This repository was archived by the owner on Jun 24, 2022. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 2k
Expand file tree
/
Copy pathDFGCommon.h
More file actions
378 lines (317 loc) · 12.7 KB
/
DFGCommon.h
File metadata and controls
378 lines (317 loc) · 12.7 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/*
* Copyright (C) 2011-2020 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "DFGCompilationMode.h"
#if ENABLE(DFG_JIT)
#include "Options.h"
#include <limits.h>
#include <wtf/text/StringImpl.h>
namespace JSC { namespace DFG {
struct Node;
typedef uint32_t BlockIndex;
static constexpr BlockIndex NoBlock = UINT_MAX;
extern const char* const tierName;
// Use RefChildren if the child ref counts haven't already been adjusted using
// other means and either of the following is true:
// - The node you're creating is MustGenerate.
// - The place where you're inserting a reference to the node you're creating
// will not also do RefChildren.
enum RefChildrenMode {
RefChildren,
DontRefChildren
};
// Use RefNode if you know that the node will be used from another node, and you
// will not already be ref'ing the node to account for that use.
enum RefNodeMode {
RefNode,
DontRefNode
};
enum SwitchKind {
SwitchImm,
SwitchChar,
SwitchString,
SwitchCell
};
inline bool verboseCompilationEnabled(CompilationMode mode = DFGMode)
{
return Options::verboseCompilation() || Options::dumpGraphAtEachPhase() || (isFTL(mode) && Options::verboseFTLCompilation());
}
inline bool logCompilationChanges(CompilationMode mode = DFGMode)
{
return verboseCompilationEnabled(mode) || Options::logCompilationChanges();
}
inline bool shouldDumpGraphAtEachPhase(CompilationMode mode)
{
if (isFTL(mode))
return Options::dumpGraphAtEachPhase() || Options::dumpDFGFTLGraphAtEachPhase();
return Options::dumpGraphAtEachPhase() || Options::dumpDFGGraphAtEachPhase();
}
inline bool validationEnabled()
{
#if ASSERT_ENABLED
return true;
#else
return Options::validateGraph() || Options::validateGraphAtEachPhase();
#endif
}
inline bool enableInt52()
{
#if USE(JSVALUE64)
return true;
#else
return false;
#endif
}
// The prediction propagator effectively does four passes, with the last pass
// being done by the separate FixuPhase.
enum PredictionPass {
// We're converging in a straight-forward forward flow fixpoint. This is the
// most conventional part of the propagator - it makes only monotonic decisions
// based on value profiles and rare case profiles. It ignores baseline JIT rare
// case profiles. The goal here is to develop a good guess of which variables
// are likely to be purely numerical, which generally doesn't require knowing
// the rare case profiles.
PrimaryPass,
// At this point we know what is numerical and what isn't. Non-numerical inputs
// to arithmetic operations will not have useful information in the Baseline JIT
// rare case profiles because Baseline may take slow path on non-numerical
// inputs even if the DFG could handle the input on the fast path. Boolean
// inputs are the most obvious example. This pass of prediction propagation will
// use Baseline rare case profiles for purely numerical operations and it will
// ignore them for everything else. The point of this pass is to develop a good
// guess of which variables are likely to be doubles.
//
// This pass is intentionally weird and goes against what is considered good
// form when writing a static analysis: a new data flow of booleans will cause
// us to ignore rare case profiles except that by then, we will have already
// propagated double types based on our prior assumption that we shouldn't
// ignore rare cases. This probably won't happen because the PrimaryPass is
// almost certainly going to establish what is and isn't numerical. But it's
// conceivable that during this pass we will discover a new boolean data flow.
// This ends up being sound because the prediction propagator could literally
// make any guesses it wants and still be sound (worst case, we OSR exit more
// often or use too general of types are run a bit slower). This will converge
// because we force monotonicity on the types of nodes and variables. So, the
// worst thing that can happen is that we violate basic laws of theoretical
// decency.
RareCasePass,
// At this point we know what is numerical and what isn't, and we also know what
// is a double and what isn't. So, we start forcing variables to be double.
// Doing so may have a cascading effect so this is a fixpoint. It's monotonic
// in the sense that once a variable is forced double, it cannot be forced in
// the other direction.
DoubleVotingPass,
// This pass occurs once we have converged. At this point we are just installing
// type checks based on the conclusions we have already reached. It's important
// for this pass to reach the same conclusions that DoubleVotingPass reached.
FixupPass
};
enum StructureRegistrationState { HaveNotStartedRegistering, AllStructuresAreRegistered };
enum StructureRegistrationResult { StructureRegisteredNormally, StructureRegisteredAndWatched };
enum OptimizationFixpointState { BeforeFixpoint, FixpointNotConverged, FixpointConverged };
// Describes the form you can expect the entire graph to be in.
enum GraphForm {
// LoadStore form means that basic blocks may freely use GetLocal, SetLocal,
// and Flush for accessing local variables and indicating where their live
// ranges ought to be. Data flow between local accesses is implicit. Liveness
// is only explicit at block heads (variablesAtHead). This is only used by
// the DFG simplifier and is only preserved by same.
//
// For example, LoadStore form gives no easy way to determine which SetLocal's
// flow into a GetLocal. As well, LoadStore form implies no restrictions on
// redundancy: you can freely emit multiple GetLocals, or multiple SetLocals
// (or any combination thereof) to the same local in the same block. LoadStore
// form does not require basic blocks to declare how they affect or use locals,
// other than implicitly by using the local ops and by preserving
// variablesAtHead. Finally, LoadStore allows flexibility in how liveness of
// locals is extended; for example you can replace a GetLocal with a Phantom
// and so long as the Phantom retains the GetLocal's children (i.e. the Phi
// most likely) then it implies that the local is still live but that it need
// not be stored to the stack necessarily. This implies that Phantom can
// reference nodes that have no result, as long as those nodes are valid
// GetLocal children (i.e. Phi, SetLocal, SetArgumentDefinitely, SetArgumentMaybe).
