1438 lines
54 KiB
C++
1438 lines
54 KiB
C++
/*
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* Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "opto/loopnode.hpp"
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#include "opto/addnode.hpp"
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#include "opto/callnode.hpp"
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#include "opto/connode.hpp"
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#include "opto/convertnode.hpp"
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#include "opto/loopnode.hpp"
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#include "opto/matcher.hpp"
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#include "opto/mulnode.hpp"
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#include "opto/opaquenode.hpp"
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#include "opto/rootnode.hpp"
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#include "opto/subnode.hpp"
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#include <fenv.h>
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#include <math.h>
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/*
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* The general idea of Loop Predication is to insert a predicate on the entry
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* path to a loop, and raise a uncommon trap if the check of the condition fails.
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* The condition checks are promoted from inside the loop body, and thus
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* the checks inside the loop could be eliminated. Currently, loop predication
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* optimization has been applied to remove array range check and loop invariant
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* checks (such as null checks).
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*/
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//-------------------------------register_control-------------------------
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void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) {
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assert(n->is_CFG(), "must be control node");
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_igvn.register_new_node_with_optimizer(n);
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loop->_body.push(n);
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set_loop(n, loop);
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// When called from beautify_loops() idom is not constructed yet.
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if (_idom != NULL) {
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set_idom(n, pred, dom_depth(pred));
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}
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}
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//------------------------------create_new_if_for_predicate------------------------
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// create a new if above the uct_if_pattern for the predicate to be promoted.
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//
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// before after
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// ---------- ----------
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// ctrl ctrl
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// | |
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// | |
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// v v
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// iff new_iff
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// / \ / \
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// / \ / \
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// v v v v
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// uncommon_proj cont_proj if_uct if_cont
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// \ | | | |
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// \ | | | |
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// v v v | v
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// rgn loop | iff
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// | | / \
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// | | / \
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// v | v v
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// uncommon_trap | uncommon_proj cont_proj
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// \ \ | |
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// \ \ | |
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// v v v v
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// rgn loop
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// |
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// |
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// v
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// uncommon_trap
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//
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//
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// We will create a region to guard the uct call if there is no one there.
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// The true projection (if_cont) of the new_iff is returned.
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// This code is also used to clone predicates to cloned loops.
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ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
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Deoptimization::DeoptReason reason,
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int opcode) {
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assert(cont_proj->is_uncommon_trap_if_pattern(reason), "must be a uct if pattern!");
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IfNode* iff = cont_proj->in(0)->as_If();
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ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
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Node *rgn = uncommon_proj->unique_ctrl_out();
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assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
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uint proj_index = 1; // region's edge corresponding to uncommon_proj
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if (!rgn->is_Region()) { // create a region to guard the call
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assert(rgn->is_Call(), "must be call uct");
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CallNode* call = rgn->as_Call();
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IdealLoopTree* loop = get_loop(call);
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rgn = new RegionNode(1);
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rgn->add_req(uncommon_proj);
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register_control(rgn, loop, uncommon_proj);
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_igvn.replace_input_of(call, 0, rgn);
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// When called from beautify_loops() idom is not constructed yet.
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if (_idom != NULL) {
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set_idom(call, rgn, dom_depth(rgn));
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}
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for (DUIterator_Fast imax, i = uncommon_proj->fast_outs(imax); i < imax; i++) {
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Node* n = uncommon_proj->fast_out(i);
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if (n->is_Load() || n->is_Store()) {
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_igvn.replace_input_of(n, 0, rgn);
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--i; --imax;
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}
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}
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} else {
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// Find region's edge corresponding to uncommon_proj
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for (; proj_index < rgn->req(); proj_index++)
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if (rgn->in(proj_index) == uncommon_proj) break;
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assert(proj_index < rgn->req(), "sanity");
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}
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Node* entry = iff->in(0);
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if (new_entry != NULL) {
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// Clonning the predicate to new location.
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entry = new_entry;
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}
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// Create new_iff
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IdealLoopTree* lp = get_loop(entry);
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IfNode* new_iff = NULL;
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if (opcode == Op_If) {
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new_iff = new IfNode(entry, iff->in(1), iff->_prob, iff->_fcnt);
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} else {
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assert(opcode == Op_RangeCheck, "no other if variant here");
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new_iff = new RangeCheckNode(entry, iff->in(1), iff->_prob, iff->_fcnt);
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}
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register_control(new_iff, lp, entry);
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Node *if_cont = new IfTrueNode(new_iff);
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Node *if_uct = new IfFalseNode(new_iff);
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if (cont_proj->is_IfFalse()) {
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// Swap
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Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
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}
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register_control(if_cont, lp, new_iff);
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register_control(if_uct, get_loop(rgn), new_iff);
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// if_uct to rgn
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_igvn.hash_delete(rgn);
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rgn->add_req(if_uct);
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// When called from beautify_loops() idom is not constructed yet.
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if (_idom != NULL) {
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Node* ridom = idom(rgn);
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Node* nrdom = dom_lca(ridom, new_iff);
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set_idom(rgn, nrdom, dom_depth(rgn));
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}
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// If rgn has phis add new edges which has the same
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// value as on original uncommon_proj pass.
