Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/opto/loopTransform.cpp
src/share/vm/opto/loopTransform.cpp
- changeset 9756
- 2be326848943
- parent 9637
- eef07cd490d4
- parent 9739
- bf9503046dd4
- child 9806
- 758c07667682
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deleted
inserted
replaced
| 9707:b87dc103bf45 | 9756:2be326848943 |
|---|---|
| 1535 return _phase->dom_lca_internal(ctrl, backedge) == ctrl; | 1535 return _phase->dom_lca_internal(ctrl, backedge) == ctrl; |
| 1536 } | 1536 } |
| 1537 | 1537 |
| 1538 //------------------------------adjust_limit----------------------------------- | 1538 //------------------------------adjust_limit----------------------------------- |
| 1539 // Helper function for add_constraint(). | 1539 // Helper function for add_constraint(). |
| 1540 Node* PhaseIdealLoop::adjust_limit(int stride_con, Node * scale, Node *offset, Node *rc_limit, Node *loop_limit, Node *pre_ctrl) { | 1540 Node* PhaseIdealLoop::adjust_limit(int stride_con, Node * scale, Node *offset, Node *rc_limit, Node *loop_limit, Node *pre_ctrl, bool round_up) { |
| 1541 // Compute "I :: (limit-offset)/scale" | 1541 // Compute "I :: (limit-offset)/scale" |
| 1542 Node *con = new (C) SubINode(rc_limit, offset); | 1542 Node *con = new (C) SubINode(rc_limit, offset); |
| 1543 register_new_node(con, pre_ctrl); | 1543 register_new_node(con, pre_ctrl); |
| 1544 Node *X = new (C) DivINode(0, con, scale); | 1544 Node *X = new (C) DivINode(0, con, scale); |
| 1545 register_new_node(X, pre_ctrl); | 1545 register_new_node(X, pre_ctrl); |
| 1546 | |
| 1547 // When the absolute value of scale is greater than one, the integer | |
| 1548 // division may round limit down so add one to the limit. | |
| 1549 if (round_up) { | |
| 1550 X = new (C) AddINode(X, _igvn.intcon(1)); | |
| 1551 register_new_node(X, pre_ctrl); | |
| 1552 } | |
| 1546 | 1553 |
| 1547 // Adjust loop limit | 1554 // Adjust loop limit |
| 1548 loop_limit = (stride_con > 0) | 1555 loop_limit = (stride_con > 0) |
| 1549 ? (Node*)(new (C) MinINode(loop_limit, X)) | 1556 ? (Node*)(new (C) MinINode(loop_limit, X)) |
| 1550 : (Node*)(new (C) MaxINode(loop_limit, X)); | 1557 : (Node*)(new (C) MaxINode(loop_limit, X)); |
| 1582 // ) | 1589 // ) |
| 1583 // | 1590 // |
| 1584 // (upper_limit-offset) may overflow or underflow. | 1591 // (upper_limit-offset) may overflow or underflow. |
| 1585 // But it is fine since main loop will either have | 1592 // But it is fine since main loop will either have |
| 1586 // less iterations or will be skipped in such case. | 1593 // less iterations or will be skipped in such case. |
| 1587 *main_limit = adjust_limit(stride_con, scale, offset, upper_limit, *main_limit, pre_ctrl); | 1594 *main_limit = adjust_limit(stride_con, scale, offset, upper_limit, *main_limit, pre_ctrl, false); |
| 1588 | 1595 |
| 1589 // The underflow limit: low_limit <= scale*I+offset. | 1596 // The underflow limit: low_limit <= scale*I+offset. |
| 1590 // For pre-loop compute | 1597 // For pre-loop compute |
| 1591 // NOT(scale*I+offset >= low_limit) | 1598 // NOT(scale*I+offset >= low_limit) |
