1/*
2 * Copyright (C) 2013 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#if ENABLE(FTL_JIT)
29
30#include "DFGBasicBlock.h"
31#include "FTLAbbreviatedTypes.h"
32
33namespace JSC { namespace FTL {
34
35// Represents the act of having lowered a DFG::Node to an LValue, and records the
36// DFG::BasicBlock that did the lowering. The LValue is what we use most often, but
37// we need to verify that we're in a block that is dominated by the one that did
38// the lowering. We're guaranteed that for each DFG::Node, there will be one
39// LoweredNodeValue that always dominates all uses of the DFG::Node; but there may
40// be others that don't dominate and we're effectively doing opportunistic GVN on
41// the lowering code.
42
43class LoweredNodeValue {
44public:
45 LoweredNodeValue()
46 : m_value(0)
47 , m_block(0)
48 {
49 }
50
51 LoweredNodeValue(LValue value, DFG::BasicBlock* block)
52 : m_value(value)
53 , m_block(block)
54 {
55 ASSERT(m_value);
56 ASSERT(m_block);
57 }
58
59 bool isSet() const { return !!m_value; }
60 bool operator!() const { return !isSet(); }
61
62 LValue value() const { return m_value; }
63 DFG::BasicBlock* block() const { return m_block; }
64
65private:
66 LValue m_value;
67 DFG::BasicBlock* m_block;
68};
69
70} } // namespace JSC::FTL
71
72#endif // ENABLE(FTL_JIT)
73