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assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last");
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bool has_phi = false;
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for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) {
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Node* use = rgn->fast_out(i);
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if (use->is_Phi() && use->outcnt() > 0) {
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assert(use->in(0) == rgn, "");
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_igvn.rehash_node_delayed(use);
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use->add_req(use->in(proj_index));
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has_phi = true;
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}
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}
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assert(!has_phi || rgn->req() > 3, "no phis when region is created");
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if (new_entry == NULL) {
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// Attach if_cont to iff
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_igvn.replace_input_of(iff, 0, if_cont);
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if (_idom != NULL) {
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set_idom(iff, if_cont, dom_depth(iff));
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}
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}
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return if_cont->as_Proj();
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}
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//------------------------------create_new_if_for_predicate------------------------
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// Create a new if below new_entry for the predicate to be cloned (IGVN optimization)
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ProjNode* PhaseIterGVN::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
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Deoptimization::DeoptReason reason,
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int opcode) {
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assert(new_entry != 0, "only used for clone predicate");
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assert(cont_proj->is_uncommon_trap_if_pattern(reason), "must be a uct if pattern!");
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IfNode* iff = cont_proj->in(0)->as_If();
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ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
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Node *rgn = uncommon_proj->unique_ctrl_out();
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assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
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uint proj_index = 1; // region's edge corresponding to uncommon_proj
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if (!rgn->is_Region()) { // create a region to guard the call
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assert(rgn->is_Call(), "must be call uct");
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CallNode* call = rgn->as_Call();
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rgn = new RegionNode(1);
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register_new_node_with_optimizer(rgn);
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rgn->add_req(uncommon_proj);
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replace_input_of(call, 0, rgn);
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} else {
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// Find region's edge corresponding to uncommon_proj
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for (; proj_index < rgn->req(); proj_index++)
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if (rgn->in(proj_index) == uncommon_proj) break;
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assert(proj_index < rgn->req(), "sanity");
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}
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// Create new_iff in new location.
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IfNode* new_iff = NULL;
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if (opcode == Op_If) {
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new_iff = new IfNode(new_entry, iff->in(1), iff->_prob, iff->_fcnt);
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} else {
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assert(opcode == Op_RangeCheck, "no other if variant here");
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new_iff = new RangeCheckNode(new_entry, iff->in(1), iff->_prob, iff->_fcnt);
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}
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register_new_node_with_optimizer(new_iff);
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Node *if_cont = new IfTrueNode(new_iff);
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Node *if_uct = new IfFalseNode(new_iff);
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if (cont_proj->is_IfFalse()) {
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// Swap
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Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
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}
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register_new_node_with_optimizer(if_cont);
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register_new_node_with_optimizer(if_uct);
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// if_uct to rgn
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hash_delete(rgn);
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rgn->add_req(if_uct);
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// If rgn has phis add corresponding new edges which has the same
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// value as on original uncommon_proj pass.
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assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last");
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bool has_phi = false;
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for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) {
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Node* use = rgn->fast_out(i);
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if (use->is_Phi() && use->outcnt() > 0) {
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rehash_node_delayed(use);
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use->add_req(use->in(proj_index));
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has_phi = true;
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}
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}
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assert(!has_phi || rgn->req() > 3, "no phis when region is created");
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return if_cont->as_Proj();
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}
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//--------------------------clone_predicate-----------------------
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ProjNode* PhaseIdealLoop::clone_predicate(ProjNode* predicate_proj, Node* new_entry,
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Deoptimization::DeoptReason reason,
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PhaseIdealLoop* loop_phase,
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PhaseIterGVN* igvn) {
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ProjNode* new_predicate_proj;
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if (loop_phase != NULL) {
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new_predicate_proj = loop_phase->create_new_if_for_predicate(predicate_proj, new_entry, reason, Op_If);
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} else {
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new_predicate_proj = igvn->create_new_if_for_predicate(predicate_proj, new_entry, reason, Op_If);
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}
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IfNode* iff = new_predicate_proj->in(0)->as_If();
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Node* ctrl = iff->in(0);
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// Match original condition since predicate's projections could be swapped.
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assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be");
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Node* opq = new Opaque1Node(igvn->C, predicate_proj->in(0)->in(1)->in(1)->in(1));
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igvn->C->add_predicate_opaq(opq);
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Node* bol = new Conv2BNode(opq);
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if (loop_phase != NULL) {
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loop_phase->register_new_node(opq, ctrl);
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loop_phase->register_new_node(bol, ctrl);
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} else {
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igvn->register_new_node_with_optimizer(opq);
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igvn->register_new_node_with_optimizer(bol);
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}
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igvn->hash_delete(iff);
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iff->set_req(1, bol);
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return new_predicate_proj;
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}
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//--------------------------clone_loop_predicates-----------------------
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// Interface from IGVN
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Node* PhaseIterGVN::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) {
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return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, clone_limit_check, NULL, this);
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}
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// Interface from PhaseIdealLoop
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Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) {
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return clone_loop_predicates(old_entry, new_entry, clone_limit_check, this, &this->_igvn);
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}
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// Clone loop predicates to cloned loops (peeled, unswitched, split_if).
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Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry,
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bool clone_limit_check,
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PhaseIdealLoop* loop_phase,
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PhaseIterGVN* igvn) {
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#ifdef ASSERT
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if (new_entry == NULL || !(new_entry->is_Proj() || new_entry->is_Region() || new_entry->is_SafePoint())) {
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if (new_entry != NULL)
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new_entry->dump();
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assert(false, "not IfTrue, IfFalse, Region or SafePoint");
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}
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#endif
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// Search original predicates
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Node* entry = old_entry;
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ProjNode* limit_check_proj = NULL;
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limit_check_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check);
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if (limit_check_proj != NULL) {
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entry = entry->in(0)->in(0);
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}
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ProjNode* profile_predicate_proj = NULL;
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ProjNode* predicate_proj = NULL;
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if (UseProfiledLoopPredicate) {
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profile_predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_profile_predicate);
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if (profile_predicate_proj != NULL) {
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entry = skip_loop_predicates(entry);
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}
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}
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if (UseLoopPredicate) {
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predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
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}
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if (predicate_proj != NULL) { // right pattern that can be used by loop predication
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// clone predicate
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new_entry = clone_predicate(predicate_proj, new_entry,
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Deoptimization::Reason_predicate,
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loop_phase, igvn);
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assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate");
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if (TraceLoopPredicate) {
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tty->print("Loop Predicate cloned: ");
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debug_only( new_entry->in(0)->dump(); );
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}
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}
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if (profile_predicate_proj != NULL) { // right pattern that can be used by loop predication
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// clone predicate
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new_entry = clone_predicate(profile_predicate_proj, new_entry,
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Deoptimization::Reason_profile_predicate,
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loop_phase, igvn);
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assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate");
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if (TraceLoopPredicate) {
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tty->print("Loop Predicate cloned: ");
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debug_only( new_entry->in(0)->dump(); );
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}
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}
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if (limit_check_proj != NULL && clone_limit_check) {
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// Clone loop limit check last to insert it before loop.
