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7004535: Clone loop predicate during loop unswitch

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Clone loop predicate for clonned loops

Reviewed-by: never
This commit is contained in:
Vladimir Kozlov 2011-04-02 10:54:15 -07:00
parent 68f1177f59
commit 00eca5e982
14 changed files with 1298 additions and 716 deletions
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32
hotspot/src/share/vm/opto/loopUnswitch.cpp
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@ -32,15 +32,17 @@
//
// orig: transformed:
// if (invariant-test) then
// predicate predicate
// loop loop
// stmt1 stmt1
// if (invariant-test) then stmt2
// stmt2 stmt4
// else endloop
// stmt3 else
// endif loop [clone]
// stmt4 stmt1 [clone]
// endloop stmt3
// endif predicate [clone]
// stmt4 loop [clone]
// endloop stmt1 [clone]
// stmt3
// stmt4 [clone]
// endloop
// endif
@ -124,8 +126,15 @@ void PhaseIdealLoop::do_unswitching (IdealLoopTree *loop, Node_List &old_new) {
ProjNode* proj_true = create_slow_version_of_loop(loop, old_new);
assert(proj_true->is_IfTrue() && proj_true->unique_ctrl_out() == head, "by construction");
#ifdef ASSERT
Node* uniqc = proj_true->unique_ctrl_out();
Node* entry = head->in(LoopNode::EntryControl);
Node* predicate = find_predicate(entry);
if (predicate != NULL) predicate = predicate->in(0);
assert(proj_true->is_IfTrue() &&
(predicate == NULL && uniqc == head ||
predicate != NULL && uniqc == predicate), "by construction");
#endif
// Increment unswitch count
LoopNode* head_clone = old_new[head->_idx]->as_Loop();
int nct = head->unswitch_count() + 1;
@ -227,21 +236,24 @@ ProjNode* PhaseIdealLoop::create_slow_version_of_loop(IdealLoopTree *loop,
register_node(ifslow, outer_loop, iff, dom_depth(iff));
// Clone the loop body. The clone becomes the fast loop. The
// original pre-header will (illegally) have 2 control users (old & new loops).
// original pre-header will (illegally) have 3 control users
// (old & new loops & new if).
clone_loop(loop, old_new, dom_depth(head), iff);
assert(old_new[head->_idx]->is_Loop(), "" );
// Fast (true) control
Node* iffast_pred = clone_loop_predicates(entry, iffast);
_igvn.hash_delete(head);
head->set_req(LoopNode::EntryControl, iffast);
set_idom(head, iffast, dom_depth(head));
head->set_req(LoopNode::EntryControl, iffast_pred);
set_idom(head, iffast_pred, dom_depth(head));
_igvn._worklist.push(head);
// Slow (false) control
Node* ifslow_pred = move_loop_predicates(entry, ifslow);
LoopNode* slow_head = old_new[head->_idx]->as_Loop();
_igvn.hash_delete(slow_head);
slow_head->set_req(LoopNode::EntryControl, ifslow);
set_idom(slow_head, ifslow, dom_depth(slow_head));
slow_head->set_req(LoopNode::EntryControl, ifslow_pred);
set_idom(slow_head, ifslow_pred, dom_depth(slow_head));
_igvn._worklist.push(slow_head);
recompute_dom_depth();