3556 lines
128 KiB
C++
3556 lines
128 KiB
C++
/*
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* Copyright (c) 1999, 2019, 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 "gc/shared/barrierSet.hpp"
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#include "gc/shared/c2/barrierSetC2.hpp"
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#include "memory/allocation.inline.hpp"
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#include "memory/resourceArea.hpp"
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#include "opto/addnode.hpp"
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#include "opto/callnode.hpp"
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#include "opto/castnode.hpp"
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#include "opto/connode.hpp"
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#include "opto/castnode.hpp"
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#include "opto/divnode.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/movenode.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 "opto/subtypenode.hpp"
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#include "utilities/macros.hpp"
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//=============================================================================
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//------------------------------split_thru_phi---------------------------------
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// Split Node 'n' through merge point if there is enough win.
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Node* PhaseIdealLoop::split_thru_phi(Node* n, Node* region, int policy) {
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if (n->Opcode() == Op_ConvI2L && n->bottom_type() != TypeLong::LONG) {
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// ConvI2L may have type information on it which is unsafe to push up
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// so disable this for now
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return NULL;
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}
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// Splitting range check CastIIs through a loop induction Phi can
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// cause new Phis to be created that are left unrelated to the loop
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// induction Phi and prevent optimizations (vectorization)
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if (n->Opcode() == Op_CastII && n->as_CastII()->has_range_check() &&
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region->is_CountedLoop() && n->in(1) == region->as_CountedLoop()->phi()) {
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return NULL;
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}
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// Bail out if 'n' is a Div or Mod node whose zero check was removed earlier (i.e. control is NULL) and its divisor is an induction variable
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// phi p of a trip-counted (integer) loop whose inputs could be zero (include zero in their type range). p could have a more precise type
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// range that does not necessarily include all values of its inputs. Since each of these inputs will be a divisor of the newly cloned nodes
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// of 'n', we need to bail out of one of these divisors could be zero (zero in its type range).
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if ((n->Opcode() == Op_DivI || n->Opcode() == Op_ModI) && n->in(0) == NULL
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&& region->is_CountedLoop() && n->in(2) == region->as_CountedLoop()->phi()) {
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Node* phi = region->as_CountedLoop()->phi();
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for (uint i = 1; i < phi->req(); i++) {
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if (_igvn.type(phi->in(i))->filter_speculative(TypeInt::ZERO) != Type::TOP) {
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// Zero could be a possible value but we already removed the zero check. Bail out to avoid a possible division by zero at a later point.
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return NULL;
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}
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}
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}
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int wins = 0;
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assert(!n->is_CFG(), "");
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assert(region->is_Region(), "");
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const Type* type = n->bottom_type();
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const TypeOopPtr* t_oop = _igvn.type(n)->isa_oopptr();
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Node* phi;
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if (t_oop != NULL && t_oop->is_known_instance_field()) {
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int iid = t_oop->instance_id();
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int index = C->get_alias_index(t_oop);
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int offset = t_oop->offset();
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phi = new PhiNode(region, type, NULL, iid, index, offset);
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} else {
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phi = PhiNode::make_blank(region, n);
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}
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uint old_unique = C->unique();
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for (uint i = 1; i < region->req(); i++) {
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Node* x;
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Node* the_clone = NULL;
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if (region->in(i) == C->top()) {
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x = C->top(); // Dead path? Use a dead data op
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} else {
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x = n->clone(); // Else clone up the data op
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the_clone = x; // Remember for possible deletion.
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// Alter data node to use pre-phi inputs
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if (n->in(0) == region)
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x->set_req( 0, region->in(i) );
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for (uint j = 1; j < n->req(); j++) {
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Node* in = n->in(j);
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if (in->is_Phi() && in->in(0) == region)
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x->set_req(j, in->in(i)); // Use pre-Phi input for the clone
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}
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}
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// Check for a 'win' on some paths
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const Type* t = x->Value(&_igvn);
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bool singleton = t->singleton();
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// A TOP singleton indicates that there are no possible values incoming
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// along a particular edge. In most cases, this is OK, and the Phi will
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// be eliminated later in an Ideal call. However, we can't allow this to
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// happen if the singleton occurs on loop entry, as the elimination of
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// the PhiNode may cause the resulting node to migrate back to a previous
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// loop iteration.
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if (singleton && t == Type::TOP) {
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// Is_Loop() == false does not confirm the absence of a loop (e.g., an
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// irreducible loop may not be indicated by an affirmative is_Loop());
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// therefore, the only top we can split thru a phi is on a backedge of
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// a loop.
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singleton &= region->is_Loop() && (i != LoopNode::EntryControl);
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}
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if (singleton) {
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wins++;
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x = ((PhaseGVN&)_igvn).makecon(t);
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} else {
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// We now call Identity to try to simplify the cloned node.
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// Note that some Identity methods call phase->type(this).
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// Make sure that the type array is big enough for
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// our new node, even though we may throw the node away.
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// (Note: This tweaking with igvn only works because x is a new node.)
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_igvn.set_type(x, t);
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// If x is a TypeNode, capture any more-precise type permanently into Node
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// otherwise it will be not updated during igvn->transform since
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// igvn->type(x) is set to x->Value() already.
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x->raise_bottom_type(t);
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Node* y = x->Identity(&_igvn);
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if (y != x) {
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wins++;
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x = y;
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} else {
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y = _igvn.hash_find(x);
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if (y) {
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wins++;
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x = y;
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} else {
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// Else x is a new node we are keeping
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// We do not need register_new_node_with_optimizer
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// because set_type has already been called.
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_igvn._worklist.push(x);
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}
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}
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}
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if (x != the_clone && the_clone != NULL)
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_igvn.remove_dead_node(the_clone);
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phi->set_req( i, x );
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}
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// Too few wins?
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if (wins <= policy) {
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_igvn.remove_dead_node(phi);
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return NULL;
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}
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// Record Phi
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register_new_node( phi, region );
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for (uint i2 = 1; i2 < phi->req(); i2++) {
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Node *x = phi->in(i2);
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// If we commoned up the cloned 'x' with another existing Node,
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// the existing Node picks up a new use. We need to make the
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// existing Node occur higher up so it dominates its uses.
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Node *old_ctrl;
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IdealLoopTree *old_loop;
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if (x->is_Con()) {
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// Constant's control is always root.
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set_ctrl(x, C->root());
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continue;
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}
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// The occasional new node
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if (x->_idx >= old_unique) { // Found a new, unplaced node?
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old_ctrl = NULL;
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old_loop = NULL; // Not in any prior loop
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} else {
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old_ctrl = get_ctrl(x);
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old_loop = get_loop(old_ctrl); // Get prior loop
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}
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// New late point must dominate new use
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Node *new_ctrl = dom_lca(old_ctrl, region->in(i2));
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if (new_ctrl == old_ctrl) // Nothing is changed
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continue;
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IdealLoopTree *new_loop = get_loop(new_ctrl);
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// Don't move x into a loop if its uses are
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// outside of loop. Otherwise x will be cloned
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// for each use outside of this loop.
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IdealLoopTree *use_loop = get_loop(region);
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if (!new_loop->is_member(use_loop) &&
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(old_loop == NULL || !new_loop->is_member(old_loop))) {
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// Take early control, later control will be recalculated
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// during next iteration of loop optimizations.
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new_ctrl = get_early_ctrl(x);
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new_loop = get_loop(new_ctrl);
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}
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// Set new location
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set_ctrl(x, new_ctrl);
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// If changing loop bodies, see if we need to collect into new body
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if (old_loop != new_loop) {
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if (old_loop && !old_loop->_child)
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old_loop->_body.yank(x);
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if (!new_loop->_child)
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new_loop->_body.push(x); // Collect body info
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}
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}
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return phi;
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}
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//------------------------------dominated_by------------------------------------
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// Replace the dominated test with an obvious true or false. Place it on the
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// IGVN worklist for later cleanup. Move control-dependent data Nodes on the
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// live path up to the dominating control.
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void PhaseIdealLoop::dominated_by( Node *prevdom, Node *iff, bool flip, bool exclude_loop_predicate ) {
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if (VerifyLoopOptimizations && PrintOpto) { tty->print_cr("dominating test"); }
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// prevdom is the dominating projection of the dominating test.
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assert( iff->is_If(), "" );
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assert(iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd || iff->Opcode() == Op_RangeCheck, "Check this code when new subtype is added");
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int pop = prevdom->Opcode();
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assert( pop == Op_IfFalse || pop == Op_IfTrue, "" );
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if (flip) {
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if (pop == Op_IfTrue)
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pop = Op_IfFalse;
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else
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pop = Op_IfTrue;
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}
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// 'con' is set to true or false to kill the dominated test.
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Node *con = _igvn.makecon(pop == Op_IfTrue ? TypeInt::ONE : TypeInt::ZERO);
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set_ctrl(con, C->root()); // Constant gets a new use
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// Hack the dominated test
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_igvn.replace_input_of(iff, 1, con);
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// If I dont have a reachable TRUE and FALSE path following the IfNode then
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// I can assume this path reaches an infinite loop. In this case it's not
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// important to optimize the data Nodes - either the whole compilation will
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// be tossed or this path (and all data Nodes) will go dead.
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if (iff->outcnt() != 2) return;
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// Make control-dependent data Nodes on the live path (path that will remain
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// once the dominated IF is removed) become control-dependent on the
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// dominating projection.
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Node* dp = iff->as_If()->proj_out_or_null(pop == Op_IfTrue);
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// Loop predicates may have depending checks which should not
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// be skipped. For example, range check predicate has two checks
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// for lower and upper bounds.
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if (dp == NULL)
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return;
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ProjNode* dp_proj = dp->as_Proj();
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ProjNode* unc_proj = iff->as_If()->proj_out(1 - dp_proj->_con)->as_Proj();
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if (exclude_loop_predicate &&
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(unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_predicate) != NULL ||
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unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_profile_predicate) != NULL ||
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unc_proj->is_uncommon_trap_proj(Deoptimization::Reason_range_check) != NULL)) {
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// If this is a range check (IfNode::is_range_check), do not
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// reorder because Compile::allow_range_check_smearing might have
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// changed the check.
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return; // Let IGVN transformation change control dependence.
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}
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IdealLoopTree *old_loop = get_loop(dp);
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for (DUIterator_Fast imax, i = dp->fast_outs(imax); i < imax; i++) {
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Node* cd = dp->fast_out(i); // Control-dependent node
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if (cd->depends_only_on_test()) {
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assert(cd->in(0) == dp, "");
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_igvn.replace_input_of(cd, 0, prevdom);
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set_early_ctrl(cd);
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IdealLoopTree *new_loop = get_loop(get_ctrl(cd));
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if (old_loop != new_loop) {
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if (!old_loop->_child) old_loop->_body.yank(cd);
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if (!new_loop->_child) new_loop->_body.push(cd);
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}
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--i;
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--imax;
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}
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}
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}
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//------------------------------has_local_phi_input----------------------------
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// Return TRUE if 'n' has Phi inputs from its local block and no other
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// block-local inputs (all non-local-phi inputs come from earlier blocks)
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Node *PhaseIdealLoop::has_local_phi_input( Node *n ) {
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Node *n_ctrl = get_ctrl(n);
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// See if some inputs come from a Phi in this block, or from before
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// this block.
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uint i;
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for( i = 1; i < n->req(); i++ ) {
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Node *phi = n->in(i);
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if( phi->is_Phi() && phi->in(0) == n_ctrl )
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break;
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}
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if( i >= n->req() )
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return NULL; // No Phi inputs; nowhere to clone thru
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// Check for inputs created between 'n' and the Phi input. These
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// must split as well; they have already been given the chance
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// (courtesy of a post-order visit) and since they did not we must
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// recover the 'cost' of splitting them by being very profitable
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// when splitting 'n'. Since this is unlikely we simply give up.
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for( i = 1; i < n->req(); i++ ) {
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Node *m = n->in(i);
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if( get_ctrl(m) == n_ctrl && !m->is_Phi() ) {
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// We allow the special case of AddP's with no local inputs.
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// This allows us to split-up address expressions.
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if (m->is_AddP() &&
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get_ctrl(m->in(2)) != n_ctrl &&
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get_ctrl(m->in(3)) != n_ctrl) {
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// Move the AddP up to dominating point
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Node* c = find_non_split_ctrl(idom(n_ctrl));
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if (c->is_OuterStripMinedLoop()) {
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c->as_Loop()->verify_strip_mined(1);
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c = c->in(LoopNode::EntryControl);
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}
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set_ctrl_and_loop(m, c);
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continue;
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}
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return NULL;
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}
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assert(n->is_Phi() || m->is_Phi() || is_dominator(get_ctrl(m), n_ctrl), "m has strange control");
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}
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return n_ctrl;
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}
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//------------------------------remix_address_expressions----------------------
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// Rework addressing expressions to get the most loop-invariant stuff
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// moved out. We'd like to do all associative operators, but it's especially
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// important (common) to do address expressions.
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Node *PhaseIdealLoop::remix_address_expressions( Node *n ) {
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if (!has_ctrl(n)) return NULL;
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Node *n_ctrl = get_ctrl(n);
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IdealLoopTree *n_loop = get_loop(n_ctrl);
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// See if 'n' mixes loop-varying and loop-invariant inputs and
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// itself is loop-varying.
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// Only interested in binary ops (and AddP)
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if( n->req() < 3 || n->req() > 4 ) return NULL;
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Node *n1_ctrl = get_ctrl(n->in( 1));
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Node *n2_ctrl = get_ctrl(n->in( 2));
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Node *n3_ctrl = get_ctrl(n->in(n->req() == 3 ? 2 : 3));
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IdealLoopTree *n1_loop = get_loop( n1_ctrl );
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IdealLoopTree *n2_loop = get_loop( n2_ctrl );
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IdealLoopTree *n3_loop = get_loop( n3_ctrl );
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// Does one of my inputs spin in a tighter loop than self?
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if( (n_loop->is_member( n1_loop ) && n_loop != n1_loop) ||
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(n_loop->is_member( n2_loop ) && n_loop != n2_loop) ||
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(n_loop->is_member( n3_loop ) && n_loop != n3_loop) )
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return NULL; // Leave well enough alone
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// Is at least one of my inputs loop-invariant?
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if( n1_loop == n_loop &&
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n2_loop == n_loop &&
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n3_loop == n_loop )
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return NULL; // No loop-invariant inputs
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int n_op = n->Opcode();
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// Replace expressions like ((V+I) << 2) with (V<<2 + I<<2).
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if( n_op == Op_LShiftI ) {
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// Scale is loop invariant
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Node *scale = n->in(2);
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Node *scale_ctrl = get_ctrl(scale);
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IdealLoopTree *scale_loop = get_loop(scale_ctrl );
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if( n_loop == scale_loop || !scale_loop->is_member( n_loop ) )
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return NULL;
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const TypeInt *scale_t = scale->bottom_type()->isa_int();
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if( scale_t && scale_t->is_con() && scale_t->get_con() >= 16 )
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return NULL; // Dont bother with byte/short masking
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// Add must vary with loop (else shift would be loop-invariant)
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Node *add = n->in(1);
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Node *add_ctrl = get_ctrl(add);
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IdealLoopTree *add_loop = get_loop(add_ctrl);
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//assert( n_loop == add_loop, "" );
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if( n_loop != add_loop ) return NULL; // happens w/ evil ZKM loops
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// Convert I-V into I+ (0-V); same for V-I
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if( add->Opcode() == Op_SubI &&
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_igvn.type( add->in(1) ) != TypeInt::ZERO ) {
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Node *zero = _igvn.intcon(0);
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set_ctrl(zero, C->root());
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Node *neg = new SubINode( _igvn.intcon(0), add->in(2) );
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register_new_node( neg, get_ctrl(add->in(2) ) );
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add = new AddINode( add->in(1), neg );
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register_new_node( add, add_ctrl );
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}
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if( add->Opcode() != Op_AddI ) return NULL;
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// See if one add input is loop invariant
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Node *add_var = add->in(1);
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Node *add_var_ctrl = get_ctrl(add_var);
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IdealLoopTree *add_var_loop = get_loop(add_var_ctrl );
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Node *add_invar = add->in(2);
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Node *add_invar_ctrl = get_ctrl(add_invar);
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IdealLoopTree *add_invar_loop = get_loop(add_invar_ctrl );
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if( add_var_loop == n_loop ) {
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} else if( add_invar_loop == n_loop ) {
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// Swap to find the invariant part
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add_invar = add_var;
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add_invar_ctrl = add_var_ctrl;
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add_invar_loop = add_var_loop;
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add_var = add->in(2);
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Node *add_var_ctrl = get_ctrl(add_var);
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IdealLoopTree *add_var_loop = get_loop(add_var_ctrl );
|
|
} else // Else neither input is loop invariant
|
|
return NULL;
|
|
if( n_loop == add_invar_loop || !add_invar_loop->is_member( n_loop ) )
|
|
return NULL; // No invariant part of the add?
|
|
|
|
// Yes! Reshape address expression!
|
|
Node *inv_scale = new LShiftINode( add_invar, scale );
|
|
Node *inv_scale_ctrl =
|
|
dom_depth(add_invar_ctrl) > dom_depth(scale_ctrl) ?
|
|
add_invar_ctrl : scale_ctrl;
|
|
register_new_node( inv_scale, inv_scale_ctrl );
|
|
Node *var_scale = new LShiftINode( add_var, scale );
|
|
register_new_node( var_scale, n_ctrl );
|
|
Node *var_add = new AddINode( var_scale, inv_scale );
|
|
register_new_node( var_add, n_ctrl );
|
|
_igvn.replace_node( n, var_add );
|
|
return var_add;
|
|
}
|
|
|
|
// Replace (I+V) with (V+I)
|
|
if( n_op == Op_AddI ||
|
|
n_op == Op_AddL ||
|
|
n_op == Op_AddF ||
|
|
n_op == Op_AddD ||
|
|
n_op == Op_MulI ||
|
|
n_op == Op_MulL ||
|
|
n_op == Op_MulF ||
|
|
n_op == Op_MulD ) {
|
|
if( n2_loop == n_loop ) {
|
|
assert( n1_loop != n_loop, "" );
|
|
n->swap_edges(1, 2);
|
|
}
|
|
}
|
|
|
|
// Replace ((I1 +p V) +p I2) with ((I1 +p I2) +p V),
|
|
// but not if I2 is a constant.
