summaryrefslogtreecommitdiffstats
path: root/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp
blob: 95472e12887f3eaccf75f979362f3b634e744165 (plain)
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
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
/*
 * Copyright (C) 2011 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. 
 */

#include "config.h"
#include "DFGSpeculativeJIT.h"

#if ENABLE(DFG_JIT)

namespace JSC { namespace DFG {

template<bool strict>
GPRReg SpeculativeJIT::fillSpeculateIntInternal(NodeIndex nodeIndex, DataFormat& returnFormat)
{
    Node& node = m_jit.graph()[nodeIndex];
    VirtualRegister virtualRegister = node.virtualRegister;
    GenerationInfo& info = m_generationInfo[virtualRegister];

    switch (info.registerFormat()) {
    case DataFormatNone: {
        GPRReg gpr = allocate();
        JITCompiler::RegisterID reg = JITCompiler::gprToRegisterID(gpr);

        if (node.isConstant()) {
            m_gprs.retain(gpr, virtualRegister, SpillOrderConstant);
            if (isInt32Constant(nodeIndex)) {
                m_jit.move(MacroAssembler::Imm32(valueOfInt32Constant(nodeIndex)), reg);
                info.fillInteger(gpr);
                returnFormat = DataFormatInteger;
                return gpr;
            }
            m_jit.move(constantAsJSValueAsImmPtr(nodeIndex), reg);
        } else if (node.isArgument()) {
            m_gprs.retain(gpr, virtualRegister, SpillOrderArgument);
            m_jit.loadPtr(m_jit.addressForArgument(m_jit.graph()[nodeIndex].argumentNumber()), reg);
        } else {
            DataFormat spillFormat = info.spillFormat();
            ASSERT(spillFormat & DataFormatJS);

            m_gprs.retain(gpr, virtualRegister, SpillOrderSpilled);

            if (spillFormat == DataFormatJSInteger) {
                // If we know this was spilled as an integer we can fill without checking.
                if (strict) {
                    m_jit.load32(JITCompiler::addressFor(virtualRegister), reg);
                    info.fillInteger(gpr);
                    returnFormat = DataFormatInteger;
                    return gpr;
                }
                m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), reg);
                info.fillJSValue(gpr, DataFormatJSInteger);
                returnFormat = DataFormatJSInteger;
                return gpr;
            }
            m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), reg);
        }

        // Fill as JSValue, and fall through.
        info.fillJSValue(gpr, DataFormatJSInteger);
        m_gprs.unlock(gpr);
    }

    case DataFormatJS: {
        // Check the value is an integer.
        GPRReg gpr = info.gpr();
        m_gprs.lock(gpr);
        JITCompiler::RegisterID reg = JITCompiler::gprToRegisterID(gpr);
        speculationCheck(m_jit.branchPtr(MacroAssembler::Below, reg, JITCompiler::tagTypeNumberRegister));
        info.fillJSValue(gpr, DataFormatJSInteger);
        // If !strict we're done, return.
        if (!strict) {
            returnFormat = DataFormatJSInteger;
            return gpr;
        }
        // else fall through & handle as DataFormatJSInteger.
        m_gprs.unlock(gpr);
    }

    case DataFormatJSInteger: {
        // In a strict fill we need to strip off the value tag.
        if (strict) {
            GPRReg gpr = info.gpr();
            GPRReg result;
            // If the register has already been locked we need to take a copy.
            // If not, we'll zero extend in place, so mark on the info that this is now type DataFormatInteger, not DataFormatJSInteger.
            if (m_gprs.isLocked(gpr))
                result = allocate();
            else {
                m_gprs.lock(gpr);
                info.fillInteger(gpr);
                result = gpr;
            }
            m_jit.zeroExtend32ToPtr(JITCompiler::gprToRegisterID(gpr), JITCompiler::gprToRegisterID(result));
            returnFormat = DataFormatInteger;
            return result;
        }

