1].instr.real(),
Some(Instruction::LoadConst { .. })
);

let is_extend = matches!(
block.instructions[i + 2].instr.real(),
Some(Instruction::ListExtend { .. } | Instruction::SetUpdate { .. })
) && u32::from(block.instructions[i + 2].arg) == 1;

let is_iter = matches!(
block.instructions[i + 3].instr.real(),
Some(Instruction::GetIter)
);

if is_build && is_const && is_extend && is_iter {
// Replace: BUILD_X 0 → NOP, keep LOAD_CONST, LIST_EXTEND → NOP
let loc = block.instructions[i].location;
block.instructions[i].instr = Instruction::Nop.into();
block.instructions[i].location = loc;
block.instructions[i + 2].instr = Instruction::Nop.into();
block.instructions[i + 2].location = loc;
i += 4;
} else {
i += 1;
}
}
}
}

/// Fold constant set literals: LOAD_CONST* + BUILD_SET N →
/// BUILD_SET 0 + LOAD_CONST (frozenset-as-tuple) + SET_UPDATE 1
fn fold_set_constants(&mut self) {
Expand Down