# HG changeset patch # User kvn # Date 1311956189 25200 # Node ID 02ee527cc0ae8657867e5a99d115f28341e363b6 # Parent efb61be7eaa751cead3c7406f2dba2d79f6418b8 7068051: SIGSEGV in PhaseIdealLoop::build_loop_late_post Summary: Removed predicate cloning from loop peeling optimization and from split fall-in paths. Reviewed-by: never diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/cfgnode.cpp --- a/src/share/vm/opto/cfgnode.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/cfgnode.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -1351,17 +1351,9 @@ static void split_once(PhaseIterGVN *igvn, Node *phi, Node *val, Node *n, Node *newn) { igvn->hash_delete(n); // Remove from hash before hacking edges - Node* predicate_proj = NULL; uint j = 1; for (uint i = phi->req()-1; i > 0; i--) { if (phi->in(i) == val) { // Found a path with val? - if (n->is_Region()) { - Node* proj = PhaseIdealLoop::find_predicate(n->in(i)); - if (proj != NULL) { - assert(predicate_proj == NULL, "only one predicate entry expected"); - predicate_proj = proj; - } - } // Add to NEW Region/Phi, no DU info newn->set_req( j++, n->in(i) ); // Remove from OLD Region/Phi @@ -1373,11 +1365,6 @@ // entire Region/Phi conglomerate has been hacked as a single huge transform. igvn->register_new_node_with_optimizer( newn ); - // Clone loop predicates - if (predicate_proj != NULL) { - newn = igvn->clone_loop_predicates(predicate_proj, newn, !n->is_CountedLoop()); - } - // Now I can point to the new node. n->add_req(newn); igvn->_worklist.push(n); @@ -1406,13 +1393,18 @@ Node *val = phi->in(i); // Constant to split for uint hit = 0; // Number of times it occurs + Node *r = phi->region(); for( ; i < phi->req(); i++ ){ // Count occurrences of constant Node *n = phi->in(i); if( !n ) return NULL; if( phase->type(n) == Type::TOP ) return NULL; - if( phi->in(i) == val ) + if( phi->in(i) == val ) { hit++; + if (PhaseIdealLoop::find_predicate(r->in(i)) != NULL) { + return NULL; // don't split loop entry path + } + } } if( hit <= 1 || // Make sure we find 2 or more @@ -1422,7 +1414,6 @@ // Now start splitting out the flow paths that merge the same value. // Split first the RegionNode. PhaseIterGVN *igvn = phase->is_IterGVN(); - Node *r = phi->region(); RegionNode *newr = new (phase->C, hit+1) RegionNode(hit+1); split_once(igvn, phi, val, r, newr); diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/ifnode.cpp --- a/src/share/vm/opto/ifnode.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/ifnode.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -255,6 +255,14 @@ predicate_x = predicate_proj; } } + if (predicate_c != NULL && (req_c > 1)) { + assert(predicate_x == NULL, "only one predicate entry expected"); + predicate_c = NULL; // Do not clone predicate below merge point + } + if (predicate_x != NULL && ((len - req_c) > 2)) { + assert(predicate_c == NULL, "only one predicate entry expected"); + predicate_x = NULL; // Do not clone predicate below merge point + } // Register the new RegionNodes but do not transform them. Cannot // transform until the entire Region/Phi conglomerate has been hacked diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/loopPredicate.cpp --- a/src/share/vm/opto/loopPredicate.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/loopPredicate.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -327,81 +327,20 @@ return new_predicate_proj; } -//--------------------------move_predicate----------------------- -// Cut predicate from old place and move it to new. -ProjNode* PhaseIdealLoop::move_predicate(ProjNode* predicate_proj, Node* new_entry, - Deoptimization::DeoptReason reason, - PhaseIdealLoop* loop_phase, - PhaseIterGVN* igvn) { - assert(new_entry != NULL, "must be"); - assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); - IfNode* iff = predicate_proj->in(0)->as_If(); - Node* old_entry = iff->in(0); - - // Cut predicate from old place. - Node* old = predicate_proj; - igvn->_worklist.push(old); - for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin;) { - Node* use = old->last_out(i); // for each use... - igvn->hash_delete(use); - igvn->_worklist.push(use); - // Update use-def info - uint uses_found = 0; - for (uint j = 0; j < use->req(); j++) { - if (use->in(j) == old) { - use->set_req(j, old_entry); - uses_found++; - if (loop_phase != NULL) { - if (use->is_CFG()) { - // When called from beautify_loops() idom is not constructed yet. - if (loop_phase->_idom != NULL) - loop_phase->set_idom(use, old_entry, loop_phase->dom_depth(use)); - } else { - loop_phase->set_ctrl(use, old_entry); - } - } - } - } - i -= uses_found; // we deleted 1 or more copies of this edge - } - - // Move predicate. - igvn->hash_delete(iff); - iff->set_req(0, new_entry); - igvn->_worklist.push(iff); - - if (loop_phase != NULL) { - // Fix up idom and ctrl. - loop_phase->set_ctrl(iff->in(1), new_entry); - loop_phase->set_ctrl(iff->in(1)->in(1), new_entry); - // When called from beautify_loops() idom is not constructed yet. - if (loop_phase->_idom != NULL) - loop_phase->set_idom(iff, new_entry, loop_phase->dom_depth(iff)); - } - - return predicate_proj; -} //--------------------------clone_loop_predicates----------------------- // Interface from IGVN Node* PhaseIterGVN::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { - return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, false, clone_limit_check, NULL, this); -} -Node* PhaseIterGVN::move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { - return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, true, clone_limit_check, NULL, this); + return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, clone_limit_check, NULL, this); } // Interface from PhaseIdealLoop Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { - return clone_loop_predicates(old_entry, new_entry, false, clone_limit_check, this, &this->_igvn); -} -Node* PhaseIdealLoop::move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { - return clone_loop_predicates(old_entry, new_entry, true, clone_limit_check, this, &this->_igvn); + return clone_loop_predicates(old_entry, new_entry, clone_limit_check, this, &this->_igvn); } // Clone loop predicates to cloned loops (peeled, unswitched, split_if). Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, - bool move_predicates, bool clone_limit_check, PhaseIdealLoop* loop_phase, PhaseIterGVN* igvn) { @@ -424,20 +363,13 @@ if (UseLoopPredicate) { ProjNode* predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); if (predicate_proj != NULL) { // right pattern that can be used by loop predication - if (move_predicates) { - new_entry = move_predicate(predicate_proj, new_entry, - Deoptimization::Reason_predicate, - loop_phase, igvn); - assert(new_entry == predicate_proj, "old predicate fall through projection"); - } else { - // clone predicate - new_entry = clone_predicate(predicate_proj, new_entry, - Deoptimization::Reason_predicate, - loop_phase, igvn); - assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate"); - } + // clone predicate + new_entry = clone_predicate(predicate_proj, new_entry, + Deoptimization::Reason_predicate, + loop_phase, igvn); + assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate"); if (TraceLoopPredicate) { - tty->print_cr("Loop Predicate %s: ", move_predicates ? "moved" : "cloned"); + tty->print("Loop Predicate cloned: "); debug_only( new_entry->in(0)->dump(); ) } } @@ -446,45 +378,18 @@ // Clone loop limit check last to insert it before loop. // Don't clone a limit check which was already finalized // for this counted loop (only one limit check is needed). - if (move_predicates) { - new_entry = move_predicate(limit_check_proj, new_entry, - Deoptimization::Reason_loop_limit_check, - loop_phase, igvn); - assert(new_entry == limit_check_proj, "old limit check fall through projection"); - } else { - new_entry = clone_predicate(limit_check_proj, new_entry, - Deoptimization::Reason_loop_limit_check, - loop_phase, igvn); - assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone limit check"); - } + new_entry = clone_predicate(limit_check_proj, new_entry, + Deoptimization::Reason_loop_limit_check, + loop_phase, igvn); + assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone limit check"); if (TraceLoopLimitCheck) { - tty->print_cr("Loop Limit Check %s: ", move_predicates ? "moved" : "cloned"); + tty->print("Loop Limit Check cloned: "); debug_only( new_entry->in(0)->dump(); ) } } return new_entry; } -//--------------------------eliminate_loop_predicates----------------------- -void PhaseIdealLoop::eliminate_loop_predicates(Node* entry) { - if (LoopLimitCheck) { - Node* predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); - if (predicate != NULL) { - entry = entry->in(0)->in(0); - } - } - if (UseLoopPredicate) { - ProjNode* predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); - if (predicate_proj != NULL) { // right pattern that can be used by loop predication - Node* n = entry->in(0)->in(1)->in(1); - assert(n->Opcode()==Op_Opaque1, "must be"); - // Remove Opaque1 node from predicates list. - // IGVN will remove this predicate check. - _igvn.replace_node(n, n->in(1)); - } - } -} - //--------------------------skip_loop_predicates------------------------------ // Skip related predicates. Node* PhaseIdealLoop::skip_loop_predicates(Node* entry) { diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/loopTransform.cpp --- a/src/share/vm/opto/loopTransform.