Mercurial > hg > shark > hotspot
changeset 2520:08eb13460b3a
7004535: Clone loop predicate during loop unswitch
Summary: Clone loop predicate for clonned loops
Reviewed-by: never
| author | kvn |
|---|---|
| date | Sat, 02 Apr 2011 10:54:15 -0700 |
| parents | 07acc51c1d2a |
| children | 13bc79b5c9c8 |
| files | src/share/vm/opto/cfgnode.cpp src/share/vm/opto/compile.cpp src/share/vm/opto/compile.hpp src/share/vm/opto/ifnode.cpp src/share/vm/opto/loopPredicate.cpp src/share/vm/opto/loopTransform.cpp src/share/vm/opto/loopUnswitch.cpp src/share/vm/opto/loopnode.cpp src/share/vm/opto/loopnode.hpp src/share/vm/opto/loopopts.cpp src/share/vm/opto/phaseX.hpp src/share/vm/opto/split_if.cpp src/share/vm/opto/superword.cpp src/share/vm/opto/vectornode.hpp |
| diffstat | 14 files changed, 1298 insertions(+), 716 deletions(-) [+] |
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--- a/src/share/vm/opto/cfgnode.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/cfgnode.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -1349,9 +1349,17 @@ 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? + 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 @@ -1362,6 +1370,12 @@ // Register the new node but do not transform it. Cannot transform until the // 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); + } + // Now I can point to the new node. n->add_req(newn); igvn->_worklist.push(n);
--- a/src/share/vm/opto/compile.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/compile.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -1632,7 +1632,6 @@ igvn.replace_node(n, n->in(1)); } assert(predicate_count()==0, "should be clean!"); - igvn.optimize(); } //------------------------------Optimize--------------------------------------- @@ -1689,7 +1688,7 @@ if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) { { TracePhase t2("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, true, UseLoopPredicate); + PhaseIdealLoop ideal_loop( igvn, true ); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 1", 2); if (failing()) return; @@ -1697,7 +1696,7 @@ // Loop opts pass if partial peeling occurred in previous pass if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) { TracePhase t3("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate); + PhaseIdealLoop ideal_loop( igvn, false ); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 2", 2); if (failing()) return; @@ -1705,7 +1704,7 @@ // Loop opts pass for loop-unrolling before CCP if(major_progress() && (loop_opts_cnt > 0)) { TracePhase t4("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate); + PhaseIdealLoop ideal_loop( igvn, false ); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 3", 2); } @@ -1743,21 +1742,13 @@ // peeling, unrolling, etc. if(loop_opts_cnt > 0) { debug_only( int cnt = 0; ); - bool loop_predication = UseLoopPredicate; while(major_progress() && (loop_opts_cnt > 0)) { TracePhase t2("idealLoop", &_t_idealLoop, true); assert( cnt++ < 40, "infinite cycle in loop optimization" ); - PhaseIdealLoop ideal_loop( igvn, true, loop_predication); + PhaseIdealLoop ideal_loop( igvn, true); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop iterations", 2); if (failing()) return; - // Perform loop predication optimization during first iteration after CCP. - // After that switch it off and cleanup unused loop predicates. - if (loop_predication) { - loop_predication = false; - cleanup_loop_predicates(igvn); - if (failing()) return; - } } }
--- a/src/share/vm/opto/compile.hpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/compile.hpp Sat Apr 02 10:54:15 2011 -0700 @@ -489,6 +489,9 @@ // remove the opaque nodes that protect the predicates so that the unused checks and // uncommon traps will be eliminated from the graph. void cleanup_loop_predicates(PhaseIterGVN &igvn); + bool is_predicate_opaq(Node * n) { + return _predicate_opaqs->contains(n); + } // Compilation environment. Arena* comp_arena() { return &_comp_arena; }
--- a/src/share/vm/opto/ifnode.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/ifnode.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -27,6 +27,7 @@ #include "opto/addnode.hpp" #include "opto/cfgnode.hpp" #include "opto/connode.hpp" +#include "opto/loopnode.hpp" #include "opto/phaseX.hpp" #include "opto/runtime.hpp" #include "opto/subnode.hpp" @@ -222,22 +223,35 @@ // Make a region merging constants and a region merging the rest uint req_c = 0; + Node* predicate_proj = NULL; for (uint ii = 1; ii < r->req(); ii++) { - if( phi->in(ii) == con1 ) { + if (phi->in(ii) == con1) { req_c++; } + Node* proj = PhaseIdealLoop::find_predicate(r->in(ii)); + if (proj != NULL) { + assert(predicate_proj == NULL, "only one predicate entry expected"); + predicate_proj = proj; + } } + Node* predicate_c = NULL; + Node* predicate_x = NULL; + Node *region_c = new (igvn->C, req_c + 1) RegionNode(req_c + 1); Node *phi_c = con1; uint len = r->req(); - Node *region_x = new (igvn->C, len - req_c + 1) RegionNode(len - req_c + 1); + Node *region_x = new (igvn->C, len - req_c) RegionNode(len - req_c); Node *phi_x = PhiNode::make_blank(region_x, phi); for (uint i = 1, i_c = 1, i_x = 1; i < len; i++) { - if( phi->in(i) == con1 ) { + if (phi->in(i) == con1) { region_c->init_req( i_c++, r ->in(i) ); + if (r->in(i) == predicate_proj) + predicate_c = predicate_proj; } else { region_x->init_req( i_x, r ->in(i) ); phi_x ->init_req( i_x++, phi->in(i) ); + if (r->in(i) == predicate_proj) + predicate_x = predicate_proj; } } @@ -277,8 +291,20 @@ // Make the true/false arms Node *iff_c_t = phase->transform(new (igvn->C, 1) IfTrueNode (iff_c)); Node *iff_c_f = phase->transform(new (igvn->C, 1) IfFalseNode(iff_c)); + if (predicate_c != NULL) { + assert(predicate_x == NULL, "only one predicate entry expected"); + // Clone loop predicates to each path + iff_c_t = igvn->clone_loop_predicates(predicate_c, iff_c_t); + iff_c_f = igvn->clone_loop_predicates(predicate_c, iff_c_f); + } Node *iff_x_t = phase->transform(new (igvn->C, 1) IfTrueNode (iff_x)); Node *iff_x_f = phase->transform(new (igvn->C, 1) IfFalseNode(iff_x)); + if (predicate_x != NULL) { + assert(predicate_c == NULL, "only one predicate entry expected"); + // Clone loop predicates to each path + iff_x_t = igvn->clone_loop_predicates(predicate_x, iff_x_t); + iff_x_f = igvn->clone_loop_predicates(predicate_x, iff_x_f); + } // Merge the TRUE paths Node *region_s = new (igvn->C, 3) RegionNode(3);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/opto/loopPredicate.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -0,0 +1,960 @@ +/* + * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "opto/loopnode.hpp" +#include "opto/addnode.hpp" +#include "opto/callnode.hpp" +#include "opto/connode.hpp" +#include "opto/loopnode.hpp" +#include "opto/mulnode.hpp" +#include "opto/rootnode.hpp" +#include "opto/subnode.hpp" + +/* + * The general idea of Loop Predication is to insert a predicate on the entry + * path to a loop, and raise a uncommon trap if the check of the condition fails. + * The condition checks are promoted from inside the loop body, and thus + * the checks inside the loop could be eliminated. Currently, loop predication + * optimization has been applied to remove array range check and loop invariant + * checks (such as null checks). +*/ + +//-------------------------------is_uncommon_trap_proj---------------------------- +// Return true if proj is the form of "proj->[region->..]call_uct" +bool PhaseIdealLoop::is_uncommon_trap_proj(ProjNode* proj, Deoptimization::DeoptReason reason) { + int path_limit = 10; + assert(proj, "invalid argument"); + Node* out = proj; + for (int ct = 0; ct < path_limit; ct++) { + out = out->unique_ctrl_out(); + if (out == NULL) + return false; + if (out->is_CallStaticJava()) { + int req = out->as_CallStaticJava()->uncommon_trap_request(); + if (req != 0) { + Deoptimization::DeoptReason trap_reason = Deoptimization::trap_request_reason(req); + if (trap_reason == reason || reason == Deoptimization::Reason_none) { + return true; + } + } + return false; // don't do further after call + } + if (out->Opcode() != Op_Region) + return false; + } + return false; +} + +//-------------------------------is_uncommon_trap_if_pattern------------------------- +// Return true for "if(test)-> proj -> ... +// | +// V +// other_proj->[region->..]call_uct" +// +// "must_reason_predicate" means the uct reason must be Reason_predicate +bool PhaseIdealLoop::is_uncommon_trap_if_pattern(ProjNode *proj, Deoptimization::DeoptReason reason) { + Node *in0 = proj->in(0); + if (!in0->is_If()) return false; + // Variation of a dead If node. + if (in0->outcnt() < 2) return false; + IfNode* iff = in0->as_If(); + + // we need "If(Conv2B(Opaque1(...)))" pattern for reason_predicate + if (reason != Deoptimization::Reason_none) { + if (iff->in(1)->Opcode() != Op_Conv2B || + iff->in(1)->in(1)->Opcode() != Op_Opaque1) { + return false; + } + } + + ProjNode* other_proj = iff->proj_out(1-proj->_con)->as_Proj(); + if (is_uncommon_trap_proj(other_proj, reason)) { + assert(reason == Deoptimization::Reason_none || + Compile::current()->is_predicate_opaq(iff->in(1)->in(1)), "should be on the list"); + return true; + } + return false; +} + +//-------------------------------register_control------------------------- +void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) { + assert(n->is_CFG(), "must be control node"); + _igvn.register_new_node_with_optimizer(n); + loop->_body.push(n); + set_loop(n, loop); + // When called from beautify_loops() idom is not constructed yet. + if (_idom != NULL) { + set_idom(n, pred, dom_depth(pred)); + } +} + +//------------------------------create_new_if_for_predicate------------------------ +// create a new if above the uct_if_pattern for the predicate to be promoted. +// +// before after +// ---------- ---------- +// ctrl ctrl +// | | +// | | +// v v +// iff new_iff +// / \ / \ +// / \ / \ +// v v v v +// uncommon_proj cont_proj if_uct if_cont +// \ | | | | +// \ | | | | +// v v v | v +// rgn loop | iff +// | | / \ +// | | / \ +// v | v v +// uncommon_trap | uncommon_proj cont_proj +// \ \ | | +// \ \ | | +// v v v v +// rgn loop +// | +// | +// v +// uncommon_trap +// +// +// We will create a region to guard the uct call if there is no one there. +// The true projecttion (if_cont) of the new_iff is returned. +// This code is also used to clone predicates to clonned loops. +ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, + Deoptimization::DeoptReason reason) { + assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!"); + IfNode* iff = cont_proj->in(0)->as_If(); + + ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); + Node *rgn = uncommon_proj->unique_ctrl_out(); + assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); + + uint proj_index = 1; // region's edge corresponding to uncommon_proj + if (!rgn->is_Region()) { // create a region to guard the call + assert(rgn->is_Call(), "must be call uct"); + CallNode* call = rgn->as_Call(); + IdealLoopTree* loop = get_loop(call); + rgn = new (C, 1) RegionNode(1); + rgn->add_req(uncommon_proj); + register_control(rgn, loop, uncommon_proj); + _igvn.hash_delete(call); + call->set_req(0, rgn); + // When called from beautify_loops() idom is not constructed yet. + if (_idom != NULL) { + set_idom(call, rgn, dom_depth(rgn)); + } + } else { + // Find region's edge corresponding to uncommon_proj + for (; proj_index < rgn->req(); proj_index++) + if (rgn->in(proj_index) == uncommon_proj) break; + assert(proj_index < rgn->req(), "sanity"); + } + + Node* entry = iff->in(0); + if (new_entry != NULL) { + // Clonning the predicate to new location. + entry = new_entry; + } + // Create new_iff + IdealLoopTree* lp = get_loop(entry); + IfNode *new_iff = iff->clone()->as_If(); + new_iff->set_req(0, entry); + register_control(new_iff, lp, entry); + Node *if_cont = new (C, 1) IfTrueNode(new_iff); + Node *if_uct = new (C, 1) IfFalseNode(new_iff); + if (cont_proj->is_IfFalse()) { + // Swap + Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; + } + register_control(if_cont, lp, new_iff); + register_control(if_uct, get_loop(rgn), new_iff); + + // if_uct to rgn + _igvn.hash_delete(rgn); + rgn->add_req(if_uct); + // When called from beautify_loops() idom is not constructed yet. + if (_idom != NULL) { + Node* ridom = idom(rgn); + Node* nrdom = dom_lca(ridom, new_iff); + set_idom(rgn, nrdom, dom_depth(rgn)); + } + + // If rgn has phis add new edges which has the same + // value as on original uncommon_proj pass. + assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); + bool has_phi = false; + for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { + Node* use = rgn->fast_out(i); + if (use->is_Phi() && use->outcnt() > 0) { + assert(use->in(0) == rgn, ""); + _igvn.hash_delete(use); + use->add_req(use->in(proj_index)); + _igvn._worklist.push(use); + has_phi = true; + } + } + assert(!has_phi || rgn->req() > 3, "no phis when region is created"); + + if (new_entry == NULL) { + // Attach if_cont to iff + _igvn.hash_delete(iff); + iff->set_req(0, if_cont); + if (_idom != NULL) { + set_idom(iff, if_cont, dom_depth(iff)); + } + } + return if_cont->as_Proj(); +} + +//------------------------------create_new_if_for_predicate------------------------ +// Create a new if below new_entry for the predicate to be cloned (IGVN optimization) +ProjNode* PhaseIterGVN::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, + Deoptimization::DeoptReason reason) { + assert(new_entry != 0, "only used for clone predicate"); + assert(PhaseIdealLoop::is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!"); + IfNode* iff = cont_proj->in(0)->as_If(); + + ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); + Node *rgn = uncommon_proj->unique_ctrl_out(); + assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); + + uint proj_index = 1; // region's edge corresponding to uncommon_proj + if (!rgn->is_Region()) { // create a region to guard the call + assert(rgn->is_Call(), "must be call uct"); + CallNode* call = rgn->as_Call(); + rgn = new (C, 1) RegionNode(1); + register_new_node_with_optimizer(rgn); + rgn->add_req(uncommon_proj); + hash_delete(call); + call->set_req(0, rgn); + } else { + // Find region's edge corresponding to uncommon_proj + for (; proj_index < rgn->req(); proj_index++) + if (rgn->in(proj_index) == uncommon_proj) break; + assert(proj_index < rgn->req(), "sanity"); + } + + // Create new_iff in new location. + IfNode *new_iff = iff->clone()->as_If(); + new_iff->set_req(0, new_entry); + + register_new_node_with_optimizer(new_iff); + Node *if_cont = new (C, 1) IfTrueNode(new_iff); + Node *if_uct = new (C, 1) IfFalseNode(new_iff); + if (cont_proj->is_IfFalse()) { + // Swap + Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; + } + register_new_node_with_optimizer(if_cont); + register_new_node_with_optimizer(if_uct); + + // if_uct to rgn + hash_delete(rgn); + rgn->add_req(if_uct); + + // If rgn has phis add corresponding new edges which has the same + // value as on original uncommon_proj pass. + assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); + bool has_phi = false; + for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { + Node* use = rgn->fast_out(i); + if (use->is_Phi() && use->outcnt() > 0) { + hash_delete(use); + use->add_req(use->in(proj_index)); + _worklist.push(use); + has_phi = true; + } + } + assert(!has_phi || rgn->req() > 3, "no phis when region is created"); + + return if_cont->as_Proj(); +} + +//--------------------------clone_predicate----------------------- +ProjNode* PhaseIdealLoop::clone_predicate(ProjNode* predicate_proj, Node* new_entry, + Deoptimization::DeoptReason reason, + PhaseIdealLoop* loop_phase, + PhaseIterGVN* igvn) { + ProjNode* new_predicate_proj; + if (loop_phase != NULL) { + new_predicate_proj = loop_phase->create_new_if_for_predicate(predicate_proj, new_entry, reason); + } else { + new_predicate_proj = igvn->create_new_if_for_predicate(predicate_proj, new_entry, reason); + } + IfNode* iff = new_predicate_proj->in(0)->as_If(); + Node* ctrl = iff->in(0); + + // Match original condition since predicate's projections could be swapped. + assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); + Node* opq = new (igvn->C, 2) Opaque1Node(igvn->C, predicate_proj->in(0)->in(1)->in(1)->in(1)); + igvn->C->add_predicate_opaq(opq); + + Node* bol = new (igvn->C, 2) Conv2BNode(opq); + if (loop_phase != NULL) { + loop_phase->register_new_node(opq, ctrl); + loop_phase->register_new_node(bol, ctrl); + } else { + igvn->register_new_node_with_optimizer(opq); + igvn->register_new_node_with_optimizer(bol); + } + igvn->hash_delete(iff); + iff->set_req(1, bol); + 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) { + return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, false, NULL, this); +} +Node* PhaseIterGVN::move_loop_predicates(Node* old_entry, Node* new_entry) { + return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, true, NULL, this); +} + +// Interface from PhaseIdealLoop +Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry) { + return clone_loop_predicates(old_entry, new_entry, false, this, &this->_igvn); +} +Node* PhaseIdealLoop::move_loop_predicates(Node* old_entry, Node* new_entry) { + return clone_loop_predicates(old_entry, new_entry, true, 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, + PhaseIdealLoop* loop_phase, + PhaseIterGVN* igvn) { +#ifdef ASSERT + if (new_entry == NULL || !