|
|
if( n_op == Op_AddP ) {
|
|
if( n2_loop == n_loop && n3_loop != n_loop ) {
|
|
if( n->in(2)->Opcode() == Op_AddP && !n->in(3)->is_Con() ) {
|
|
Node *n22_ctrl = get_ctrl(n->in(2)->in(2));
|
|
Node *n23_ctrl = get_ctrl(n->in(2)->in(3));
|
|
IdealLoopTree *n22loop = get_loop( n22_ctrl );
|
|
IdealLoopTree *n23_loop = get_loop( n23_ctrl );
|
|
if( n22loop != n_loop && n22loop->is_member(n_loop) &&
|
|
n23_loop == n_loop ) {
|
|
Node *add1 = new AddPNode( n->in(1), n->in(2)->in(2), n->in(3) );
|
|
// Stuff new AddP in the loop preheader
|
|
register_new_node( add1, n_loop->_head->in(LoopNode::EntryControl) );
|
|
Node *add2 = new AddPNode( n->in(1), add1, n->in(2)->in(3) );
|
|
register_new_node( add2, n_ctrl );
|
|
_igvn.replace_node( n, add2 );
|
|
return add2;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Replace (I1 +p (I2 + V)) with ((I1 +p I2) +p V)
|
|
if (n2_loop != n_loop && n3_loop == n_loop) {
|
|
if (n->in(3)->Opcode() == Op_AddX) {
|
|
Node *V = n->in(3)->in(1);
|
|
Node *I = n->in(3)->in(2);
|
|
if (is_member(n_loop,get_ctrl(V))) {
|
|
} else {
|
|
Node *tmp = V; V = I; I = tmp;
|
|
}
|
|
if (!is_member(n_loop,get_ctrl(I))) {
|
|
Node *add1 = new AddPNode(n->in(1), n->in(2), I);
|
|
// Stuff new AddP in the loop preheader
|
|
register_new_node(add1, n_loop->_head->in(LoopNode::EntryControl));
|
|
Node *add2 = new AddPNode(n->in(1), add1, V);
|
|
register_new_node(add2, n_ctrl);
|
|
_igvn.replace_node(n, add2);
|
|
return add2;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
// Optimize ((in1[2*i] * in2[2*i]) + (in1[2*i+1] * in2[2*i+1]))
|
|
Node *PhaseIdealLoop::convert_add_to_muladd(Node* n) {
|
|
assert(n->Opcode() == Op_AddI, "sanity");
|
|
Node * nn = NULL;
|
|
Node * in1 = n->in(1);
|
|
Node * in2 = n->in(2);
|
|
if (in1->Opcode() == Op_MulI && in2->Opcode() == Op_MulI) {
|
|
IdealLoopTree* loop_n = get_loop(get_ctrl(n));
|
|
if (loop_n->is_counted() &&
|
|
loop_n->_head->as_Loop()->is_valid_counted_loop() &&
|
|
Matcher::match_rule_supported(Op_MulAddVS2VI) &&
|
|
Matcher::match_rule_supported(Op_MulAddS2I)) {
|
|
Node* mul_in1 = in1->in(1);
|
|
Node* mul_in2 = in1->in(2);
|
|
Node* mul_in3 = in2->in(1);
|
|
Node* mul_in4 = in2->in(2);
|
|
if (mul_in1->Opcode() == Op_LoadS &&
|
|
mul_in2->Opcode() == Op_LoadS &&
|
|
mul_in3->Opcode() == Op_LoadS &&
|
|
mul_in4->Opcode() == Op_LoadS) {
|
|
IdealLoopTree* loop1 = get_loop(get_ctrl(mul_in1));
|
|
IdealLoopTree* loop2 = get_loop(get_ctrl(mul_in2));
|
|
IdealLoopTree* loop3 = get_loop(get_ctrl(mul_in3));
|
|
IdealLoopTree* loop4 = get_loop(get_ctrl(mul_in4));
|
|
IdealLoopTree* loop5 = get_loop(get_ctrl(in1));
|
|
IdealLoopTree* loop6 = get_loop(get_ctrl(in2));
|
|
// All nodes should be in the same counted loop.
|
|
if (loop_n == loop1 && loop_n == loop2 && loop_n == loop3 &&
|
|
loop_n == loop4 && loop_n == loop5 && loop_n == loop6) {
|
|
Node* adr1 = mul_in1->in(MemNode::Address);
|
|
Node* adr2 = mul_in2->in(MemNode::Address);
|
|
Node* adr3 = mul_in3->in(MemNode::Address);
|
|
Node* adr4 = mul_in4->in(MemNode::Address);
|
|
if (adr1->is_AddP() && adr2->is_AddP() && adr3->is_AddP() && adr4->is_AddP()) {
|
|
if ((adr1->in(AddPNode::Base) == adr3->in(AddPNode::Base)) &&
|
|
(adr2->in(AddPNode::Base) == adr4->in(AddPNode::Base))) {
|
|
nn = new MulAddS2INode(mul_in1, mul_in2, mul_in3, mul_in4);
|
|
register_new_node(nn, get_ctrl(n));
|
|
_igvn.replace_node(n, nn);
|
|
return nn;
|
|
} else if ((adr1->in(AddPNode::Base) == adr4->in(AddPNode::Base)) &&
|
|
(adr2->in(AddPNode::Base) == adr3->in(AddPNode::Base))) {
|
|
nn = new MulAddS2INode(mul_in1, mul_in2, mul_in4, mul_in3);
|
|
register_new_node(nn, get_ctrl(n));
|
|
_igvn.replace_node(n, nn);
|
|
return nn;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return nn;
|
|
}
|
|
|
|
//------------------------------conditional_move-------------------------------
|
|
// Attempt to replace a Phi with a conditional move. We have some pretty
|
|
// strict profitability requirements. All Phis at the merge point must
|
|
// be converted, so we can remove the control flow. We need to limit the
|
|
// number of c-moves to a small handful. All code that was in the side-arms
|
|
// of the CFG diamond is now speculatively executed. This code has to be
|
|
// "cheap enough". We are pretty much limited to CFG diamonds that merge
|
|
// 1 or 2 items with a total of 1 or 2 ops executed speculatively.
|
|
Node *PhaseIdealLoop::conditional_move( Node *region ) {
|
|
|
|
assert(region->is_Region(), "sanity check");
|
|
if (region->req() != 3) return NULL;
|
|
|
|
// Check for CFG diamond
|
|
Node *lp = region->in(1);
|
|
Node *rp = region->in(2);
|
|
if (!lp || !rp) return NULL;
|
|
Node *lp_c = lp->in(0);
|
|
if (lp_c == NULL || lp_c != rp->in(0) || !lp_c->is_If()) return NULL;
|
|
IfNode *iff = lp_c->as_If();
|
|
|
|
// Check for ops pinned in an arm of the diamond.
|
|
// Can't remove the control flow in this case
|
|
if (lp->outcnt() > 1) return NULL;
|
|
if (rp->outcnt() > 1) return NULL;
|
|
|
|
IdealLoopTree* r_loop = get_loop(region);
|
|
assert(r_loop == get_loop(iff), "sanity");
|
|
// Always convert to CMOVE if all results are used only outside this loop.
|
|
bool used_inside_loop = (r_loop == _ltree_root);
|
|
|
|
// Check profitability
|
|
int cost = 0;
|
|
int phis = 0;
|
|
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
|
|
Node *out = region->fast_out(i);
|
|
if (!out->is_Phi()) continue; // Ignore other control edges, etc
|
|
phis++;
|
|
PhiNode* phi = out->as_Phi();
|
|
BasicType bt = phi->type()->basic_type();
|
|
switch (bt) {
|
|
case T_DOUBLE:
|
|
case T_FLOAT:
|
|
if (C->use_cmove()) {
|
|
continue; //TODO: maybe we want to add some cost
|
|
}
|
|
cost += Matcher::float_cmove_cost(); // Could be very expensive
|
|
break;
|
|
case T_LONG: {
|
|
cost += Matcher::long_cmove_cost(); // May encodes as 2 CMOV's
|
|
}
|
|
case T_INT: // These all CMOV fine
|
|
case T_ADDRESS: { // (RawPtr)
|
|
cost++;
|
|
break;
|
|
}
|
|
case T_NARROWOOP: // Fall through
|
|
case T_OBJECT: { // Base oops are OK, but not derived oops
|
|
const TypeOopPtr *tp = phi->type()->make_ptr()->isa_oopptr();
|
|
// Derived pointers are Bad (tm): what's the Base (for GC purposes) of a
|
|
// CMOVE'd derived pointer? It's a CMOVE'd derived base. Thus
|
|
// CMOVE'ing a derived pointer requires we also CMOVE the base. If we
|
|
// have a Phi for the base here that we convert to a CMOVE all is well
|
|
// and good. But if the base is dead, we'll not make a CMOVE. Later
|
|
// the allocator will have to produce a base by creating a CMOVE of the
|
|
// relevant bases. This puts the allocator in the business of
|
|
// manufacturing expensive instructions, generally a bad plan.
|
|
// Just Say No to Conditionally-Moved Derived Pointers.
|
|
if (tp && tp->offset() != 0)
|
|
return NULL;
|
|
cost++;
|
|
break;
|
|
}
|
|
default:
|
|
return NULL; // In particular, can't do memory or I/O
|
|
}
|
|
// Add in cost any speculative ops
|
|
for (uint j = 1; j < region->req(); j++) {
|
|
Node *proj = region->in(j);
|
|
Node *inp = phi->in(j);
|
|
if (get_ctrl(inp) == proj) { // Found local op
|
|
cost++;
|
|
// Check for a chain of dependent ops; these will all become
|
|
// speculative in a CMOV.
|
|
for (uint k = 1; k < inp->req(); k++)
|
|
if (get_ctrl(inp->in(k)) == proj)
|
|
cost += ConditionalMoveLimit; // Too much speculative goo
|
|
}
|
|
}
|
|
// See if the Phi is used by a Cmp or Narrow oop Decode/Encode.
|
|
// This will likely Split-If, a higher-payoff operation.
|
|
for (DUIterator_Fast kmax, k = phi->fast_outs(kmax); k < kmax; k++) {
|
|
Node* use = phi->fast_out(k);
|
|
if (use->is_Cmp() || use->is_DecodeNarrowPtr() || use->is_EncodeNarrowPtr())
|
|
cost += ConditionalMoveLimit;
|
|
// Is there a use inside the loop?
|
|
// Note: check only basic types since CMoveP is pinned.
|
|
if (!used_inside_loop && is_java_primitive(bt)) {
|
|
IdealLoopTree* u_loop = get_loop(has_ctrl(use) ? get_ctrl(use) : use);
|
|
if (r_loop == u_loop || r_loop->is_member(u_loop)) {
|
|
used_inside_loop = true;
|
|
}
|
|
}
|
|
}
|
|
}//for
|
|
Node* bol = iff->in(1);
|
|
if (bol->Opcode() == Op_Opaque4) {
|
|
return NULL; // Ignore loop predicate checks (the Opaque4 ensures they will go away)
|
|
}
|
|
assert(bol->Opcode() == Op_Bool, "Unexpected node");
|
|
int cmp_op = bol->in(1)->Opcode();
|
|
if (cmp_op == Op_SubTypeCheck) { // SubTypeCheck expansion expects an IfNode
|
|
return NULL;
|
|
}
|
|
// It is expensive to generate flags from a float compare.
|
|
// Avoid duplicated float compare.
|
|
if (phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL;
|
|
|
|
float infrequent_prob = PROB_UNLIKELY_MAG(3);
|
|
// Ignore cost and blocks frequency if CMOVE can be moved outside the loop.
|
|
if (used_inside_loop) {
|
|
if (cost >= ConditionalMoveLimit) return NULL; // Too much goo
|
|
|
|
// BlockLayoutByFrequency optimization moves infrequent branch
|
|
// from hot path. No point in CMOV'ing in such case (110 is used
|
|
// instead of 100 to take into account not exactness of float value).
|
|
if (BlockLayoutByFrequency) {
|
|
infrequent_prob = MAX2(infrequent_prob, (float)BlockLayoutMinDiamondPercentage/110.0f);
|
|
}
|
|
}
|
|
// Check for highly predictable branch. No point in CMOV'ing if
|
|
// we are going to predict accurately all the time.
|
|
if (C->use_cmove() && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) {
|
|
//keep going
|
|
} else if (iff->_prob < infrequent_prob ||
|
|
iff->_prob > (1.0f - infrequent_prob))
|
|
return NULL;
|
|
|
|
// --------------
|
|
// Now replace all Phis with CMOV's
|
|
Node *cmov_ctrl = iff->in(0);
|
|
uint flip = (lp->Opcode() == Op_IfTrue);
|
|
Node_List wq;
|
|
while (1) {
|
|
PhiNode* phi = NULL;
|
|
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
|
|
Node *out = region->fast_out(i);
|
|
if (out->is_Phi()) {
|
|
phi = out->as_Phi();
|
|
break;
|
|
}
|
|
}
|
|
if (phi == NULL) break;
|
|
if (PrintOpto && VerifyLoopOptimizations) { tty->print_cr("CMOV"); }
|
|
// Move speculative ops
|
|
wq.push(phi);
|
|
while (wq.size() > 0) {
|
|
Node *n = wq.pop();
|
|
for (uint j = 1; j < n->req(); j++) {
|
|
Node* m = n->in(j);
|
|
if (m != NULL && !is_dominator(get_ctrl(m), cmov_ctrl)) {
|
|
#ifndef PRODUCT
|
|
if (PrintOpto && VerifyLoopOptimizations) {
|
|
tty->print(" speculate: ");
|
|
m->dump();
|
|
}
|
|
#endif
|
|
set_ctrl(m, cmov_ctrl);
|
|
wq.push(m);
|
|
}
|
|
}
|
|
}
|
|
Node *cmov = CMoveNode::make(cmov_ctrl, iff->in(1), phi->in(1+flip), phi->in(2-flip), _igvn.type(phi));
|
|
register_new_node( cmov, cmov_ctrl );
|
|
_igvn.replace_node( phi, cmov );
|
|
#ifndef PRODUCT
|
|
if (TraceLoopOpts) {
|
|
tty->print("CMOV ");
|
|
r_loop->dump_head();
|
|
if (Verbose) {
|
|
bol->in(1)->dump(1);
|
|
cmov->dump(1);
|
|
}
|
|
}
|
|
if (VerifyLoopOptimizations) verify();
|
|
#endif
|
|
}
|
|
|
|
// The useless CFG diamond will fold up later; see the optimization in
|
|
// RegionNode::Ideal.
|
|
_igvn._worklist.push(region);
|
|
|
|
return iff->in(1);
|
|
}
|
|
|
|
static void enqueue_cfg_uses(Node* m, Unique_Node_List& wq) {
|
|
for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
|
|
Node* u = m->fast_out(i);
|
|
if (u->is_CFG()) {
|
|
if (u->Opcode() == Op_NeverBranch) {
|
|
u = ((NeverBranchNode*)u)->proj_out(0);
|
|
enqueue_cfg_uses(u, wq);
|
|
} else {
|
|
wq.push(u);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Try moving a store out of a loop, right before the loop
|
|
Node* PhaseIdealLoop::try_move_store_before_loop(Node* n, Node *n_ctrl) {
|
|
// Store has to be first in the loop body
|
|
IdealLoopTree *n_loop = get_loop(n_ctrl);
|
|
if (n->is_Store() && n_loop != _ltree_root &&
|
|
n_loop->is_loop() && n_loop->_head->is_Loop() &&
|
|
n->in(0) != NULL) {
|
|
Node* address = n->in(MemNode::Address);
|
|
Node* value = n->in(MemNode::ValueIn);
|
|
Node* mem = n->in(MemNode::Memory);
|
|
IdealLoopTree* address_loop = get_loop(get_ctrl(address));
|
|
IdealLoopTree* value_loop = get_loop(get_ctrl(value));
|
|
|
|
// - address and value must be loop invariant
|
|
// - memory must be a memory Phi for the loop
|
|
// - Store must be the only store on this memory slice in the
|
|
// loop: if there's another store following this one then value
|
|
// written at iteration i by the second store could be overwritten
|
|
// at iteration i+n by the first store: it's not safe to move the
|
|
// first store out of the loop
|
|
// - nothing must observe the memory Phi: it guarantees no read
|
|
// before the store, we are also guaranteed the store post
|
|
// dominates the loop head (ignoring a possible early
|
|
// exit). Otherwise there would be extra Phi involved between the
|
|
// loop's Phi and the store.
|
|
// - there must be no early exit from the loop before the Store
|
|
// (such an exit most of the time would be an extra use of the
|
|
// memory Phi but sometimes is a bottom memory Phi that takes the
|
|
// store as input).
|
|
|
|
if (!n_loop->is_member(address_loop) &&
|
|
!n_loop->is_member(value_loop) &&
|
|
mem->is_Phi() && mem->in(0) == n_loop->_head &&
|
|
mem->outcnt() == 1 &&
|
|
mem->in(LoopNode::LoopBackControl) == n) {
|
|
|
|
assert(n_loop->_tail != NULL, "need a tail");
|
|
assert(is_dominator(n_ctrl, n_loop->_tail), "store control must not be in a branch in the loop");
|
|
|
|
// Verify that there's no early exit of the loop before the store.
|
|
bool ctrl_ok = false;
|
|
{
|
|
// Follow control from loop head until n, we exit the loop or
|
|
// we reach the tail
|
|
ResourceMark rm;
|
|
Unique_Node_List wq;
|
|
wq.push(n_loop->_head);
|
|
|
|
for (uint next = 0; next < wq.size(); ++next) {
|
|
Node *m = wq.at(next);
|
|
if (m == n->in(0)) {
|
|
ctrl_ok = true;
|
|
continue;
|
|
}
|
|
assert(!has_ctrl(m), "should be CFG");
|
|
if (!n_loop->is_member(get_loop(m)) || m == n_loop->_tail) {
|
|
ctrl_ok = false;
|
|
break;
|
|
}
|
|
enqueue_cfg_uses(m, wq);
|
|
if (wq.size() > 10) {
|
|
ctrl_ok = false;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (ctrl_ok) {
|
|
// move the Store
|
|
_igvn.replace_input_of(mem, LoopNode::LoopBackControl, mem);
|
|
_igvn.replace_input_of(n, 0, n_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl));
|
|
_igvn.replace_input_of(n, MemNode::Memory, mem->in(LoopNode::EntryControl));
|
|
// Disconnect the phi now. An empty phi can confuse other
|
|
// optimizations in this pass of loop opts.
|
|
_igvn.replace_node(mem, mem->in(LoopNode::EntryControl));
|
|
n_loop->_body.yank(mem);
|
|
|
|
set_ctrl_and_loop(n, n->in(0));
|
|
|
|
return n;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
// Try moving a store out of a loop, right after the loop
|
|
void PhaseIdealLoop::try_move_store_after_loop(Node* n) {
|
|
if (n->is_Store() && n->in(0) != NULL) {
|
|
Node *n_ctrl = get_ctrl(n);
|
|
IdealLoopTree *n_loop = get_loop(n_ctrl);
|
|
// Store must be in a loop
|
|
if (n_loop != _ltree_root && !n_loop->_irreducible) {
|
|
Node* address = n->in(MemNode::Address);
|
|
Node* value = n->in(MemNode::ValueIn);
|
|
IdealLoopTree* address_loop = get_loop(get_ctrl(address));
|
|
// address must be loop invariant
|
|
if (!n_loop->is_member(address_loop)) {
|
|
// Store must be last on this memory slice in the loop and
|
|
// nothing in the loop must observe it
|
|
Node* phi = NULL;
|
|
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
|
|
Node* u = n->fast_out(i);
|
|
if (has_ctrl(u)) { // control use?
