1 /*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "opto/opaquenode.hpp"
27 #include "opto/phaseX.hpp"
28
29 //=============================================================================
30 // Do not allow value-numbering
hash() const31 uint Opaque1Node::hash() const { return NO_HASH; }
cmp(const Node & n) const32 bool Opaque1Node::cmp( const Node &n ) const {
33 return (&n == this); // Always fail except on self
34 }
35
36 //------------------------------Identity---------------------------------------
37 // If _major_progress, then more loop optimizations follow. Do NOT remove
38 // the opaque Node until no more loop ops can happen. Note the timing of
39 // _major_progress; it's set in the major loop optimizations THEN comes the
40 // call to IterGVN and any chance of hitting this code. Hence there's no
41 // phase-ordering problem with stripping Opaque1 in IGVN followed by some
42 // more loop optimizations that require it.
Identity(PhaseGVN * phase)43 Node* Opaque1Node::Identity(PhaseGVN* phase) {
44 return phase->C->major_progress() ? this : in(1);
45 }
46
47 //=============================================================================
48 // A node to prevent unwanted optimizations. Allows constant folding. Stops
49 // value-numbering, most Ideal calls or Identity functions. This Node is
50 // specifically designed to prevent the pre-increment value of a loop trip
51 // counter from being live out of the bottom of the loop (hence causing the
52 // pre- and post-increment values both being live and thus requiring an extra
53 // temp register and an extra move). If we "accidentally" optimize through
54 // this kind of a Node, we'll get slightly pessimal, but correct, code. Thus
55 // it's OK to be slightly sloppy on optimizations here.
56
57 // Do not allow value-numbering
hash() const58 uint Opaque2Node::hash() const { return NO_HASH; }
cmp(const Node & n) const59 bool Opaque2Node::cmp( const Node &n ) const {
60 return (&n == this); // Always fail except on self
61 }
62
Value(PhaseGVN * phase) const63 const Type* Opaque4Node::Value(PhaseGVN* phase) const {
64 return phase->type(in(1));
65 }
66
67 //=============================================================================
68
hash() const69 uint ProfileBooleanNode::hash() const { return NO_HASH; }
cmp(const Node & n) const70 bool ProfileBooleanNode::cmp( const Node &n ) const {
71 return (&n == this);
72 }
73
Ideal(PhaseGVN * phase,bool can_reshape)74 Node *ProfileBooleanNode::Ideal(PhaseGVN *phase, bool can_reshape) {
75 if (can_reshape && _delay_removal) {
76 _delay_removal = false;
77 return this;
78 } else {
79 return NULL;
80 }
81 }
82
Identity(PhaseGVN * phase)83 Node* ProfileBooleanNode::Identity(PhaseGVN* phase) {
84 if (_delay_removal) {
85 return this;
86 } else {
87 assert(_consumed, "profile should be consumed before elimination");
88 return in(1);
89 }
90 }
91