(new_entry->is_Proj() || new_entry->is_Region() || new_entry->is_SafePoint())) { + if (new_entry != NULL) + new_entry->dump(); + assert(false, "not IfTrue, IfFalse, Region or SafePoint"); + } +#endif + // Search original predicates + Node* entry = old_entry; + 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 + assert(entry->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); + 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"); + } + if (TraceLoopPredicate) { + tty->print_cr("Loop Predicate %s: ", move_predicates ? "moved" : "cloned"); + debug_only( new_entry->in(0)->dump(); ) + } + } + } + return new_entry; +} + +//--------------------------eliminate_loop_predicates----------------------- +void PhaseIdealLoop::eliminate_loop_predicates(Node* entry) { + 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) { + Node* predicate = NULL; + if (UseLoopPredicate) { + predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); + if (predicate != NULL) { // right pattern that can be used by loop predication + assert(entry->is_Proj() && entry->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); + IfNode* iff = entry->in(0)->as_If(); + ProjNode* uncommon_proj = iff->proj_out(1 - entry->as_Proj()->_con); + Node* rgn = uncommon_proj->unique_ctrl_out(); + assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); + entry = entry->in(0)->in(0); + while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) { + uncommon_proj = entry->in(0)->as_If()->proj_out(1 - entry->as_Proj()->_con); + if (uncommon_proj->unique_ctrl_out() != rgn) + break; + entry = entry->in(0)->in(0); + } + } + } + return entry; +} + +//--------------------------find_predicate_insertion_point------------------- +// Find a good location to insert a predicate +ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) { + if (start_c == NULL || !start_c->is_Proj()) + return NULL; + if (is_uncommon_trap_if_pattern(start_c->as_Proj(), reason)) { + return start_c->as_Proj(); + } + return NULL; +} + +//--------------------------find_predicate------------------------------------ +// Find a predicate +Node* PhaseIdealLoop::find_predicate(Node* entry) { + Node* predicate = NULL; + if (UseLoopPredicate) { + predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); + if (predicate != NULL) { // right pattern that can be used by loop predication + assert(entry->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); + return entry; + } + } + return NULL; +} + +//------------------------------Invariance----------------------------------- +// Helper class for loop_predication_impl to compute invariance on the fly and +// clone invariants. +class Invariance : public StackObj { + VectorSet _visited, _invariant; + Node_Stack _stack; + VectorSet _clone_visited; + Node_List _old_new; // map of old to new (clone) + IdealLoopTree* _lpt; + PhaseIdealLoop* _phase; + + // Helper function to set up the invariance for invariance computation + // If n is a known invariant, set up directly. Otherwise, look up the + // the possibility to push n onto the stack for further processing. + void visit(Node* use, Node* n) { + if (_lpt->is_invariant(n)) { // known invariant + _invariant.set(n->_idx); + } else if (!n->is_CFG()) { + Node *n_ctrl = _phase->ctrl_or_self(n); + Node *u_ctrl = _phase->ctrl_or_self(use); // self if use is a CFG + if (_phase->is_dominator(n_ctrl, u_ctrl)) { + _stack.push(n, n->in(0) == NULL ? 1 : 0); + } + } + } + + // Compute invariance for "the_node" and (possibly) all its inputs recursively + // on the fly + void compute_invariance(Node* n) { + assert(_visited.test(n->_idx), "must be"); + visit(n, n); + while (_stack.is_nonempty()) { + Node* n = _stack.node(); + uint idx = _stack.index(); + if (idx == n->req()) { // all inputs are processed + _stack.pop(); + // n is invariant if it's inputs are all invariant + bool all_inputs_invariant = true; + for (uint i = 0; i < n->req(); i++) { + Node* in = n->in(i); + if (in == NULL) continue; + assert(_visited.test(in->_idx), "must have visited input"); + if (!_invariant.test(in->_idx)) { // bad guy + all_inputs_invariant = false; + break; + } + } + if (all_inputs_invariant) { + _invariant.set(n->_idx); // I am a invariant too + } + } else { // process next input + _stack.set_index(idx + 1); + Node* m = n->in(idx); + if (m != NULL && !_visited.test_set(m->_idx)) { + visit(n, m); + } + } + } + } + + // Helper function to set up _old_new map for clone_nodes. + // If n is a known invariant, set up directly ("clone" of n == n). + // Otherwise, push n onto the stack for real cloning. + void clone_visit(Node* n) { + assert(_invariant.test(n->_idx), "must be invariant"); + if (_lpt->is_invariant(n)) { // known invariant + _old_new.map(n->_idx, n); + } else { // to be cloned + assert(!n->is_CFG(), "should not see CFG here"); + _stack.push(n, n->in(0) == NULL ? 1 : 0); + } + } + + // Clone "n" and (possibly) all its inputs recursively + void clone_nodes(Node* n, Node* ctrl) { + clone_visit(n); + while (_stack.is_nonempty()) { + Node* n = _stack.node(); + uint idx = _stack.index(); + if (idx == n->req()) { // all inputs processed, clone n! + _stack.pop(); + // clone invariant node + Node* n_cl = n->clone(); + _old_new.map(n->_idx, n_cl); + _phase->register_new_node(n_cl, ctrl); + for (uint i = 0; i < n->req(); i++) { + Node* in = n_cl->in(i); + if (in == NULL) continue; + n_cl->set_req(i, _old_new[in->_idx]); + } + } else { // process next input + _stack.set_index(idx + 1); + Node* m = n->in(idx); + if (m != NULL && !_clone_visited.test_set(m->_idx)) { + clone_visit(m); // visit the input + } + } + } + } + + public: + Invariance(Arena* area, IdealLoopTree* lpt) : + _lpt(lpt), _phase(lpt->_phase), + _visited(area), _invariant(area), _stack(area, 10 /* guess */), + _clone_visited(area), _old_new(area) + {} + + // Map old to n for invariance computation and clone + void map_ctrl(Node* old, Node* n) { + assert(old->is_CFG() && n->is_CFG(), "must be"); + _old_new.map(old->_idx, n); // "clone" of old is n + _invariant.set(old->_idx); // old is invariant + _clone_visited.set(old->_idx); + } + + // Driver function to compute invariance + bool is_invariant(Node* n) { + if (!_visited.test_set(n->_idx)) + compute_invariance(n); + return (_invariant.test(n->_idx) != 0); + } + + // Driver function to clone invariant + Node* clone(Node* n, Node* ctrl) { + assert(ctrl->is_CFG(), "must be"); + assert(_invariant.test(n->_idx), "must be an invariant"); + if (!_clone_visited.test(n->_idx)) + clone_nodes(n, ctrl); + return _old_new[n->_idx]; + } +}; + +//------------------------------is_range_check_if ----------------------------------- +// Returns true if the predicate of iff is in "scale*iv + offset u< load_range(ptr)" format +// Note: this function is particularly designed for loop predication. We require load_range +// and offset to be loop invariant computed on the fly by "invar" +bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const { + if (!is_loop_exit(iff)) { + return false; + } + if (!iff->in(1)->is_Bool()) { + return false; + } + const BoolNode *bol = iff->in(1)->as_Bool(); + if (bol->_test._test != BoolTest::lt) { + return false; + } + if (!bol->in(1)->is_Cmp()) { + return false; + } + const CmpNode *cmp = bol->in(1)->as_Cmp(); + if (cmp->Opcode() != Op_CmpU) { + return false; + } + Node* range = cmp->in(2); + if (range->Opcode() != Op_LoadRange) { + const TypeInt* tint = phase->_igvn.type(range)->isa_int(); + if (!OptimizeFill || tint == NULL || tint->empty() || tint->_lo < 0) { + // Allow predication on positive values that aren't LoadRanges. + // This allows optimization of loops where the length of the + // array is a known value and doesn't need to be loaded back + // from the array. + return false; + } + } + if (!invar.is_invariant(range)) { + return false; + } + Node *iv = _head->as_CountedLoop()->phi(); + int scale = 0; + Node *offset = NULL; + if (!phase->is_scaled_iv_plus_offset(cmp->in(1), iv, &scale, &offset)) { + return false; + } + if (offset && !invar.is_invariant(offset)) { // offset must be invariant + return false; + } + return true; +} + +//------------------------------rc_predicate----------------------------------- +// Create a range check predicate +// +// for (i = init; i < limit; i += stride) { +// a[scale*i+offset] +// } +// +// Compute max(scale*i + offset) for init <= i < limit and build the predicate +// as "max(scale*i + offset) u< a.length". +// +// There are two cases for max(scale*i + offset): +// (1) stride*scale > 0 +// max(scale*i + offset) = scale*(limit-stride) + offset +// (2) stride*scale < 0 +// max(scale*i + offset) = scale*init + offset +BoolNode* PhaseIdealLoop::rc_predicate(Node* ctrl, + int scale, Node* offset, + Node* init, Node* limit, Node* stride, + Node* range, bool upper) { + DEBUG_ONLY(ttyLocker ttyl); + if (TraceLoopPredicate) tty->print("rc_predicate "); + + Node* max_idx_expr = init; + int stride_con = stride->get_int(); + if ((stride_con > 0) == (scale > 0) == upper) { + max_idx_expr = new (C, 3) SubINode(limit, stride); + register_new_node(max_idx_expr, ctrl); + if (TraceLoopPredicate) tty->print("(limit - stride) "); + } else { + if (TraceLoopPredicate) tty->print("init "); + } + + if (scale != 1) { + ConNode* con_scale = _igvn.intcon(scale); + max_idx_expr = new (C, 3) MulINode(max_idx_expr, con_scale); + register_new_node(max_idx_expr, ctrl); + if (TraceLoopPredicate) tty->print("* %d ", scale); + } + + if (offset && (!offset->is_Con() || offset->get_int() != 0)){ + max_idx_expr = new (C, 3) AddINode(max_idx_expr, offset); + register_new_node(max_idx_expr, ctrl); + if (TraceLoopPredicate) + if (offset->is_Con()) tty->print("+ %d ", offset->get_int()); + else tty->print("+ offset "); + } + + CmpUNode* cmp = new (C, 3) CmpUNode(max_idx_expr, range); + register_new_node(cmp, ctrl); + BoolNode* bol = new (C, 2) BoolNode(cmp, BoolTest::lt); + register_new_node(bol, ctrl); + + if (TraceLoopPredicate) tty->print_cr("<u range"); + return bol; +} + +//------------------------------ loop_predication_impl-------------------------- +// Insert loop predicates for null checks and range checks +bool PhaseIdealLoop::loop_predication_impl(IdealLoopTree *loop) { + if (!UseLoopPredicate) return false; + + if (!loop->_head->is_Loop()) { + // Could be a simple region when irreducible loops are present. + return false; + } + + if (loop->_head->unique_ctrl_out()->Opcode() == Op_NeverBranch) { + // do nothing for infinite loops + return false; + } + + CountedLoopNode *cl = NULL; + if (loop->_head->is_CountedLoop()) { + cl = loop->_head->as_CountedLoop(); + // do nothing for iteration-splitted loops + if (!cl->is_normal_loop()) return false; + } + + LoopNode *lpn = loop->_head->as_Loop(); + Node* entry = lpn->in(LoopNode::EntryControl); + + ProjNode *predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); + if (!predicate_proj) { +#ifndef PRODUCT + if (TraceLoopPredicate) { + tty->print("missing predicate:"); + loop->dump_head(); + lpn->dump(1); + } +#endif + return false; + } + ConNode* zero = _igvn.intcon(0); + set_ctrl(zero, C->root()); + + ResourceArea *area = Thread::current()->resource_area(); + Invariance invar(area, loop); + + // Create list of if-projs such that a newer proj dominates all older + // projs in the list, and they all dominate loop->tail() + Node_List if_proj_list(area); + LoopNode *head = loop->_head->as_Loop(); + Node *current_proj = loop->tail(); //start from tail + while (current_proj != head) { + if (loop == get_loop(current_proj) && // still in the loop ? + current_proj->is_Proj() && // is a projection ? + current_proj->in(0)->Opcode() == Op_If) { // is a if projection ? + if_proj_list.push(current_proj); + } + current_proj = idom(current_proj); + } + + bool hoisted = false; // true if at least one proj is promoted + while (if_proj_list.size() > 0) { + // Following are changed to nonnull when a predicate can be hoisted + ProjNode* new_predicate_proj = NULL; + + ProjNode* proj = if_proj_list.pop()->as_Proj(); + IfNode* iff = proj->in(0)->as_If(); + + if (!is_uncommon_trap_if_pattern(proj, Deoptimization::Reason_none)) { + if (loop->is_loop_exit(iff)) { + // stop processing the remaining projs in the list because the execution of them + // depends on the condition of "iff" (iff->in(1)). + break; + } else { + // Both arms are inside the loop. There are two cases: + // (1) there is one backward branch. In this case, any remaining proj + // in the if_proj list post-dominates "iff". So, the condition of "iff" + // does not determine the execution the remining projs directly, and we + // can safely continue. + // (2) both arms are forwarded, i.e. a diamond shape. In this case, "proj" + // does not dominate loop->tail(), so it can not be in the if_proj list. + continue; + } + } + + Node* test = iff->in(1); + if (!test->is_Bool()){ //Conv2B, ... + continue; + } + BoolNode* bol = test->as_Bool(); + if (invar.is_invariant(bol)) { + // Invariant test + new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL, + Deoptimization::Reason_predicate); + Node* ctrl = new_predicate_proj->in(0)->as_If()->in(0); + BoolNode* new_predicate_bol = invar.clone(bol, ctrl)->as_Bool(); + + // Negate test if necessary + bool negated = false; + if (proj->_con != predicate_proj->_con) { + new_predicate_bol = new (C, 2) BoolNode(new_predicate_bol->in(1), new_predicate_bol->_test.negate()); + register_new_node(new_predicate_bol, ctrl); + negated = true; + } + IfNode* new_predicate_iff = new_predicate_proj->in(0)->as_If(); + _igvn.hash_delete(new_predicate_iff); + new_predicate_iff->set_req(1, new_predicate_bol); +#ifndef PRODUCT + if (TraceLoopPredicate) { + tty->print("Predicate invariant if%s: %d ", negated ? " negated" : "", new_predicate_iff->_idx); + loop->dump_head(); + } else if (TraceLoopOpts) { + tty->print("Predicate IC "); + loop->dump_head(); + } +#endif + } else if (cl != NULL && loop->is_range_check_if(iff, this, invar)) { + assert(proj->_con == predicate_proj->_con, "must match"); + + // Range check for counted loops + const Node* cmp = bol->in(1)->as_Cmp(); + Node* idx = cmp->in(1); + assert(!invar.is_invariant(idx), "index is variant"); + assert(cmp->in(2)->Opcode() == Op_LoadRange || OptimizeFill, "must be"); + Node* rng = cmp->in(2); + assert(invar.is_invariant(rng), "range must be invariant"); + int scale = 1; + Node* offset = zero; + bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset); + assert(ok, "must be index expression"); + + Node* init = cl->init_trip(); + Node* limit = cl->limit(); + Node* stride = cl->stride(); + + // Build if's for the upper and lower bound tests. The + // lower_bound test will dominate the upper bound test and all + // cloned or created nodes will use the lower bound test as + // their declared control. + ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); + ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); + assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate"); + Node *ctrl = lower_bound_proj->in(0)->as_If()->in(0); + + // Perform cloning to keep Invariance state correct since the + // late schedule will place invariant things in the loop. + rng = invar.clone(rng, ctrl); + if (offset && offset != zero) { + assert(invar.is_invariant(offset), "offset must be loop invariant"); + offset = invar.clone(offset, ctrl); + } + + // Test the lower bound + Node* lower_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, false); + IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If(); + _igvn.hash_delete(lower_bound_iff); + lower_bound_iff->set_req(1, lower_bound_bol); + if (TraceLoopPredicate) tty->print_cr("lower bound check if: %d", lower_bound_iff->_idx); + + // Test the upper bound + Node* upper_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, true); + IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If(); + _igvn.hash_delete(upper_bound_iff); + upper_bound_iff->set_req(1, upper_bound_bol); + if (TraceLoopPredicate) tty->print_cr("upper bound check if: %d", lower_bound_iff->_idx); + + // Fall through into rest of the clean up code which will move + // any dependent nodes onto the upper bound test. + new_predicate_proj = upper_bound_proj; + +#ifndef PRODUCT + if (TraceLoopOpts && !TraceLoopPredicate) { + tty->print("Predicate RC "); + loop->dump_head(); + } +#endif + } else { + // Loop variant check (for example, range check in non-counted loop) + // with uncommon trap. + continue; + } + assert(new_predicate_proj != NULL, "sanity"); + // Success - attach condition (new_predicate_bol) to predicate if + invar.map_ctrl(proj, new_predicate_proj); // so that invariance test can be appropriate + + // Eliminate the old If in the loop body + dominated_by( new_predicate_proj, iff, proj->_con != new_predicate_proj->_con ); + + hoisted = true; + C->set_major_progress(); + } // end while + +#ifndef PRODUCT + // report that the loop predication has been actually performed + // for this loop + if (TraceLoopPredicate && hoisted) { + tty->print("Loop Predication Performed:"); + loop->dump_head(); + } +#endif + + return hoisted; +} + +//------------------------------loop_predication-------------------------------- +// driver routine for loop predication optimization +bool IdealLoopTree::loop_predication( PhaseIdealLoop *phase) { + bool hoisted = false; + // Recursively promote predicates + if (_child) { + hoisted = _child->loop_predication( phase); + } + + // self + if (!_irreducible && !tail()->is_top()) { + hoisted |= phase->loop_predication_impl(this); + } + + if (_next) { //sibling + hoisted |= _next->loop_predication( phase); + } + + return hoisted; +} +