//
// LoadStore form also implies that Phis need not have children. By default,
// they end up having no children if you enter LoadStore using the canonical
// way (call Graph::dethread).
//
// LoadStore form is suitable for CFG transformations, as well as strength
// reduction, folding, and CSE.
LoadStore,
// ThreadedCPS form means that basic blocks list up-front which locals they
// expect to be live at the head, and which locals they make available at the
// tail. ThreadedCPS form also implies that:
//
// - GetLocals and SetLocals are not redundant within a basic block.
//
// - All GetLocals and Flushes are linked directly to the last access point
// of the variable, which must not be another GetLocal.
//
// - Phantom(Phi) is not legal, but PhantomLocal is.
//
// ThreadedCPS form is suitable for data flow analysis (CFA, prediction
// propagation), register allocation, and code generation.
ThreadedCPS,
// SSA form. See DFGSSAConversionPhase.h for a description.
SSA
};
// Describes the state of the UnionFind structure of VariableAccessData's.
enum UnificationState {
// BasicBlock-local accesses to variables are appropriately unified with each other.
LocallyUnified,
// Unification has been performed globally.
GloballyUnified
};
// Describes how reference counts in the graph behave.
enum RefCountState {
// Everything has refCount() == 1.
EverythingIsLive,
// Set after DCE has run.
ExactRefCount
};
enum OperandSpeculationMode { AutomaticOperandSpeculation, ManualOperandSpeculation };
enum ProofStatus { NeedsCheck, IsProved };
inline bool isProved(ProofStatus proofStatus)
{
ASSERT(proofStatus == IsProved || proofStatus == NeedsCheck);
return proofStatus == IsProved;
}
inline ProofStatus proofStatusForIsProved(bool isProved)
{
return isProved ? IsProved : NeedsCheck;
}
enum KillStatus { DoesNotKill, DoesKill };
inline bool doesKill(KillStatus killStatus)
{
ASSERT(killStatus == DoesNotKill || killStatus == DoesKill);
return killStatus == DoesKill;
}
inline KillStatus killStatusForDoesKill(bool doesKill)
{
return doesKill ? DoesKill : DoesNotKill;
}
enum class PlanStage {
Initial,
AfterFixup
};
// If possible, this will acquire a lock to make sure that if multiple threads
// start crashing at the same time, you get coherent dump output. Use this only
// when you're forcing a crash with diagnostics.
void startCrashing();
JS_EXPORT_PRIVATE bool isCrashing();
struct NodeAndIndex {
NodeAndIndex()
: node(nullptr)
, index(UINT_MAX)
{
}
NodeAndIndex(Node* node, unsigned index)
: node(node)
, index(index)
{
ASSERT(!node == (index == UINT_MAX));
}
bool operator!() const
{
return !node;
}
Node* node;
unsigned index;
};
// A less-than operator for strings that is useful for generating string switches. Sorts by <
// relation on characters. Ensures that if a is a prefix of b, then a < b.
bool stringLessThan(StringImpl& a, StringImpl& b);
} } // namespace JSC::DFG
namespace WTF {
void printInternal(PrintStream&, JSC::DFG::OptimizationFixpointState);
void printInternal(PrintStream&, JSC::DFG::GraphForm);
void printInternal(PrintStream&, JSC::DFG::UnificationState);
void printInternal(PrintStream&, JSC::DFG::RefCountState);
void printInternal(PrintStream&, JSC::DFG::ProofStatus);
} // namespace WTF
#endif // ENABLE(DFG_JIT)
namespace JSC { namespace DFG {
// Put things here that must be defined even if ENABLE(DFG_JIT) is false.
enum CapabilityLevel {
CannotCompile,
CanCompile,
CanCompileAndInline,
CapabilityLevelNotSet
};
inline bool canCompile(CapabilityLevel level)
{
switch (level) {
case CanCompile:
case CanCompileAndInline:
return true;
default:
return false;
}
}
inline bool canInline(CapabilityLevel level)
{
switch (level) {
case CanCompileAndInline:
return true;
default:
return false;
}
}
inline CapabilityLevel leastUpperBound(CapabilityLevel a, CapabilityLevel b)
{
switch (a) {
case CannotCompile:
return CannotCompile;
case CanCompile:
switch (b) {
case CanCompile:
case CanCompileAndInline:
return CanCompile;
default:
return CannotCompile;
}
case CanCompileAndInline:
return b;
case CapabilityLevelNotSet:
ASSERT_NOT_REACHED();
return CannotCompile;
}
ASSERT_NOT_REACHED();
return CannotCompile;
}
// Unconditionally disable DFG disassembly support if the DFG is not compiled in.
inline bool shouldDumpDisassembly(CompilationMode mode = DFGMode)
{
#if ENABLE(DFG_JIT)
return Options::dumpDisassembly() || Options::dumpDFGDisassembly() || (isFTL(mode) && Options::dumpFTLDisassembly());
#else
UNUSED_PARAM(mode);
return false;
#endif
}
} } // namespace JSC::DFG
namespace WTF {
void printInternal(PrintStream&, JSC::DFG::CapabilityLevel);
} // namespace WTF