|
|
IdealLoopTree *u_loop = get_loop(get_ctrl(u));
|
|
if (!n_loop->is_member(u_loop)) {
|
|
continue;
|
|
}
|
|
if (u->is_Phi() && u->in(0) == n_loop->_head) {
|
|
assert(_igvn.type(u) == Type::MEMORY, "bad phi");
|
|
// multiple phis on the same slice are possible
|
|
if (phi != NULL) {
|
|
return;
|
|
}
|
|
phi = u;
|
|
continue;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
if (phi != NULL) {
|
|
// Nothing in the loop before the store (next iteration)
|
|
// must observe the stored value
|
|
bool mem_ok = true;
|
|
{
|
|
ResourceMark rm;
|
|
Unique_Node_List wq;
|
|
wq.push(phi);
|
|
for (uint next = 0; next < wq.size() && mem_ok; ++next) {
|
|
Node *m = wq.at(next);
|
|
for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax && mem_ok; i++) {
|
|
Node* u = m->fast_out(i);
|
|
if (u->is_Store() || u->is_Phi()) {
|
|
if (u != n) {
|
|
wq.push(u);
|
|
mem_ok = (wq.size() <= 10);
|
|
}
|
|
} else {
|
|
mem_ok = false;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (mem_ok) {
|
|
// Move the store out of the loop if the LCA of all
|
|
// users (except for the phi) is outside the loop.
|
|
Node* hook = new Node(1);
|
|
hook->init_req(0, n_ctrl); // Add an input to prevent hook from being dead
|
|
_igvn.rehash_node_delayed(phi);
|
|
int count = phi->replace_edge(n, hook);
|
|
assert(count > 0, "inconsistent phi");
|
|
|
|
// Compute latest point this store can go
|
|
Node* lca = get_late_ctrl(n, get_ctrl(n));
|
|
if (lca->is_OuterStripMinedLoop()) {
|
|
lca = lca->in(LoopNode::EntryControl);
|
|
}
|
|
if (n_loop->is_member(get_loop(lca))) {
|
|
// LCA is in the loop - bail out
|
|
_igvn.replace_node(hook, n);
|
|
return;
|
|
}
|
|
#ifdef ASSERT
|
|
if (n_loop->_head->is_Loop() && n_loop->_head->as_Loop()->is_strip_mined()) {
|
|
assert(n_loop->_head->Opcode() == Op_CountedLoop, "outer loop is a strip mined");
|
|
n_loop->_head->as_Loop()->verify_strip_mined(1);
|
|
Node* outer = n_loop->_head->as_CountedLoop()->outer_loop();
|
|
IdealLoopTree* outer_loop = get_loop(outer);
|
|
assert(n_loop->_parent == outer_loop, "broken loop tree");
|
|
assert(get_loop(lca) == outer_loop, "safepoint in outer loop consume all memory state");
|
|
}
|
|
#endif
|
|
|
|
// Move store out of the loop
|
|
_igvn.replace_node(hook, n->in(MemNode::Memory));
|
|
_igvn.replace_input_of(n, 0, lca);
|
|
set_ctrl_and_loop(n, lca);
|
|
|
|
// Disconnect the phi now. An empty phi can confuse other
|
|
// optimizations in this pass of loop opts..
|
|
if (phi->in(LoopNode::LoopBackControl) == phi) {
|
|
_igvn.replace_node(phi, phi->in(LoopNode::EntryControl));
|
|
n_loop->_body.yank(phi);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//------------------------------split_if_with_blocks_pre-----------------------
|
|
// Do the real work in a non-recursive function. Data nodes want to be
|
|
// cloned in the pre-order so they can feed each other nicely.
|
|
Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
|
|
// Cloning these guys is unlikely to win
|
|
int n_op = n->Opcode();
|
|
if (n_op == Op_MergeMem) {
|
|
return n;
|
|
}
|
|
if (n->is_Proj()) {
|
|
return n;
|
|
}
|
|
// Do not clone-up CmpFXXX variations, as these are always
|
|
// followed by a CmpI
|
|
if (n->is_Cmp()) {
|
|
return n;
|
|
}
|
|
// Attempt to use a conditional move instead of a phi/branch
|
|
if (ConditionalMoveLimit > 0 && n_op == Op_Region) {
|
|
Node *cmov = conditional_move( n );
|
|
if (cmov) {
|
|
return cmov;
|
|
}
|
|
}
|
|
if (n->is_CFG() || n->is_LoadStore()) {
|
|
return n;
|
|
}
|
|
if (n->is_Opaque1() || // Opaque nodes cannot be mod'd
|
|
n_op == Op_Opaque2) {
|
|
if (!C->major_progress()) { // If chance of no more loop opts...
|
|
_igvn._worklist.push(n); // maybe we'll remove them
|
|
}
|
|
return n;
|
|
}
|
|
|
|
if (n->is_Con()) {
|
|
return n; // No cloning for Con nodes
|
|
}
|
|
|
|
Node *n_ctrl = get_ctrl(n);
|
|
if (!n_ctrl) {
|
|
return n; // Dead node
|
|
}
|
|
|
|
Node* res = try_move_store_before_loop(n, n_ctrl);
|
|
if (res != NULL) {
|
|
return n;
|
|
}
|
|
|
|
// Attempt to remix address expressions for loop invariants
|
|
Node *m = remix_address_expressions( n );
|
|
if( m ) return m;
|
|
|
|
if (n_op == Op_AddI) {
|
|
Node *nn = convert_add_to_muladd( n );
|
|
if ( nn ) return nn;
|
|
}
|
|
|
|
if (n->is_ConstraintCast()) {
|
|
Node* dom_cast = n->as_ConstraintCast()->dominating_cast(&_igvn, this);
|
|
// ConstraintCastNode::dominating_cast() uses node control input to determine domination.
|
|
// Node control inputs don't necessarily agree with loop control info (due to
|
|
// transformations happened in between), thus additional dominance check is needed
|
|
// to keep loop info valid.
|
|
if (dom_cast != NULL && is_dominator(get_ctrl(dom_cast), get_ctrl(n))) {
|
|
_igvn.replace_node(n, dom_cast);
|
|
return dom_cast;
|
|
}
|
|
}
|
|
|
|
// Determine if the Node has inputs from some local Phi.
|
|
// Returns the block to clone thru.
|
|
Node *n_blk = has_local_phi_input( n );
|
|
if( !n_blk ) return n;
|
|
|
|
// Do not clone the trip counter through on a CountedLoop
|
|
// (messes up the canonical shape).
|
|
if ((n_blk->is_CountedLoop() || (n_blk->is_Loop() && n_blk->as_Loop()->is_transformed_long_loop())) && n->Opcode() == Op_AddI) {
|
|
return n;
|
|
}
|
|
|
|
// Check for having no control input; not pinned. Allow
|
|
// dominating control.
|
|
if (n->in(0)) {
|
|
Node *dom = idom(n_blk);
|
|
if (dom_lca(n->in(0), dom) != n->in(0)) {
|
|
return n;
|
|
}
|
|
}
|
|
// Policy: when is it profitable. You must get more wins than
|
|
// policy before it is considered profitable. Policy is usually 0,
|
|
// so 1 win is considered profitable. Big merges will require big
|
|
// cloning, so get a larger policy.
|
|
int policy = n_blk->req() >> 2;
|
|
|
|
// If the loop is a candidate for range check elimination,
|
|
// delay splitting through it's phi until a later loop optimization
|
|
if (n_blk->is_CountedLoop()) {
|
|
IdealLoopTree *lp = get_loop(n_blk);
|
|
if (lp && lp->_rce_candidate) {
|
|
return n;
|
|
}
|
|
}
|
|
|
|
if (must_throttle_split_if()) return n;
|
|
|
|
// Split 'n' through the merge point if it is profitable
|
|
Node *phi = split_thru_phi( n, n_blk, policy );
|
|
if (!phi) return n;
|
|
|
|
// Found a Phi to split thru!
|
|
// Replace 'n' with the new phi
|
|
_igvn.replace_node( n, phi );
|
|
// Moved a load around the loop, 'en-registering' something.
|
|
if (n_blk->is_Loop() && n->is_Load() &&
|
|
!phi->in(LoopNode::LoopBackControl)->is_Load())
|
|
C->set_major_progress();
|
|
|
|
return phi;
|
|
}
|
|
|
|
static bool merge_point_too_heavy(Compile* C, Node* region) {
|
|
// Bail out if the region and its phis have too many users.
|
|
int weight = 0;
|
|
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
|
|
weight += region->fast_out(i)->outcnt();
|
|
}
|
|
int nodes_left = C->max_node_limit() - C->live_nodes();
|
|
if (weight * 8 > nodes_left) {
|
|
if (PrintOpto) {
|
|
tty->print_cr("*** Split-if bails out: %d nodes, region weight %d", C->unique(), weight);
|
|
}
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static bool merge_point_safe(Node* region) {
|
|
// 4799512: Stop split_if_with_blocks from splitting a block with a ConvI2LNode
|
|
// having a PhiNode input. This sidesteps the dangerous case where the split
|
|
// ConvI2LNode may become TOP if the input Value() does not
|
|
// overlap the ConvI2L range, leaving a node which may not dominate its
|
|
// uses.
|
|
// A better fix for this problem can be found in the BugTraq entry, but
|
|
// expediency for Mantis demands this hack.
|
|
#ifdef _LP64
|
|
for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
|
|
Node* n = region->fast_out(i);
|
|
if (n->is_Phi()) {
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* m = n->fast_out(j);
|
|
if (m->Opcode() == Op_ConvI2L)
|
|
return false;
|
|
if (m->is_CastII() && m->isa_CastII()->has_range_check()) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
|
|
//------------------------------place_near_use---------------------------------
|
|
// Place some computation next to use but not inside inner loops.
|
|
// For inner loop uses move it to the preheader area.
|
|
Node *PhaseIdealLoop::place_near_use(Node *useblock) const {
|
|
IdealLoopTree *u_loop = get_loop( useblock );
|
|
if (u_loop->_irreducible) {
|
|
return useblock;
|
|
}
|
|
if (u_loop->_child) {
|
|
if (useblock == u_loop->_head && u_loop->_head->is_OuterStripMinedLoop()) {
|
|
return u_loop->_head->in(LoopNode::EntryControl);
|
|
}
|
|
return useblock;
|
|
}
|
|
return u_loop->_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
}
|
|
|
|
|
|
bool PhaseIdealLoop::identical_backtoback_ifs(Node *n) {
|
|
if (!n->is_If() || n->is_CountedLoopEnd()) {
|
|
return false;
|
|
}
|
|
if (!n->in(0)->is_Region()) {
|
|
return false;
|
|
}
|
|
Node* region = n->in(0);
|
|
Node* dom = idom(region);
|
|
if (!dom->is_If() || dom->in(1) != n->in(1)) {
|
|
return false;
|
|
}
|
|
IfNode* dom_if = dom->as_If();
|
|
Node* proj_true = dom_if->proj_out(1);
|
|
Node* proj_false = dom_if->proj_out(0);
|
|
|
|
for (uint i = 1; i < region->req(); i++) {
|
|
if (is_dominator(proj_true, region->in(i))) {
|
|
continue;
|
|
}
|
|
if (is_dominator(proj_false, region->in(i))) {
|
|
continue;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
bool PhaseIdealLoop::can_split_if(Node* n_ctrl) {
|
|
if (must_throttle_split_if()) {
|
|
return false;
|
|
}
|
|
|
|
// Do not do 'split-if' if irreducible loops are present.
|
|
if (_has_irreducible_loops) {
|
|
return false;
|
|
}
|
|
|
|
if (merge_point_too_heavy(C, n_ctrl)) {
|
|
return false;
|
|
}
|
|
|
|
// Do not do 'split-if' if some paths are dead. First do dead code
|
|
// elimination and then see if its still profitable.
|
|
for (uint i = 1; i < n_ctrl->req(); i++) {
|
|
if (n_ctrl->in(i) == C->top()) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// If trying to do a 'Split-If' at the loop head, it is only
|
|
// profitable if the cmp folds up on BOTH paths. Otherwise we
|
|
// risk peeling a loop forever.
|
|
|
|
// CNC - Disabled for now. Requires careful handling of loop
|
|
// body selection for the cloned code. Also, make sure we check
|
|
// for any input path not being in the same loop as n_ctrl. For
|
|
// irreducible loops we cannot check for 'n_ctrl->is_Loop()'
|
|
// because the alternative loop entry points won't be converted
|
|
// into LoopNodes.
|
|
IdealLoopTree *n_loop = get_loop(n_ctrl);
|
|
for (uint j = 1; j < n_ctrl->req(); j++) {
|
|
if (get_loop(n_ctrl->in(j)) != n_loop) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Check for safety of the merge point.
|
|
if (!merge_point_safe(n_ctrl)) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Detect if the node is the inner strip-mined loop
|
|
// Return: NULL if it's not the case, or the exit of outer strip-mined loop
|
|
static Node* is_inner_of_stripmined_loop(const Node* out) {
|
|
Node* out_le = NULL;
|
|
|
|
if (out->is_CountedLoopEnd()) {
|
|
const CountedLoopNode* loop = out->as_CountedLoopEnd()->loopnode();
|
|
|
|
if (loop != NULL && loop->is_strip_mined()) {
|
|
out_le = loop->in(LoopNode::EntryControl)->as_OuterStripMinedLoop()->outer_loop_exit();
|
|
}
|
|
}
|
|
|
|
return out_le;
|
|
}
|
|
|
|
//------------------------------split_if_with_blocks_post----------------------
|
|
// Do the real work in a non-recursive function. CFG hackery wants to be
|
|
// in the post-order, so it can dirty the I-DOM info and not use the dirtied
|
|
// info.
|
|
void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
|
|
|
|
// Cloning Cmp through Phi's involves the split-if transform.
|
|
// FastLock is not used by an If
|
|
if (n->is_Cmp() && !n->is_FastLock()) {
|
|
Node *n_ctrl = get_ctrl(n);
|
|
// Determine if the Node has inputs from some local Phi.
|
|
// Returns the block to clone thru.
|
|
Node *n_blk = has_local_phi_input(n);
|
|
if (n_blk != n_ctrl) {
|
|
return;
|
|
}
|
|
|
|
if (!can_split_if(n_ctrl)) {
|
|
return;
|
|
}
|
|
|
|
if (n->outcnt() != 1) {
|
|
return; // Multiple bool's from 1 compare?
|
|
}
|
|
Node *bol = n->unique_out();
|
|
assert(bol->is_Bool(), "expect a bool here");
|
|
if (bol->outcnt() != 1) {
|
|
return;// Multiple branches from 1 compare?
|
|
}
|
|
Node *iff = bol->unique_out();
|
|
|
|
// Check some safety conditions
|
|
if (iff->is_If()) { // Classic split-if?
|
|
if (iff->in(0) != n_ctrl) {
|
|
return; // Compare must be in same blk as if
|
|
}
|
|
} else if (iff->is_CMove()) { // Trying to split-up a CMOVE
|
|
// Can't split CMove with different control edge.
|
|
if (iff->in(0) != NULL && iff->in(0) != n_ctrl ) {
|
|
return;
|
|
}
|
|
if (get_ctrl(iff->in(2)) == n_ctrl ||
|
|
get_ctrl(iff->in(3)) == n_ctrl) {
|
|
return; // Inputs not yet split-up
|
|
}
|
|
if (get_loop(n_ctrl) != get_loop(get_ctrl(iff))) {
|
|
return; // Loop-invar test gates loop-varying CMOVE
|
|
}
|
|
} else {
|
|
return; // some other kind of node, such as an Allocate
|
|
}
|
|
|
|
// When is split-if profitable? Every 'win' on means some control flow
|
|
// goes dead, so it's almost always a win.
|
|
int policy = 0;
|
|
// Split compare 'n' through the merge point if it is profitable
|
|
Node *phi = split_thru_phi( n, n_ctrl, policy);
|
|
if (!phi) {
|
|
return;
|
|
}
|
|
|
|
// Found a Phi to split thru!
|
|
// Replace 'n' with the new phi
|
|
_igvn.replace_node(n, phi);
|
|
|
|
// Now split the bool up thru the phi
|
|
Node *bolphi = split_thru_phi(bol, n_ctrl, -1);
|
|
guarantee(bolphi != NULL, "null boolean phi node");
|
|
|
|
_igvn.replace_node(bol, bolphi);
|
|
assert(iff->in(1) == bolphi, "");
|
|
|
|
if (bolphi->Value(&_igvn)->singleton()) {
|
|
return;
|
|
}
|
|
|
|
// Conditional-move? Must split up now
|
|
if (!iff->is_If()) {
|
|
Node *cmovphi = split_thru_phi(iff, n_ctrl, -1);
|
|
_igvn.replace_node(iff, cmovphi);
|
|
return;
|
|
}
|
|
|
|
// Now split the IF
|
|
do_split_if(iff);
|
|
return;
|
|
}
|
|
|
|
// Two identical ifs back to back can be merged
|
|
if (identical_backtoback_ifs(n) && can_split_if(n->in(0))) {
|
|
Node *n_ctrl = n->in(0);
|
|
PhiNode* bolphi = PhiNode::make_blank(n_ctrl, n->in(1));
|
|
IfNode* dom_if = idom(n_ctrl)->as_If();
|
|
Node* proj_true = dom_if->proj_out(1);
|
|
Node* proj_false = dom_if->proj_out(0);
|
|
Node* con_true = _igvn.makecon(TypeInt::ONE);
|
|
Node* con_false = _igvn.makecon(TypeInt::ZERO);
|
|
|
|
for (uint i = 1; i < n_ctrl->req(); i++) {
|
|
if (is_dominator(proj_true, n_ctrl->in(i))) {
|
|
bolphi->init_req(i, con_true);
|
|
} else {
|
|
assert(is_dominator(proj_false, n_ctrl->in(i)), "bad if");
|
|
bolphi->init_req(i, con_false);
|
|
}
|
|
}
|
|
register_new_node(bolphi, n_ctrl);
|
|
_igvn.replace_input_of(n, 1, bolphi);
|
|
|
|
// Now split the IF
|
|
do_split_if(n);
|
|
return;
|
|
}
|
|
|
|
// Check for an IF ready to split; one that has its
|
|
// condition codes input coming from a Phi at the block start.
|
|
int n_op = n->Opcode();
|
|
|
|
// Check for an IF being dominated by another IF same test
|
|
if (n_op == Op_If ||
|
|
n_op == Op_RangeCheck) {
|
|
Node *bol = n->in(1);
|
|
uint max = bol->outcnt();
|
|
// Check for same test used more than once?