--- a/src/share/vm/opto/loopTransform.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/loopTransform.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -301,6 +301,132 @@ // peeled-loop backedge has 2 users. // Step 3: Cut the backedge on the clone (so its not a loop) and remove the // extra backedge user. +// +// orig +// +// stmt1 +// | +// v +// loop predicate +// | +// v +// loop<----+ +// | | +// stmt2 | +// | | +// v | +// if ^ +// / \ | +// / \ | +// v v | +// false true | +// / \ | +// / ----+ +// | +// v +// exit +// +// +// after clone loop +// +// stmt1 +// | +// v +// loop predicate +// / \ +// clone / \ orig +// / \ +// / \ +// v v +// +---->loop clone loop<----+ +// | | | | +// | stmt2 clone stmt2 | +// | | | | +// | v v | +// ^ if clone If ^ +// | / \ / \ | +// | / \ / \ | +// | v v v v | +// | true false false true | +// | / \ / \ | +// +---- \ / ----+ +// \ / +// 1v v2 +// region +// | +// v +// exit +// +// +// after peel and predicate move +// +// stmt1 +// / +// / +// clone / orig +// / +// / +----------+ +// / | | +// / loop predicate | +// / | | +// v v | +// TOP-->loop clone loop<----+ | +// | | | | +// stmt2 clone stmt2 | | +// | | | ^ +// v v | | +// if clone If ^ | +// / \ / \ | | +// / \ / \ | | +// v v v v | | +// true false false true | | +// | \ / \ | | +// | \ / ----+ ^ +// | \ / | +// | 1v v2 | +// v region | +// | | | +// | v | +// | exit | +// | | +// +--------------->-----------------+ +// +// +// final graph +// +// stmt1 +// | +// v +// stmt2 clone +// | +// v +// if clone +// / | +// / | +// v v +// false true +// | | +// | v +// | loop predicate +// | | +// | v +// | loop<----+ +// | | | +// | stmt2 | +// | | | +// | v | +// v if ^ +// | / \ | +// | / \ | +// | v v | +// | false true | +// | | \ | +// v v --+ +// region +// | +// v +// exit +// void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) { C->set_major_progress(); @@ -315,9 +441,10 @@ loop->dump_head(); } #endif - Node *h = loop->_head; - if (h->is_CountedLoop()) { - CountedLoopNode *cl = h->as_CountedLoop(); + Node* head = loop->_head; + bool counted_loop = head->is_CountedLoop(); + if (counted_loop) { + CountedLoopNode *cl = head->as_CountedLoop(); assert(cl->trip_count() > 0, "peeling a fully unrolled loop"); cl->set_trip_count(cl->trip_count() - 1); if (cl->is_main_loop()) { @@ -330,11 +457,11 @@ #endif } } + Node* entry = head->in(LoopNode::EntryControl); // Step 1: Clone the loop body. The clone becomes the peeled iteration. // The pre-loop illegally has 2 control users (old & new loops). - clone_loop( loop, old_new, dom_depth(loop->_head) ); - + clone_loop( loop, old_new, dom_depth(head) ); // Step 2: Make the old-loop fall-in edges point to the peeled iteration. // Do this by making the old-loop fall-in edges act as if they came @@ -342,12 +469,15 @@ // 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. - for (DUIterator_Fast jmax, j = loop->_head->fast_outs(jmax); j < jmax; j++) { - Node* old = loop->_head->fast_out(j); - if( old->in(0) == loop->_head && old->req() == 3 && - (old->is_Loop() || old->is_Phi()) ) { - Node *new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx]; - if( !new_exit_value ) // Backedge value is ALSO loop invariant? + Node* new_exit_value = old_new[head->in(LoopNode::LoopBackControl)->_idx]; + new_exit_value = move_loop_predicates(entry, new_exit_value); + _igvn.hash_delete(head); + head->set_req(LoopNode::EntryControl, new_exit_value); + 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]; + 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); _igvn.hash_delete(old); @@ -358,12 +488,12 @@ // Step 3: Cut the backedge on the clone (so its not a loop) and remove the // extra backedge user. - Node *nnn = old_new[loop->_head->_idx]; - _igvn.hash_delete(nnn); - nnn->set_req(LoopNode::LoopBackControl, C->top()); - for (DUIterator_Fast j2max, j2 = nnn->fast_outs(j2max); j2 < j2max; j2++) { - Node* use = nnn->fast_out(j2); - if( use->in(0) == nnn && use->req() == 3 && use->is_Phi() ) { + Node* new_head = old_new[head->_idx]; + _igvn.hash_delete(new_head); + new_head->set_req(LoopNode::LoopBackControl, C->top()); + for (DUIterator_Fast j2max, j2 = new_head->fast_outs(j2max); j2 < j2max; j2++) { + Node* use = new_head->fast_out(j2); + if (use->in(0) == new_head && use->req() == 3 && use->is_Phi()) { _igvn.hash_delete(use); use->set_req(LoopNode::LoopBackControl, C->top()); } @@ -371,15 +501,15 @@ // Step 4: Correct dom-depth info. Set to loop-head depth. - int dd = dom_depth(loop->_head); - set_idom(loop->_head, loop->_head->in(1), dd); + int dd = dom_depth(head); + set_idom(head, head->in(1), dd); for (uint j3 = 0; j3 < loop->_body.size(); j3++) { Node *old = loop->_body.at(j3); Node *nnn = old_new[old->_idx]; if (!has_ctrl(nnn)) set_idom(nnn, idom(nnn), dd-1); // While we're at it, remove any SafePoints from the peeled code - if( old->Opcode() == Op_SafePoint ) { + if (old->Opcode() == Op_SafePoint) { Node *nnn = old_new[old->_idx]; lazy_replace(nnn,nnn->in(TypeFunc::Control)); } @@ -1659,7 +1789,7 @@ bool needs_guard = !cl->is_main_loop() && !cl->is_post_loop(); if (needs_guard) { // Check for an obvious zero trip guard. - Node* inctrl = cl->in(LoopNode::EntryControl); + Node* inctrl = PhaseIdealLoop::skip_loop_predicates(cl->in(LoopNode::EntryControl)); if (inctrl->Opcode() == Op_IfTrue) { // The test should look like just the backedge of a CountedLoop Node* iff = inctrl->in(0); @@ -1861,651 +1991,8 @@ return true; } -//-------------------------------is_uncommon_trap_proj---------------------------- -// Return true if proj is the form of "proj->[region->..]call_uct" -bool PhaseIdealLoop::is_uncommon_trap_proj(ProjNode* proj, Deoptimization::DeoptReason reason) { - int path_limit = 10; - assert(proj, "invalid argument"); - Node* out = proj; - for (int ct = 0; ct < path_limit; ct++) { - out = out->unique_ctrl_out(); - if (out == NULL || out->is_Root() || out->is_Start()) - return false; - if (out->is_CallStaticJava()) { - int req = out->as_CallStaticJava()->uncommon_trap_request(); - if (req != 0) { - Deoptimization::DeoptReason trap_reason = Deoptimization::trap_request_reason(req); - if (trap_reason == reason || reason == Deoptimization::Reason_none) { - return true; - } - } - return false; // don't do further after call - } - } - return false; -} -//-------------------------------is_uncommon_trap_if_pattern------------------------- -// Return true for "if(test)-> proj -> ... -// | -// V -// other_proj->[region->..]call_uct" -// -// "must_reason_predicate" means the uct reason must be Reason_predicate -bool PhaseIdealLoop::is_uncommon_trap_if_pattern(ProjNode *proj, Deoptimization::DeoptReason reason) { - Node *in0 = proj->in(0); - if (!in0->is_If()) return false; - // Variation of a dead If node. - if (in0->outcnt() < 2) return false; - IfNode* iff = in0->as_If(); - - // we need "If(Conv2B(Opaque1(...)))" pattern for reason_predicate - if (reason != Deoptimization::Reason_none) { - if (iff->in(1)->Opcode() != Op_Conv2B || - iff->in(1)->in(1)->Opcode() != Op_Opaque1) { - return false; - } - } - - ProjNode* other_proj = iff->proj_out(1-proj->_con)->as_Proj(); - return is_uncommon_trap_proj(other_proj, reason); -} - -//-------------------------------register_control------------------------- -void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) { - assert(n->is_CFG(), "must be control node"); - _igvn.register_new_node_with_optimizer(n); - loop->_body.push(n); - set_loop(n, loop); - // When called from beautify_loops() idom is not constructed yet. - if (_idom != NULL) { - set_idom(n, pred, dom_depth(pred)); - } -} - -//------------------------------create_new_if_for_predicate------------------------ -// create a new if above the uct_if_pattern for the predicate to be promoted. -// -// before after -// ---------- ---------- -// ctrl ctrl -// | | -// | | -// v v -// iff new_iff -// / \ / \ -// / \ / \ -// v v v v -// uncommon_proj cont_proj if_uct if_cont -// \ | | | | -// \ | | | | -// v v v | v -// rgn loop | iff -// | | / \ -// | | / \ -// v | v v -// uncommon_trap | uncommon_proj cont_proj -// \ \ | | -// \ \ | | -// v v v v -// rgn loop -// | -// | -// v -// uncommon_trap -// -// -// We will create a region to guard the uct call if there is no one there. -// The true projecttion (if_cont) of the new_iff is returned. -// This code is also used to clone predicates to clonned loops. -ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, - Deoptimization::DeoptReason reason) { - assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!"); - IfNode* iff = cont_proj->in(0)->as_If(); - - ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); - Node *rgn = uncommon_proj->unique_ctrl_out(); - assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); - - if (!rgn->is_Region()) { // create a region to guard the call - assert(rgn->is_Call(), "must be call uct"); - CallNode* call = rgn->as_Call(); - IdealLoopTree* loop = get_loop(call); - rgn = new (C, 1) RegionNode(1); - rgn->add_req(uncommon_proj); - register_control(rgn, loop, uncommon_proj); - _igvn.hash_delete(call); - call->set_req(0, rgn); - // When called from beautify_loops() idom is not constructed yet. - if (_idom != NULL) { - set_idom(call, rgn, dom_depth(rgn)); - } - } - - Node* entry = iff->in(0); - if (new_entry != NULL) { - // Clonning the predicate to new location. - entry = new_entry; - } - // Create new_iff - IdealLoopTree* lp = get_loop(entry); - IfNode *new_iff = new (C, 2) IfNode(entry, NULL, iff->_prob, iff->_fcnt); - register_control(new_iff, lp, entry); - Node *if_cont = new (C, 1) IfTrueNode(new_iff); - Node *if_uct = new (C, 1) IfFalseNode(new_iff); - if (cont_proj->is_IfFalse()) { - // Swap - Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; - } - register_control(if_cont, lp, new_iff); - register_control(if_uct, get_loop(rgn), new_iff); - - // if_uct to rgn - _igvn.hash_delete(rgn); - rgn->add_req(if_uct); - // When called from beautify_loops() idom is not constructed yet. - if (_idom != NULL) { - Node* ridom = idom(rgn); - Node* nrdom = dom_lca(ridom, new_iff); - set_idom(rgn, nrdom, dom_depth(rgn)); - } - // rgn must have no phis - assert(!rgn->as_Region()->has_phi(), "region must have no phis"); - - if (new_entry == NULL) { - // Attach if_cont to iff - _igvn.hash_delete(iff); - iff->set_req(0, if_cont); - if (_idom != NULL) { - set_idom(iff, if_cont, dom_depth(iff)); - } - } - return if_cont->as_Proj(); -} - -//--------------------------find_predicate_insertion_point------------------- -// Find a good location to insert a predicate -ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) { - if (start_c == NULL || !start_c->is_Proj()) - return NULL; - if (is_uncommon_trap_if_pattern(start_c->as_Proj(), reason)) { - return start_c->as_Proj(); - } - return NULL; -} - -//--------------------------find_predicate------------------------------------ -// Find a predicate -Node* PhaseIdealLoop::find_predicate(Node* entry) { - Node* predicate = NULL; - if (UseLoopPredicate) { - predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); - if (predicate != NULL) { // right pattern that can be used by loop predication - assert(entry->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); - return entry; - } - } - return NULL; -} - -//------------------------------Invariance----------------------------------- -// Helper class for loop_predication_impl to compute invariance on the fly and -// clone invariants. -class Invariance : public StackObj { - VectorSet _visited, _invariant; - Node_Stack _stack; - VectorSet _clone_visited; - Node_List _old_new; // map of old to new (clone) - IdealLoopTree* _lpt; - PhaseIdealLoop* _phase; - - // Helper function to set up the invariance for invariance computation - // If n is a known invariant, set up directly. Otherwise, look up the - // the possibility to push n onto the stack for further processing. - void visit(Node* use, Node* n) { - if (_lpt->is_invariant(n)) { // known invariant - _invariant.set(n->_idx); - } else if (!n->is_CFG()) { - Node *n_ctrl = _phase->ctrl_or_self(n); - Node *u_ctrl = _phase->ctrl_or_self(use); // self if use is a CFG - if (_phase->is_dominator(n_ctrl, u_ctrl)) { - _stack.push(n, n->in(0) == NULL ? 1 : 0); - } - } - } - - // Compute invariance for "the_node" and (possibly) all its inputs recursively - // on the fly - void compute_invariance(Node* n) { - assert(_visited.test(n->_idx), "must be"); - visit(n, n); - while (_stack.is_nonempty()) { - Node* n = _stack.node(); - uint idx = _stack.index(); - if (idx == n->req()) { // all inputs are processed - _stack.pop(); - // n is invariant if it's inputs are all invariant - bool all_inputs_invariant = true; - for (uint i = 0; i < n->req(); i++) { - Node* in = n->in(i); - if (in == NULL) continue; - assert(_visited.test(in->_idx), "must have visited input"); - if (!_invariant.test(in->_idx)) { // bad guy - all_inputs_invariant = false; - break; - } - } - if (all_inputs_invariant) { - _invariant.set(n->_idx); // I am a invariant too - } - } else { // process next input - _stack.set_index(idx + 1); - Node* m = n->in(idx); - if (m != NULL && !_visited.test_set(m->_idx)) { - visit(n, m); - } - } - } - } - - // Helper function to set up _old_new map for clone_nodes. - // If n is a known invariant, set up directly ("clone" of n == n). - // Otherwise, push n onto the stack for real cloning. - void clone_visit(Node* n) { - assert(_invariant.test(n->_idx), "must be invariant"); - if (_lpt->is_invariant(n)) { // known invariant - _old_new.map(n->_idx, n); - } else{ // to be cloned - assert (!n->is_CFG(), "should not see CFG here"); - _stack.push(n, n->in(0) == NULL ? 1 : 0); - } - } - - // Clone "n" and (possibly) all its inputs recursively - void clone_nodes(Node* n, Node* ctrl) { - clone_visit(n); - while (_stack.is_nonempty()) { - Node* n = _stack.node(); - uint idx = _stack.index(); - if (idx == n->req()) { // all inputs processed, clone n! - _stack.pop(); - // clone invariant node - Node* n_cl = n->clone(); - _old_new.map(n->_idx, n_cl); - _phase->register_new_node(n_cl, ctrl); - for (uint i = 0; i < n->req(); i++) { - Node* in = n_cl->in(i); - if (in == NULL) continue; - n_cl->set_req(i, _old_new[in->_idx]); - } - } else { // process next input - _stack.set_index(idx + 1); - Node* m = n->in(idx); - if (m != NULL && !_clone_visited.test_set(m->_idx)) { - clone_visit(m); // visit the input - } - } - } - } - - public: - Invariance(Arena* area, IdealLoopTree* lpt) : - _lpt(lpt), _phase(lpt->_phase), - _visited(area), _invariant(area), _stack(area, 10 /* guess */), - _clone_visited(area), _old_new(area) - {} - - // Map old to n for invariance computation and clone - void map_ctrl(Node* old, Node* n) { - assert(old->is_CFG() && n->is_CFG(), "must be"); - _old_new.map(old->_idx, n); // "clone" of old is n - _invariant.set(old->_idx); // old is invariant - _clone_visited.set(old->_idx); - } - - // Driver function to compute invariance - bool is_invariant(Node* n) { - if (!_visited.test_set(n->_idx)) - compute_invariance(n); - return (_invariant.test(n->_idx) != 0); - } - - // Driver function to clone invariant - Node* clone(Node* n, Node* ctrl) { - assert(ctrl->is_CFG(), "must be"); - assert(_invariant.test(n->_idx), "must be an invariant"); - if (!_clone_visited.test(n->_idx)) - clone_nodes(n, ctrl); - return _old_new[n->_idx]; - } -}; - -//------------------------------is_range_check_if ----------------------------------- -// Returns true if the predicate of iff is in "scale*iv + offset u< load_range(ptr)" format -// Note: this function is particularly designed for loop predication. We require load_range -// and offset to be loop invariant computed on the fly by "invar" -bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const { - if (!is_loop_exit(iff)) { - return false; - } - if (!iff->in(1)->is_Bool()) { - return false; - } - const BoolNode *bol = iff->in(1)->as_Bool(); - if (bol->_test._test != BoolTest::lt) { - return false; - } - if (!bol->in(1)->is_Cmp()) { - return false; - } - const CmpNode *cmp = bol->in(1)->as_Cmp(); - if (cmp->Opcode() != Op_CmpU ) { - return false; - } - Node* range = cmp->in(2); - if (range->Opcode() != Op_LoadRange) { - const TypeInt* tint = phase->_igvn.type(range)->isa_int(); - if (!OptimizeFill || tint == NULL || tint->empty() || tint->_lo < 0) { - // Allow predication on positive values that aren't LoadRanges. - // This allows optimization of loops where the length of the - // array is a known value and doesn't need to be loaded back - // from the array. - return false; - } - } - if (!invar.is_invariant(range)) { - return false; - } - Node *iv = _head->as_CountedLoop()->phi(); - int scale = 0; - Node *offset = NULL; - if (!phase->is_scaled_iv_plus_offset(cmp->in(1), iv, &scale, &offset)) { - return false; - } - if(offset && !invar.is_invariant(offset)) { // offset must be invariant - return false; - } - return true; -} - -//------------------------------rc_predicate----------------------------------- -// Create a range check predicate -// -// for (i = init; i < limit; i += stride) { -// a[scale*i+offset] -// } -// -// Compute max(scale*i + offset) for init <= i < limit and build the predicate -// as "max(scale*i + offset) u< a.length". -// -// There are two cases for max(scale*i + offset): -// (1) stride*scale > 0 -// max(scale*i + offset) = scale*(limit-stride) + offset -// (2) stride*scale < 0 -// max(scale*i + offset) = scale*init + offset -BoolNode* PhaseIdealLoop::rc_predicate(Node* ctrl, - int scale, Node* offset, - Node* init, Node* limit, Node* stride, - Node* range, bool upper) { - DEBUG_ONLY(ttyLocker ttyl); - if (TraceLoopPredicate) tty->print("rc_predicate "); - - Node* max_idx_expr = init; - int stride_con = stride->get_int(); - if ((stride_con > 0) == (scale > 0) == upper) { - max_idx_expr = new (C, 3) SubINode(limit, stride); - register_new_node(max_idx_expr, ctrl); - if (TraceLoopPredicate) tty->print("(limit - stride) "); - } else { - if (TraceLoopPredicate) tty->print("init "); - } - - if (scale != 1) { - ConNode* con_scale = _igvn.intcon(scale); - max_idx_expr = new (C, 3) MulINode(max_idx_expr, con_scale); - register_new_node(max_idx_expr, ctrl); - if (TraceLoopPredicate) tty->print("* %d ", scale); - } - - if (offset && (!offset->is_Con() || offset->get_int() != 0)){ - max_idx_expr = new (C, 3) AddINode(max_idx_expr, offset); - register_new_node(max_idx_expr, ctrl); - if (TraceLoopPredicate) - if (offset->is_Con()) tty->print("+ %d ", offset->get_int()); - else tty->print("+ offset "); - } - - CmpUNode* cmp = new (C, 3) CmpUNode(max_idx_expr, range); - register_new_node(cmp, ctrl); - BoolNode* bol = new (C, 2) BoolNode(cmp, BoolTest::lt); - register_new_node(bol, ctrl); - - if (TraceLoopPredicate) tty->print_cr("<u range"); - return bol; -} - -//------------------------------ loop_predication_impl-------------------------- -// Insert loop predicates for null checks and range checks -bool PhaseIdealLoop::loop_predication_impl(IdealLoopTree *loop) { - if (!UseLoopPredicate) return false; - - if (!loop->_head->is_Loop()) { - // Could be a simple region when irreducible loops are present. - return false; - } - - if (loop->_head->unique_ctrl_out()->Opcode() == Op_NeverBranch) { - // do nothing for infinite loops - return false; - } - - CountedLoopNode *cl = NULL; - if (loop->_head->is_CountedLoop()) { - cl = loop->_head->as_CountedLoop(); - // do nothing for iteration-splitted loops - if (!cl->is_normal_loop()) return false; - } - - LoopNode *lpn = loop->_head->as_Loop(); - Node* entry = lpn->in(LoopNode::EntryControl); - - ProjNode *predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); - if (!predicate_proj) { -#ifndef PRODUCT - if (TraceLoopPredicate) { - tty->print("missing predicate:"); - loop->dump_head(); - lpn->dump(1); - } -#endif - return false; - } - ConNode* zero = _igvn.intcon(0); - set_ctrl(zero, C->root()); - - ResourceArea *area = Thread::current()->resource_area(); - Invariance invar(area, loop); - - // Create list of if-projs such that a newer proj dominates all older - // projs in the list, and they all dominate loop->tail() - Node_List if_proj_list(area); - LoopNode *head = loop->_head->as_Loop(); - Node *current_proj = loop->tail(); //start from tail - while ( current_proj != head ) { - if (loop == get_loop(current_proj) && // still in the loop ? - current_proj->is_Proj() && // is a projection ? - current_proj->in(0)->Opcode() == Op_If) { // is a if projection ? - if_proj_list.push(current_proj); - } - current_proj = idom(current_proj); - } - - bool hoisted = false; // true if at least one proj is promoted - while (if_proj_list.size() > 0) { - // Following are changed to nonnull when a predicate can be hoisted - ProjNode* new_predicate_proj = NULL; - - ProjNode* proj = if_proj_list.pop()->as_Proj(); - IfNode* iff = proj->in(0)->as_If(); - - if (!is_uncommon_trap_if_pattern(proj, Deoptimization::Reason_none)) { - if (loop->is_loop_exit(iff)) { - // stop processing the remaining projs in the list because the execution of them - // depends on the condition of "iff" (iff->in(1)). - break; - } else { - // Both arms are inside the loop. There are two cases: - // (1) there is one backward branch. In this case, any remaining proj - // in the if_proj list post-dominates "iff". So, the condition of "iff" - // does not determine the execution the remining projs directly, and we - // can safely continue. - // (2) both arms are forwarded, i.e. a diamond shape. In this case, "proj" - // does not dominate loop->tail(), so it can not be in the if_proj list. - continue; - } - } - - Node* test = iff->in(1); - if (!test->is_Bool()){ //Conv2B, ... - continue; - } - BoolNode* bol = test->as_Bool(); - if (invar.is_invariant(bol)) { - // Invariant test - new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL, - Deoptimization::Reason_predicate); - Node* ctrl = new_predicate_proj->in(0)->as_If()->in(0); - BoolNode* new_predicate_bol = invar.clone(bol, ctrl)->as_Bool(); - - // Negate test if necessary - bool negated = false; - if (proj->_con != predicate_proj->_con) { - new_predicate_bol = new (C, 2) BoolNode(new_predicate_bol->in(1), new_predicate_bol->_test.negate()); - register_new_node(new_predicate_bol, ctrl); - negated = true; - } - IfNode* new_predicate_iff = new_predicate_proj->in(0)->as_If(); - _igvn.hash_delete(new_predicate_iff); - new_predicate_iff->set_req(1, new_predicate_bol); -#ifndef PRODUCT - if (TraceLoopPredicate) { - tty->print("Predicate invariant if%s: %d ", negated ? " negated" : "", new_predicate_iff->_idx); - loop->dump_head(); - } else if (TraceLoopOpts) { - tty->print("Predicate IC "); - loop->dump_head(); - } -#endif - } else if (cl != NULL && loop->is_range_check_if(iff, this, invar)) { - assert(proj->_con == predicate_proj->_con, "must match"); - - // Range check for counted loops - const Node* cmp = bol->in(1)->as_Cmp(); - Node* idx = cmp->in(1); - assert(!invar.is_invariant(idx), "index is variant"); - assert(cmp->in(2)->Opcode() == Op_LoadRange || OptimizeFill, "must be"); - Node* rng = cmp->in(2); - assert(invar.is_invariant(rng), "range must be invariant"); - int scale = 1; - Node* offset = zero; - bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset); - assert(ok, "must be index expression"); - - Node* init = cl->init_trip(); - Node* limit = cl->limit(); - Node* stride = cl->stride(); - - // Build if's for the upper and lower bound tests. The - // lower_bound test will dominate the upper bound test and all - // cloned or created nodes will use the lower bound test as - // their declared control. - ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); - ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); - assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate"); - Node *ctrl = lower_bound_proj->in(0)->as_If()->in(0); - - // Perform cloning to keep Invariance state correct since the - // late schedule will place invariant things in the loop. - rng = invar.clone(rng, ctrl); - if (offset && offset != zero) { - assert(invar.is_invariant(offset), "offset must be loop invariant"); - offset = invar.clone(offset, ctrl); - } - - // Test the lower bound - Node* lower_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, false); - IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If(); - _igvn.hash_delete(lower_bound_iff); - lower_bound_iff->set_req(1, lower_bound_bol); - if (TraceLoopPredicate) tty->print_cr("lower bound check if: %d", lower_bound_iff->_idx); - - // Test the upper bound - Node* upper_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, true); - IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If(); - _igvn.hash_delete(upper_bound_iff); - upper_bound_iff->set_req(1, upper_bound_bol); - if (TraceLoopPredicate) tty->print_cr("upper bound check if: %d", lower_bound_iff->_idx); - - // Fall through into rest of the clean up code which will move - // any dependent nodes onto the upper bound test. - new_predicate_proj = upper_bound_proj; - -#ifndef PRODUCT - if (TraceLoopOpts && !TraceLoopPredicate) { - tty->print("Predicate RC "); - loop->dump_head(); - } -#endif - } else { - // Loop variant check (for example, range check in non-counted loop) - // with uncommon trap. - continue; - } - assert(new_predicate_proj != NULL, "sanity"); - // Success - attach condition (new_predicate_bol) to predicate if - invar.map_ctrl(proj, new_predicate_proj); // so that invariance test can be appropriate - - // Eliminate the old If in the loop body - dominated_by( new_predicate_proj, iff, proj->_con != new_predicate_proj->_con ); - - hoisted = true; - C->set_major_progress(); - } // end while - -#ifndef PRODUCT - // report that the loop predication has been actually performed - // for this loop - if (TraceLoopPredicate && hoisted) { - tty->print("Loop Predication Performed:"); - loop->dump_head(); - } -#endif - - return hoisted; -} - -//------------------------------loop_predication-------------------------------- -// driver routine for loop predication optimization -bool IdealLoopTree::loop_predication( PhaseIdealLoop *phase) { - bool hoisted = false; - // Recursively promote predicates - if ( _child ) { - hoisted = _child->loop_predication( phase); - } - - // self - if (!_irreducible && !tail()->is_top()) { - hoisted |= phase->loop_predication_impl(this); - } - - if ( _next ) { //sibling - hoisted |= _next->loop_predication( phase); - } - - return hoisted; -} - - +//============================================================================= // Process all the loops in the loop tree and replace any fill // patterns with an intrisc version. bool PhaseIdealLoop::do_intrinsify_fill() { @@ -2762,6 +2249,13 @@ return false; } +#ifndef PRODUCT + if (TraceLoopOpts) { + tty->print("ArrayFill "); + lpt->dump_head(); + } +#endif + // Now replace the whole loop body by a call to a fill routine that // covers the same region as the loop. Node* base = store->in(MemNode::Address)->as_AddP()->in(AddPNode::Base);
--- a/src/share/vm/opto/loopUnswitch.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/loopUnswitch.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -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 @@ 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 @@ 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();