        GPRReg gpr = info.gpr();
        m_gprs.lock(gpr);
        returnFormat = DataFormatJSInteger;
        return gpr;
    }

    case DataFormatInteger: {
        GPRReg gpr = info.gpr();
        m_gprs.lock(gpr);
        returnFormat = DataFormatInteger;
        return gpr;
    }

    case DataFormatDouble:
    case DataFormatCell:
    case DataFormatJSDouble:
    case DataFormatJSCell: {
        terminateSpeculativeExecution();
        returnFormat = DataFormatInteger;
        return allocate();
    }
    }

    ASSERT_NOT_REACHED();
    return InvalidGPRReg;
}

SpeculationCheck::SpeculationCheck(MacroAssembler::Jump check, SpeculativeJIT* jit, unsigned recoveryIndex)
    : m_check(check)
    , m_nodeIndex(jit->m_compileIndex)
    , m_recoveryIndex(recoveryIndex)
{
    for (GPRReg gpr = gpr0; gpr < numberOfGPRs; next(gpr)) {
        VirtualRegister virtualRegister = jit->m_gprs.name(gpr);
        if (virtualRegister != InvalidVirtualRegister) {
            GenerationInfo& info =  jit->m_generationInfo[virtualRegister];
            m_gprInfo[gpr].nodeIndex = info.nodeIndex();
            m_gprInfo[gpr].format = info.registerFormat();
        } else
            m_gprInfo[gpr].nodeIndex = NoNode;
    }
    for (FPRReg fpr = fpr0; fpr < numberOfFPRs; next(fpr)) {
        VirtualRegister virtualRegister = jit->m_fprs.name(fpr);
        if (virtualRegister != InvalidVirtualRegister) {
            GenerationInfo& info =  jit->m_generationInfo[virtualRegister];
            ASSERT(info.registerFormat() == DataFormatDouble);
            m_fprInfo[fpr] = info.nodeIndex();
        } else
            m_fprInfo[fpr] = NoNode;
    }
}

GPRReg SpeculativeJIT::fillSpeculateInt(NodeIndex nodeIndex, DataFormat& returnFormat)
{
    return fillSpeculateIntInternal<false>(nodeIndex, returnFormat);
}

GPRReg SpeculativeJIT::fillSpeculateIntStrict(NodeIndex nodeIndex)
{
    DataFormat mustBeDataFormatInteger;
    GPRReg result = fillSpeculateIntInternal<true>(nodeIndex, mustBeDataFormatInteger);
    ASSERT(mustBeDataFormatInteger == DataFormatInteger);
    return result;
}

GPRReg SpeculativeJIT::fillSpeculateCell(NodeIndex nodeIndex)
{
    Node& node = m_jit.graph()[nodeIndex];
    VirtualRegister virtualRegister = node.virtualRegister;
    GenerationInfo& info = m_generationInfo[virtualRegister];

    switch (info.registerFormat()) {
    case DataFormatNone: {
        GPRReg gpr = allocate();
        JITCompiler::RegisterID reg = JITCompiler::gprToRegisterID(gpr);

        if (node.isConstant()) {
            m_gprs.retain(gpr, virtualRegister, SpillOrderConstant);
            JSValue jsValue = constantAsJSValue(nodeIndex);
            if (jsValue.isCell()) {
                m_jit.move(MacroAssembler::TrustedImmPtr(jsValue.asCell()), reg);
                info.fillJSValue(gpr, DataFormatJSCell);
                return gpr;
            }
            terminateSpeculativeExecution();
            return gpr;
        }
        if (node.isArgument()) {
            m_gprs.retain(gpr, virtualRegister, SpillOrderArgument);
            m_jit.loadPtr(m_jit.addressForArgument(m_jit.graph()[nodeIndex].argumentNumber()), reg);
            speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, reg, JITCompiler::tagMaskRegister));
            info.fillJSValue(gpr, DataFormatJSCell);
            return gpr;
        }
        ASSERT(info.spillFormat() & DataFormatJS);
        m_gprs.retain(gpr, virtualRegister, SpillOrderSpilled);
        m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), reg);

        if (info.spillFormat() != DataFormatJSCell)
            speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, reg, JITCompiler::tagMaskRegister));
        info.fillJSValue(gpr, DataFormatJSCell);
        return gpr;
    }

    case DataFormatCell:
    case DataFormatJSCell: {
        GPRReg gpr = info.gpr();
        m_gprs.lock(gpr);
        return gpr;
    }

    case DataFormatJS: {
        GPRReg gpr = info.gpr();
        m_gprs.lock(gpr);
        JITCompiler::RegisterID reg = JITCompiler::gprToRegisterID(gpr);
        speculationCheck(m_jit.branchTestPtr(MacroAssembler::NonZero, reg, JITCompiler::tagMaskRegister));
        info.fillJSValue(gpr, DataFormatJSCell);
        return gpr;
    }

    case DataFormatJSInteger:
    case DataFormatInteger:
    case DataFormatJSDouble:
    case DataFormatDouble: {
        terminateSpeculativeExecution();
        return allocate();
    }
    }

    ASSERT_NOT_REACHED();
    return InvalidGPRReg;
}

bool SpeculativeJIT::compile(Node& node)
{
    checkConsistency();

    NodeType op = node.op;

    switch (op) {
    case Int32Constant:
    case DoubleConstant:
    case JSConstant:
        initConstantInfo(m_compileIndex);
        break;
    
    case Argument:
        initArgumentInfo(m_compileIndex);
        break;

    case BitAnd:
    case BitOr:
    case BitXor:
        if (isInt32Constant(node.child1)) {
            SpeculateIntegerOperand op2(this, node.child2);
            GPRTemporary result(this, op2);

            bitOp(op, valueOfInt32Constant(node.child1), op2.registerID(), result.registerID());

            integerResult(result.gpr(), m_compileIndex);
        } else if (isInt32Constant(node.child2)) {
            SpeculateIntegerOperand op1(this, node.child1);
            GPRTemporary result(this, op1);

            bitOp(op, valueOfInt32Constant(node.child2), op1.registerID(), result.registerID());

            integerResult(result.gpr(), m_compileIndex);
        } else {
            SpeculateIntegerOperand op1(this, node.child1);
            SpeculateIntegerOperand op2(this, node.child2);
            GPRTemporary result(this, op1, op2);

            MacroAssembler::RegisterID reg1 = op1.registerID();
            MacroAssembler::RegisterID reg2 = op2.registerID();
            bitOp(op, reg1, reg2, result.registerID());

            integerResult(result.gpr(), m_compileIndex);
        }
        break;

    case BitRShift:
    case BitLShift:
    case BitURShift:
        if (isInt32Constant(node.child2)) {
            SpeculateIntegerOperand op1(this, node.child1);
            GPRTemporary result(this, op1);

            shiftOp(op, op1.registerID(), valueOfInt32Constant(node.child2) & 0x1f, result.registerID());

            integerResult(result.gpr(), m_compileIndex);
        } else {
            // Do not allow shift amount to be used as the result, MacroAssembler does not permit this.
            SpeculateIntegerOperand op1(this, node.child1);
            SpeculateIntegerOperand op2(this, node.child2);
            GPRTemporary result(this, op1);

            MacroAssembler::RegisterID reg1 = op1.registerID();
            MacroAssembler::RegisterID reg2 = op2.registerID();
            shiftOp(op, reg1, reg2, result.registerID());

            integerResult(result.gpr(), m_compileIndex);
        }
        break;

    case UInt32ToNumber: {
        IntegerOperand op1(this, node.child1);
        GPRTemporary result(this, op1);

        // Test the operand is positive.
        speculationCheck(m_jit.branch32(MacroAssembler::LessThan, op1.registerID(), TrustedImm32(0)));

        m_jit.move(op1.registerID(), result.registerID());
        integerResult(result.gpr(), m_compileIndex, op1.format());
        break;
    }

    case NumberToInt32: {
        SpeculateIntegerOperand op1(this, node.child1);
        GPRTemporary result(this, op1);
        m_jit.move(op1.registerID(), result.registerID());
        integerResult(result.gpr(), m_compileIndex, op1.format());
        break;
    }

    case Int32ToNumber: {
        SpeculateIntegerOperand op1(this, node.child1);
        GPRTemporary result(this, op1);
        m_jit.move(op1.registerID(), result.registerID());
        integerResult(result.gpr(), m_compileIndex, op1.format());
        break;
    }
    case ValueToInt32: {
        SpeculateIntegerOperand op1(this, node.child1);
        GPRTemporary result(this, op1);
        m_jit.move(op1.registerID(), result.registerID());
        integerResult(result.gpr(), m_compileIndex, op1.format());
        break;
    }

    case ValueToNumber: {
        SpeculateIntegerOperand op1(this, node.child1);
        GPRTemporary result(this, op1);
        m_jit.move(op1.registerID(), result.registerID());
        integerResult(result.gpr(), m_compileIndex, op1.format());
        break;
    }

    case ValueAdd:
    case ArithAdd: {
        SpeculateIntegerOperand op1(this, node.child1);
        SpeculateIntegerOperand op2(this, node.child2);
        GPRTemporary result(this, op1, op2);

        GPRReg gpr1 = op1.gpr();
        GPRReg gpr2 = op2.gpr();
        GPRReg gprResult = result.gpr();
        MacroAssembler::Jump check = m_jit.branchAdd32(MacroAssembler::Overflow, JITCompiler::gprToRegisterID(gpr1), JITCompiler::gprToRegisterID(gpr2), JITCompiler::gprToRegisterID(gprResult));

        if (gpr1 == gprResult)
            speculationCheck(check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr2));
        else if (gpr2 == gprResult)
            speculationCheck(check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr1));
        else
            speculationCheck(check);

        integerResult(gprResult, m_compileIndex);
        break;
    }

    case ArithSub: {
        SpeculateIntegerOperand op1(this, node.child1);
        SpeculateIntegerOperand op2(this, node.child2);
        GPRTemporary result(this);

        MacroAssembler::RegisterID reg1 = op1.registerID();
        MacroAssembler::RegisterID reg2 = op2.registerID();
        speculationCheck(m_jit.branchSub32(MacroAssembler::Overflow, reg1, reg2, result.registerID()));

        integerResult(result.gpr(), m_compileIndex);
        break;
    }

    case ArithMul: {
        SpeculateIntegerOperand op1(this, node.child1);
        SpeculateIntegerOperand op2(this, node.child2);
        GPRTemporary result(this);

        MacroAssembler::RegisterID reg1 = op1.registerID();
        MacroAssembler::RegisterID reg2 = op2.registerID();
        speculationCheck(m_jit.branchMul32(MacroAssembler::Overflow, reg1, reg2, result.registerID()));
        speculationCheck(m_jit.branchTest32(MacroAssembler::Zero, result.registerID()));

        integerResult(result.gpr(), m_compileIndex);
        break;
    }

    case ArithDiv: {
        SpeculateIntegerOperand op1(this, node.child1);
        SpeculateIntegerOperand op2(this, node.child2);
        GPRTemporary result(this, op1, op2);

        terminateSpeculativeExecution();

        integerResult(result.gpr(), m_compileIndex);
        break;
    }

    case ArithMod: {
        SpeculateIntegerOperand op1(this, node.child1);
        SpeculateIntegerOperand op2(this, node.child2);
        GPRTemporary result(this, op1, op2);

        terminateSpeculativeExecution();

        integerResult(result.gpr(), m_compileIndex);
        break;
    }

    case GetByVal: {
        NodeIndex alias = node.child3;
        if (alias != NoNode) {
            // FIXME: result should be able to reuse child1, child2. Should have an 'UnusedOperand' type.
            JSValueOperand aliasedValue(this, node.child3);
            GPRTemporary result(this, aliasedValue);
            m_jit.move(aliasedValue.registerID(), result.registerID());
            jsValueResult(result.gpr(), m_compileIndex);
            break;
        }

        SpeculateCellOperand base(this, node.child1);
        SpeculateStrictInt32Operand property(this, node.child2);
        GPRTemporary storage(this);

        MacroAssembler::RegisterID baseReg = base.registerID();
        MacroAssembler::RegisterID propertyReg = property.registerID();
        MacroAssembler::RegisterID storageReg = storage.registerID();

        // Get the array storage. We haven't yet checked this is a JSArray, so this is only safe if
        // an access with offset JSArray::storageOffset() is valid for all JSCells!
        m_jit.loadPtr(MacroAssembler::Address(baseReg, JSArray::storageOffset()), storageReg);

        // Check that base is an array, and that property is contained within m_vector (< m_vectorLength).
        speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, MacroAssembler::Address(baseReg), MacroAssembler::TrustedImmPtr(m_jit.globalData()->jsArrayVPtr)));
        speculationCheck(m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(baseReg, JSArray::vectorLengthOffset())));

        // FIXME: In cases where there are subsequent by_val accesses to the same base it might help to cache
        // the storage pointer - especially if there happens to be another register free right now. If we do so,
        // then we'll need to allocate a new temporary for result.
        GPRTemporary& result = storage;
        m_jit.loadPtr(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])), result.registerID());
        speculationCheck(m_jit.branchTestPtr(MacroAssembler::Zero, result.registerID()));

        jsValueResult(result.gpr(), m_compileIndex);
        break;
    }

    case PutByVal:
    case PutByValAlias: {
        SpeculateStrictInt32Operand property(this, node.child2);
        GPRTemporary storage(this);

        MacroAssembler::RegisterID propertyReg;
        MacroAssembler::RegisterID storageReg;

        // This block also defines the scope for base, and all bails to the non-speculative path.
        // At the end of this scope base will be release, and as such may be reused by for 'value'.
        //
        // If we've already read from this location on the speculative pass, then it cannot be beyond array bounds, or a hole.
        if (op == PutByValAlias) {
            SpeculateCellOperand base(this, node.child1);

            // Map base & property into registers, allocate a register for storage.
            propertyReg = property.registerID();
            storageReg = storage.registerID();
            MacroAssembler::RegisterID baseReg = base.registerID();

            // Get the array storage.
            m_jit.loadPtr(MacroAssembler::Address(baseReg, JSArray::storageOffset()), storageReg);
        } else {
            SpeculateCellOperand base(this, node.child1);

            // Map base & property into registers, allocate a register for storage.
            propertyReg = property.registerID();
            storageReg = storage.registerID();
            MacroAssembler::RegisterID baseReg = base.registerID();

            // Check that base is an array, and that property is contained within m_vector (< m_vectorLength).
            speculationCheck(m_jit.branchPtr(MacroAssembler::NotEqual, MacroAssembler::Address(baseReg), MacroAssembler::TrustedImmPtr(m_jit.globalData()->jsArrayVPtr)));
            speculationCheck(m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(baseReg, JSArray::vectorLengthOffset())));

            // Get the array storage.
            m_jit.loadPtr(MacroAssembler::Address(baseReg, JSArray::storageOffset()), storageReg);

            // Check if we're writing to a hole; if so increment m_numValuesInVector.
            MacroAssembler::Jump notHoleValue = m_jit.branchTestPtr(MacroAssembler::NonZero, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
            m_jit.add32(TrustedImm32(1), MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_numValuesInVector)));

            // If we're writing to a hole we might be growing the array; 
            MacroAssembler::Jump lengthDoesNotNeedUpdate = m_jit.branch32(MacroAssembler::Below, propertyReg, MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_length)));
            m_jit.add32(TrustedImm32(1), propertyReg);
            m_jit.store32(propertyReg, MacroAssembler::Address(storageReg, OBJECT_OFFSETOF(ArrayStorage, m_length)));
            m_jit.sub32(TrustedImm32(1), propertyReg);

            lengthDoesNotNeedUpdate.link(&m_jit);
            notHoleValue.link(&m_jit);
        }
        // After this point base goes out of scope. This may free the register.
        // As such, after this point we'd better not have any bails out to the non-speculative path!

        // Store the value to the array.
        JSValueOperand value(this, node.child3);
        MacroAssembler::RegisterID valueReg = value.registerID();
        m_jit.storePtr(valueReg, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));

        noResult(m_compileIndex);
        break;
    }

    case Return: {
        ASSERT(JITCompiler::callFrameRegister != JITCompiler::regT1);
        ASSERT(JITCompiler::regT1 != JITCompiler::returnValueRegister);
        ASSERT(JITCompiler::returnValueRegister != JITCompiler::callFrameRegister);

        // Return the result in returnValueRegister.
        JSValueOperand op1(this, node.child1);
        m_jit.move(op1.registerID(), JITCompiler::returnValueRegister);

        // Grab the return address.
        m_jit.emitGetFromCallFrameHeaderPtr(RegisterFile::ReturnPC, JITCompiler::regT1);
        // Restore our caller's "r".
        m_jit.emitGetFromCallFrameHeaderPtr(RegisterFile::CallerFrame, JITCompiler::callFrameRegister);
        // Return.
        m_jit.restoreReturnAddressBeforeReturn(JITCompiler::regT1);
        m_jit.ret();
        
        noResult(m_compileIndex);
        break;
    }

    case ConvertThis: {
        SpeculateCellOperand thisValue(this, node.child1);
        GPRTemporary temp(this);

        m_jit.loadPtr(JITCompiler::Address(thisValue.registerID(), JSCell::structureOffset()), temp.registerID());
        speculationCheck(m_jit.branchTest8(JITCompiler::NonZero, JITCompiler::Address(temp.registerID(), Structure::typeInfoFlagsOffset()), JITCompiler::TrustedImm32(NeedsThisConversion)));

        cellResult(thisValue.gpr(), m_compileIndex);
        break;
    }

    case GetById: {
        JSValueOperand base(this, node.child1);
        GPRReg baseGPR = base.gpr();
        flushRegisters();

        GPRResult result(this);
        callOperation(operationGetById, result.gpr(), baseGPR, identifier(node.identifierNumber()));
        jsValueResult(result.gpr(), m_compileIndex);
        break;
    }

    case PutById: {
        JSValueOperand base(this, node.child1);
        JSValueOperand value(this, node.child2);
        GPRReg valueGPR = value.gpr();
        GPRReg baseGPR = base.gpr();
        flushRegisters();

        callOperation(m_jit.codeBlock()->isStrictMode() ? operationPutByIdStrict : operationPutByIdNonStrict, valueGPR, baseGPR, identifier(node.identifierNumber()));
        noResult(m_compileIndex);
        break;
    }

    case PutByIdDirect: {
        JSValueOperand base(this, node.child1);
        JSValueOperand value(this, node.child2);
        GPRReg valueGPR = value.gpr();
        GPRReg baseGPR = base.gpr();
        flushRegisters();

        callOperation(m_jit.codeBlock()->isStrictMode() ? operationPutByIdDirectStrict : operationPutByIdDirectNonStrict, valueGPR, baseGPR, identifier(node.identifierNumber()));
        noResult(m_compileIndex);
        break;
    }

    case GetGlobalVar: {
        GPRTemporary result(this);

        JSVariableObject* globalObject = m_jit.codeBlock()->globalObject();
        m_jit.loadPtr(globalObject->addressOfRegisters(), result.registerID());
        m_jit.loadPtr(JITCompiler::addressForGlobalVar(result.registerID(), node.varNumber()), result.registerID());

        jsValueResult(result.gpr(), m_compileIndex);
        break;
    }

    case PutGlobalVar: {
        JSValueOperand value(this, node.child1);
        GPRTemporary temp(this);

        JSVariableObject* globalObject = m_jit.codeBlock()->globalObject();
        m_jit.loadPtr(globalObject->addressOfRegisters(), temp.registerID());
        m_jit.storePtr(value.registerID(), JITCompiler::addressForGlobalVar(temp.registerID(), node.varNumber()));

        noResult(m_compileIndex);
        break;
    }
    }

    // Check if generation for the speculative path has failed catastrophically. :-)
    // In the future, we may want to throw away the code we've generated in this case.
    // For now, there is no point generating any further code, return immediately.
    if (m_didTerminate)
        return false;

    if (node.mustGenerate())
        use(m_compileIndex);

    checkConsistency();

    return true;
}

bool SpeculativeJIT::compile()
{
    ASSERT(!m_compileIndex);
    Node* nodes = m_jit.graph().begin();

    for (; m_compileIndex < m_jit.graph().size(); ++m_compileIndex) {
#if DFG_DEBUG_VERBOSE
        fprintf(stderr, "index(%d)\n", (int)m_compileIndex);
#endif

        Node& node = nodes[m_compileIndex];
        if (!node.refCount)
            continue;
        if (!compile(node))
            return false;
    }
    return true;
}

} } // namespace JSC::DFG

#endif