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/loopTransform.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -509,14 +509,13 @@ // backedges) and then map to the new peeled iteration. This leaves // the pre-loop with only 1 user (the new peeled iteration), but the // peeled-loop backedge has 2 users. - Node* new_exit_value = old_new[head->in(LoopNode::LoopBackControl)->_idx]; - new_exit_value = move_loop_predicates(entry, new_exit_value, !counted_loop); + Node* new_entry = old_new[head->in(LoopNode::LoopBackControl)->_idx]; _igvn.hash_delete(head); - head->set_req(LoopNode::EntryControl, new_exit_value); + head->set_req(LoopNode::EntryControl, new_entry); for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) { Node* old = head->fast_out(j); if (old->in(0) == loop->_head && old->req() == 3 && old->is_Phi()) { - new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx]; + Node* new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx]; if (!new_exit_value ) // Backedge value is ALSO loop invariant? // Then loop body backedge value remains the same. new_exit_value = old->in(LoopNode::LoopBackControl); diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/loopUnswitch.cpp --- a/src/share/vm/opto/loopUnswitch.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/loopUnswitch.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -255,7 +255,7 @@ _igvn._worklist.push(head); // Slow (false) control - Node* ifslow_pred = move_loop_predicates(entry, ifslow, !counted_loop); + Node* ifslow_pred = clone_loop_predicates(entry, ifslow, !counted_loop); LoopNode* slow_head = old_new[head->_idx]->as_Loop(); _igvn.hash_delete(slow_head); slow_head->set_req(LoopNode::EntryControl, ifslow_pred); diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/loopnode.cpp --- a/src/share/vm/opto/loopnode.cpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/loopnode.cpp Fri Jul 29 09:16:29 2011 -0700 @@ -1167,9 +1167,8 @@ outer = igvn.register_new_node_with_optimizer(outer, _head); phase->set_created_loop_node(); - Node* pred = phase->clone_loop_predicates(ctl, outer, true); // Outermost loop falls into '_head' loop - _head->set_req(LoopNode::EntryControl, pred); + _head->set_req(LoopNode::EntryControl, outer); _head->del_req(outer_idx); // Split all the Phis up between '_head' loop and 'outer' loop. for (DUIterator_Fast jmax, j = _head->fast_outs(jmax); j < jmax; j++) { diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/loopnode.hpp --- a/src/share/vm/opto/loopnode.hpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/loopnode.hpp Fri Jul 29 09:16:29 2011 -0700 @@ -877,19 +877,13 @@ Deoptimization::DeoptReason reason, PhaseIdealLoop* loop_phase, PhaseIterGVN* igvn); - static ProjNode* move_predicate(ProjNode* predicate_proj, Node* new_entry, - Deoptimization::DeoptReason reason, - PhaseIdealLoop* loop_phase, - PhaseIterGVN* igvn); + static Node* clone_loop_predicates(Node* old_entry, Node* new_entry, - bool move_predicates, bool clone_limit_check, PhaseIdealLoop* loop_phase, PhaseIterGVN* igvn); Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); - Node* move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); - void eliminate_loop_predicates(Node* entry); static Node* skip_loop_predicates(Node* entry); // Find a good location to insert a predicate diff -r efb61be7eaa7 -r 02ee527cc0ae src/share/vm/opto/phaseX.hpp --- a/src/share/vm/opto/phaseX.hpp Tue Jun 28 15:24:29 2011 -0700 +++ b/src/share/vm/opto/phaseX.hpp Fri Jul 29 09:16:29 2011 -0700 @@ -473,7 +473,6 @@ // Clone loop predicates. Defined in loopTransform.cpp. Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); - Node* move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); // Create a new if below new_entry for the predicate to be cloned ProjNode* create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, Deoptimization::DeoptReason reason);