|
|
if (max > 1 && bol->is_Bool()) {
|
|
// Search up IDOMs to see if this IF is dominated.
|
|
Node *cutoff = get_ctrl(bol);
|
|
|
|
// Now search up IDOMs till cutoff, looking for a dominating test
|
|
Node *prevdom = n;
|
|
Node *dom = idom(prevdom);
|
|
while (dom != cutoff) {
|
|
if (dom->req() > 1 && dom->in(1) == bol && prevdom->in(0) == dom) {
|
|
// It's invalid to move control dependent data nodes in the inner
|
|
// strip-mined loop, because:
|
|
// 1) break validation of LoopNode::verify_strip_mined()
|
|
// 2) move code with side-effect in strip-mined loop
|
|
// Move to the exit of outer strip-mined loop in that case.
|
|
Node* out_le = is_inner_of_stripmined_loop(dom);
|
|
if (out_le != NULL) {
|
|
prevdom = out_le;
|
|
}
|
|
// Replace the dominated test with an obvious true or false.
|
|
// Place it on the IGVN worklist for later cleanup.
|
|
C->set_major_progress();
|
|
dominated_by(prevdom, n, false, true);
|
|
#ifndef PRODUCT
|
|
if( VerifyLoopOptimizations ) verify();
|
|
#endif
|
|
return;
|
|
}
|
|
prevdom = dom;
|
|
dom = idom(prevdom);
|
|
}
|
|
}
|
|
}
|
|
|
|
// See if a shared loop-varying computation has no loop-varying uses.
|
|
// Happens if something is only used for JVM state in uncommon trap exits,
|
|
// like various versions of induction variable+offset. Clone the
|
|
// computation per usage to allow it to sink out of the loop.
|
|
if (has_ctrl(n) && !n->in(0)) {// n not dead and has no control edge (can float about)
|
|
Node *n_ctrl = get_ctrl(n);
|
|
IdealLoopTree *n_loop = get_loop(n_ctrl);
|
|
if( n_loop != _ltree_root ) {
|
|
DUIterator_Fast imax, i = n->fast_outs(imax);
|
|
for (; i < imax; i++) {
|
|
Node* u = n->fast_out(i);
|
|
if( !has_ctrl(u) ) break; // Found control user
|
|
IdealLoopTree *u_loop = get_loop(get_ctrl(u));
|
|
if( u_loop == n_loop ) break; // Found loop-varying use
|
|
if( n_loop->is_member( u_loop ) ) break; // Found use in inner loop
|
|
if( u->Opcode() == Op_Opaque1 ) break; // Found loop limit, bugfix for 4677003
|
|
}
|
|
bool did_break = (i < imax); // Did we break out of the previous loop?
|
|
if (!did_break && n->outcnt() > 1) { // All uses in outer loops!
|
|
Node *late_load_ctrl = NULL;
|
|
if (n->is_Load()) {
|
|
// If n is a load, get and save the result from get_late_ctrl(),
|
|
// to be later used in calculating the control for n's clones.
|
|
clear_dom_lca_tags();
|
|
late_load_ctrl = get_late_ctrl(n, n_ctrl);
|
|
}
|
|
// If n is a load, and the late control is the same as the current
|
|
// control, then the cloning of n is a pointless exercise, because
|
|
// GVN will ensure that we end up where we started.
|
|
if (!n->is_Load() || late_load_ctrl != n_ctrl) {
|
|
for (DUIterator_Last jmin, j = n->last_outs(jmin); j >= jmin; ) {
|
|
Node *u = n->last_out(j); // Clone private computation per use
|
|
_igvn.rehash_node_delayed(u);
|
|
Node *x = n->clone(); // Clone computation
|
|
Node *x_ctrl = NULL;
|
|
if( u->is_Phi() ) {
|
|
// Replace all uses of normal nodes. Replace Phi uses
|
|
// individually, so the separate Nodes can sink down
|
|
// different paths.
|
|
uint k = 1;
|
|
while( u->in(k) != n ) k++;
|
|
u->set_req( k, x );
|
|
// x goes next to Phi input path
|
|
x_ctrl = u->in(0)->in(k);
|
|
--j;
|
|
} else { // Normal use
|
|
// Replace all uses
|
|
for( uint k = 0; k < u->req(); k++ ) {
|
|
if( u->in(k) == n ) {
|
|
u->set_req( k, x );
|
|
--j;
|
|
}
|
|
}
|
|
x_ctrl = get_ctrl(u);
|
|
}
|
|
|
|
// Find control for 'x' next to use but not inside inner loops.
|
|
// For inner loop uses get the preheader area.
|
|
x_ctrl = place_near_use(x_ctrl);
|
|
|
|
if (n->is_Load()) {
|
|
// For loads, add a control edge to a CFG node outside of the loop
|
|
// to force them to not combine and return back inside the loop
|
|
// during GVN optimization (4641526).
|
|
//
|
|
// Because we are setting the actual control input, factor in
|
|
// the result from get_late_ctrl() so we respect any
|
|
// anti-dependences. (6233005).
|
|
x_ctrl = dom_lca(late_load_ctrl, x_ctrl);
|
|
|
|
// Don't allow the control input to be a CFG splitting node.
|
|
// Such nodes should only have ProjNodes as outs, e.g. IfNode
|
|
// should only have IfTrueNode and IfFalseNode (4985384).
|
|
x_ctrl = find_non_split_ctrl(x_ctrl);
|
|
|
|
IdealLoopTree* x_loop = get_loop(x_ctrl);
|
|
Node* x_head = x_loop->_head;
|
|
if (x_head->is_Loop() && (x_head->is_OuterStripMinedLoop() || x_head->as_Loop()->is_strip_mined()) && is_dominator(n_ctrl, x_head)) {
|
|
// Anti dependence analysis is sometimes too
|
|
// conservative: a store in the outer strip mined loop
|
|
// can prevent a load from floating out of the outer
|
|
// strip mined loop but the load may not be referenced
|
|
// from the safepoint: loop strip mining verification
|
|
// code reports a problem in that case. Make sure the
|
|
// load is not moved in the outer strip mined loop in
|
|
// that case.
|
|
x_ctrl = x_head->as_Loop()->skip_strip_mined()->in(LoopNode::EntryControl);
|
|
}
|
|
assert(dom_depth(n_ctrl) <= dom_depth(x_ctrl), "n is later than its clone");
|
|
|
|
x->set_req(0, x_ctrl);
|
|
}
|
|
register_new_node(x, x_ctrl);
|
|
|
|
// Some institutional knowledge is needed here: 'x' is
|
|
// yanked because if the optimizer runs GVN on it all the
|
|
// cloned x's will common up and undo this optimization and
|
|
// be forced back in the loop.
|
|
// I tried setting control edges on the x's to force them to
|
|
// not combine, but the matching gets worried when it tries
|
|
// to fold a StoreP and an AddP together (as part of an
|
|
// address expression) and the AddP and StoreP have
|
|
// different controls.
|
|
BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
|
|
if (!x->is_Load() && !x->is_DecodeNarrowPtr() && !x->is_AddP() && !bs->is_gc_barrier_node(x)) {
|
|
_igvn._worklist.yank(x);
|
|
}
|
|
}
|
|
_igvn.remove_dead_node(n);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
try_move_store_after_loop(n);
|
|
|
|
// Check for Opaque2's who's loop has disappeared - who's input is in the
|
|
// same loop nest as their output. Remove 'em, they are no longer useful.
|
|
if( n_op == Op_Opaque2 &&
|
|
n->in(1) != NULL &&
|
|
get_loop(get_ctrl(n)) == get_loop(get_ctrl(n->in(1))) ) {
|
|
_igvn.replace_node( n, n->in(1) );
|
|
}
|
|
}
|
|
|
|
//------------------------------split_if_with_blocks---------------------------
|
|
// Check for aggressive application of 'split-if' optimization,
|
|
// using basic block level info.
|
|
void PhaseIdealLoop::split_if_with_blocks(VectorSet &visited, Node_Stack &nstack) {
|
|
Node* root = C->root();
|
|
visited.set(root->_idx); // first, mark root as visited
|
|
// Do pre-visit work for root
|
|
Node* n = split_if_with_blocks_pre(root);
|
|
uint cnt = n->outcnt();
|
|
uint i = 0;
|
|
|
|
while (true) {
|
|
// Visit all children
|
|
if (i < cnt) {
|
|
Node* use = n->raw_out(i);
|
|
++i;
|
|
if (use->outcnt() != 0 && !visited.test_set(use->_idx)) {
|
|
// Now do pre-visit work for this use
|
|
use = split_if_with_blocks_pre(use);
|
|
nstack.push(n, i); // Save parent and next use's index.
|
|
n = use; // Process all children of current use.
|
|
cnt = use->outcnt();
|
|
i = 0;
|
|
}
|
|
}
|
|
else {
|
|
// All of n's children have been processed, complete post-processing.
|
|
if (cnt != 0 && !n->is_Con()) {
|
|
assert(has_node(n), "no dead nodes");
|
|
split_if_with_blocks_post(n);
|
|
}
|
|
if (must_throttle_split_if()) {
|
|
nstack.clear();
|
|
}
|
|
if (nstack.is_empty()) {
|
|
// Finished all nodes on stack.
|
|
break;
|
|
}
|
|
// Get saved parent node and next use's index. Visit the rest of uses.
|
|
n = nstack.node();
|
|
cnt = n->outcnt();
|
|
i = nstack.index();
|
|
nstack.pop();
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//=============================================================================
|
|
//
|
|
// C L O N E A L O O P B O D Y
|
|
//
|
|
|
|
//------------------------------clone_iff--------------------------------------
|
|
// Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
|
|
// "Nearly" because all Nodes have been cloned from the original in the loop,
|
|
// but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
|
|
// through the Phi recursively, and return a Bool.
|
|
Node* PhaseIdealLoop::clone_iff(PhiNode *phi, IdealLoopTree *loop) {
|
|
|
|
// Convert this Phi into a Phi merging Bools
|
|
uint i;
|
|
for (i = 1; i < phi->req(); i++) {
|
|
Node *b = phi->in(i);
|
|
if (b->is_Phi()) {
|
|
_igvn.replace_input_of(phi, i, clone_iff(b->as_Phi(), loop));
|
|
} else {
|
|
assert(b->is_Bool() || b->Opcode() == Op_Opaque4, "");
|
|
}
|
|
}
|
|
|
|
Node* n = phi->in(1);
|
|
Node* sample_opaque = NULL;
|
|
Node *sample_bool = NULL;
|
|
if (n->Opcode() == Op_Opaque4) {
|
|
sample_opaque = n;
|
|
sample_bool = n->in(1);
|
|
assert(sample_bool->is_Bool(), "wrong type");
|
|
} else {
|
|
sample_bool = n;
|
|
}
|
|
Node *sample_cmp = sample_bool->in(1);
|
|
|
|
// Make Phis to merge the Cmp's inputs.
|
|
PhiNode *phi1 = new PhiNode(phi->in(0), Type::TOP);
|
|
PhiNode *phi2 = new PhiNode(phi->in(0), Type::TOP);
|
|
for (i = 1; i < phi->req(); i++) {
|
|
Node *n1 = sample_opaque == NULL ? phi->in(i)->in(1)->in(1) : phi->in(i)->in(1)->in(1)->in(1);
|
|
Node *n2 = sample_opaque == NULL ? phi->in(i)->in(1)->in(2) : phi->in(i)->in(1)->in(1)->in(2);
|
|
phi1->set_req(i, n1);
|
|
phi2->set_req(i, n2);
|
|
phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
|
|
phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
|
|
}
|
|
// See if these Phis have been made before.
|
|
// Register with optimizer
|
|
Node *hit1 = _igvn.hash_find_insert(phi1);
|
|
if (hit1) { // Hit, toss just made Phi
|
|
_igvn.remove_dead_node(phi1); // Remove new phi
|
|
assert(hit1->is_Phi(), "" );
|
|
phi1 = (PhiNode*)hit1; // Use existing phi
|
|
} else { // Miss
|
|
_igvn.register_new_node_with_optimizer(phi1);
|
|
}
|
|
Node *hit2 = _igvn.hash_find_insert(phi2);
|
|
if (hit2) { // Hit, toss just made Phi
|
|
_igvn.remove_dead_node(phi2); // Remove new phi
|
|
assert(hit2->is_Phi(), "" );
|
|
phi2 = (PhiNode*)hit2; // Use existing phi
|
|
} else { // Miss
|
|
_igvn.register_new_node_with_optimizer(phi2);
|
|
}
|
|
// Register Phis with loop/block info
|
|
set_ctrl(phi1, phi->in(0));
|
|
set_ctrl(phi2, phi->in(0));
|
|
// Make a new Cmp
|
|
Node *cmp = sample_cmp->clone();
|
|
cmp->set_req(1, phi1);
|
|
cmp->set_req(2, phi2);
|
|
_igvn.register_new_node_with_optimizer(cmp);
|
|
set_ctrl(cmp, phi->in(0));
|
|
|
|
// Make a new Bool
|
|
Node *b = sample_bool->clone();
|
|
b->set_req(1,cmp);
|
|
_igvn.register_new_node_with_optimizer(b);
|
|
set_ctrl(b, phi->in(0));
|
|
|
|
if (sample_opaque != NULL) {
|
|
Node* opaque = sample_opaque->clone();
|
|
opaque->set_req(1, b);
|
|
_igvn.register_new_node_with_optimizer(opaque);
|
|
set_ctrl(opaque, phi->in(0));
|
|
return opaque;
|
|
}
|
|
|
|
assert(b->is_Bool(), "");
|
|
return b;
|
|
}
|
|
|
|
//------------------------------clone_bool-------------------------------------
|
|
// Passed in a Phi merging (recursively) some nearly equivalent Bool/Cmps.
|
|
// "Nearly" because all Nodes have been cloned from the original in the loop,
|
|
// but the fall-in edges to the Cmp are different. Clone bool/Cmp pairs
|
|
// through the Phi recursively, and return a Bool.
|
|
CmpNode *PhaseIdealLoop::clone_bool( PhiNode *phi, IdealLoopTree *loop ) {
|
|
uint i;
|
|
// Convert this Phi into a Phi merging Bools
|
|
for( i = 1; i < phi->req(); i++ ) {
|
|
Node *b = phi->in(i);
|
|
if( b->is_Phi() ) {
|
|
_igvn.replace_input_of(phi, i, clone_bool( b->as_Phi(), loop ));
|
|
} else {
|
|
assert( b->is_Cmp() || b->is_top(), "inputs are all Cmp or TOP" );
|
|
}
|
|
}
|
|
|
|
Node *sample_cmp = phi->in(1);
|
|
|
|
// Make Phis to merge the Cmp's inputs.
|
|
PhiNode *phi1 = new PhiNode( phi->in(0), Type::TOP );
|
|
PhiNode *phi2 = new PhiNode( phi->in(0), Type::TOP );
|
|
for( uint j = 1; j < phi->req(); j++ ) {
|
|
Node *cmp_top = phi->in(j); // Inputs are all Cmp or TOP
|
|
Node *n1, *n2;
|
|
if( cmp_top->is_Cmp() ) {
|
|
n1 = cmp_top->in(1);
|
|
n2 = cmp_top->in(2);
|
|
} else {
|
|
n1 = n2 = cmp_top;
|
|
}
|
|
phi1->set_req( j, n1 );
|
|
phi2->set_req( j, n2 );
|
|
phi1->set_type(phi1->type()->meet_speculative(n1->bottom_type()));
|
|
phi2->set_type(phi2->type()->meet_speculative(n2->bottom_type()));
|
|
}
|
|
|
|
// See if these Phis have been made before.
|
|
// Register with optimizer
|
|
Node *hit1 = _igvn.hash_find_insert(phi1);
|
|
if( hit1 ) { // Hit, toss just made Phi
|
|
_igvn.remove_dead_node(phi1); // Remove new phi
|
|
assert( hit1->is_Phi(), "" );
|
|
phi1 = (PhiNode*)hit1; // Use existing phi
|
|
} else { // Miss
|
|
_igvn.register_new_node_with_optimizer(phi1);
|
|
}
|
|
Node *hit2 = _igvn.hash_find_insert(phi2);
|
|
if( hit2 ) { // Hit, toss just made Phi
|
|
_igvn.remove_dead_node(phi2); // Remove new phi
|
|
assert( hit2->is_Phi(), "" );
|
|
phi2 = (PhiNode*)hit2; // Use existing phi
|
|
} else { // Miss
|
|
_igvn.register_new_node_with_optimizer(phi2);
|
|
}
|
|
// Register Phis with loop/block info
|
|
set_ctrl(phi1, phi->in(0));
|
|
set_ctrl(phi2, phi->in(0));
|
|
// Make a new Cmp
|
|
Node *cmp = sample_cmp->clone();
|
|
cmp->set_req( 1, phi1 );
|
|
cmp->set_req( 2, phi2 );
|
|
_igvn.register_new_node_with_optimizer(cmp);
|
|
set_ctrl(cmp, phi->in(0));
|
|
|
|
assert( cmp->is_Cmp(), "" );
|
|
return (CmpNode*)cmp;
|
|
}
|
|
|
|
//------------------------------sink_use---------------------------------------
|
|
// If 'use' was in the loop-exit block, it now needs to be sunk
|
|
// below the post-loop merge point.
|
|
void PhaseIdealLoop::sink_use( Node *use, Node *post_loop ) {
|
|
if (!use->is_CFG() && get_ctrl(use) == post_loop->in(2)) {
|
|
set_ctrl(use, post_loop);
|
|
for (DUIterator j = use->outs(); use->has_out(j); j++)
|
|
sink_use(use->out(j), post_loop);
|
|
}
|
|
}
|
|
|
|
void PhaseIdealLoop::clone_loop_handle_data_uses(Node* old, Node_List &old_new,
|
|
IdealLoopTree* loop, IdealLoopTree* outer_loop,
|
|
Node_List*& split_if_set, Node_List*& split_bool_set,
|
|
Node_List*& split_cex_set, Node_List& worklist,
|
|
uint new_counter, CloneLoopMode mode) {
|
|
Node* nnn = old_new[old->_idx];
|
|
// Copy uses to a worklist, so I can munge the def-use info
|
|
// with impunity.
|
|
for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++)
|
|
worklist.push(old->fast_out(j));
|
|
|
|
while( worklist.size() ) {
|
|
Node *use = worklist.pop();
|
|
if (!has_node(use)) continue; // Ignore dead nodes
|
|
if (use->in(0) == C->top()) continue;
|
|
IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use );
|
|
// Check for data-use outside of loop - at least one of OLD or USE
|
|
// must not be a CFG node.