--- a/src/share/vm/opto/loopnode.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/loopnode.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -341,7 +341,12 @@ // assert(x->Opcode() == Op_Loop, "regular loops only"); C->print_method("Before CountedLoop", 3); - +#ifndef PRODUCT + if (TraceLoopOpts) { + tty->print("Counted "); + loop->dump_head(); + } +#endif // If compare points to incr, we are ok. Otherwise the compare // can directly point to the phi; in this case adjust the compare so that // it points to the incr by adjusting the limit. @@ -864,8 +869,10 @@ Node *outer = new (phase->C, 3) LoopNode( ctl, _head->in(outer_idx) ); outer = igvn.register_new_node_with_optimizer(outer, _head); phase->set_created_loop_node(); + + Node* pred = phase->clone_loop_predicates(ctl, outer); // Outermost loop falls into '_head' loop - _head->set_req(LoopNode::EntryControl, outer); + _head->set_req(LoopNode::EntryControl, pred); _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++) { @@ -1103,12 +1110,13 @@ // backedges into a private merge point and use the merge point as // the one true backedge. if( _head->req() > 3 ) { - // Merge the many backedges into a single backedge. + // Merge the many backedges into a single backedge but leave + // the hottest backedge as separate edge for the following peel. merge_many_backedges( phase ); result = true; } - // If I am a shared header (multiple backedges), peel off myself loop. + // If I have one hot backedge, peel off myself loop. // I better be the outermost loop. if( _head->req() > 3 ) { split_outer_loop( phase ); @@ -1433,9 +1441,9 @@ tty->print("Loop: N%d/N%d ",_head->_idx,_tail->_idx); if (_irreducible) tty->print(" IRREDUCIBLE"); if (UseLoopPredicate) { - Node* entry = _head->in(LoopNode::EntryControl); - if (entry != NULL && entry->is_Proj() && - PhaseIdealLoop::is_uncommon_trap_if_pattern(entry->as_Proj(), Deoptimization::Reason_predicate)) { + Node* entry = PhaseIdealLoop::find_predicate_insertion_point(_head->in(LoopNode::EntryControl), + Deoptimization::Reason_predicate); + if (entry != NULL) { tty->print(" predicated"); } } @@ -1541,7 +1549,7 @@ //----------------------------build_and_optimize------------------------------- // Create a PhaseLoop. Build the ideal Loop tree. Map each Ideal Node to // its corresponding LoopNode. If 'optimize' is true, do some loop cleanups. -void PhaseIdealLoop::build_and_optimize(bool do_split_ifs, bool do_loop_pred) { +void PhaseIdealLoop::build_and_optimize(bool do_split_ifs) { ResourceMark rm; int old_progress = C->major_progress(); @@ -1573,6 +1581,13 @@ // Do not need a safepoint at the top level _ltree_root->_has_sfpt = 1; + // Initialize Dominators. + // Checked in clone_loop_predicate() during beautify_loops(). + _idom_size = 0; + _idom = NULL; + _dom_depth = NULL; + _dom_stk = NULL; + // Empty pre-order array allocate_preorders(); @@ -1698,8 +1713,9 @@ return; } - // some parser-inserted loop predicates could never be used by loop - // predication. Eliminate them before loop optimization + // Some parser-inserted loop predicates could never be used by loop + // predication or they were moved away from loop during some optimizations. + // For example, peeling. Eliminate them before next loop optimizations. if (UseLoopPredicate) { eliminate_useless_predicates(); } @@ -1750,7 +1766,7 @@ } // Perform loop predication before iteration splitting - if (do_loop_pred && C->has_loops() && !C->major_progress()) { + if (C->has_loops() && !C->major_progress() && (C->predicate_count() > 0)) { _ltree_root->_child->loop_predication(this); } @@ -1793,8 +1809,20 @@ C->set_major_progress(); } - // Convert scalar to superword operations + // Keep loop predicates and perform optimizations with them + // until no more loop optimizations could be done. + // After that switch predicates off and do more loop optimizations. + if (!C->major_progress() && (C->predicate_count() > 0)) { + C->cleanup_loop_predicates(_igvn); +#ifndef PRODUCT + if (TraceLoopOpts) { + tty->print_cr("PredicatesOff"); + } +#endif + C->set_major_progress(); + } + // Convert scalar to superword operations at the end of all loop opts. if (UseSuperWord && C->has_loops() && !C->major_progress()) { // SuperWord transform SuperWord sw(this);
--- a/src/share/vm/opto/loopnode.hpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/loopnode.hpp Sat Apr 02 10:54:15 2011 -0700 @@ -706,11 +706,11 @@ _dom_lca_tags(arena()), // Thread::resource_area _verify_me(NULL), _verify_only(true) { - build_and_optimize(false, false); + build_and_optimize(false); } // build the loop tree and perform any requested optimizations - void build_and_optimize(bool do_split_if, bool do_loop_pred); + void build_and_optimize(bool do_split_if); public: // Dominators for the sea of nodes @@ -721,13 +721,13 @@ Node *dom_lca_internal( Node *n1, Node *n2 ) const; // Compute the Ideal Node to Loop mapping - PhaseIdealLoop( PhaseIterGVN &igvn, bool do_split_ifs, bool do_loop_pred) : + PhaseIdealLoop( PhaseIterGVN &igvn, bool do_split_ifs) : PhaseTransform(Ideal_Loop), _igvn(igvn), _dom_lca_tags(arena()), // Thread::resource_area _verify_me(NULL), _verify_only(false) { - build_and_optimize(do_split_ifs, do_loop_pred); + build_and_optimize(do_split_ifs); } // Verify that verify_me made the same decisions as a fresh run. @@ -737,7 +737,7 @@ _dom_lca_tags(arena()), // Thread::resource_area _verify_me(verify_me), _verify_only(false) { - build_and_optimize(false, false); + build_and_optimize(false); } // Build and verify the loop tree without modifying the graph. This @@ -830,7 +830,26 @@ Deoptimization::DeoptReason reason); void register_control(Node* n, IdealLoopTree *loop, Node* pred); - // Find a good location to insert a predicate + // Clone loop predicates to cloned loops (peeled, unswitched) + static ProjNode* clone_predicate(ProjNode* predicate_proj, Node* new_entry, + 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, + PhaseIdealLoop* loop_phase, + PhaseIterGVN* igvn); + Node* clone_loop_predicates(Node* old_entry, Node* new_entry); + Node* move_loop_predicates(Node* old_entry, Node* new_entry); + + void eliminate_loop_predicates(Node* entry); + static Node* skip_loop_predicates(Node* entry); + + // Find a good location to insert a predicate static ProjNode* find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason); // Find a predicate static Node* find_predicate(Node* entry);
--- a/src/share/vm/opto/loopopts.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/loopopts.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -2139,9 +2139,12 @@ // // orig // -// stmt1 -// | -// v +// stmt1 +// | +// v +// loop predicate +// | +// v // loop<----+ // | | // stmt2 | @@ -2172,6 +2175,9 @@ // after clone loop // // stmt1 +// | +// v +// loop predicate // / \ // clone / \ orig // / \ @@ -2210,12 +2216,15 @@ // after partial peel // // stmt1 +// | +// v +// loop predicate // / // clone / orig // / TOP // / \ // v v -// TOP->region region----+ +// TOP->loop loop----+ // | | | // stmt2 stmt2 | // | | | @@ -2253,13 +2262,17 @@ // stmt1 // | // v +// stmt2 clone +// | +// v // ........> ifA clone // : / | // dom / | // : v v // : false true // : | | -// : | stmt2 clone +// : | v +// : | loop predicate // : | | // : | v // : | newloop<-----+ @@ -2289,6 +2302,7 @@ // bool PhaseIdealLoop::partial_peel( IdealLoopTree *loop, Node_List &old_new ) { + assert(!loop->_head->is_CountedLoop(), "Non-counted loop only"); if (!loop->_head->is_Loop()) { return false; } @@ -2316,6 +2330,7 @@ } } + Node* entry = head->in(LoopNode::EntryControl); int dd = dom_depth(head); // Step 1: find cut point @@ -2612,6 +2627,8 @@ // Backedge of the surviving new_head (the clone) is original last_peel _igvn.hash_delete(new_head_clone); + Node* new_entry = move_loop_predicates(entry, new_head_clone->in(LoopNode::EntryControl)); + new_head_clone->set_req(LoopNode::EntryControl, new_entry); new_head_clone->set_req(LoopNode::LoopBackControl, last_peel); _igvn._worklist.push(new_head_clone);
--- a/src/share/vm/opto/phaseX.hpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/phaseX.hpp Sat Apr 02 10:54:15 2011 -0700 @@ -471,6 +471,13 @@ _delay_transform = delay; } + // Clone loop predicates. Defined in loopTransform.cpp. + Node* clone_loop_predicates(Node* old_entry, Node* new_entry); + Node* move_loop_predicates(Node* old_entry, Node* new_entry); + // 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); + #ifndef PRODUCT protected: // Sub-quadratic implementation of VerifyIterativeGVN.
--- a/src/share/vm/opto/split_if.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/split_if.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -399,6 +399,9 @@ #ifndef PRODUCT if( PrintOpto && VerifyLoopOptimizations ) tty->print_cr("Split-if"); + if (TraceLoopOpts) { + tty->print_cr("SplitIf"); + } #endif C->set_major_progress(); Node *region = iff->in(0);
--- a/src/share/vm/opto/superword.cpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/superword.cpp Sat Apr 02 10:54:15 2011 -0700 @@ -1132,6 +1132,13 @@ void SuperWord::output() { if (_packset.length() == 0) return; +#ifndef PRODUCT + if (TraceLoopOpts) { + tty->print("SuperWord "); + lpt()->dump_head(); + } +#endif + // MUST ENSURE main loop's initial value is properly aligned: // (iv_initial_value + min_iv_offset) % vector_width_in_bytes() == 0
--- a/src/share/vm/opto/vectornode.hpp Sat Apr 02 09:49:27 2011 -0700 +++ b/src/share/vm/opto/vectornode.hpp Sat Apr 02 10:54:15 2011 -0700 @@ -32,6 +32,7 @@ //------------------------------VectorNode-------------------------------------- // Vector Operation class VectorNode : public Node { + virtual uint size_of() const { return sizeof(*this); } protected: uint _length; // vector length virtual BasicType elt_basic_type() const = 0; // Vector element basic type