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// Don't clone a limit check which was already finalized
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// for this counted loop (only one limit check is needed).
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new_entry = clone_predicate(limit_check_proj, new_entry,
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Deoptimization::Reason_loop_limit_check,
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loop_phase, igvn);
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assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone limit check");
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if (TraceLoopLimitCheck) {
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tty->print("Loop Limit Check cloned: ");
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debug_only( new_entry->in(0)->dump(); )
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}
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}
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return new_entry;
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}
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//--------------------------skip_loop_predicates------------------------------
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// Skip related predicates.
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Node* PhaseIdealLoop::skip_loop_predicates(Node* entry) {
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IfNode* iff = entry->in(0)->as_If();
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ProjNode* uncommon_proj = iff->proj_out(1 - entry->as_Proj()->_con);
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Node* rgn = uncommon_proj->unique_ctrl_out();
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assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
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entry = entry->in(0)->in(0);
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while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) {
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uncommon_proj = entry->in(0)->as_If()->proj_out(1 - entry->as_Proj()->_con);
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if (uncommon_proj->unique_ctrl_out() != rgn)
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break;
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entry = entry->in(0)->in(0);
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}
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return entry;
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}
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Node* PhaseIdealLoop::skip_all_loop_predicates(Node* entry) {
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Node* predicate = NULL;
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predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check);
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if (predicate != NULL) {
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entry = entry->in(0)->in(0);
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}
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if (UseProfiledLoopPredicate) {
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predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_profile_predicate);
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if (predicate != NULL) { // right pattern that can be used by loop predication
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entry = skip_loop_predicates(entry);
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}
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}
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if (UseLoopPredicate) {
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predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
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if (predicate != NULL) { // right pattern that can be used by loop predication
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entry = skip_loop_predicates(entry);
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}
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}
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return entry;
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}
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//--------------------------find_predicate_insertion_point-------------------
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// Find a good location to insert a predicate
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ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) {
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if (start_c == NULL || !start_c->is_Proj())
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return NULL;
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if (start_c->as_Proj()->is_uncommon_trap_if_pattern(reason)) {
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return start_c->as_Proj();
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}
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return NULL;
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}
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//--------------------------find_predicate------------------------------------
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// Find a predicate
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Node* PhaseIdealLoop::find_predicate(Node* entry) {
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Node* predicate = NULL;
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predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check);
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if (predicate != NULL) { // right pattern that can be used by loop predication
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return entry;
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}
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if (UseLoopPredicate) {
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predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
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if (predicate != NULL) { // right pattern that can be used by loop predication
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return entry;
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}
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}
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if (UseProfiledLoopPredicate) {
|
|
predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_profile_predicate);
|
|
if (predicate != NULL) { // right pattern that can be used by loop predication
|
|
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) {
|
|
// If n's control is a predicate that was moved out of the
|
|
// loop, it was marked invariant but n is only invariant if
|
|
// it depends only on that test. Otherwise, unless that test
|
|
// is out of the loop, it's not invariant.
|
|
if (n->is_CFG() || n->depends_only_on_test() || n->in(0) == NULL || !_phase->is_member(_lpt, n->in(0))) {
|
|
_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) :
|
|
_visited(area), _invariant(area),
|
|
_stack(area, 10 /* guess */),
|
|
_clone_visited(area), _old_new(area),
|
|
_lpt(lpt), _phase(lpt->_phase)
|
|
{
|
|
LoopNode* head = _lpt->_head->as_Loop();
|
|
Node* entry = head->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
if (entry->outcnt() != 1) {
|
|
// If a node is pinned between the predicates and the loop
|
|
// entry, we won't be able to move any node in the loop that
|
|
// depends on it above it in a predicate. Mark all those nodes
|
|
// as non loop invariatnt.
