Perl_op_convert_list - only short circuit CONST OPs with an IsCOW SV #23296
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Currently, a CONST OP's SV will not have the `IsCOW` flag set if the PV buffer was truncated such that it is too small to be COWed. In which case, not short circuting `Perl_op_convert_list` causes the OP to undergo constant folding, resulting in a CONST OP with an SV that can participate in COW. This means that the commit which introduced the short-circuit for CONST OPs accidentally introduced a regression: Perl@a902d92 This commit adds an additional check to ensure that short circuiting does not happen when the CONST OP SV cannot be COWed. This is a short term workaround given the proximity to the next stable release. Perl#23290 seems like the more appropriate fix, but is a bigger change, so will be held until the next development cycle.
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Currently, a CONST OP's SV will not have the
IsCOWflag set if the PV buffer was truncated such that it is too small to be COWed. In which case, not short circutingPerl_op_convert_listcauses the OP to undergo constant folding, resulting in a CONST OP with an SV that can participate in COW.This means that the commit which introduced the short-circuit for CONST OPs accidentally introduced a performance regression:
a902d92
This commit adds an additional check to ensure that short circuiting does not happen when the CONST OP SV cannot be COWed. This is a short term workaround given the proximity to the next stable release. #23290 seems like the more appropriate fix, but is a bigger change, so will be held until the next development cycle.