+ case OP_SORT: {
+ /* make @a = sort @a act in-place */
+
+ /* will point to RV2AV or PADAV op on LHS/RHS of assign */
+ OP *oleft, *oright;
+ OP *o2;
+
+ o->op_opt = 1;
+
+ /* check that RHS of sort is a single plain array */
+ oright = cUNOPo->op_first;
+ if (!oright || oright->op_type != OP_PUSHMARK)
+ break;
+ oright = cUNOPx(oright)->op_sibling;
+ if (!oright)
+ break;
+ if (oright->op_type == OP_NULL) { /* skip sort block/sub */
+ oright = cUNOPx(oright)->op_sibling;
+ }
+
+ if (!oright ||
+ (oright->op_type != OP_RV2AV && oright->op_type != OP_PADAV)
+ || oright->op_next != o
+ || (oright->op_private & OPpLVAL_INTRO)
+ )
+ break;
+
+ /* o2 follows the chain of op_nexts through the LHS of the
+ * assign (if any) to the aassign op itself */
+ o2 = o->op_next;
+ if (!o2 || o2->op_type != OP_NULL)
+ break;
+ o2 = o2->op_next;
+ if (!o2 || o2->op_type != OP_PUSHMARK)
+ break;
+ o2 = o2->op_next;
+ if (o2 && o2->op_type == OP_GV)
+ o2 = o2->op_next;
+ if (!o2
+ || (o2->op_type != OP_PADAV && o2->op_type != OP_RV2AV)
+ || (o2->op_private & OPpLVAL_INTRO)
+ )
+ break;
+ oleft = o2;
+ o2 = o2->op_next;
+ if (!o2 || o2->op_type != OP_NULL)
+ break;
+ o2 = o2->op_next;
+ if (!o2 || o2->op_type != OP_AASSIGN
+ || (o2->op_flags & OPf_WANT) != OPf_WANT_VOID)
+ break;
+
+ /* check the array is the same on both sides */
+ if (oleft->op_type == OP_RV2AV) {
+ if (oright->op_type != OP_RV2AV
+ || !cUNOPx(oright)->op_first
+ || cUNOPx(oright)->op_first->op_type != OP_GV
+ || cGVOPx_gv(cUNOPx(oleft)->op_first) !=
+ cGVOPx_gv(cUNOPx(oright)->op_first)
+ )
+ break;
+ }
+ else if (oright->op_type != OP_PADAV
+ || oright->op_targ != oleft->op_targ
+ )
+ break;
+
+ /* transfer MODishness etc from LHS arg to RHS arg */
+ oright->op_flags = oleft->op_flags;
+ o->op_private |= OPpSORT_INPLACE;
+
+ /* excise push->gv->rv2av->null->aassign */
+ o2 = o->op_next->op_next;
+ op_null(o2); /* PUSHMARK */
+ o2 = o2->op_next;
+ if (o2->op_type == OP_GV) {
+ op_null(o2); /* GV */
+ o2 = o2->op_next;
+ }
+ op_null(o2); /* RV2AV or PADAV */
+ o2 = o2->op_next->op_next;
+ op_null(o2); /* AASSIGN */
+
+ o->op_next = o2->op_next;
+
+ break;
+ }
+
+
+