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comparison src/share/vm/opto/escape.cpp @ 18041:52b4284cb496

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Merge with jdk8u20-b26
author Gilles Duboscq <duboscq@ssw.jku.at>
date Wed, 15 Oct 2014 16:02:50 +0200
parents 4ca6dc0799b6 87b5e00100fe
children 7848fc12602b
comparison
equal deleted inserted replaced
17606:45d7b2c7029d 18041:52b4284cb496
708 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) { 708 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
709 // Stored value escapes in unsafe access. 709 // Stored value escapes in unsafe access.
710 Node *val = n->in(MemNode::ValueIn); 710 Node *val = n->in(MemNode::ValueIn);
711 PointsToNode* ptn = ptnode_adr(val->_idx); 711 PointsToNode* ptn = ptnode_adr(val->_idx);
712 assert(ptn != NULL, "node should be registered"); 712 assert(ptn != NULL, "node should be registered");
713 ptn->set_escape_state(PointsToNode::GlobalEscape); 713 set_escape_state(ptn, PointsToNode::GlobalEscape);
714 // Add edge to object for unsafe access with offset. 714 // Add edge to object for unsafe access with offset.
715 PointsToNode* adr_ptn = ptnode_adr(adr->_idx); 715 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
716 assert(adr_ptn != NULL, "node should be registered"); 716 assert(adr_ptn != NULL, "node should be registered");
717 if (adr_ptn->is_Field()) { 717 if (adr_ptn->is_Field()) {
718 assert(adr_ptn->as_Field()->is_oop(), "should be oop field"); 718 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
1577 field->fields_escape_state() == PointsToNode::NoEscape, "sanity"); 1577 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1578 if (field->offset() == Type::OffsetBot) { 1578 if (field->offset() == Type::OffsetBot) {
1579 jobj->set_scalar_replaceable(false); 1579 jobj->set_scalar_replaceable(false);
1580 return; 1580 return;
1581 } 1581 }
1582 // 2. An object is not scalar replaceable if the field into which it is
1583 // stored has multiple bases one of which is null.
1584 if (field->base_count() > 1) {
1585 for (BaseIterator i(field); i.has_next(); i.next()) {
1586 PointsToNode* base = i.get();
1587 if (base == null_obj) {
1588 jobj->set_scalar_replaceable(false);
1589 return;
1590 }
1591 }
1592 }
1582 } 1593 }
1583 assert(use->is_Field() || use->is_LocalVar(), "sanity"); 1594 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1584 // 2. An object is not scalar replaceable if it is merged with other objects. 1595 // 3. An object is not scalar replaceable if it is merged with other objects.
1585 for (EdgeIterator j(use); j.has_next(); j.next()) { 1596 for (EdgeIterator j(use); j.has_next(); j.next()) {
1586 PointsToNode* ptn = j.get(); 1597 PointsToNode* ptn = j.get();
1587 if (ptn->is_JavaObject() && ptn != jobj) { 1598 if (ptn->is_JavaObject() && ptn != jobj) {
1588 // Mark all objects. 1599 // Mark all objects.
1589 jobj->set_scalar_replaceable(false); 1600 jobj->set_scalar_replaceable(false);
1598 for (EdgeIterator j(jobj); j.has_next(); j.next()) { 1609 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1599 // Non-escaping object node should point only to field nodes. 1610 // Non-escaping object node should point only to field nodes.
1600 FieldNode* field = j.get()->as_Field(); 1611 FieldNode* field = j.get()->as_Field();
1601 int offset = field->as_Field()->offset(); 1612 int offset = field->as_Field()->offset();
1602 1613
1603 // 3. An object is not scalar replaceable if it has a field with unknown 1614 // 4. An object is not scalar replaceable if it has a field with unknown
1604 // offset (array's element is accessed in loop). 1615 // offset (array's element is accessed in loop).
1605 if (offset == Type::OffsetBot) { 1616 if (offset == Type::OffsetBot) {
1606 jobj->set_scalar_replaceable(false); 1617 jobj->set_scalar_replaceable(false);
1607 return; 1618 return;
1608 } 1619 }
1609 // 4. Currently an object is not scalar replaceable if a LoadStore node 1620 // 5. Currently an object is not scalar replaceable if a LoadStore node
1610 // access its field since the field value is unknown after it. 1621 // access its field since the field value is unknown after it.
1611 // 1622 //
1612 Node* n = field->ideal_node(); 1623 Node* n = field->ideal_node();
1613 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1624 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1614 if (n->fast_out(i)->is_LoadStore()) { 1625 if (n->fast_out(i)->is_LoadStore()) {
1615 jobj->set_scalar_replaceable(false); 1626 jobj->set_scalar_replaceable(false);
1616 return; 1627 return;
1617 } 1628 }
1618 } 1629 }
1619 1630
1620 // 5. Or the address may point to more then one object. This may produce 1631 // 6. Or the address may point to more then one object. This may produce
1621 // the false positive result (set not scalar replaceable) 1632 // the false positive result (set not scalar replaceable)
1622 // since the flow-insensitive escape analysis can't separate 1633 // since the flow-insensitive escape analysis can't separate
1623 // the case when stores overwrite the field's value from the case 1634 // the case when stores overwrite the field's value from the case
1624 // when stores happened on different control branches. 1635 // when stores happened on different control branches.
1625 // 1636 //