|
|
Unique_Node_List wq;
|
|
wq.push(entry);
|
|
for (uint next = 0; next < wq.size(); ++next) {
|
|
Node *n = wq.at(next);
|
|
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
|
|
Node* u = n->fast_out(i);
|
|
if (!u->is_CFG()) {
|
|
Node* c = _phase->get_ctrl(u);
|
|
if (_lpt->is_member(_phase->get_loop(c)) || _phase->is_dominator(c, head)) {
|
|
_visited.set(u->_idx);
|
|
wq.push(u);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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 && !iff->is_RangeCheck()) {
|
|
const TypeInt* tint = phase->_igvn.type(range)->isa_int();
|
|
if (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(IdealLoopTree *loop, Node* ctrl,
|
|
int scale, Node* offset,
|
|
Node* init, Node* limit, jint stride,
|
|
Node* range, bool upper, bool &overflow) {
|
|
jint con_limit = (limit != NULL && limit->is_Con()) ? limit->get_int() : 0;
|
|
jint con_init = init->is_Con() ? init->get_int() : 0;
|
|
jint con_offset = offset->is_Con() ? offset->get_int() : 0;
|
|
|
|
stringStream* predString = NULL;
|
|
if (TraceLoopPredicate) {
|
|
predString = new stringStream();
|
|
predString->print("rc_predicate ");
|
|
}
|
|
|
|
overflow = false;
|
|
Node* max_idx_expr = NULL;
|
|
const TypeInt* idx_type = TypeInt::INT;
|
|
if ((stride > 0) == (scale > 0) == upper) {
|
|
guarantee(limit != NULL, "sanity");
|
|
if (TraceLoopPredicate) {
|
|
if (limit->is_Con()) {
|
|
predString->print("(%d ", con_limit);
|
|
} else {
|
|
predString->print("(limit ");
|
|
}
|
|
predString->print("- %d) ", stride);
|
|
}
|
|
// Check if (limit - stride) may overflow
|
|
const TypeInt* limit_type = _igvn.type(limit)->isa_int();
|
|
jint limit_lo = limit_type->_lo;
|
|
jint limit_hi = limit_type->_hi;
|
|
if ((stride > 0 && (java_subtract(limit_lo, stride) < limit_lo)) ||
|
|
(stride < 0 && (java_subtract(limit_hi, stride) > limit_hi))) {
|
|
// No overflow possible
|
|
ConINode* con_stride = _igvn.intcon(stride);
|
|
set_ctrl(con_stride, C->root());
|
|
max_idx_expr = new SubINode(limit, con_stride);
|
|
idx_type = TypeInt::make(limit_lo - stride, limit_hi - stride, limit_type->_widen);
|
|
} else {
|
|
// May overflow
|
|
overflow = true;
|
|
limit = new ConvI2LNode(limit);
|
|
register_new_node(limit, ctrl);
|
|
ConLNode* con_stride = _igvn.longcon(stride);
|
|
set_ctrl(con_stride, C->root());
|
|
max_idx_expr = new SubLNode(limit, con_stride);
|
|
}
|
|
register_new_node(max_idx_expr, ctrl);
|
|
} else {
|
|
if (TraceLoopPredicate) {
|
|
if (init->is_Con()) {
|
|
predString->print("%d ", con_init);
|
|
} else {
|
|
predString->print("init ");
|
|
}
|
|
}
|
|
idx_type = _igvn.type(init)->isa_int();
|
|
max_idx_expr = init;
|
|
}
|
|
|
|
if (scale != 1) {
|
|
ConNode* con_scale = _igvn.intcon(scale);
|
|
set_ctrl(con_scale, C->root());
|
|
if (TraceLoopPredicate) {
|
|
predString->print("* %d ", scale);
|
|
}
|
|
// Check if (scale * max_idx_expr) may overflow
|
|
const TypeInt* scale_type = TypeInt::make(scale);
|
|
MulINode* mul = new MulINode(max_idx_expr, con_scale);
|
|
idx_type = (TypeInt*)mul->mul_ring(idx_type, scale_type);
|
|
if (overflow || TypeInt::INT->higher_equal(idx_type)) {
|
|
// May overflow
|
|
mul->destruct();
|
|
if (!overflow) {
|
|
max_idx_expr = new ConvI2LNode(max_idx_expr);
|
|
register_new_node(max_idx_expr, ctrl);
|
|
}
|
|
overflow = true;
|
|
con_scale = _igvn.longcon(scale);
|
|
set_ctrl(con_scale, C->root());
|
|
max_idx_expr = new MulLNode(max_idx_expr, con_scale);
|
|
} else {
|
|
// No overflow possible
|
|
max_idx_expr = mul;
|
|
}
|
|
register_new_node(max_idx_expr, ctrl);
|
|
}
|
|
|
|
if (offset && (!offset->is_Con() || con_offset != 0)){
|
|
if (TraceLoopPredicate) {
|
|
if (offset->is_Con()) {
|
|
predString->print("+ %d ", con_offset);
|
|
} else {
|
|
predString->print("+ offset");
|
|
}
|
|
}
|
|
// Check if (max_idx_expr + offset) may overflow
|
|
const TypeInt* offset_type = _igvn.type(offset)->isa_int();
|
|
jint lo = java_add(idx_type->_lo, offset_type->_lo);
|
|
jint hi = java_add(idx_type->_hi, offset_type->_hi);
|
|
if (overflow || (lo > hi) ||
|
|
((idx_type->_lo & offset_type->_lo) < 0 && lo >= 0) ||
|
|
((~(idx_type->_hi | offset_type->_hi)) < 0 && hi < 0)) {
|
|
// May overflow
|
|
if (!overflow) {
|
|
max_idx_expr = new ConvI2LNode(max_idx_expr);
|
|
register_new_node(max_idx_expr, ctrl);
|
|
}
|
|
overflow = true;
|
|
offset = new ConvI2LNode(offset);
|
|
register_new_node(offset, ctrl);
|
|
max_idx_expr = new AddLNode(max_idx_expr, offset);
|
|
} else {
|
|
// No overflow possible
|
|
max_idx_expr = new AddINode(max_idx_expr, offset);
|
|
}
|
|
register_new_node(max_idx_expr, ctrl);
|
|
}
|
|
|
|
CmpNode* cmp = NULL;
|
|
if (overflow) {
|
|
// Integer expressions may overflow, do long comparison
|
|
range = new ConvI2LNode(range);
|
|
register_new_node(range, ctrl);
|
|
cmp = new CmpULNode(max_idx_expr, range);
|
|
} else {
|
|
cmp = new CmpUNode(max_idx_expr, range);
|
|
}
|
|
register_new_node(cmp, ctrl);
|
|
BoolNode* bol = new BoolNode(cmp, BoolTest::lt);
|
|
register_new_node(bol, ctrl);
|
|
|
|
if (TraceLoopPredicate) {
|
|
predString->print_cr("<u range");
|
|
tty->print("%s", predString->as_string());
|
|
}
|
|
return bol;
|
|
}
|
|
|
|
// Should loop predication look not only in the path from tail to head
|
|
// but also in branches of the loop body?
