Now optimising for $a (reverse ...)

p4raw-id: //depot/perl@23113

diff --git a/op.c b/op.c
index 8ceaa09..23b12b7 100644 (file)
--- a/op.c
+++ b/op.c
@@ -6719,7 +6719,8 @@ Perl_peep(pTHX_ register OP *o)
        }
 
        case OP_REVERSE: {
-           OP *ourmark, *theirmark, *ourlast, *iter;
+           OP *ourmark, *theirmark, *ourlast, *iter, *expushmark;
+           OP *gvop = NULL;
            LISTOP *enter, *exlist;
            o->op_opt = 1;
 
@@ -6731,6 +6732,19 @@ Perl_peep(pTHX_ register OP *o)
                if (!enter)
                    break;
            }
+           /* for $a (...) will have OP_GV then OP_RV2GV here.  */
+           if (enter->op_type == OP_GV) {
+               gvop = (OP *) enter;
+               enter = (LISTOP *) enter->op_next;
+               if (!enter)
+                   break;
+               if (enter->op_type != OP_RV2GV)
+                   break;
+               enter = (LISTOP *) enter->op_next;
+               if (!enter)
+                   break;
+           }
+
            if (enter->op_type != OP_ENTERITER)
                break;
 
@@ -6738,7 +6752,12 @@ Perl_peep(pTHX_ register OP *o)
            if (!iter || iter->op_type != OP_ITER)
                break;
            
-           exlist = (LISTOP *) enter->op_last;
+           expushmark = enter->op_first;
+           if (!expushmark || expushmark->op_type != OP_NULL
+               || expushmark->op_targ != OP_PUSHMARK)
+               break;
+
+           exlist = (LISTOP *) expushmark->op_sibling;
            if (!exlist || exlist->op_type != OP_NULL
                || exlist->op_targ != OP_LIST)
                break;
@@ -6770,7 +6789,7 @@ Perl_peep(pTHX_ register OP *o)
               ours.  */
            theirmark->op_next = ourmark->op_next;
            theirmark->op_flags = ourmark->op_flags;
-           ourlast->op_next = (OP *) enter;
+           ourlast->op_next = gvop ? gvop : (OP *) enter;
            op_null(ourmark);
            op_null(o);
            enter->op_private |= OPpITER_REVERSED;