Remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BORROW)` in JIT · Issue #148235 · python/cpython · GitHub

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

cc: @Fidget-Spinner

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

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

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

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

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

Remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BORROW)` in JIT · Issue #148235 · python/cpython · GitHub

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Remove duplicate uops _LOAD_CONST_UNDER_INLINE(_BORROW) in JIT #148235

Feature or enhancement

Proposal:

Has this already been discussed elsewhere?

Links to previous discussion of this feature:

Linked PRs

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	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();
	}

	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);
	}

Remove duplicate uops `_LOAD_CONST_UNDER_INLINE(_BORROW)` in JIT · Issue #148235 · python/cpython · GitHub

Repository navigation

Remove duplicate uops _LOAD_CONST_UNDER_INLINE(_BORROW) in JIT #148235

Description

Feature or enhancement

Proposal:

Has this already been discussed elsewhere?

Links to previous discussion of this feature:

Linked PRs

Activity

NekoAsakura commented on Apr 8, 2026

Fidget-Spinner commented on Apr 8, 2026

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