diff options
Diffstat (limited to 'peep.c')
| -rw-r--r-- | peep.c | 49 |
1 files changed, 49 insertions, 0 deletions
@@ -3951,6 +3951,55 @@ Perl_rpeep(pTHX_ OP *o) /* NULL the previous op ptrs, so rpeep can continue */ oldoldop = NULL; oldop = NULL; } + + /* Combine a simple SASSIGN OP with an AELEMFAST_LEX lvalue + * into a single OP. This optimization covers arbitrarily + * complicated RHS OP trees. */ + + if (!(o->op_private & (OPpASSIGN_BACKWARDS|OPpASSIGN_CV_TO_GV)) + && (lval->op_type == OP_NULL) && (lval->op_private == 2) && + (cBINOPx(lval)->op_first->op_type == OP_AELEMFAST_LEX) && + ((I8)(cBINOPx(lval)->op_first->op_private) >= 0) + ) { + OP * lex = cBINOPx(lval)->op_first; + /* SASSIGN's bitfield flags, such as op_moresib and + * op_slabbed, will be carried over unchanged. */ + OpTYPE_set(o, OP_AELEMFASTLEX_STORE); + + /* Explicitly craft the new OP's op_flags, carrying + * some bits over from the SASSIGN */ + o->op_flags = ( + OPf_KIDS | OPf_STACKED | + (o->op_flags & (OPf_WANT|OPf_PARENS)) + ); + + /* Copy the AELEMFAST_LEX op->private, which contains + * the key index. */ + o->op_private = lex->op_private; + + /* Take the targ from the AELEMFAST_LEX */ + o->op_targ = lex->op_targ; lex->op_targ = 0; + + assert(oldop->op_type == OP_AELEMFAST_LEX); + /* oldoldop can be arbitrarily deep in the RHS OP tree */ + oldoldop->op_next = o; + + /* Even when (rhs != oldoldop), rhs might still have a + * relevant op_next ptr to lex. (Updating it here can + * also cause other ops in the RHS to get the desired + * op_next pointer, presumably thanks to the finalizer.) + * This is definitely truewhen rhs is OP_NULL with a + * LOGOP kid (e.g. orassign). There may be other cases. */ + if (rhs->op_next == lex) + rhs->op_next = o; + + /* Now null-out the AELEMFAST_LEX */ + op_null(lex); + + /* NULL the previous op ptrs, so rpeep can continue */ + oldop = oldoldop; oldoldop = NULL; + } + break; } |