|
|
#ifdef ASSERT
|
|
if (loop->_head->as_Loop()->is_strip_mined() && outer_loop->is_member(use_loop) && !loop->is_member(use_loop) && old_new[use->_idx] == NULL) {
|
|
Node* sfpt = loop->_head->as_CountedLoop()->outer_safepoint();
|
|
assert(mode != IgnoreStripMined, "incorrect cloning mode");
|
|
assert((mode == ControlAroundStripMined && use == sfpt) || !use->is_reachable_from_root(), "missed a node");
|
|
}
|
|
#endif
|
|
if (!loop->is_member(use_loop) && !outer_loop->is_member(use_loop) && (!old->is_CFG() || !use->is_CFG())) {
|
|
|
|
// If the Data use is an IF, that means we have an IF outside of the
|
|
// loop that is switching on a condition that is set inside of the
|
|
// loop. Happens if people set a loop-exit flag; then test the flag
|
|
// in the loop to break the loop, then test is again outside of the
|
|
// loop to determine which way the loop exited.
|
|
// Loop predicate If node connects to Bool node through Opaque1 node.
|
|
if (use->is_If() || use->is_CMove() || C->is_predicate_opaq(use) || use->Opcode() == Op_Opaque4) {
|
|
// Since this code is highly unlikely, we lazily build the worklist
|
|
// of such Nodes to go split.
|
|
if (!split_if_set) {
|
|
split_if_set = new Node_List();
|
|
}
|
|
split_if_set->push(use);
|
|
}
|
|
if (use->is_Bool()) {
|
|
if (!split_bool_set) {
|
|
split_bool_set = new Node_List();
|
|
}
|
|
split_bool_set->push(use);
|
|
}
|
|
if (use->Opcode() == Op_CreateEx) {
|
|
if (!split_cex_set) {
|
|
split_cex_set = new Node_List();
|
|
}
|
|
split_cex_set->push(use);
|
|
}
|
|
|
|
|
|
// Get "block" use is in
|
|
uint idx = 0;
|
|
while( use->in(idx) != old ) idx++;
|
|
Node *prev = use->is_CFG() ? use : get_ctrl(use);
|
|
assert(!loop->is_member(get_loop(prev)) && !outer_loop->is_member(get_loop(prev)), "" );
|
|
Node *cfg = prev->_idx >= new_counter
|
|
? prev->in(2)
|
|
: idom(prev);
|
|
if( use->is_Phi() ) // Phi use is in prior block
|
|
cfg = prev->in(idx); // NOT in block of Phi itself
|
|
if (cfg->is_top()) { // Use is dead?
|
|
_igvn.replace_input_of(use, idx, C->top());
|
|
continue;
|
|
}
|
|
|
|
// If use is referenced through control edge... (idx == 0)
|
|
if (mode == IgnoreStripMined && idx == 0) {
|
|
LoopNode *head = loop->_head->as_Loop();
|
|
if (head->is_strip_mined() && is_dominator(head->outer_loop_exit(), prev)) {
|
|
// That node is outside the inner loop, leave it outside the
|
|
// outer loop as well to not confuse verification code.
|
|
assert(!loop->_parent->is_member(use_loop), "should be out of the outer loop");
|
|
_igvn.replace_input_of(use, 0, head->outer_loop_exit());
|
|
continue;
|
|
}
|
|
}
|
|
|
|
while(!outer_loop->is_member(get_loop(cfg))) {
|
|
prev = cfg;
|
|
cfg = cfg->_idx >= new_counter ? cfg->in(2) : idom(cfg);
|
|
}
|
|
// If the use occurs after merging several exits from the loop, then
|
|
// old value must have dominated all those exits. Since the same old
|
|
// value was used on all those exits we did not need a Phi at this
|
|
// merge point. NOW we do need a Phi here. Each loop exit value
|
|
// is now merged with the peeled body exit; each exit gets its own
|
|
// private Phi and those Phis need to be merged here.
|
|
Node *phi;
|
|
if( prev->is_Region() ) {
|
|
if( idx == 0 ) { // Updating control edge?
|
|
phi = prev; // Just use existing control
|
|
} else { // Else need a new Phi
|
|
phi = PhiNode::make( prev, old );
|
|
// Now recursively fix up the new uses of old!
|
|
for( uint i = 1; i < prev->req(); i++ ) {
|
|
worklist.push(phi); // Onto worklist once for each 'old' input
|
|
}
|
|
}
|
|
} else {
|
|
// Get new RegionNode merging old and new loop exits
|
|
prev = old_new[prev->_idx];
|
|
assert( prev, "just made this in step 7" );
|
|
if( idx == 0) { // Updating control edge?
|
|
phi = prev; // Just use existing control
|
|
} else { // Else need a new Phi
|
|
// Make a new Phi merging data values properly
|
|
phi = PhiNode::make( prev, old );
|
|
phi->set_req( 1, nnn );
|
|
}
|
|
}
|
|
// If inserting a new Phi, check for prior hits
|
|
if( idx != 0 ) {
|
|
Node *hit = _igvn.hash_find_insert(phi);
|
|
if( hit == NULL ) {
|
|
_igvn.register_new_node_with_optimizer(phi); // Register new phi
|
|
} else { // or
|
|
// Remove the new phi from the graph and use the hit
|
|
_igvn.remove_dead_node(phi);
|
|
phi = hit; // Use existing phi
|
|
}
|
|
set_ctrl(phi, prev);
|
|
}
|
|
// Make 'use' use the Phi instead of the old loop body exit value
|
|
_igvn.replace_input_of(use, idx, phi);
|
|
if( use->_idx >= new_counter ) { // If updating new phis
|
|
// Not needed for correctness, but prevents a weak assert
|
|
// in AddPNode from tripping (when we end up with different
|
|
// base & derived Phis that will become the same after
|
|
// IGVN does CSE).
|
|
Node *hit = _igvn.hash_find_insert(use);
|
|
if( hit ) // Go ahead and re-hash for hits.
|
|
_igvn.replace_node( use, hit );
|
|
}
|
|
|
|
// If 'use' was in the loop-exit block, it now needs to be sunk
|
|
// below the post-loop merge point.
|
|
sink_use( use, prev );
|
|
}
|
|
}
|
|
}
|
|
|
|
static void clone_outer_loop_helper(Node* n, const IdealLoopTree *loop, const IdealLoopTree* outer_loop,
|
|
const Node_List &old_new, Unique_Node_List& wq, PhaseIdealLoop* phase,
|
|
bool check_old_new) {
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* u = n->fast_out(j);
|
|
assert(check_old_new || old_new[u->_idx] == NULL, "shouldn't have been cloned");
|
|
if (!u->is_CFG() && (!check_old_new || old_new[u->_idx] == NULL)) {
|
|
Node* c = phase->get_ctrl(u);
|
|
IdealLoopTree* u_loop = phase->get_loop(c);
|
|
assert(!loop->is_member(u_loop), "can be in outer loop or out of both loops only");
|
|
if (outer_loop->is_member(u_loop)) {
|
|
wq.push(u);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void PhaseIdealLoop::clone_outer_loop(LoopNode* head, CloneLoopMode mode, IdealLoopTree *loop,
|
|
IdealLoopTree* outer_loop, int dd, Node_List &old_new,
|
|
Node_List& extra_data_nodes) {
|
|
if (head->is_strip_mined() && mode != IgnoreStripMined) {
|
|
CountedLoopNode* cl = head->as_CountedLoop();
|
|
Node* l = cl->outer_loop();
|
|
Node* tail = cl->outer_loop_tail();
|
|
IfNode* le = cl->outer_loop_end();
|
|
Node* sfpt = cl->outer_safepoint();
|
|
CountedLoopEndNode* cle = cl->loopexit();
|
|
CountedLoopNode* new_cl = old_new[cl->_idx]->as_CountedLoop();
|
|
CountedLoopEndNode* new_cle = new_cl->as_CountedLoop()->loopexit_or_null();
|
|
Node* cle_out = cle->proj_out(false);
|
|
|
|
Node* new_sfpt = NULL;
|
|
Node* new_cle_out = cle_out->clone();
|
|
old_new.map(cle_out->_idx, new_cle_out);
|
|
if (mode == CloneIncludesStripMined) {
|
|
// clone outer loop body
|
|
Node* new_l = l->clone();
|
|
Node* new_tail = tail->clone();
|
|
IfNode* new_le = le->clone()->as_If();
|
|
new_sfpt = sfpt->clone();
|
|
|
|
set_loop(new_l, outer_loop->_parent);
|
|
set_idom(new_l, new_l->in(LoopNode::EntryControl), dd);
|
|
set_loop(new_cle_out, outer_loop->_parent);
|
|
set_idom(new_cle_out, new_cle, dd);
|
|
set_loop(new_sfpt, outer_loop->_parent);
|
|
set_idom(new_sfpt, new_cle_out, dd);
|
|
set_loop(new_le, outer_loop->_parent);
|
|
set_idom(new_le, new_sfpt, dd);
|
|
set_loop(new_tail, outer_loop->_parent);
|
|
set_idom(new_tail, new_le, dd);
|
|
set_idom(new_cl, new_l, dd);
|
|
|
|
old_new.map(l->_idx, new_l);
|
|
old_new.map(tail->_idx, new_tail);
|
|
old_new.map(le->_idx, new_le);
|
|
old_new.map(sfpt->_idx, new_sfpt);
|
|
|
|
new_l->set_req(LoopNode::LoopBackControl, new_tail);
|
|
new_l->set_req(0, new_l);
|
|
new_tail->set_req(0, new_le);
|
|
new_le->set_req(0, new_sfpt);
|
|
new_sfpt->set_req(0, new_cle_out);
|
|
new_cle_out->set_req(0, new_cle);
|
|
new_cl->set_req(LoopNode::EntryControl, new_l);
|
|
|
|
_igvn.register_new_node_with_optimizer(new_l);
|
|
_igvn.register_new_node_with_optimizer(new_tail);
|
|
_igvn.register_new_node_with_optimizer(new_le);
|
|
} else {
|
|
Node *newhead = old_new[loop->_head->_idx];
|
|
newhead->as_Loop()->clear_strip_mined();
|
|
_igvn.replace_input_of(newhead, LoopNode::EntryControl, newhead->in(LoopNode::EntryControl)->in(LoopNode::EntryControl));
|
|
set_idom(newhead, newhead->in(LoopNode::EntryControl), dd);
|
|
}
|
|
// Look at data node that were assigned a control in the outer
|
|
// loop: they are kept in the outer loop by the safepoint so start
|
|
// from the safepoint node's inputs.
|
|
IdealLoopTree* outer_loop = get_loop(l);
|
|
Node_Stack stack(2);
|
|
stack.push(sfpt, 1);
|
|
uint new_counter = C->unique();
|
|
while (stack.size() > 0) {
|
|
Node* n = stack.node();
|
|
uint i = stack.index();
|
|
while (i < n->req() &&
|
|
(n->in(i) == NULL ||
|
|
!has_ctrl(n->in(i)) ||
|
|
get_loop(get_ctrl(n->in(i))) != outer_loop ||
|
|
(old_new[n->in(i)->_idx] != NULL && old_new[n->in(i)->_idx]->_idx >= new_counter))) {
|
|
i++;
|
|
}
|
|
if (i < n->req()) {
|
|
stack.set_index(i+1);
|
|
stack.push(n->in(i), 0);
|
|
} else {
|
|
assert(old_new[n->_idx] == NULL || n == sfpt || old_new[n->_idx]->_idx < new_counter, "no clone yet");
|
|
Node* m = n == sfpt ? new_sfpt : n->clone();
|
|
if (m != NULL) {
|
|
for (uint i = 0; i < n->req(); i++) {
|
|
if (m->in(i) != NULL && old_new[m->in(i)->_idx] != NULL) {
|
|
m->set_req(i, old_new[m->in(i)->_idx]);
|
|
}
|
|
}
|
|
} else {
|
|
assert(n == sfpt && mode != CloneIncludesStripMined, "where's the safepoint clone?");
|
|
}
|
|
if (n != sfpt) {
|
|
extra_data_nodes.push(n);
|
|
_igvn.register_new_node_with_optimizer(m);
|
|
assert(get_ctrl(n) == cle_out, "what other control?");
|
|
set_ctrl(m, new_cle_out);
|
|
old_new.map(n->_idx, m);
|
|
}
|
|
stack.pop();
|
|
}
|
|
}
|
|
if (mode == CloneIncludesStripMined) {
|
|
_igvn.register_new_node_with_optimizer(new_sfpt);
|
|
_igvn.register_new_node_with_optimizer(new_cle_out);
|
|
}
|
|
// Some other transformation may have pessimistically assign some
|
|
// data nodes to the outer loop. Set their control so they are out
|
|
// of the outer loop.
|
|
ResourceMark rm;
|
|
Unique_Node_List wq;
|
|
for (uint i = 0; i < extra_data_nodes.size(); i++) {
|
|
Node* old = extra_data_nodes.at(i);
|
|
clone_outer_loop_helper(old, loop, outer_loop, old_new, wq, this, true);
|
|
}
|
|
Node* new_ctrl = cl->outer_loop_exit();
|
|
assert(get_loop(new_ctrl) != outer_loop, "must be out of the loop nest");
|
|
for (uint i = 0; i < wq.size(); i++) {
|
|
Node* n = wq.at(i);
|
|
set_ctrl(n, new_ctrl);
|
|
clone_outer_loop_helper(n, loop, outer_loop, old_new, wq, this, false);
|
|
}
|
|
} else {
|
|
Node *newhead = old_new[loop->_head->_idx];
|
|
set_idom(newhead, newhead->in(LoopNode::EntryControl), dd);
|
|
}
|
|
}
|
|
|
|
//------------------------------clone_loop-------------------------------------
|
|
//
|
|
// C L O N E A L O O P B O D Y
|
|
//
|
|
// This is the basic building block of the loop optimizations. It clones an
|
|
// entire loop body. It makes an old_new loop body mapping; with this mapping
|
|
// you can find the new-loop equivalent to an old-loop node. All new-loop
|
|
// nodes are exactly equal to their old-loop counterparts, all edges are the
|
|
// same. All exits from the old-loop now have a RegionNode that merges the
|
|
// equivalent new-loop path. This is true even for the normal "loop-exit"
|
|
// condition. All uses of loop-invariant old-loop values now come from (one
|
|
// or more) Phis that merge their new-loop equivalents.
|
|
//
|
|
// This operation leaves the graph in an illegal state: there are two valid
|
|
// control edges coming from the loop pre-header to both loop bodies. I'll
|
|
// definitely have to hack the graph after running this transform.
|
|
//
|
|
// From this building block I will further edit edges to perform loop peeling
|
|
// or loop unrolling or iteration splitting (Range-Check-Elimination), etc.
|
|
//
|
|
// Parameter side_by_size_idom:
|
|
// When side_by_size_idom is NULL, the dominator tree is constructed for
|
|
// the clone loop to dominate the original. Used in construction of
|
|
// pre-main-post loop sequence.
|
|
// When nonnull, the clone and original are side-by-side, both are
|
|
// dominated by the side_by_side_idom node. Used in construction of
|
|
// unswitched loops.
|
|
void PhaseIdealLoop::clone_loop( IdealLoopTree *loop, Node_List &old_new, int dd,
|
|
CloneLoopMode mode, Node* side_by_side_idom) {
|
|
|
|
LoopNode* head = loop->_head->as_Loop();
|
|
head->verify_strip_mined(1);
|
|
|
|
if (C->do_vector_loop() && PrintOpto) {
|
|
const char* mname = C->method()->name()->as_quoted_ascii();
|
|
if (mname != NULL) {
|
|
tty->print("PhaseIdealLoop::clone_loop: for vectorize method %s\n", mname);
|
|
}
|
|
}
|
|
|
|
CloneMap& cm = C->clone_map();
|
|
Dict* dict = cm.dict();
|
|
if (C->do_vector_loop()) {
|
|
cm.set_clone_idx(cm.max_gen()+1);
|
|
#ifndef PRODUCT
|
|
if (PrintOpto) {
|
|
tty->print_cr("PhaseIdealLoop::clone_loop: _clone_idx %d", cm.clone_idx());
|
|
loop->dump_head();
|
|
}
|
|
#endif
|
|
}
|
|
|
|
// Step 1: Clone the loop body. Make the old->new mapping.
|
|
uint i;
|
|
for( i = 0; i < loop->_body.size(); i++ ) {
|
|
Node *old = loop->_body.at(i);
|
|
Node *nnn = old->clone();
|
|
old_new.map( old->_idx, nnn );
|
|
if (C->do_vector_loop()) {
|
|
cm.verify_insert_and_clone(old, nnn, cm.clone_idx());
|
|
}
|
|
_igvn.register_new_node_with_optimizer(nnn);
|
|
}
|
|
|
|
IdealLoopTree* outer_loop = (head->is_strip_mined() && mode != IgnoreStripMined) ? get_loop(head->as_CountedLoop()->outer_loop()) : loop;
|
|
|
|
// Step 2: Fix the edges in the new body. If the old input is outside the
|
|
// loop use it. If the old input is INside the loop, use the corresponding
|
|
// new node instead.
|
|
for( i = 0; i < loop->_body.size(); i++ ) {
|
|
Node *old = loop->_body.at(i);
|
|
Node *nnn = old_new[old->_idx];
|
|
// Fix CFG/Loop controlling the new node
|
|
if (has_ctrl(old)) {
|
|
set_ctrl(nnn, old_new[get_ctrl(old)->_idx]);
|
|
} else {
|
|
set_loop(nnn, outer_loop->_parent);
|
|
if (old->outcnt() > 0) {
|
|
set_idom( nnn, old_new[idom(old)->_idx], dd );
|
|
}
|
|
}
|
|
// Correct edges to the new node
|
|
for( uint j = 0; j < nnn->req(); j++ ) {
|
|
Node *n = nnn->in(j);
|
|
if( n ) {
|
|
IdealLoopTree *old_in_loop = get_loop( has_ctrl(n) ? get_ctrl(n) : n );
|
|
if( loop->is_member( old_in_loop ) )
|
|
nnn->set_req(j, old_new[n->_idx]);
|
|
}
|
|
}
|
|
_igvn.hash_find_insert(nnn);
|
|
}
|
|
|
|
Node_List extra_data_nodes; // data nodes in the outer strip mined loop
|
|
clone_outer_loop(head, mode, loop, outer_loop, dd, old_new, extra_data_nodes);
|
|
|
|
// Step 3: Now fix control uses. Loop varying control uses have already
|
|
// been fixed up (as part of all input edges in Step 2). Loop invariant
|
|
// control uses must be either an IfFalse or an IfTrue. Make a merge
|
|
// point to merge the old and new IfFalse/IfTrue nodes; make the use
|
|
// refer to this.
|
|
Node_List worklist;
|
|
uint new_counter = C->unique();
|
|
for( i = 0; i < loop->_body.size(); i++ ) {
|
|
Node* old = loop->_body.at(i);
|
|
if( !old->is_CFG() ) continue;
|
|
|
|
// Copy uses to a worklist, so I can munge the def-use info
|
|
// with impunity.