|
|
bool PhaseIdealLoop::loop_predication_should_follow_branches(IdealLoopTree *loop, ProjNode *predicate_proj, float& loop_trip_cnt) {
|
|
if (!UseProfiledLoopPredicate) {
|
|
return false;
|
|
}
|
|
|
|
if (predicate_proj == NULL) {
|
|
return false;
|
|
}
|
|
|
|
LoopNode* head = loop->_head->as_Loop();
|
|
bool follow_branches = true;
|
|
IdealLoopTree* l = loop->_child;
|
|
// For leaf loops and loops with a single inner loop
|
|
while (l != NULL && follow_branches) {
|
|
IdealLoopTree* child = l;
|
|
if (child->_child != NULL &&
|
|
child->_head->is_OuterStripMinedLoop()) {
|
|
assert(child->_child->_next == NULL, "only one inner loop for strip mined loop");
|
|
assert(child->_child->_head->is_CountedLoop() && child->_child->_head->as_CountedLoop()->is_strip_mined(), "inner loop should be strip mined");
|
|
child = child->_child;
|
|
}
|
|
if (child->_child != NULL || child->_irreducible) {
|
|
follow_branches = false;
|
|
}
|
|
l = l->_next;
|
|
}
|
|
if (follow_branches) {
|
|
loop->compute_profile_trip_cnt(this);
|
|
if (head->is_profile_trip_failed()) {
|
|
follow_branches = false;
|
|
} else {
|
|
loop_trip_cnt = head->profile_trip_cnt();
|
|
if (head->is_CountedLoop()) {
|
|
CountedLoopNode* cl = head->as_CountedLoop();
|
|
if (cl->phi() != NULL) {
|
|
const TypeInt* t = _igvn.type(cl->phi())->is_int();
|
|
float worst_case_trip_cnt = ((float)t->_hi - t->_lo) / ABS(cl->stride_con());
|
|
if (worst_case_trip_cnt < loop_trip_cnt) {
|
|
loop_trip_cnt = worst_case_trip_cnt;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return follow_branches;
|
|
}
|
|
|
|
// Compute probability of reaching some CFG node from a fixed
|
|
// dominating CFG node
|
|
class PathFrequency {
|
|
private:
|
|
Node* _dom; // frequencies are computed relative to this node
|
|
Node_Stack _stack;
|
|
GrowableArray<float> _freqs_stack; // keep track of intermediate result at regions
|
|
GrowableArray<float> _freqs; // cache frequencies
|
|
PhaseIdealLoop* _phase;
|
|
|
|
public:
|
|
PathFrequency(Node* dom, PhaseIdealLoop* phase)
|
|
: _dom(dom), _stack(0), _phase(phase) {
|
|
}
|
|
|
|
float to(Node* n) {
|
|
// post order walk on the CFG graph from n to _dom
|
|
fesetround(FE_TOWARDZERO); // make sure rounding doesn't push frequency above 1
|
|
IdealLoopTree* loop = _phase->get_loop(_dom);
|
|
Node* c = n;
|
|
for (;;) {
|
|
assert(_phase->get_loop(c) == loop, "have to be in the same loop");
|
|
if (c == _dom || _freqs.at_grow(c->_idx, -1) >= 0) {
|
|
float f = c == _dom ? 1 : _freqs.at(c->_idx);
|
|
Node* prev = c;
|
|
while (_stack.size() > 0 && prev == c) {
|
|
Node* n = _stack.node();
|
|
if (!n->is_Region()) {
|
|
if (_phase->get_loop(n) != _phase->get_loop(n->in(0))) {
|
|
// Found an inner loop: compute frequency of reaching this
|
|
// exit from the loop head by looking at the number of
|
|
// times each loop exit was taken
|
|
IdealLoopTree* inner_loop = _phase->get_loop(n->in(0));
|
|
LoopNode* inner_head = inner_loop->_head->as_Loop();
|
|
assert(_phase->get_loop(n) == loop, "only 1 inner loop");
|
|
if (inner_head->is_OuterStripMinedLoop()) {
|
|
inner_head->verify_strip_mined(1);
|
|
if (n->in(0) == inner_head->in(LoopNode::LoopBackControl)->in(0)) {
|
|
n = n->in(0)->in(0)->in(0);
|
|
}
|
|
inner_loop = inner_loop->_child;
|
|
inner_head = inner_loop->_head->as_Loop();
|
|
inner_head->verify_strip_mined(1);
|
|
}
|
|
fesetround(FE_UPWARD); // make sure rounding doesn't push frequency above 1
|
|
float loop_exit_cnt = 0.0f;
|
|
for (uint i = 0; i < inner_loop->_body.size(); i++) {
|
|
Node *n = inner_loop->_body[i];
|
|
float c = inner_loop->compute_profile_trip_cnt_helper(n);
|
|
loop_exit_cnt += c;
|
|
}
|
|
fesetround(FE_TOWARDZERO);
|
|
float cnt = -1;
|
|
if (n->in(0)->is_If()) {
|
|
IfNode* iff = n->in(0)->as_If();
|
|
float p = n->in(0)->as_If()->_prob;
|
|
if (n->Opcode() == Op_IfFalse) {
|
|
p = 1 - p;
|
|
}
|
|
if (p > PROB_MIN) {
|
|
cnt = p * iff->_fcnt;
|
|
} else {
|
|
cnt = 0;
|
|
}
|
|
} else {
|
|
assert(n->in(0)->is_Jump(), "unsupported node kind");
|
|
JumpNode* jmp = n->in(0)->as_Jump();
|
|
float p = n->in(0)->as_Jump()->_probs[n->as_JumpProj()->_con];
|
|
cnt = p * jmp->_fcnt;
|
|
}
|
|
float this_exit_f = cnt > 0 ? cnt / loop_exit_cnt : 0;
|
|
assert(this_exit_f <= 1 && this_exit_f >= 0, "Incorrect frequency");
|
|
f = f * this_exit_f;
|
|
assert(f <= 1 && f >= 0, "Incorrect frequency");
|
|
} else {
|
|
float p = -1;
|
|
if (n->in(0)->is_If()) {
|
|
p = n->in(0)->as_If()->_prob;
|
|
