a more robust fix #17911
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a more robust fix #17911
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…r alignment" This reverts commit a760468. This change is fragile, the next change avoids the need for such manual padding.
Fixes Perl#17871 The op slab allocator code made the assumption that since OP and hence OPSLOT contain pointers, the base of each of those would be an integral number of sizeof(pointer) (pointer units) from the beginning of OPSLAB. This assumption is non-portable, and broke calculating the location of the slab based on the address of the op slot and the op slot offset on m68k platforms. To avoid that, this change now stores the opslot_offset as the offset in pointer units from the beginning of opslab_slots rather than from the beginning of the slab. If alignment on a pointer boundary for OPs is required, the compiler will align opslab_opslots and since we work in pointer units from there, any allocated op slots will also be aligned. If we assume PADOFFSET is no larger than a pointer and requires no stricter alignment and structures in themselves have no stricter alignment requirements then since we work in pointer units all core OP structures should have sufficient alignment (if this isn't true, then it's not a new problem, and not the problem I'm trying to solve here.) I haven't been able to test this on m68k hardware (the emulator I tried to use can't maintain a network connection.)
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Fixes #17871