|
|
for (DUIterator_Fast jmax, j = old->fast_outs(jmax); j < jmax; j++)
|
|
worklist.push(old->fast_out(j));
|
|
|
|
while( worklist.size() ) { // Visit all uses
|
|
Node *use = worklist.pop();
|
|
if (!has_node(use)) continue; // Ignore dead nodes
|
|
IdealLoopTree *use_loop = get_loop( has_ctrl(use) ? get_ctrl(use) : use );
|
|
if( !loop->is_member( use_loop ) && use->is_CFG() ) {
|
|
// Both OLD and USE are CFG nodes here.
|
|
assert( use->is_Proj(), "" );
|
|
Node* nnn = old_new[old->_idx];
|
|
|
|
Node* newuse = NULL;
|
|
if (head->is_strip_mined() && mode != IgnoreStripMined) {
|
|
CountedLoopNode* cl = head->as_CountedLoop();
|
|
CountedLoopEndNode* cle = cl->loopexit();
|
|
Node* cle_out = cle->proj_out_or_null(false);
|
|
if (use == cle_out) {
|
|
IfNode* le = cl->outer_loop_end();
|
|
use = le->proj_out(false);
|
|
use_loop = get_loop(use);
|
|
if (mode == CloneIncludesStripMined) {
|
|
nnn = old_new[le->_idx];
|
|
} else {
|
|
newuse = old_new[cle_out->_idx];
|
|
}
|
|
}
|
|
}
|
|
if (newuse == NULL) {
|
|
newuse = use->clone();
|
|
}
|
|
|
|
// Clone the loop exit control projection
|
|
if (C->do_vector_loop()) {
|
|
cm.verify_insert_and_clone(use, newuse, cm.clone_idx());
|
|
}
|
|
newuse->set_req(0,nnn);
|
|
_igvn.register_new_node_with_optimizer(newuse);
|
|
set_loop(newuse, use_loop);
|
|
set_idom(newuse, nnn, dom_depth(nnn) + 1 );
|
|
|
|
// We need a Region to merge the exit from the peeled body and the
|
|
// exit from the old loop body.
|
|
RegionNode *r = new RegionNode(3);
|
|
// Map the old use to the new merge point
|
|
old_new.map( use->_idx, r );
|
|
uint dd_r = MIN2(dom_depth(newuse),dom_depth(use));
|
|
assert( dd_r >= dom_depth(dom_lca(newuse,use)), "" );
|
|
|
|
// The original user of 'use' uses 'r' instead.
|
|
for (DUIterator_Last lmin, l = use->last_outs(lmin); l >= lmin;) {
|
|
Node* useuse = use->last_out(l);
|
|
_igvn.rehash_node_delayed(useuse);
|
|
uint uses_found = 0;
|
|
if( useuse->in(0) == use ) {
|
|
useuse->set_req(0, r);
|
|
uses_found++;
|
|
if( useuse->is_CFG() ) {
|
|
// This is not a dom_depth > dd_r because when new
|
|
// control flow is constructed by a loop opt, a node and
|
|
// its dominator can end up at the same dom_depth
|
|
assert(dom_depth(useuse) >= dd_r, "");
|
|
set_idom(useuse, r, dom_depth(useuse));
|
|
}
|
|
}
|
|
for( uint k = 1; k < useuse->req(); k++ ) {
|
|
if( useuse->in(k) == use ) {
|
|
useuse->set_req(k, r);
|
|
uses_found++;
|
|
if (useuse->is_Loop() && k == LoopNode::EntryControl) {
|
|
// This is not a dom_depth > dd_r because when new
|
|
// control flow is constructed by a loop opt, a node
|
|
// and its dominator can end up at the same dom_depth
|
|
assert(dom_depth(useuse) >= dd_r , "");
|
|
set_idom(useuse, r, dom_depth(useuse));
|
|
}
|
|
}
|
|
}
|
|
l -= uses_found; // we deleted 1 or more copies of this edge
|
|
}
|
|
|
|
// Now finish up 'r'
|
|
r->set_req( 1, newuse );
|
|
r->set_req( 2, use );
|
|
_igvn.register_new_node_with_optimizer(r);
|
|
set_loop(r, use_loop);
|
|
set_idom(r, !side_by_side_idom ? newuse->in(0) : side_by_side_idom, dd_r);
|
|
} // End of if a loop-exit test
|
|
}
|
|
}
|
|
|
|
// Step 4: If loop-invariant use is not control, it must be dominated by a
|
|
// loop exit IfFalse/IfTrue. Find "proper" loop exit. Make a Region
|
|
// there if needed. Make a Phi there merging old and new used values.
|
|
Node_List *split_if_set = NULL;
|
|
Node_List *split_bool_set = NULL;
|
|
Node_List *split_cex_set = NULL;
|
|
for( i = 0; i < loop->_body.size(); i++ ) {
|
|
Node* old = loop->_body.at(i);
|
|
clone_loop_handle_data_uses(old, old_new, loop, outer_loop, split_if_set,
|
|
split_bool_set, split_cex_set, worklist, new_counter,
|
|
mode);
|
|
}
|
|
|
|
for (i = 0; i < extra_data_nodes.size(); i++) {
|
|
Node* old = extra_data_nodes.at(i);
|
|
clone_loop_handle_data_uses(old, old_new, loop, outer_loop, split_if_set,
|
|
split_bool_set, split_cex_set, worklist, new_counter,
|
|
mode);
|
|
}
|
|
|
|
// Check for IFs that need splitting/cloning. Happens if an IF outside of
|
|
// the loop uses a condition set in the loop. The original IF probably
|
|
// takes control from one or more OLD Regions (which in turn get from NEW
|
|
// Regions). In any case, there will be a set of Phis for each merge point
|
|
// from the IF up to where the original BOOL def exists the loop.
|
|
if (split_if_set) {
|
|
while (split_if_set->size()) {
|
|
Node *iff = split_if_set->pop();
|
|
if (iff->in(1)->is_Phi()) {
|
|
Node *b = clone_iff(iff->in(1)->as_Phi(), loop);
|
|
_igvn.replace_input_of(iff, 1, b);
|
|
}
|
|
}
|
|
}
|
|
if (split_bool_set) {
|
|
while (split_bool_set->size()) {
|
|
Node *b = split_bool_set->pop();
|
|
Node *phi = b->in(1);
|
|
assert(phi->is_Phi(), "");
|
|
CmpNode *cmp = clone_bool((PhiNode*)phi, loop);
|
|
_igvn.replace_input_of(b, 1, cmp);
|
|
}
|
|
}
|
|
if (split_cex_set) {
|
|
while (split_cex_set->size()) {
|
|
Node *b = split_cex_set->pop();
|
|
assert(b->in(0)->is_Region(), "");
|
|
assert(b->in(1)->is_Phi(), "");
|
|
assert(b->in(0)->in(0) == b->in(1)->in(0), "");
|
|
split_up(b, b->in(0), NULL);
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
|
|
//---------------------- stride_of_possible_iv -------------------------------------
|
|
// Looks for an iff/bool/comp with one operand of the compare
|
|
// being a cycle involving an add and a phi,
|
|
// with an optional truncation (left-shift followed by a right-shift)
|
|
// of the add. Returns zero if not an iv.
|
|
int PhaseIdealLoop::stride_of_possible_iv(Node* iff) {
|
|
Node* trunc1 = NULL;
|
|
Node* trunc2 = NULL;
|
|
const TypeInt* ttype = NULL;
|
|
if (!iff->is_If() || iff->in(1) == NULL || !iff->in(1)->is_Bool()) {
|
|
return 0;
|
|
}
|
|
BoolNode* bl = iff->in(1)->as_Bool();
|
|
Node* cmp = bl->in(1);
|
|
if (!cmp || (cmp->Opcode() != Op_CmpI && cmp->Opcode() != Op_CmpU)) {
|
|
return 0;
|
|
}
|
|
// Must have an invariant operand
|
|
if (is_member(get_loop(iff), get_ctrl(cmp->in(2)))) {
|
|
return 0;
|
|
}
|
|
Node* add2 = NULL;
|
|
Node* cmp1 = cmp->in(1);
|
|
if (cmp1->is_Phi()) {
|
|
// (If (Bool (CmpX phi:(Phi ...(Optional-trunc(AddI phi add2))) )))
|
|
Node* phi = cmp1;
|
|
for (uint i = 1; i < phi->req(); i++) {
|
|
Node* in = phi->in(i);
|
|
Node* add = CountedLoopNode::match_incr_with_optional_truncation(in,
|
|
&trunc1, &trunc2, &ttype);
|
|
if (add && add->in(1) == phi) {
|
|
add2 = add->in(2);
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
// (If (Bool (CmpX addtrunc:(Optional-trunc((AddI (Phi ...addtrunc...) add2)) )))
|
|
Node* addtrunc = cmp1;
|
|
Node* add = CountedLoopNode::match_incr_with_optional_truncation(addtrunc,
|
|
&trunc1, &trunc2, &ttype);
|
|
if (add && add->in(1)->is_Phi()) {
|
|
Node* phi = add->in(1);
|
|
for (uint i = 1; i < phi->req(); i++) {
|
|
if (phi->in(i) == addtrunc) {
|
|
add2 = add->in(2);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (add2 != NULL) {
|
|
const TypeInt* add2t = _igvn.type(add2)->is_int();
|
|
if (add2t->is_con()) {
|
|
return add2t->get_con();
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
//---------------------- stay_in_loop -------------------------------------
|
|
// Return the (unique) control output node that's in the loop (if it exists.)
|
|
Node* PhaseIdealLoop::stay_in_loop( Node* n, IdealLoopTree *loop) {
|
|
Node* unique = NULL;
|
|
if (!n) return NULL;
|
|
for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
|
|
Node* use = n->fast_out(i);
|
|
if (!has_ctrl(use) && loop->is_member(get_loop(use))) {
|
|
if (unique != NULL) {
|
|
return NULL;
|
|
}
|
|
unique = use;
|
|
}
|
|
}
|
|
return unique;
|
|
}
|
|
|
|
//------------------------------ register_node -------------------------------------
|
|
// Utility to register node "n" with PhaseIdealLoop
|
|
void PhaseIdealLoop::register_node(Node* n, IdealLoopTree *loop, Node* pred, int ddepth) {
|
|
_igvn.register_new_node_with_optimizer(n);
|
|
loop->_body.push(n);
|
|
if (n->is_CFG()) {
|
|
set_loop(n, loop);
|
|
set_idom(n, pred, ddepth);
|
|
} else {
|
|
set_ctrl(n, pred);
|
|
}
|
|
}
|
|
|
|
//------------------------------ proj_clone -------------------------------------
|
|
// Utility to create an if-projection
|
|
ProjNode* PhaseIdealLoop::proj_clone(ProjNode* p, IfNode* iff) {
|
|
ProjNode* c = p->clone()->as_Proj();
|
|
c->set_req(0, iff);
|
|
return c;
|
|
}
|
|
|
|
//------------------------------ short_circuit_if -------------------------------------
|
|
// Force the iff control output to be the live_proj
|
|
Node* PhaseIdealLoop::short_circuit_if(IfNode* iff, ProjNode* live_proj) {
|
|
guarantee(live_proj != NULL, "null projection");
|
|
int proj_con = live_proj->_con;
|
|
assert(proj_con == 0 || proj_con == 1, "false or true projection");
|
|
Node *con = _igvn.intcon(proj_con);
|
|
set_ctrl(con, C->root());
|
|
if (iff) {
|
|
iff->set_req(1, con);
|
|
}
|
|
return con;
|
|
}
|
|
|
|
//------------------------------ insert_if_before_proj -------------------------------------
|
|
// Insert a new if before an if projection (* - new node)
|
|
//
|
|
// before
|
|
// if(test)
|
|
// / \
|
|
// v v
|
|
// other-proj proj (arg)
|
|
//
|
|
// after
|
|
// if(test)
|
|
// / \
|
|
// / v
|
|
// | * proj-clone
|
|
// v |
|
|
// other-proj v
|
|
// * new_if(relop(cmp[IU](left,right)))
|
|
// / \
|
|
// v v
|
|
// * new-proj proj
|
|
// (returned)
|
|
//
|
|
ProjNode* PhaseIdealLoop::insert_if_before_proj(Node* left, bool Signed, BoolTest::mask relop, Node* right, ProjNode* proj) {
|
|
IfNode* iff = proj->in(0)->as_If();
|
|
IdealLoopTree *loop = get_loop(proj);
|
|
ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj();
|
|
int ddepth = dom_depth(proj);
|
|
|
|
_igvn.rehash_node_delayed(iff);
|
|
_igvn.rehash_node_delayed(proj);
|
|
|
|
proj->set_req(0, NULL); // temporary disconnect
|
|
ProjNode* proj2 = proj_clone(proj, iff);
|
|
register_node(proj2, loop, iff, ddepth);
|
|
|
|
Node* cmp = Signed ? (Node*) new CmpINode(left, right) : (Node*) new CmpUNode(left, right);
|
|
register_node(cmp, loop, proj2, ddepth);
|
|
|
|
BoolNode* bol = new BoolNode(cmp, relop);
|
|
register_node(bol, loop, proj2, ddepth);
|
|
|
|
int opcode = iff->Opcode();
|
|
assert(opcode == Op_If || opcode == Op_RangeCheck, "unexpected opcode");
|
|
IfNode* new_if = (opcode == Op_If) ? new IfNode(proj2, bol, iff->_prob, iff->_fcnt):
|
|
new RangeCheckNode(proj2, bol, iff->_prob, iff->_fcnt);
|
|
register_node(new_if, loop, proj2, ddepth);
|
|
|
|
proj->set_req(0, new_if); // reattach
|
|
set_idom(proj, new_if, ddepth);
|
|
|
|
ProjNode* new_exit = proj_clone(other_proj, new_if)->as_Proj();
|
|
guarantee(new_exit != NULL, "null exit node");
|
|
register_node(new_exit, get_loop(other_proj), new_if, ddepth);
|
|
|
|
return new_exit;
|
|
}
|
|
|
|
//------------------------------ insert_region_before_proj -------------------------------------
|
|
// Insert a region before an if projection (* - new node)
|
|
//
|
|
// before
|
|
// if(test)
|
|
// / |
|
|
// v |
|
|
// proj v
|
|
// other-proj
|
|
//
|
|
// after
|
|
// if(test)
|
|
// / |
|
|
// v |
|
|
// * proj-clone v
|
|
// | other-proj
|
|
// v
|
|
// * new-region
|
|
// |
|
|
// v
|
|
// * dum_if
|
|
// / \
|
|
// v \
|
|
// * dum-proj v
|
|
// proj
|
|
//
|
|
RegionNode* PhaseIdealLoop::insert_region_before_proj(ProjNode* proj) {
|
|
IfNode* iff = proj->in(0)->as_If();
|
|
IdealLoopTree *loop = get_loop(proj);
|
|
ProjNode *other_proj = iff->proj_out(!proj->is_IfTrue())->as_Proj();
|
|
int ddepth = dom_depth(proj);
|
|
|
|
_igvn.rehash_node_delayed(iff);
|
|
_igvn.rehash_node_delayed(proj);
|
|
|
|
proj->set_req(0, NULL); // temporary disconnect
|
|
ProjNode* proj2 = proj_clone(proj, iff);
|
|
register_node(proj2, loop, iff, ddepth);
|
|
|
|
RegionNode* reg = new RegionNode(2);
|
|
reg->set_req(1, proj2);
|
|
register_node(reg, loop, iff, ddepth);
|
|
|
|
IfNode* dum_if = new IfNode(reg, short_circuit_if(NULL, proj), iff->_prob, iff->_fcnt);
|
|
register_node(dum_if, loop, reg, ddepth);
|
|
|
|
proj->set_req(0, dum_if); // reattach
|
|
set_idom(proj, dum_if, ddepth);
|
|
|
|
ProjNode* dum_proj = proj_clone(other_proj, dum_if);
|
|
register_node(dum_proj, loop, dum_if, ddepth);
|
|
|
|
return reg;
|
|
}
|
|
|
|
//------------------------------ insert_cmpi_loop_exit -------------------------------------
|
|
// Clone a signed compare loop exit from an unsigned compare and
|
|
// insert it before the unsigned cmp on the stay-in-loop path.
|
|
// All new nodes inserted in the dominator tree between the original
|
|
// if and it's projections. The original if test is replaced with
|
|
// a constant to force the stay-in-loop path.
|
|
//
|
|
// This is done to make sure that the original if and it's projections
|
|
// still dominate the same set of control nodes, that the ctrl() relation
|
|
// from data nodes to them is preserved, and that their loop nesting is
|
|
// preserved.
|
|
//
|
|
// before
|
|
// if(i <u limit) unsigned compare loop exit
|
|
// / |
|
|
// v v
|
|
// exit-proj stay-in-loop-proj
|
|
//
|
|
// after
|
|
// if(stay-in-loop-const) original if
|
|
// / |
|
|
// / v
|
|
// / if(i < limit) new signed test
|
|
// / / |
|
|
// / / v
|
|
// / / if(i <u limit) new cloned unsigned test
|
|
// / / / |
|
|
// v v v |
|
|
// region |
|
|
// | |
|
|
// dum-if |
|
|
// / | |
|
|
// ether | |
|
|
// v v
|
|
// exit-proj stay-in-loop-proj
|
|
//
|
|
IfNode* PhaseIdealLoop::insert_cmpi_loop_exit(IfNode* if_cmpu, IdealLoopTree *loop) {
|
|
const bool Signed = true;
|
|
const bool Unsigned = false;
|
|
|
|
BoolNode* bol = if_cmpu->in(1)->as_Bool();
|
|
if (bol->_test._test != BoolTest::lt) return NULL;
|
|
CmpNode* cmpu = bol->in(1)->as_Cmp();
|
|
if (cmpu->Opcode() != Op_CmpU) return NULL;
|
|
int stride = stride_of_possible_iv(if_cmpu);
|
|
if (stride == 0) return NULL;
|
|
|
|
Node* lp_proj = stay_in_loop(if_cmpu, loop);
|
|
guarantee(lp_proj != NULL, "null loop node");
|
|
|
|
ProjNode* lp_continue = lp_proj->as_Proj();
|
|
ProjNode* lp_exit = if_cmpu->proj_out(!lp_continue->is_IfTrue())->as_Proj();
|
|
if (!lp_exit->is_IfFalse()) {
|
|
// The loop exit condition is (i <u limit) ==> (i >= 0 && i < limit).
|
|
// We therefore can't add a single exit condition.
|
|
return NULL;
|
|
}
|
|
// The loop exit condition is !(i <u limit) ==> (i < 0 || i >= limit).
|
|
// Split out the exit condition (i < 0) for stride < 0 or (i >= limit) for stride > 0.
