Description

NekoAsakura

opened on Apr 8, 2026

Issue body actions

Feature or enhancement

Proposal:

_INSERT_1_LOAD_CONST_INLINE(_BORROW) and _LOAD_CONST_UNDER_INLINE(_BORROW) have identical stack effects — they're basically the same thing with different names.

cpython/Python/bytecodes.c

Lines 5927 to 5937 in 0b20bff

	tier2 op(_INSERT_1_LOAD_CONST_INLINE, (ptr/4, left -- res, l)) {
	res = PyStackRef_FromPyObjectNew(ptr);
	l = left;
	INPUTS_DEAD();
	}
	tier2 op(_INSERT_1_LOAD_CONST_INLINE_BORROW, (ptr/4, left -- res, l)) {
	res = PyStackRef_FromPyObjectBorrow(ptr);
	l = left;
	INPUTS_DEAD();
	}

cpython/Python/bytecodes.c

Lines 5968 to 5978 in 0b20bff

	tier2 op(_LOAD_CONST_UNDER_INLINE, (ptr/4, old -- value, new)) {
	new = old;
	DEAD(old);
	value = PyStackRef_FromPyObjectNew(ptr);
	}
	tier2 op(_LOAD_CONST_UNDER_INLINE_BORROW, (ptr/4, old -- value, new)) {
	new = old;
	DEAD(old);
	value = PyStackRef_FromPyObjectBorrow(ptr);
	}

_LOAD_CONST_UNDER_INLINE(_BORROW) already has entries in op_without_push, so remove_unneeded_uops can properly simplify it. However _INSERT_1 don't, thus we should rename all _INSERT_1 usages to _LOAD_CONST_UNDER and remove the duplicate definitions.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

#148230 (comment)

Linked PRs

• gh-148235: remove duplicate uops _LOAD_CONST_UNDER_INLINE(_BORROW) in JIT #148236

Activity

1. NekoAsakura

   added

   type-featureA feature request or enhancementA feature request or enhancement

   on Apr 8, 2026
2. NekoAsakura commented on Apr 8, 2026

   

   NekoAsakura

   on Apr 8, 2026

   MemberAuthor

   More actions

   cc: @Fidget-Spinner
3. NekoAsakura

   added 2 commits that reference this issue on Apr 8, 2026

   pythongh-148235: remove duplicate uops `_INSERT_1_LOAD_CONST_INLINE(_…

   4f4d25d

   pythongh-148235: remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BOR…

   8af132b
4. NekoAsakura

   changed the title [-]Remove duplicate uops `_INSERT_1_LOAD_CONST_INLINE(_BORROW)` in JIT[/-] [+]Remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BORROW)` in JIT[/+] on Apr 8, 2026
5. NekoAsakura

   added a commit that references this issue on Apr 8, 2026

   pythongh-148235: remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BOR…

   5f63c41
6. Fidget-Spinner

   added a commit that references this issue on Apr 8, 2026

   gh-148235: remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BORROW)` …

   7563585
7. Fidget-Spinner commented on Apr 8, 2026

   

   Fidget-Spinner

   on Apr 8, 2026

   Member

   More actions

   In the future, smaller issues like these can go under #148211. Thanks!
8. Fidget-Spinner

   closed this as completedon Apr 8, 2026
9. ljfp

   added a commit that references this issue on Apr 25, 2026

   pythongh-148235: remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BOR…

   ebb1a4d

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