1/*
2 * Copyright (C) 2017 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#include "config.h"
27#include "AirRegLiveness.h"
28
29#if ENABLE(B3_JIT)
30
31#include "AirArgInlines.h"
32#include "AirInstInlines.h"
33
34namespace JSC { namespace B3 { namespace Air {
35
36RegLiveness::RegLiveness(Code& code)
37 : m_liveAtHead(code.size())
38 , m_liveAtTail(code.size())
39 , m_actions(code.size())
40{
41 // Compute constraints.
42 for (BasicBlock* block : code) {
43 ActionsForBoundary& actionsForBoundary = m_actions[block];
44 actionsForBoundary.resize(block->size() + 1);
45
46 for (size_t instIndex = block->size(); instIndex--;) {
47 Inst& inst = block->at(instIndex);
48 inst.forEach<Reg>(
49 [&] (Reg& reg, Arg::Role role, Bank, Width) {
50 if (Arg::isEarlyUse(role))
51 actionsForBoundary[instIndex].use.add(reg);
52 if (Arg::isEarlyDef(role))
53 actionsForBoundary[instIndex].def.add(reg);
54 if (Arg::isLateUse(role))
55 actionsForBoundary[instIndex + 1].use.add(reg);
56 if (Arg::isLateDef(role))
57 actionsForBoundary[instIndex + 1].def.add(reg);
58 });
59 }
60 }
61
62 // The liveAtTail of each block automatically contains the LateUse's of the terminal.
63 for (BasicBlock* block : code) {
64 RegisterSet& liveAtTail = m_liveAtTail[block];
65
66 block->last().forEach<Reg>(
67 [&] (Reg& reg, Arg::Role role, Bank, Width) {
68 if (Arg::isLateUse(role))
69 liveAtTail.add(reg);
70 });
71 }
72
73 BitVector dirtyBlocks;
74 for (size_t blockIndex = code.size(); blockIndex--;)
75 dirtyBlocks.set(blockIndex);
76
77 bool changed;
78 do {
79 changed = false;
80
81 for (size_t blockIndex = code.size(); blockIndex--;) {
82 BasicBlock* block = code[blockIndex];
83 if (!block)
84 continue;
85
86 if (!dirtyBlocks.quickClear(blockIndex))
87 continue;
88
89 LocalCalc localCalc(*this, block);
90 for (size_t instIndex = block->size(); instIndex--;)
91 localCalc.execute(instIndex);
92
93 // Handle the early def's of the first instruction.
94 block->at(0).forEach<Reg>(
95 [&] (Reg& reg, Arg::Role role, Bank, Width) {
96 if (Arg::isEarlyDef(role))
97 localCalc.m_workset.remove(reg);
98 });
99
100 RegisterSet& liveAtHead = m_liveAtHead[block];
101 if (liveAtHead.subsumes(localCalc.m_workset))
102 continue;
103
104 liveAtHead.merge(localCalc.m_workset);
105
106 for (BasicBlock* predecessor : block->predecessors()) {
107 RegisterSet& liveAtTail = m_liveAtTail[predecessor];
108 if (liveAtTail.subsumes(localCalc.m_workset))
109 continue;
110
111 liveAtTail.merge(localCalc.m_workset);
112 dirtyBlocks.quickSet(predecessor->index());
113 changed = true;
114 }
115 }
116 } while (changed);
117}
118
119RegLiveness::~RegLiveness()
120{
121}
122
123RegLiveness::LocalCalcForUnifiedTmpLiveness::LocalCalcForUnifiedTmpLiveness(UnifiedTmpLiveness& liveness, BasicBlock* block)
124 : LocalCalcBase(block)
125 , m_code(liveness.code)
126 , m_actions(liveness.actions[block])
127{
128 for (Tmp tmp : liveness.liveAtTail(block)) {
129 if (tmp.isReg())
130 m_workset.add(tmp.reg());
131 }
132}
133
134void RegLiveness::LocalCalcForUnifiedTmpLiveness::execute(unsigned instIndex)
135{
136 for (unsigned index : m_actions[instIndex + 1].def) {
137 Tmp tmp = Tmp::tmpForLinearIndex(m_code, index);
138 if (tmp.isReg())
139 m_workset.remove(tmp.reg());
140 }
141 for (unsigned index : m_actions[instIndex].use) {
142 Tmp tmp = Tmp::tmpForLinearIndex(m_code, index);
143 if (tmp.isReg())
144 m_workset.add(tmp.reg());
145 }
146}
147
148} } } // namespace JSC::B3::Air
149
150#endif // ENABLE(B3_JIT)
151
152