|
|
Node* limit = NULL;
|
|
if (stride > 0) {
|
|
limit = cmpu->in(2);
|
|
} else {
|
|
limit = _igvn.makecon(TypeInt::ZERO);
|
|
set_ctrl(limit, C->root());
|
|
}
|
|
// Create a new region on the exit path
|
|
RegionNode* reg = insert_region_before_proj(lp_exit);
|
|
guarantee(reg != NULL, "null region node");
|
|
|
|
// Clone the if-cmpu-true-false using a signed compare
|
|
BoolTest::mask rel_i = stride > 0 ? bol->_test._test : BoolTest::ge;
|
|
ProjNode* cmpi_exit = insert_if_before_proj(cmpu->in(1), Signed, rel_i, limit, lp_continue);
|
|
reg->add_req(cmpi_exit);
|
|
|
|
// Clone the if-cmpu-true-false
|
|
BoolTest::mask rel_u = bol->_test._test;
|
|
ProjNode* cmpu_exit = insert_if_before_proj(cmpu->in(1), Unsigned, rel_u, cmpu->in(2), lp_continue);
|
|
reg->add_req(cmpu_exit);
|
|
|
|
// Force original if to stay in loop.
|
|
short_circuit_if(if_cmpu, lp_continue);
|
|
|
|
return cmpi_exit->in(0)->as_If();
|
|
}
|
|
|
|
//------------------------------ remove_cmpi_loop_exit -------------------------------------
|
|
// Remove a previously inserted signed compare loop exit.
|
|
void PhaseIdealLoop::remove_cmpi_loop_exit(IfNode* if_cmp, IdealLoopTree *loop) {
|
|
Node* lp_proj = stay_in_loop(if_cmp, loop);
|
|
assert(if_cmp->in(1)->in(1)->Opcode() == Op_CmpI &&
|
|
stay_in_loop(lp_proj, loop)->is_If() &&
|
|
stay_in_loop(lp_proj, loop)->in(1)->in(1)->Opcode() == Op_CmpU, "inserted cmpi before cmpu");
|
|
Node *con = _igvn.makecon(lp_proj->is_IfTrue() ? TypeInt::ONE : TypeInt::ZERO);
|
|
set_ctrl(con, C->root());
|
|
if_cmp->set_req(1, con);
|
|
}
|
|
|
|
//------------------------------ scheduled_nodelist -------------------------------------
|
|
// Create a post order schedule of nodes that are in the
|
|
// "member" set. The list is returned in "sched".
|
|
// The first node in "sched" is the loop head, followed by
|
|
// nodes which have no inputs in the "member" set, and then
|
|
// followed by the nodes that have an immediate input dependence
|
|
// on a node in "sched".
|
|
void PhaseIdealLoop::scheduled_nodelist( IdealLoopTree *loop, VectorSet& member, Node_List &sched ) {
|
|
|
|
assert(member.test(loop->_head->_idx), "loop head must be in member set");
|
|
VectorSet visited;
|
|
Node_Stack nstack(loop->_body.size());
|
|
|
|
Node* n = loop->_head; // top of stack is cached in "n"
|
|
uint idx = 0;
|
|
visited.set(n->_idx);
|
|
|
|
// Initially push all with no inputs from within member set
|
|
for(uint i = 0; i < loop->_body.size(); i++ ) {
|
|
Node *elt = loop->_body.at(i);
|
|
if (member.test(elt->_idx)) {
|
|
bool found = false;
|
|
for (uint j = 0; j < elt->req(); j++) {
|
|
Node* def = elt->in(j);
|
|
if (def && member.test(def->_idx) && def != elt) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found && elt != loop->_head) {
|
|
nstack.push(n, idx);
|
|
n = elt;
|
|
assert(!visited.test(n->_idx), "not seen yet");
|
|
visited.set(n->_idx);
|
|
}
|
|
}
|
|
}
|
|
|
|
// traverse out's that are in the member set
|
|
while (true) {
|
|
if (idx < n->outcnt()) {
|
|
Node* use = n->raw_out(idx);
|
|
idx++;
|
|
if (!visited.test_set(use->_idx)) {
|
|
if (member.test(use->_idx)) {
|
|
nstack.push(n, idx);
|
|
n = use;
|
|
idx = 0;
|
|
}
|
|
}
|
|
} else {
|
|
// All outputs processed
|
|
sched.push(n);
|
|
if (nstack.is_empty()) break;
|
|
n = nstack.node();
|
|
idx = nstack.index();
|
|
nstack.pop();
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//------------------------------ has_use_in_set -------------------------------------
|
|
// Has a use in the vector set
|
|
bool PhaseIdealLoop::has_use_in_set( Node* n, VectorSet& vset ) {
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = n->fast_out(j);
|
|
if (vset.test(use->_idx)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
//------------------------------ has_use_internal_to_set -------------------------------------
|
|
// Has use internal to the vector set (ie. not in a phi at the loop head)
|
|
bool PhaseIdealLoop::has_use_internal_to_set( Node* n, VectorSet& vset, IdealLoopTree *loop ) {
|
|
Node* head = loop->_head;
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = n->fast_out(j);
|
|
if (vset.test(use->_idx) && !(use->is_Phi() && use->in(0) == head)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
//------------------------------ clone_for_use_outside_loop -------------------------------------
|
|
// clone "n" for uses that are outside of loop
|
|
int PhaseIdealLoop::clone_for_use_outside_loop( IdealLoopTree *loop, Node* n, Node_List& worklist ) {
|
|
int cloned = 0;
|
|
assert(worklist.size() == 0, "should be empty");
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = n->fast_out(j);
|
|
if( !loop->is_member(get_loop(has_ctrl(use) ? get_ctrl(use) : use)) ) {
|
|
worklist.push(use);
|
|
}
|
|
}
|
|
while( worklist.size() ) {
|
|
Node *use = worklist.pop();
|
|
if (!has_node(use) || use->in(0) == C->top()) continue;
|
|
uint j;
|
|
for (j = 0; j < use->req(); j++) {
|
|
if (use->in(j) == n) break;
|
|
}
|
|
assert(j < use->req(), "must be there");
|
|
|
|
// clone "n" and insert it between the inputs of "n" and the use outside the loop
|
|
Node* n_clone = n->clone();
|
|
_igvn.replace_input_of(use, j, n_clone);
|
|
cloned++;
|
|
Node* use_c;
|
|
if (!use->is_Phi()) {
|
|
use_c = has_ctrl(use) ? get_ctrl(use) : use->in(0);
|
|
} else {
|
|
// Use in a phi is considered a use in the associated predecessor block
|
|
use_c = use->in(0)->in(j);
|
|
}
|
|
set_ctrl(n_clone, use_c);
|
|
assert(!loop->is_member(get_loop(use_c)), "should be outside loop");
|
|
get_loop(use_c)->_body.push(n_clone);
|
|
_igvn.register_new_node_with_optimizer(n_clone);
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("loop exit cloning old: %d new: %d newbb: %d", n->_idx, n_clone->_idx, get_ctrl(n_clone)->_idx);
|
|
}
|
|
#endif
|
|
}
|
|
return cloned;
|
|
}
|
|
|
|
|
|
//------------------------------ clone_for_special_use_inside_loop -------------------------------------
|
|
// clone "n" for special uses that are in the not_peeled region.
|
|
// If these def-uses occur in separate blocks, the code generator
|
|
// marks the method as not compilable. For example, if a "BoolNode"
|
|
// is in a different basic block than the "IfNode" that uses it, then
|
|
// the compilation is aborted in the code generator.
|
|
void PhaseIdealLoop::clone_for_special_use_inside_loop( IdealLoopTree *loop, Node* n,
|
|
VectorSet& not_peel, Node_List& sink_list, Node_List& worklist ) {
|
|
if (n->is_Phi() || n->is_Load()) {
|
|
return;
|
|
}
|
|
assert(worklist.size() == 0, "should be empty");
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = n->fast_out(j);
|
|
if ( not_peel.test(use->_idx) &&
|
|
(use->is_If() || use->is_CMove() || use->is_Bool()) &&
|
|
use->in(1) == n) {
|
|
worklist.push(use);
|
|
}
|
|
}
|
|
if (worklist.size() > 0) {
|
|
// clone "n" and insert it between inputs of "n" and the use
|
|
Node* n_clone = n->clone();
|
|
loop->_body.push(n_clone);
|
|
_igvn.register_new_node_with_optimizer(n_clone);
|
|
set_ctrl(n_clone, get_ctrl(n));
|
|
sink_list.push(n_clone);
|
|
not_peel.set(n_clone->_idx);
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("special not_peeled cloning old: %d new: %d", n->_idx, n_clone->_idx);
|
|
}
|
|
#endif
|
|
while( worklist.size() ) {
|
|
Node *use = worklist.pop();
|
|
_igvn.rehash_node_delayed(use);
|
|
for (uint j = 1; j < use->req(); j++) {
|
|
if (use->in(j) == n) {
|
|
use->set_req(j, n_clone);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//------------------------------ insert_phi_for_loop -------------------------------------
|
|
// Insert phi(lp_entry_val, back_edge_val) at use->in(idx) for loop lp if phi does not already exist
|
|
void PhaseIdealLoop::insert_phi_for_loop( Node* use, uint idx, Node* lp_entry_val, Node* back_edge_val, LoopNode* lp ) {
|
|
Node *phi = PhiNode::make(lp, back_edge_val);
|
|
phi->set_req(LoopNode::EntryControl, lp_entry_val);
|
|
// Use existing phi if it already exists
|
|
Node *hit = _igvn.hash_find_insert(phi);
|
|
if( hit == NULL ) {
|
|
_igvn.register_new_node_with_optimizer(phi);
|
|
set_ctrl(phi, lp);
|
|
} else {
|
|
// Remove the new phi from the graph and use the hit
|
|
_igvn.remove_dead_node(phi);
|
|
phi = hit;
|
|
}
|
|
_igvn.replace_input_of(use, idx, phi);
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
//------------------------------ is_valid_loop_partition -------------------------------------
|
|
// Validate the loop partition sets: peel and not_peel
|
|
bool PhaseIdealLoop::is_valid_loop_partition( IdealLoopTree *loop, VectorSet& peel, Node_List& peel_list,
|
|
VectorSet& not_peel ) {
|
|
uint i;
|
|
// Check that peel_list entries are in the peel set
|
|
for (i = 0; i < peel_list.size(); i++) {
|
|
if (!peel.test(peel_list.at(i)->_idx)) {
|
|
return false;
|
|
}
|
|
}
|
|
// Check at loop members are in one of peel set or not_peel set
|
|
for (i = 0; i < loop->_body.size(); i++ ) {
|
|
Node *def = loop->_body.at(i);
|
|
uint di = def->_idx;
|
|
// Check that peel set elements are in peel_list
|
|
if (peel.test(di)) {
|
|
if (not_peel.test(di)) {
|
|
return false;
|
|
}
|
|
// Must be in peel_list also
|
|
bool found = false;
|
|
for (uint j = 0; j < peel_list.size(); j++) {
|
|
if (peel_list.at(j)->_idx == di) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
return false;
|
|
}
|
|
} else if (not_peel.test(di)) {
|
|
if (peel.test(di)) {
|
|
return false;
|
|
}
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
//------------------------------ is_valid_clone_loop_exit_use -------------------------------------
|
|
// Ensure a use outside of loop is of the right form
|
|
bool PhaseIdealLoop::is_valid_clone_loop_exit_use( IdealLoopTree *loop, Node* use, uint exit_idx) {
|
|
Node *use_c = has_ctrl(use) ? get_ctrl(use) : use;
|
|
return (use->is_Phi() &&
|
|
use_c->is_Region() && use_c->req() == 3 &&
|
|
(use_c->in(exit_idx)->Opcode() == Op_IfTrue ||
|
|
use_c->in(exit_idx)->Opcode() == Op_IfFalse ||
|
|
use_c->in(exit_idx)->Opcode() == Op_JumpProj) &&
|
|
loop->is_member( get_loop( use_c->in(exit_idx)->in(0) ) ) );
|
|
}
|
|
|
|
//------------------------------ is_valid_clone_loop_form -------------------------------------
|
|
// Ensure that all uses outside of loop are of the right form
|
|
bool PhaseIdealLoop::is_valid_clone_loop_form( IdealLoopTree *loop, Node_List& peel_list,
|
|
uint orig_exit_idx, uint clone_exit_idx) {
|
|
uint len = peel_list.size();
|
|
for (uint i = 0; i < len; i++) {
|
|
Node *def = peel_list.at(i);
|
|
|
|
for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
|
|
Node *use = def->fast_out(j);
|
|
Node *use_c = has_ctrl(use) ? get_ctrl(use) : use;
|
|
if (!loop->is_member(get_loop(use_c))) {
|
|
// use is not in the loop, check for correct structure
|
|
if (use->in(0) == def) {
|
|
// Okay
|
|
} else if (!is_valid_clone_loop_exit_use(loop, use, orig_exit_idx)) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
//------------------------------ partial_peel -------------------------------------
|
|
// Partially peel (aka loop rotation) the top portion of a loop (called
|
|
// the peel section below) by cloning it and placing one copy just before
|
|
// the new loop head and the other copy at the bottom of the new loop.
|
|
//
|
|
// before after where it came from
|
|
//
|
|
// stmt1 stmt1
|
|
// loop: stmt2 clone
|
|
// stmt2 if condA goto exitA clone
|
|
// if condA goto exitA new_loop: new
|
|
// stmt3 stmt3 clone
|
|
// if !condB goto loop if condB goto exitB clone
|
|
// exitB: stmt2 orig
|
|
// stmt4 if !condA goto new_loop orig
|
|
// exitA: goto exitA
|
|
// exitB:
|
|
// stmt4
|
|
// exitA:
|
|
//
|
|
// Step 1: find the cut point: an exit test on probable
|
|
// induction variable.
|
|
// Step 2: schedule (with cloning) operations in the peel
|
|
// section that can be executed after the cut into
|
|
// the section that is not peeled. This may need
|
|
// to clone operations into exit blocks. For
|
|
// instance, a reference to A[i] in the not-peel
|
|
// section and a reference to B[i] in an exit block
|
|
// may cause a left-shift of i by 2 to be placed
|
|
// in the peel block. This step will clone the left
|
|
// shift into the exit block and sink the left shift
|
|
// from the peel to the not-peel section.
|
|
// Step 3: clone the loop, retarget the control, and insert
|
|
// phis for values that are live across the new loop
|
|
// head. This is very dependent on the graph structure
|
|
// from clone_loop. It creates region nodes for
|
|
// exit control and associated phi nodes for values
|
|
// flow out of the loop through that exit. The region
|
|
// node is dominated by the clone's control projection.
|
|
// So the clone's peel section is placed before the
|
|
// new loop head, and the clone's not-peel section is
|
|
// forms the top part of the new loop. The original
|
|
// peel section forms the tail of the new loop.
|
|
// Step 4: update the dominator tree and recompute the
|
|
// dominator depth.
|
|
//
|
|
// orig
|
|
//
|
|
// stmt1
|
|
// |
|
|
// v
|
|
// loop predicate
|
|
// |
|
|
// v
|
|
// loop<----+
|
|
// | |
|
|
// stmt2 |
|
|
// | |
|
|
// v |
|
|
// ifA |
|
|
// / | |
|
|
// v v |
|
|
// false true ^ <-- last_peel
|
|
// / | |
|
|
// / ===|==cut |
|
|
// / stmt3 | <-- first_not_peel
|
|
// / | |
|
|
// | v |
|
|
// v ifB |
|
|
// exitA: / \ |
|
|
// / \ |
|
|
// v v |
|
|
// false true |
|
|
// / \ |
|
|
// / ----+
|
|
// |
|
|
// v
|
|
// exitB:
|
|
// stmt4
|
|
//
|
|
//
|
|
// after clone loop
|
|
//
|
|
// stmt1
|
|
// |
|
|
// v
|
|
// loop predicate
|
|
// / \
|
|
// clone / \ orig
|
|
// / \
|
|
// / \
|
|
// v v
|
|
// +---->loop loop<----+
|
|
// | | | |
|
|
// | stmt2 stmt2 |
|
|
// | | | |
|
|
// | v v |
|
|
// | ifA ifA |
|
|
// | | \ / | |
|
|
// | v v v v |
|
|
// ^ true false false true ^ <-- last_peel
|
|
// | | ^ \ / | |
|
|
// | cut==|== \ \ / ===|==cut |
|
|
// | stmt3 \ \ / stmt3 | <-- first_not_peel
|
|
// | | dom | | | |
|
|
// | v \ 1v v2 v |
|
|
// | ifB regionA ifB |
|
|
// | / \ | / \ |
|
|
// | / \ v / \ |
|
|
// | v v exitA: v v |
|
|
// | true false false true |
|
|
// | / ^ \ / \ |
|
|
// +---- \ \ / ----+
|
|
// dom \ /
|
|
// \ 1v v2
|
|
// regionB
|
|
// |
|
|
// v
|
|
// exitB:
|
|
// stmt4
|
|
//
|
|
//
|
|
// after partial peel
|
|
//
|
|
// stmt1
|
|
// |
|
|
// v
|
|
// loop predicate
|
|
// /
|
|
// clone / orig
|
|
// / TOP
|
|
// / \
|
|
// v v
|
|
// TOP->loop loop----+
|
|
// | | |
|
|
// stmt2 stmt2 |
|
|
// | | |
|
|
// v v |
|
|
// ifA ifA |
|
|
// | \ / | |
|
|
// v v v v |
|
|
// true false false true | <-- last_peel
|
|
// | ^ \ / +------|---+
|
|
// +->newloop \ \ / === ==cut | |
|
|
// | stmt3 \ \ / TOP | |
|
|
// | | dom | | stmt3 | | <-- first_not_peel
|
|
// | v \ 1v v2 v | |
|
|
// | ifB regionA ifB ^ v
|
|
// | / \ | / \ | |
|
|
// | / \ v / \ | |
|
|
// | v v exitA: v v | |
|
|
// | true false false true | |
|
|
// | / ^ \ / \ | |
|
|
// | | \ \ / v | |
|
|
// | | dom \ / TOP | |
|
|
// | | \ 1v v2 | |
|
|
// ^ v regionB | |
|
|
// | | | | |
|
|
// | | v ^ v
|
|
// | | exitB: | |
|
|
// | | stmt4 | |
|
|
// | +------------>-----------------+ |
|
|
// | |
|
|
// +-----------------<---------------------+
|
|
//
|
|
//
|
|
// final graph
|
|
//
|
|
// stmt1
|
|
// |
|
|
// v
|
|
// loop predicate
|
|
// |
|
|
// v
|
|
// stmt2 clone
|
|
// |
|
|
// v
|
|
// ........> ifA clone
|
|
// : / |
|
|
// dom / |
|
|
// : v v
|
|
// : false true
|
|
// : | |
|
|
// : | v
|
|
// : | newloop<-----+
|
|
// : | | |
|
|
// : | stmt3 clone |
|
|
// : | | |
|
|
// : | v |
|
|
// : | ifB |
|
|
// : | / \ |
|
|
// : | v v |
|
|
// : | false true |
|
|
// : | | | |
|
|
// : | v stmt2 |
|
|
// : | exitB: | |
|
|
// : | stmt4 v |
|
|
// : | ifA orig |
|
|
// : | / \ |
|
|
// : | / \ |
|
|
// : | v v |
|
|
// : | false true |
|
|
// : | / \ |
|
|
// : v v -----+
|
|
// RegionA
|
|
// |
|
|
// v
|
|
// exitA
|
|
//
|
|
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;
|
|
}
|
|
LoopNode *head = loop->_head->as_Loop();
|
|
|
|
if (head->is_partial_peel_loop() || head->partial_peel_has_failed()) {
|
|
return false;
|
|
}
|
|
|
|
// Check for complex exit control
|
|
for (uint ii = 0; ii < loop->_body.size(); ii++) {
|
|
Node *n = loop->_body.at(ii);
|
|
int opc = n->Opcode();
|
|
if (n->is_Call() ||
|
|
opc == Op_Catch ||
|
|
opc == Op_CatchProj ||
|
|
opc == Op_Jump ||
|
|
opc == Op_JumpProj) {
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("\nExit control too complex: lp: %d", head->_idx);
|
|
}
|
|
#endif
|
|
return false;
|
|
}
|
|
}
|
|
|
|
int dd = dom_depth(head);
|
|
|
|
// Step 1: find cut point
|
|
|
|
// Walk up dominators to loop head looking for first loop exit
|
|
// which is executed on every path thru loop.