if (n->Opcode() == Op_IfFalse) {
|
|
p = 1 - p;
|
|
}
|
|
} else {
|
|
assert(n->in(0)->is_Jump(), "unsupported node kind");
|
|
p = n->in(0)->as_Jump()->_probs[n->as_JumpProj()->_con];
|
|
}
|
|
f = f * p;
|
|
assert(f <= 1 && f >= 0, "Incorrect frequency");
|
|
}
|
|
_freqs.at_put_grow(n->_idx, (float)f, -1);
|
|
_stack.pop();
|
|
} else {
|
|
float prev_f = _freqs_stack.pop();
|
|
float new_f = f;
|
|
f = new_f + prev_f;
|
|
assert(f <= 1 && f >= 0, "Incorrect frequency");
|
|
uint i = _stack.index();
|
|
if (i < n->req()) {
|
|
c = n->in(i);
|
|
_stack.set_index(i+1);
|
|
_freqs_stack.push(f);
|
|
} else {
|
|
_freqs.at_put_grow(n->_idx, f, -1);
|
|
_stack.pop();
|
|
}
|
|
}
|
|
}
|
|
if (_stack.size() == 0) {
|
|
fesetround(FE_TONEAREST);
|
|
assert(f >= 0 && f <= 1, "should have been computed");
|
|
return f;
|
|
}
|
|
} else if (c->is_Loop()) {
|
|
ShouldNotReachHere();
|
|
c = c->in(LoopNode::EntryControl);
|
|
} else if (c->is_Region()) {
|
|
_freqs_stack.push(0);
|
|
_stack.push(c, 2);
|
|
c = c->in(1);
|
|
} else {
|
|
if (c->is_IfProj()) {
|
|
IfNode* iff = c->in(0)->as_If();
|
|
if (iff->_prob == PROB_UNKNOWN) {
|
|
// assume never taken
|
|
_freqs.at_put_grow(c->_idx, 0, -1);
|
|
} else if (_phase->get_loop(c) != _phase->get_loop(iff)) {
|
|
if (iff->_fcnt == COUNT_UNKNOWN) {
|
|
// assume never taken
|
|
_freqs.at_put_grow(c->_idx, 0, -1);
|
|
} else {
|
|
// skip over loop
|
|
_stack.push(c, 1);
|
|
c = _phase->get_loop(c->in(0))->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
}
|
|
} else {
|
|
_stack.push(c, 1);
|
|
c = iff;
|
|
}
|
|
} else if (c->is_JumpProj()) {
|
|
JumpNode* jmp = c->in(0)->as_Jump();
|
|
if (_phase->get_loop(c) != _phase->get_loop(jmp)) {
|
|
if (jmp->_fcnt == COUNT_UNKNOWN) {
|
|
// assume never taken
|
|
_freqs.at_put_grow(c->_idx, 0, -1);
|
|
} else {
|
|
// skip over loop
|
|
_stack.push(c, 1);
|
|
c = _phase->get_loop(c->in(0))->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
}
|
|
} else {
|
|
_stack.push(c, 1);
|
|
c = jmp;
|
|
}
|
|
} else if (c->Opcode() == Op_CatchProj &&
|
|
c->in(0)->Opcode() == Op_Catch &&
|
|
c->in(0)->in(0)->is_Proj() &&
|
|
c->in(0)->in(0)->in(0)->is_Call()) {
|
|
// assume exceptions are never thrown
|
|
uint con = c->as_Proj()->_con;
|
|
if (con == CatchProjNode::fall_through_index) {
|
|
Node* call = c->in(0)->in(0)->in(0)->in(0);
|
|
if (_phase->get_loop(call) != _phase->get_loop(c)) {
|
|
_freqs.at_put_grow(c->_idx, 0, -1);
|
|
} else {
|
|
c = call;
|
|
}
|
|
} else {
|
|
assert(con >= CatchProjNode::catch_all_index, "what else?");
|
|
_freqs.at_put_grow(c->_idx, 0, -1);
|
|
}
|
|
} else if (c->unique_ctrl_out() == NULL && !c->is_If() && !c->is_Jump()) {
|
|
ShouldNotReachHere();
|
|
} else {
|
|
c = c->in(0);
|
|
}
|
|
}
|
|
}
|
|
ShouldNotReachHere();
|
|
return -1;
|
|
}
|
|
};
|
|
|
|
void PhaseIdealLoop::loop_predication_follow_branches(Node *n, IdealLoopTree *loop, float loop_trip_cnt,
|
|
PathFrequency& pf, Node_Stack& stack, VectorSet& seen,
|
|
Node_List& if_proj_list) {
|
|
assert(n->is_Region(), "start from a region");
|
|
Node* tail = loop->tail();
|
|
stack.push(n, 1);
|
|
do {
|
|
Node* c = stack.node();
|
|
assert(c->is_Region() || c->is_IfProj(), "only region here");
|
|
uint i = stack.index();
|
|
|
|
if (i < c->req()) {
|
|
stack.set_index(i+1);
|
|
Node* in = c->in(i);
|
|
while (!is_dominator(in, tail) && !seen.test_set(in->_idx)) {
|
|
IdealLoopTree* in_loop = get_loop(in);
|
|
if (in_loop != loop) {
|
|
in = in_loop->_head->in(LoopNode::EntryControl);
|
|
} else if (in->is_Region()) {
|
|
stack.push(in, 1);
|
|
break;
|
|
} else if (in->is_IfProj() &&
|
|
in->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none) &&
|
|
(in->in(0)->Opcode() == Op_If ||
|
|
in->in(0)->Opcode() == Op_RangeCheck)) {
|
|
if (pf.to(in) * loop_trip_cnt >= 1) {
|
|
stack.push(in, 1);
|
|
}
|
|
in = in->in(0);
|
|
} else {
|
|
in = in->in(0);
|
|
}
|
|
}
|
|
} else {
|
|
if (c->is_IfProj()) {
|
|
if_proj_list.push(c);
|
|
}
|
|
stack.pop();
|
|
}
|
|
|
|
} while (stack.size() > 0);
|
|
}
|
|
|
|
|
|
bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree *loop, ProjNode* proj, ProjNode *predicate_proj,
|
|
CountedLoopNode *cl, ConNode* zero, Invariance& invar,
|
|
Deoptimization::DeoptReason reason) {
|
|
// Following are changed to nonnull when a predicate can be hoisted
|
|
ProjNode* new_predicate_proj = NULL;
|
|
IfNode* iff = proj->in(0)->as_If();
|
|
Node* test = iff->in(1);
|
|
if (!test->is_Bool()){ //Conv2B, ...
