https://perl5.git.perl.org/perl5.git/commitdiff/d68c938a1e6c6b4bfe907decbb4929780ee06eae Why was this done? Perl_croak_memory_wrap is supposed to be a static linkage, not globally visible C function, in every perl .o file that the CC/linker should toss the static func if its not used. I wanted to avoid the PLT/GOT runtime C symbol substitution/LDPRELOAD mechanism and let the CC turn Perl_croak_memory_wrap into a single conditional jump (offset from current instruction pointer), with no return and no C stack entry, jump instruction instead of call get_EIP //x86 32 only mov eax, *(eax_aka_eip+offset into PLT) call eaxThread Next