|
|
IfNode *peel_if = NULL;
|
|
IfNode *peel_if_cmpu = NULL;
|
|
|
|
Node *iff = loop->tail();
|
|
while (iff != head) {
|
|
if (iff->is_If()) {
|
|
Node *ctrl = get_ctrl(iff->in(1));
|
|
if (ctrl->is_top()) return false; // Dead test on live IF.
|
|
// If loop-varying exit-test, check for induction variable
|
|
if (loop->is_member(get_loop(ctrl)) &&
|
|
loop->is_loop_exit(iff) &&
|
|
is_possible_iv_test(iff)) {
|
|
Node* cmp = iff->in(1)->in(1);
|
|
if (cmp->Opcode() == Op_CmpI) {
|
|
peel_if = iff->as_If();
|
|
} else {
|
|
assert(cmp->Opcode() == Op_CmpU, "must be CmpI or CmpU");
|
|
peel_if_cmpu = iff->as_If();
|
|
}
|
|
}
|
|
}
|
|
iff = idom(iff);
|
|
}
|
|
|
|
// Prefer signed compare over unsigned compare.
|
|
IfNode* new_peel_if = NULL;
|
|
if (peel_if == NULL) {
|
|
if (!PartialPeelAtUnsignedTests || peel_if_cmpu == NULL) {
|
|
return false; // No peel point found
|
|
}
|
|
new_peel_if = insert_cmpi_loop_exit(peel_if_cmpu, loop);
|
|
if (new_peel_if == NULL) {
|
|
return false; // No peel point found
|
|
}
|
|
peel_if = new_peel_if;
|
|
}
|
|
Node* last_peel = stay_in_loop(peel_if, loop);
|
|
Node* first_not_peeled = stay_in_loop(last_peel, loop);
|
|
if (first_not_peeled == NULL || first_not_peeled == head) {
|
|
return false;
|
|
}
|
|
|
|
#ifndef PRODUCT
|
|
if (TraceLoopOpts) {
|
|
tty->print("PartialPeel ");
|
|
loop->dump_head();
|
|
}
|
|
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("before partial peel one iteration");
|
|
Node_List wl;
|
|
Node* t = head->in(2);
|
|
while (true) {
|
|
wl.push(t);
|
|
if (t == head) break;
|
|
t = idom(t);
|
|
}
|
|
while (wl.size() > 0) {
|
|
Node* tt = wl.pop();
|
|
tt->dump();
|
|
if (tt == last_peel) tty->print_cr("-- cut --");
|
|
}
|
|
}
|
|
#endif
|
|
VectorSet peel;
|
|
VectorSet not_peel;
|
|
Node_List peel_list;
|
|
Node_List worklist;
|
|
Node_List sink_list;
|
|
|
|
uint estimate = loop->est_loop_clone_sz(1);
|
|
if (exceeding_node_budget(estimate)) {
|
|
return false;
|
|
}
|
|
|
|
// Set of cfg nodes to peel are those that are executable from
|
|
// the head through last_peel.
|
|
assert(worklist.size() == 0, "should be empty");
|
|
worklist.push(head);
|
|
peel.set(head->_idx);
|
|
while (worklist.size() > 0) {
|
|
Node *n = worklist.pop();
|
|
if (n != last_peel) {
|
|
for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = n->fast_out(j);
|
|
if (use->is_CFG() &&
|
|
loop->is_member(get_loop(use)) &&
|
|
!peel.test_set(use->_idx)) {
|
|
worklist.push(use);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Set of non-cfg nodes to peel are those that are control
|
|
// dependent on the cfg nodes.
|
|
for (uint i = 0; i < loop->_body.size(); i++) {
|
|
Node *n = loop->_body.at(i);
|
|
Node *n_c = has_ctrl(n) ? get_ctrl(n) : n;
|
|
if (peel.test(n_c->_idx)) {
|
|
peel.set(n->_idx);
|
|
} else {
|
|
not_peel.set(n->_idx);
|
|
}
|
|
}
|
|
|
|
// Step 2: move operations from the peeled section down into the
|
|
// not-peeled section
|
|
|
|
// Get a post order schedule of nodes in the peel region
|
|
// Result in right-most operand.
|
|
scheduled_nodelist(loop, peel, peel_list);
|
|
|
|
assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition");
|
|
|
|
// For future check for too many new phis
|
|
uint old_phi_cnt = 0;
|
|
for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) {
|
|
Node* use = head->fast_out(j);
|
|
if (use->is_Phi()) old_phi_cnt++;
|
|
}
|
|
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("\npeeled list");
|
|
}
|
|
#endif
|
|
|
|
// Evacuate nodes in peel region into the not_peeled region if possible
|
|
uint new_phi_cnt = 0;
|
|
uint cloned_for_outside_use = 0;
|
|
for (uint i = 0; i < peel_list.size();) {
|
|
Node* n = peel_list.at(i);
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) n->dump();
|
|
#endif
|
|
bool incr = true;
|
|
if (!n->is_CFG()) {
|
|
if (has_use_in_set(n, not_peel)) {
|
|
// If not used internal to the peeled region,
|
|
// move "n" from peeled to not_peeled region.
|
|
if (!has_use_internal_to_set(n, peel, loop)) {
|
|
// if not pinned and not a load (which maybe anti-dependent on a store)
|
|
// and not a CMove (Matcher expects only bool->cmove).
|
|
if (n->in(0) == NULL && !n->is_Load() && !n->is_CMove()) {
|
|
cloned_for_outside_use += clone_for_use_outside_loop(loop, n, worklist);
|
|
sink_list.push(n);
|
|
peel.remove(n->_idx);
|
|
not_peel.set(n->_idx);
|
|
peel_list.remove(i);
|
|
incr = false;
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("sink to not_peeled region: %d newbb: %d",
|
|
n->_idx, get_ctrl(n)->_idx);
|
|
}
|
|
#endif
|
|
}
|
|
} else {
|
|
// Otherwise check for special def-use cases that span
|
|
// the peel/not_peel boundary such as bool->if
|
|
clone_for_special_use_inside_loop(loop, n, not_peel, sink_list, worklist);
|
|
new_phi_cnt++;
|
|
}
|
|
}
|
|
}
|
|
if (incr) i++;
|
|
}
|
|
|
|
estimate += cloned_for_outside_use + new_phi_cnt;
|
|
bool exceed_node_budget = !may_require_nodes(estimate);
|
|
bool exceed_phi_limit = new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta;
|
|
|
|
if (exceed_node_budget || exceed_phi_limit) {
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("\nToo many new phis: %d old %d new cmpi: %c",
|
|
new_phi_cnt, old_phi_cnt, new_peel_if != NULL?'T':'F');
|
|
}
|
|
#endif
|
|
if (new_peel_if != NULL) {
|
|
remove_cmpi_loop_exit(new_peel_if, loop);
|
|
}
|
|
// Inhibit more partial peeling on this loop
|
|
assert(!head->is_partial_peel_loop(), "not partial peeled");
|
|
head->mark_partial_peel_failed();
|
|
if (cloned_for_outside_use > 0) {
|
|
// Terminate this round of loop opts because
|
|
// the graph outside this loop was changed.
|
|
C->set_major_progress();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Step 3: clone loop, retarget control, and insert new phis
|
|
|
|
// Create new loop head for new phis and to hang
|
|
// the nodes being moved (sinked) from the peel region.
|
|
LoopNode* new_head = new LoopNode(last_peel, last_peel);
|
|
new_head->set_unswitch_count(head->unswitch_count()); // Preserve
|
|
_igvn.register_new_node_with_optimizer(new_head);
|
|
assert(first_not_peeled->in(0) == last_peel, "last_peel <- first_not_peeled");
|
|
_igvn.replace_input_of(first_not_peeled, 0, new_head);
|
|
set_loop(new_head, loop);
|
|
loop->_body.push(new_head);
|
|
not_peel.set(new_head->_idx);
|
|
set_idom(new_head, last_peel, dom_depth(first_not_peeled));
|
|
set_idom(first_not_peeled, new_head, dom_depth(first_not_peeled));
|
|
|
|
while (sink_list.size() > 0) {
|
|
Node* n = sink_list.pop();
|
|
set_ctrl(n, new_head);
|
|
}
|
|
|
|
assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition");
|
|
|
|
clone_loop(loop, old_new, dd, IgnoreStripMined);
|
|
|
|
const uint clone_exit_idx = 1;
|
|
const uint orig_exit_idx = 2;
|
|
assert(is_valid_clone_loop_form(loop, peel_list, orig_exit_idx, clone_exit_idx), "bad clone loop");
|
|
|
|
Node* head_clone = old_new[head->_idx];
|
|
LoopNode* new_head_clone = old_new[new_head->_idx]->as_Loop();
|
|
Node* orig_tail_clone = head_clone->in(2);
|
|
|
|
// Add phi if "def" node is in peel set and "use" is not
|
|
|
|
for (uint i = 0; i < peel_list.size(); i++) {
|
|
Node *def = peel_list.at(i);
|
|
if (!def->is_CFG()) {
|
|
for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
|
|
Node *use = def->fast_out(j);
|
|
if (has_node(use) && use->in(0) != C->top() &&
|
|
(!peel.test(use->_idx) ||
|
|
(use->is_Phi() && use->in(0) == head)) ) {
|
|
worklist.push(use);
|
|
}
|
|
}
|
|
while( worklist.size() ) {
|
|
Node *use = worklist.pop();
|
|
for (uint j = 1; j < use->req(); j++) {
|
|
Node* n = use->in(j);
|
|
if (n == def) {
|
|
|
|
// "def" is in peel set, "use" is not in peel set
|
|
// or "use" is in the entry boundary (a phi) of the peel set
|
|
|
|
Node* use_c = has_ctrl(use) ? get_ctrl(use) : use;
|
|
|
|
if ( loop->is_member(get_loop( use_c )) ) {
|
|
// use is in loop
|
|
if (old_new[use->_idx] != NULL) { // null for dead code
|
|
Node* use_clone = old_new[use->_idx];
|
|
_igvn.replace_input_of(use, j, C->top());
|
|
insert_phi_for_loop( use_clone, j, old_new[def->_idx], def, new_head_clone );
|
|
}
|
|
} else {
|
|
assert(is_valid_clone_loop_exit_use(loop, use, orig_exit_idx), "clone loop format");
|
|
// use is not in the loop, check if the live range includes the cut
|
|
Node* lp_if = use_c->in(orig_exit_idx)->in(0);
|
|
if (not_peel.test(lp_if->_idx)) {
|
|
assert(j == orig_exit_idx, "use from original loop");
|
|
insert_phi_for_loop( use, clone_exit_idx, old_new[def->_idx], def, new_head_clone );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Step 3b: retarget control
|
|
|
|
// Redirect control to the new loop head if a cloned node in
|
|
// the not_peeled region has control that points into the peeled region.
|
|
// This necessary because the cloned peeled region will be outside
|
|
// the loop.
|
|
// from to
|
|
// cloned-peeled <---+
|
|
// new_head_clone: | <--+
|
|
// cloned-not_peeled in(0) in(0)
|
|
// orig-peeled
|
|
|
|
for (uint i = 0; i < loop->_body.size(); i++) {
|
|
Node *n = loop->_body.at(i);
|
|
if (!n->is_CFG() && n->in(0) != NULL &&
|
|
not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) {
|
|
Node* n_clone = old_new[n->_idx];
|
|
_igvn.replace_input_of(n_clone, 0, new_head_clone);
|
|
}
|
|
}
|
|
|
|
// Backedge of the surviving new_head (the clone) is original last_peel
|
|
_igvn.replace_input_of(new_head_clone, LoopNode::LoopBackControl, last_peel);
|
|
|
|
// Cut first node in original not_peel set
|
|
_igvn.rehash_node_delayed(new_head); // Multiple edge updates:
|
|
new_head->set_req(LoopNode::EntryControl, C->top()); // use rehash_node_delayed / set_req instead of
|
|
new_head->set_req(LoopNode::LoopBackControl, C->top()); // multiple replace_input_of calls
|
|
|
|
// Copy head_clone back-branch info to original head
|
|
// and remove original head's loop entry and
|
|
// clone head's back-branch
|
|
_igvn.rehash_node_delayed(head); // Multiple edge updates
|
|
head->set_req(LoopNode::EntryControl, head_clone->in(LoopNode::LoopBackControl));
|
|
head->set_req(LoopNode::LoopBackControl, C->top());
|
|
_igvn.replace_input_of(head_clone, LoopNode::LoopBackControl, C->top());
|
|
|
|
// Similarly modify the phis
|
|
for (DUIterator_Fast kmax, k = head->fast_outs(kmax); k < kmax; k++) {
|
|
Node* use = head->fast_out(k);
|
|
if (use->is_Phi() && use->outcnt() > 0) {
|
|
Node* use_clone = old_new[use->_idx];
|
|
_igvn.rehash_node_delayed(use); // Multiple edge updates
|
|
use->set_req(LoopNode::EntryControl, use_clone->in(LoopNode::LoopBackControl));
|
|
use->set_req(LoopNode::LoopBackControl, C->top());
|
|
_igvn.replace_input_of(use_clone, LoopNode::LoopBackControl, C->top());
|
|
}
|
|
}
|
|
|
|
// Step 4: update dominator tree and dominator depth
|
|
|
|
set_idom(head, orig_tail_clone, dd);
|
|
recompute_dom_depth();
|
|
|
|
// Inhibit more partial peeling on this loop
|
|
new_head_clone->set_partial_peel_loop();
|
|
C->set_major_progress();
|
|
loop->record_for_igvn();
|
|
|
|
#ifndef PRODUCT
|
|
if (TracePartialPeeling) {
|
|
tty->print_cr("\nafter partial peel one iteration");
|
|
Node_List wl;
|
|
Node* t = last_peel;
|
|
while (true) {
|
|
wl.push(t);
|
|
if (t == head_clone) break;
|
|
t = idom(t);
|
|
}
|
|
while (wl.size() > 0) {
|
|
Node* tt = wl.pop();
|
|
if (tt == head) tty->print_cr("orig head");
|
|
else if (tt == new_head_clone) tty->print_cr("new head");
|
|
else if (tt == head_clone) tty->print_cr("clone head");
|
|
tt->dump();
|
|
}
|
|
}
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
//------------------------------reorg_offsets----------------------------------
|
|
// Reorganize offset computations to lower register pressure. Mostly
|
|
// prevent loop-fallout uses of the pre-incremented trip counter (which are
|
|
// then alive with the post-incremented trip counter forcing an extra
|
|
// register move)
|
|
void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) {
|
|
// Perform it only for canonical counted loops.
|
|
// Loop's shape could be messed up by iteration_split_impl.
|
|
if (!loop->_head->is_CountedLoop())
|
|
return;
|
|
if (!loop->_head->as_Loop()->is_valid_counted_loop())
|
|
return;
|
|
|
|
CountedLoopNode *cl = loop->_head->as_CountedLoop();
|
|
CountedLoopEndNode *cle = cl->loopexit();
|
|
Node *exit = cle->proj_out(false);
|
|
Node *phi = cl->phi();
|
|
|
|
// Check for the special case when using the pre-incremented trip-counter on
|
|
// the fall-out path (forces the pre-incremented and post-incremented trip
|
|
// counter to be live at the same time). Fix this by adjusting to use the
|
|
// post-increment trip counter.
|
|
|
|
bool progress = true;
|
|
while (progress) {
|
|
progress = false;
|
|
for (DUIterator_Fast imax, i = phi->fast_outs(imax); i < imax; i++) {
|
|
Node* use = phi->fast_out(i); // User of trip-counter
|
|
if (!has_ctrl(use)) continue;
|
|
Node *u_ctrl = get_ctrl(use);
|
|
if (use->is_Phi()) {
|
|
u_ctrl = NULL;
|
|
for (uint j = 1; j < use->req(); j++)
|
|
if (use->in(j) == phi)
|
|
u_ctrl = dom_lca(u_ctrl, use->in(0)->in(j));
|
|
}
|
|
IdealLoopTree *u_loop = get_loop(u_ctrl);
|
|
// Look for loop-invariant use
|
|
if (u_loop == loop) continue;
|
|
if (loop->is_member(u_loop)) continue;
|
|
// Check that use is live out the bottom. Assuming the trip-counter
|
|
// update is right at the bottom, uses of of the loop middle are ok.
|
|
if (dom_lca(exit, u_ctrl) != exit) continue;
|
|
// Hit! Refactor use to use the post-incremented tripcounter.
|
|
// Compute a post-increment tripcounter.
|
|
Node* c = exit;
|
|
if (cl->is_strip_mined()) {
|
|
IdealLoopTree* outer_loop = get_loop(cl->outer_loop());
|
|
if (!outer_loop->is_member(u_loop)) {
|
|
c = cl->outer_loop_exit();
|
|
}
|
|
}
|
|
Node *opaq = new Opaque2Node(C, cle->incr());
|
|
register_new_node(opaq, c);
|
|
Node *neg_stride = _igvn.intcon(-cle->stride_con());
|
|
set_ctrl(neg_stride, C->root());
|
|
Node *post = new AddINode(opaq, neg_stride);
|
|
register_new_node(post, c);
|
|
_igvn.rehash_node_delayed(use);
|
|
for (uint j = 1; j < use->req(); j++) {
|
|
if (use->in(j) == phi)
|
|
use->set_req(j, post);
|
|
}
|
|
// Since DU info changed, rerun loop
|
|
progress = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
}
|