|
|
return false;
|
|
}
|
|
BoolNode* bol = test->as_Bool();
|
|
if (invar.is_invariant(bol)) {
|
|
// Invariant test
|
|
new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL,
|
|
reason,
|
|
iff->Opcode());
|
|
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 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)) {
|
|
// 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");
|
|
Node* rng = cmp->in(2);
|
|
assert(rng->Opcode() == Op_LoadRange || iff->is_RangeCheck() || _igvn.type(rng)->is_int()->_lo >= 0, "must be");
|
|
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();
|
|
// Limit is not exact.
|
|
// Calculate exact limit here.
|
|
// Note, counted loop's test is '<' or '>'.
|
|
Node* limit = exact_limit(loop);
|
|
int stride = cl->stride()->get_int();
|
|
|
|
// 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.
|
|
|
|
// Perform cloning to keep Invariance state correct since the
|
|
// late schedule will place invariant things in the loop.
|
|
Node *ctrl = predicate_proj->in(0)->as_If()->in(0);
|
|
rng = invar.clone(rng, ctrl);
|
|
if (offset && offset != zero) {
|
|
assert(invar.is_invariant(offset), "offset must be loop invariant");
|
|
offset = invar.clone(offset, ctrl);
|
|
}
|
|
// If predicate expressions may overflow in the integer range, longs are used.
|
|
bool overflow = false;
|
|
|
|
// Test the lower bound
|
|
BoolNode* lower_bound_bol = rc_predicate(loop, ctrl, scale, offset, init, limit, stride, rng, false, overflow);
|
|
// Negate test if necessary
|
|
bool negated = false;
|
|
if (proj->_con != predicate_proj->_con) {
|
|
lower_bound_bol = new BoolNode(lower_bound_bol->in(1), lower_bound_bol->_test.negate());
|
|
register_new_node(lower_bound_bol, ctrl);
|
|
negated = true;
|
|
}
|
|
ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, reason, overflow ? Op_If : iff->Opcode());
|
|
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: %s %d ", negated ? " negated" : "", lower_bound_iff->_idx);
|
|
|
|
// Test the upper bound
|
|
BoolNode* upper_bound_bol = rc_predicate(loop, lower_bound_proj, scale, offset, init, limit, stride, rng, true, overflow);
|
|
negated = false;
|
|
if (proj->_con != predicate_proj->_con) {
|
|
upper_bound_bol = new BoolNode(upper_bound_bol->in(1), upper_bound_bol->_test.negate());
|
|
register_new_node(upper_bound_bol, ctrl);
|
|
negated = true;
|
|
}
|
|
ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, reason, overflow ? Op_If : iff->Opcode());
|
|
assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate");
|
|
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: %s %d ", negated ? " negated" : "", 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;
|
|
|
|
if (iff->is_RangeCheck()) {
|
|
new_predicate_proj = insert_skeleton_predicate(iff, loop, proj, predicate_proj, upper_bound_proj, scale, offset, init, limit, stride, rng, overflow, reason);
|
|
}
|
|
|
|
#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.
|
|
return false;
|
|
}
|
|
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 );
|
|
|
|
C->set_major_progress();
|
|
return true;
|
|
}
|
|
|
|
|
|
// After pre/main/post loops are created, we'll put a copy of some
|
|
// range checks between the pre and main loop to validate the value
|
|
// of the main loop induction variable. Make a copy of the predicates
|
|
// here with an opaque node as a place holder for the value (will be
|
|
// updated by PhaseIdealLoop::update_skeleton_predicate()).
|
|
ProjNode* PhaseIdealLoop::insert_skeleton_predicate(IfNode* iff, IdealLoopTree *loop,
|
|
ProjNode* proj, ProjNode *predicate_proj,
|
|
ProjNode* upper_bound_proj,
|
|
int scale, Node* offset,
|
|
Node* init, Node* limit, jint stride,
|
|
Node* rng, bool &overflow,
|
|
Deoptimization::DeoptReason reason) {
|
|
assert(proj->_con && predicate_proj->_con, "not a range check?");
|
|
Node* opaque_init = new Opaque1Node(C, init);
|
|
register_new_node(opaque_init, upper_bound_proj);
|
|
BoolNode* bol = rc_predicate(loop, upper_bound_proj, scale, offset, opaque_init, limit, stride, rng, (stride > 0) != (scale > 0), overflow);
|
|
Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1)); // This will go away once loop opts are over
|
|
register_new_node(opaque_bol, upper_bound_proj);
|
|
ProjNode* new_proj = create_new_if_for_predicate(predicate_proj, NULL, reason, overflow ? Op_If : iff->Opcode());
|
|
_igvn.replace_input_of(new_proj->in(0), 1, opaque_bol);
|
|
assert(opaque_init->outcnt() > 0, "should be used");
|
|
return new_proj;
|
|
}
|
|
|
|
//------------------------------ 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;
|
|
}
|
|
LoopNode* head = loop->_head->as_Loop();
|
|
|
|
if (head->unique_ctrl_out()->Opcode() == Op_NeverBranch) {
|
|
// do nothing for infinite loops
|
|
return false;
|
|
}
|
|
|
|
if (head->is_OuterStripMinedLoop()) {
|
|
return false;
|
|
}
|
|
|
|
CountedLoopNode *cl = NULL;
|
|
if (head->is_valid_counted_loop()) {
|
|
cl = head->as_CountedLoop();
|
|
// do nothing for iteration-splitted loops
|
|
if (!cl->is_normal_loop()) return false;
|
|
// Avoid RCE if Counted loop's test is '!='.