| 1592 // scale*I+offset < low_limit | 1599 // scale*I+offset < low_limit |
| 1618 // since (0-min_int) == min_int. It may be fine for stride > 0 | 1625 // since (0-min_int) == min_int. It may be fine for stride > 0 |
| 1619 // but for stride < 0 X will be < original_limit. To avoid it | 1626 // but for stride < 0 X will be < original_limit. To avoid it |
| 1620 // max(pre_limit, original_limit) is used in do_range_check(). | 1627 // max(pre_limit, original_limit) is used in do_range_check(). |
| 1621 } | 1628 } |
| 1622 // Pass (-stride) to indicate pre_loop_cond = NOT(main_loop_cond); | 1629 // Pass (-stride) to indicate pre_loop_cond = NOT(main_loop_cond); |
| 1623 *pre_limit = adjust_limit((-stride_con), scale, offset, low_limit, *pre_limit, pre_ctrl); | 1630 *pre_limit = adjust_limit((-stride_con), scale, offset, low_limit, *pre_limit, pre_ctrl, |
| 1631 scale_con > 1 && stride_con > 0); | |
| 1624 | 1632 |
| 1625 } else { // stride_con*scale_con < 0 | 1633 } else { // stride_con*scale_con < 0 |
| 1626 // For negative stride*scale pre-loop checks for overflow and | 1634 // For negative stride*scale pre-loop checks for overflow and |
| 1627 // post-loop for underflow. | 1635 // post-loop for underflow. |
| 1628 // | 1636 // |
| 1644 set_ctrl(one, C->root()); | 1652 set_ctrl(one, C->root()); |
| 1645 | 1653 |
| 1646 Node *plus_one = new (C) AddINode(offset, one); | 1654 Node *plus_one = new (C) AddINode(offset, one); |
| 1647 register_new_node( plus_one, pre_ctrl ); | 1655 register_new_node( plus_one, pre_ctrl ); |
| 1648 // Pass (-stride) to indicate pre_loop_cond = NOT(main_loop_cond); | 1656 // Pass (-stride) to indicate pre_loop_cond = NOT(main_loop_cond); |
| 1649 *pre_limit = adjust_limit((-stride_con), scale, plus_one, upper_limit, *pre_limit, pre_ctrl); | 1657 *pre_limit = adjust_limit((-stride_con), scale, plus_one, upper_limit, *pre_limit, pre_ctrl, |
| 1658 scale_con < -1 && stride_con > 0); | |
| 1650 | 1659 |
| 1651 if (low_limit->get_int() == -max_jint) { | 1660 if (low_limit->get_int() == -max_jint) { |
| 1652 if (!RangeLimitCheck) return; | 1661 if (!RangeLimitCheck) return; |
| 1653 // We need this guard when scale*main_limit+offset >= limit | 1662 // We need this guard when scale*main_limit+offset >= limit |
| 1654 // due to underflow. So we need execute main-loop while | 1663 // due to underflow. So we need execute main-loop while |
| 1679 // I < (low_limit-(offset+1))/scale | 1688 // I < (low_limit-(offset+1))/scale |
| 1680 // else /* scale > 0 and stride < 0 */ | 1689 // else /* scale > 0 and stride < 0 */ |
| 1681 // I > (low_limit-(offset+1))/scale | 1690 // I > (low_limit-(offset+1))/scale |
| 1682 // ) | 1691 // ) |
| 1683 | 1692 |
| 1684 *main_limit = adjust_limit(stride_con, scale, plus_one, low_limit, *main_limit, pre_ctrl); | 1693 *main_limit = adjust_limit(stride_con, scale, plus_one, low_limit, *main_limit, pre_ctrl, |
| 1694 false); | |
| 1685 } | 1695 } |
| 1686 } | 1696 } |
| 1687 | 1697 |
| 1688 | 1698 |
| 1689 //------------------------------is_scaled_iv--------------------------------- | 1699 //------------------------------is_scaled_iv--------------------------------- |
