GH-120024: Change LOAD_FAST instructions to LOAD_FAST_TEMP when it is guaranteed the reference is consumed immediately.
#125192
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markshannon
changed the title
LOAD_FAST instructions to LOAD_FAST_TEMP when it is guaranteed the reference is consumed immediately.
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This PR adds a
LOAD_FAST_TEMPinstruction for loading locals to the evaluation stack that are used as short-lived values within an expression. Distinguishing theseLOAD_FASTinstructions will allow us to avoid expensive reference counting operations in these cases.This is marked as draft, as it has no value until the default build supports reference counts in tags.
The stats show that 3/4 of all
LOAD_FAST(including theLOAD_FASTs inLOAD_FAST_LOAD_FAST) are converted toLOAD_FAST_TEMP.Before merging, a few tests need fixing and the choice of superinstructions needs updating.