|
|
BoolTest::mask bt = cl->loopexit()->test_trip();
|
|
if (bt != BoolTest::lt && bt != BoolTest::gt)
|
|
cl = NULL;
|
|
}
|
|
|
|
Node* entry = head->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
ProjNode *loop_limit_proj = NULL;
|
|
ProjNode *predicate_proj = NULL;
|
|
ProjNode *profile_predicate_proj = NULL;
|
|
// Loop limit check predicate should be near the loop.
|
|
loop_limit_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check);
|
|
if (loop_limit_proj != NULL) {
|
|
entry = loop_limit_proj->in(0)->in(0);
|
|
}
|
|
bool has_profile_predicates = false;
|
|
profile_predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_profile_predicate);
|
|
if (profile_predicate_proj != NULL) {
|
|
Node* n = skip_loop_predicates(entry);
|
|
// Check if predicates were already added to the profile predicate
|
|
// block
|
|
if (n != entry->in(0)->in(0) || n->outcnt() != 1) {
|
|
has_profile_predicates = true;
|
|
}
|
|
entry = n;
|
|
}
|
|
predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
|
|
|
|
float loop_trip_cnt = -1;
|
|
bool follow_branches = loop_predication_should_follow_branches(loop, profile_predicate_proj, loop_trip_cnt);
|
|
assert(!follow_branches || loop_trip_cnt >= 0, "negative trip count?");
|
|
|
|
if (predicate_proj == NULL && !follow_branches) {
|
|
#ifndef PRODUCT
|
|
if (TraceLoopPredicate) {
|
|
tty->print("missing predicate:");
|
|
loop->dump_head();
|
|
head->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);
|
|
Node_List regions(area);
|
|
Node *current_proj = loop->tail(); //start from tail
|
|
|
|
|
|
Node_List controls(area);
|
|
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 ||
|
|
current_proj->in(0)->Opcode() == Op_RangeCheck)) { // is a if projection ?
|
|
if_proj_list.push(current_proj);
|
|
}
|
|
if (follow_branches &&
|
|
current_proj->Opcode() == Op_Region &&
|
|
loop == get_loop(current_proj)) {
|
|
regions.push(current_proj);
|
|
}
|
|
current_proj = idom(current_proj);
|
|
}
|
|
|
|
bool hoisted = false; // true if at least one proj is promoted
|
|
|
|
if (!has_profile_predicates) {
|
|
while (if_proj_list.size() > 0) {
|
|
Node* n = if_proj_list.pop();
|
|
|
|
ProjNode* proj = n->as_Proj();
|
|
IfNode* iff = proj->in(0)->as_If();
|
|
|
|
CallStaticJavaNode* call = proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none);
|
|
if (call == NULL) {
|
|
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;
|
|
}
|
|
}
|
|
Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(call->uncommon_trap_request());
|
|
if (reason == Deoptimization::Reason_predicate) {
|
|
break;
|
|
}
|
|
|
|
if (predicate_proj != NULL) {
|
|
hoisted = loop_predication_impl_helper(loop, proj, predicate_proj, cl, zero, invar, Deoptimization::Reason_predicate) | hoisted;
|
|
}
|
|
} // end while
|
|
}
|
|
|
|
Node_List if_proj_list_freq(area);
|
|
if (follow_branches) {
|
|
PathFrequency pf(loop->_head, this);
|
|
|
|
// Some projections were skipped by regular predicates because of
|
|
// an early loop exit. Try them with profile data.
|
|
while (if_proj_list.size() > 0) {
|
|
Node* proj = if_proj_list.pop();
|
|
float f = pf.to(proj);
|
|
if (proj->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none) &&
|
|
f * loop_trip_cnt >= 1) {
|
|
hoisted = loop_predication_impl_helper(loop, proj->as_Proj(), profile_predicate_proj, cl, zero, invar, Deoptimization::Reason_profile_predicate) | hoisted;
|
|
}
|
|
}
|
|
|
|
// And look into all branches
|
|
Node_Stack stack(0);
|
|
VectorSet seen(Thread::current()->resource_area());
|
|
while (regions.size() > 0) {
|
|
Node* c = regions.pop();
|
|
loop_predication_follow_branches(c, loop, loop_trip_cnt, pf, stack, seen, if_proj_list_freq);
|
|
}
|
|
|
|
for (uint i = 0; i < if_proj_list_freq.size(); i++) {
|
|
ProjNode* proj = if_proj_list_freq.at(i)->as_Proj();
|
|
hoisted = loop_predication_impl_helper(loop, proj, profile_predicate_proj, cl, zero, invar, Deoptimization::Reason_profile_predicate) | hoisted;
|
|
}
|
|
}
|
|
|
|
#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
|
|
|
|
head->verify_strip_mined(1);
|
|
|
|
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;
|
|
}
|