OP_BACKREF_WITH_LEVEL 1664 ext/mbstring/oniguruma/regcomp.c r = add_opcode(reg, OP_BACKREF_WITH_LEVEL); OP_BACKREF_WITH_LEVEL 5721 ext/mbstring/oniguruma/regcomp.c { OP_BACKREF_WITH_LEVEL, "backref_at_level", ARG_SPECIAL }, OP_BACKREF_WITH_LEVEL 5988 ext/mbstring/oniguruma/regcomp.c case OP_BACKREF_WITH_LEVEL: OP_BACKREF_WITH_LEVEL 2281 ext/mbstring/oniguruma/regexec.c case OP_BACKREF_WITH_LEVEL: