Regression(r188105): Seems to have caused crashes during PLT on some iPads
[WebKit-https.git] / Source / JavaScriptCore / dfg / DFGSpeculativeJIT.cpp
1 /*
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25
26 #include "config.h"
27 #include "DFGSpeculativeJIT.h"
28
29 #if ENABLE(DFG_JIT)
30
31 #include "BinarySwitch.h"
32 #include "DFGAbstractInterpreterInlines.h"
33 #include "DFGArrayifySlowPathGenerator.h"
34 #include "DFGCallArrayAllocatorSlowPathGenerator.h"
35 #include "DFGCallCreateDirectArgumentsSlowPathGenerator.h"
36 #include "DFGMayExit.h"
37 #include "DFGOSRExitFuzz.h"
38 #include "DFGSaneStringGetByValSlowPathGenerator.h"
39 #include "DFGSlowPathGenerator.h"
40 #include "DirectArguments.h"
41 #include "JSCInlines.h"
42 #include "JSEnvironmentRecord.h"
43 #include "JSLexicalEnvironment.h"
44 #include "LinkBuffer.h"
45 #include "ScopedArguments.h"
46 #include "ScratchRegisterAllocator.h"
47 #include "WriteBarrierBuffer.h"
48 #include <wtf/MathExtras.h>
49
50 namespace JSC { namespace DFG {
51
52 SpeculativeJIT::SpeculativeJIT(JITCompiler& jit)
53     : m_compileOkay(true)
54     , m_jit(jit)
55     , m_currentNode(0)
56     , m_lastGeneratedNode(LastNodeType)
57     , m_indexInBlock(0)
58     , m_generationInfo(m_jit.graph().frameRegisterCount())
59     , m_state(m_jit.graph())
60     , m_interpreter(m_jit.graph(), m_state)
61     , m_stream(&jit.jitCode()->variableEventStream)
62     , m_minifiedGraph(&jit.jitCode()->minifiedDFG)
63     , m_isCheckingArgumentTypes(false)
64 {
65 }
66
67 SpeculativeJIT::~SpeculativeJIT()
68 {
69 }
70
71 void SpeculativeJIT::emitAllocateJSArray(GPRReg resultGPR, Structure* structure, GPRReg storageGPR, unsigned numElements)
72 {
73     ASSERT(hasUndecided(structure->indexingType()) || hasInt32(structure->indexingType()) || hasDouble(structure->indexingType()) || hasContiguous(structure->indexingType()));
74     
75     GPRTemporary scratch(this);
76     GPRTemporary scratch2(this);
77     GPRReg scratchGPR = scratch.gpr();
78     GPRReg scratch2GPR = scratch2.gpr();
79     
80     unsigned vectorLength = std::max(BASE_VECTOR_LEN, numElements);
81     
82     JITCompiler::JumpList slowCases;
83     
84     slowCases.append(
85         emitAllocateBasicStorage(TrustedImm32(vectorLength * sizeof(JSValue) + sizeof(IndexingHeader)), storageGPR));
86     m_jit.subPtr(TrustedImm32(vectorLength * sizeof(JSValue)), storageGPR);
87     emitAllocateJSObject<JSArray>(resultGPR, TrustedImmPtr(structure), storageGPR, scratchGPR, scratch2GPR, slowCases);
88     
89     m_jit.store32(TrustedImm32(numElements), MacroAssembler::Address(storageGPR, Butterfly::offsetOfPublicLength()));
90     m_jit.store32(TrustedImm32(vectorLength), MacroAssembler::Address(storageGPR, Butterfly::offsetOfVectorLength()));
91     
92     if (hasDouble(structure->indexingType()) && numElements < vectorLength) {
93 #if USE(JSVALUE64)
94         m_jit.move(TrustedImm64(bitwise_cast<int64_t>(PNaN)), scratchGPR);
95         for (unsigned i = numElements; i < vectorLength; ++i)
96             m_jit.store64(scratchGPR, MacroAssembler::Address(storageGPR, sizeof(double) * i));
97 #else
98         EncodedValueDescriptor value;
99         value.asInt64 = JSValue::encode(JSValue(JSValue::EncodeAsDouble, PNaN));
100         for (unsigned i = numElements; i < vectorLength; ++i) {
101             m_jit.store32(TrustedImm32(value.asBits.tag), MacroAssembler::Address(storageGPR, sizeof(double) * i + OBJECT_OFFSETOF(JSValue, u.asBits.tag)));
102             m_jit.store32(TrustedImm32(value.asBits.payload), MacroAssembler::Address(storageGPR, sizeof(double) * i + OBJECT_OFFSETOF(JSValue, u.asBits.payload)));
103         }
104 #endif
105     }
106     
107     // I want a slow path that also loads out the storage pointer, and that's
108     // what this custom CallArrayAllocatorSlowPathGenerator gives me. It's a lot
109     // of work for a very small piece of functionality. :-/
110     addSlowPathGenerator(std::make_unique<CallArrayAllocatorSlowPathGenerator>(
111         slowCases, this, operationNewArrayWithSize, resultGPR, storageGPR,
112         structure, numElements));
113 }
114
115 void SpeculativeJIT::emitGetLength(InlineCallFrame* inlineCallFrame, GPRReg lengthGPR, bool includeThis)
116 {
117     if (inlineCallFrame && !inlineCallFrame->isVarargs())
118         m_jit.move(TrustedImm32(inlineCallFrame->arguments.size() - !includeThis), lengthGPR);
119     else {
120         VirtualRegister argumentCountRegister;
121         if (!inlineCallFrame)
122             argumentCountRegister = VirtualRegister(JSStack::ArgumentCount);
123         else
124             argumentCountRegister = inlineCallFrame->argumentCountRegister;
125         m_jit.load32(JITCompiler::payloadFor(argumentCountRegister), lengthGPR);
126         if (!includeThis)
127             m_jit.sub32(TrustedImm32(1), lengthGPR);
128     }
129 }
130
131 void SpeculativeJIT::emitGetLength(CodeOrigin origin, GPRReg lengthGPR, bool includeThis)
132 {
133     emitGetLength(origin.inlineCallFrame, lengthGPR, includeThis);
134 }
135
136 void SpeculativeJIT::emitGetCallee(CodeOrigin origin, GPRReg calleeGPR)
137 {
138     if (origin.inlineCallFrame) {
139         if (origin.inlineCallFrame->isClosureCall) {
140             m_jit.loadPtr(
141                 JITCompiler::addressFor(origin.inlineCallFrame->calleeRecovery.virtualRegister()),
142                 calleeGPR);
143         } else {
144             m_jit.move(
145                 TrustedImmPtr(origin.inlineCallFrame->calleeRecovery.constant().asCell()),
146                 calleeGPR);
147         }
148     } else
149         m_jit.loadPtr(JITCompiler::addressFor(JSStack::Callee), calleeGPR);
150 }
151
152 void SpeculativeJIT::emitGetArgumentStart(CodeOrigin origin, GPRReg startGPR)
153 {
154     m_jit.addPtr(
155         TrustedImm32(
156             JITCompiler::argumentsStart(origin).offset() * static_cast<int>(sizeof(Register))),
157         GPRInfo::callFrameRegister, startGPR);
158 }
159
160 MacroAssembler::Jump SpeculativeJIT::emitOSRExitFuzzCheck()
161 {
162     if (!doOSRExitFuzzing())
163         return MacroAssembler::Jump();
164     
165     MacroAssembler::Jump result;
166     
167     m_jit.pushToSave(GPRInfo::regT0);
168     m_jit.load32(&g_numberOfOSRExitFuzzChecks, GPRInfo::regT0);
169     m_jit.add32(TrustedImm32(1), GPRInfo::regT0);
170     m_jit.store32(GPRInfo::regT0, &g_numberOfOSRExitFuzzChecks);
171     unsigned atOrAfter = Options::fireOSRExitFuzzAtOrAfter();
172     unsigned at = Options::fireOSRExitFuzzAt();
173     if (at || atOrAfter) {
174         unsigned threshold;
175         MacroAssembler::RelationalCondition condition;
176         if (atOrAfter) {
177             threshold = atOrAfter;
178             condition = MacroAssembler::Below;
179         } else {
180             threshold = at;
181             condition = MacroAssembler::NotEqual;
182         }
183         MacroAssembler::Jump ok = m_jit.branch32(
184             condition, GPRInfo::regT0, MacroAssembler::TrustedImm32(threshold));
185         m_jit.popToRestore(GPRInfo::regT0);
186         result = m_jit.jump();
187         ok.link(&m_jit);
188     }
189     m_jit.popToRestore(GPRInfo::regT0);
190     
191     return result;
192 }
193
194 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Node* node, MacroAssembler::Jump jumpToFail)
195 {
196     if (!m_compileOkay)
197         return;
198     ASSERT(m_isCheckingArgumentTypes || m_canExit);
199     JITCompiler::Jump fuzzJump = emitOSRExitFuzzCheck();
200     if (fuzzJump.isSet()) {
201         JITCompiler::JumpList jumpsToFail;
202         jumpsToFail.append(fuzzJump);
203         jumpsToFail.append(jumpToFail);
204         m_jit.appendExitInfo(jumpsToFail);
205     } else
206         m_jit.appendExitInfo(jumpToFail);
207     m_jit.jitCode()->appendOSRExit(OSRExit(kind, jsValueSource, m_jit.graph().methodOfGettingAValueProfileFor(node), this, m_stream->size()));
208 }
209
210 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Node* node, const MacroAssembler::JumpList& jumpsToFail)
211 {
212     if (!m_compileOkay)
213         return;
214     ASSERT(m_isCheckingArgumentTypes || m_canExit);
215     JITCompiler::Jump fuzzJump = emitOSRExitFuzzCheck();
216     if (fuzzJump.isSet()) {
217         JITCompiler::JumpList myJumpsToFail;
218         myJumpsToFail.append(jumpsToFail);
219         myJumpsToFail.append(fuzzJump);
220         m_jit.appendExitInfo(myJumpsToFail);
221     } else
222         m_jit.appendExitInfo(jumpsToFail);
223     m_jit.jitCode()->appendOSRExit(OSRExit(kind, jsValueSource, m_jit.graph().methodOfGettingAValueProfileFor(node), this, m_stream->size()));
224 }
225
226 OSRExitJumpPlaceholder SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Node* node)
227 {
228     if (!m_compileOkay)
229         return OSRExitJumpPlaceholder();
230     ASSERT(m_isCheckingArgumentTypes || m_canExit);
231     unsigned index = m_jit.jitCode()->osrExit.size();
232     m_jit.appendExitInfo();
233     m_jit.jitCode()->appendOSRExit(OSRExit(kind, jsValueSource, m_jit.graph().methodOfGettingAValueProfileFor(node), this, m_stream->size()));
234     return OSRExitJumpPlaceholder(index);
235 }
236
237 OSRExitJumpPlaceholder SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Edge nodeUse)
238 {
239     ASSERT(m_isCheckingArgumentTypes || m_canExit);
240     return speculationCheck(kind, jsValueSource, nodeUse.node());
241 }
242
243 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Edge nodeUse, MacroAssembler::Jump jumpToFail)
244 {
245     ASSERT(m_isCheckingArgumentTypes || m_canExit);
246     speculationCheck(kind, jsValueSource, nodeUse.node(), jumpToFail);
247 }
248
249 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Edge nodeUse, const MacroAssembler::JumpList& jumpsToFail)
250 {
251     ASSERT(m_isCheckingArgumentTypes || m_canExit);
252     speculationCheck(kind, jsValueSource, nodeUse.node(), jumpsToFail);
253 }
254
255 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Node* node, MacroAssembler::Jump jumpToFail, const SpeculationRecovery& recovery)
256 {
257     if (!m_compileOkay)
258         return;
259     ASSERT(m_isCheckingArgumentTypes || m_canExit);
260     unsigned recoveryIndex = m_jit.jitCode()->appendSpeculationRecovery(recovery);
261     m_jit.appendExitInfo(jumpToFail);
262     m_jit.jitCode()->appendOSRExit(OSRExit(kind, jsValueSource, m_jit.graph().methodOfGettingAValueProfileFor(node), this, m_stream->size(), recoveryIndex));
263 }
264
265 void SpeculativeJIT::speculationCheck(ExitKind kind, JSValueSource jsValueSource, Edge nodeUse, MacroAssembler::Jump jumpToFail, const SpeculationRecovery& recovery)
266 {
267     ASSERT(m_isCheckingArgumentTypes || m_canExit);
268     speculationCheck(kind, jsValueSource, nodeUse.node(), jumpToFail, recovery);
269 }
270
271 void SpeculativeJIT::emitInvalidationPoint(Node* node)
272 {
273     if (!m_compileOkay)
274         return;
275     ASSERT(m_canExit);
276     OSRExitCompilationInfo& info = m_jit.appendExitInfo(JITCompiler::JumpList());
277     m_jit.jitCode()->appendOSRExit(OSRExit(
278         UncountableInvalidation, JSValueSource(),
279         m_jit.graph().methodOfGettingAValueProfileFor(node),
280         this, m_stream->size()));
281     info.m_replacementSource = m_jit.watchpointLabel();
282     ASSERT(info.m_replacementSource.isSet());
283     noResult(node);
284 }
285
286 void SpeculativeJIT::terminateSpeculativeExecution(ExitKind kind, JSValueRegs jsValueRegs, Node* node)
287 {
288     ASSERT(m_isCheckingArgumentTypes || m_canExit);
289     if (!m_compileOkay)
290         return;
291     speculationCheck(kind, jsValueRegs, node, m_jit.jump());
292     m_compileOkay = false;
293     if (verboseCompilationEnabled())
294         dataLog("Bailing compilation.\n");
295 }
296
297 void SpeculativeJIT::terminateSpeculativeExecution(ExitKind kind, JSValueRegs jsValueRegs, Edge nodeUse)
298 {
299     ASSERT(m_isCheckingArgumentTypes || m_canExit);
300     terminateSpeculativeExecution(kind, jsValueRegs, nodeUse.node());
301 }
302
303 void SpeculativeJIT::typeCheck(JSValueSource source, Edge edge, SpeculatedType typesPassedThrough, MacroAssembler::Jump jumpToFail)
304 {
305     ASSERT(needsTypeCheck(edge, typesPassedThrough));
306     m_interpreter.filter(edge, typesPassedThrough);
307     speculationCheck(BadType, source, edge.node(), jumpToFail);
308 }
309
310 RegisterSet SpeculativeJIT::usedRegisters()
311 {
312     RegisterSet result;
313     
314     for (unsigned i = GPRInfo::numberOfRegisters; i--;) {
315         GPRReg gpr = GPRInfo::toRegister(i);
316         if (m_gprs.isInUse(gpr))
317             result.set(gpr);
318     }
319     for (unsigned i = FPRInfo::numberOfRegisters; i--;) {
320         FPRReg fpr = FPRInfo::toRegister(i);
321         if (m_fprs.isInUse(fpr))
322             result.set(fpr);
323     }
324     
325     result.merge(RegisterSet::specialRegisters());
326     
327     return result;
328 }
329
330 void SpeculativeJIT::addSlowPathGenerator(std::unique_ptr<SlowPathGenerator> slowPathGenerator)
331 {
332     m_slowPathGenerators.append(WTF::move(slowPathGenerator));
333 }
334
335 void SpeculativeJIT::runSlowPathGenerators()
336 {
337     for (unsigned i = 0; i < m_slowPathGenerators.size(); ++i)
338         m_slowPathGenerators[i]->generate(this);
339 }
340
341 // On Windows we need to wrap fmod; on other platforms we can call it directly.
342 // On ARMv7 we assert that all function pointers have to low bit set (point to thumb code).
343 #if CALLING_CONVENTION_IS_STDCALL || CPU(ARM_THUMB2)
344 static double JIT_OPERATION fmodAsDFGOperation(double x, double y)
345 {
346     return fmod(x, y);
347 }
348 #else
349 #define fmodAsDFGOperation fmod
350 #endif
351
352 void SpeculativeJIT::clearGenerationInfo()
353 {
354     for (unsigned i = 0; i < m_generationInfo.size(); ++i)
355         m_generationInfo[i] = GenerationInfo();
356     m_gprs = RegisterBank<GPRInfo>();
357     m_fprs = RegisterBank<FPRInfo>();
358 }
359
360 SilentRegisterSavePlan SpeculativeJIT::silentSavePlanForGPR(VirtualRegister spillMe, GPRReg source)
361 {
362     GenerationInfo& info = generationInfoFromVirtualRegister(spillMe);
363     Node* node = info.node();
364     DataFormat registerFormat = info.registerFormat();
365     ASSERT(registerFormat != DataFormatNone);
366     ASSERT(registerFormat != DataFormatDouble);
367         
368     SilentSpillAction spillAction;
369     SilentFillAction fillAction;
370         
371     if (!info.needsSpill())
372         spillAction = DoNothingForSpill;
373     else {
374 #if USE(JSVALUE64)
375         ASSERT(info.gpr() == source);
376         if (registerFormat == DataFormatInt32)
377             spillAction = Store32Payload;
378         else if (registerFormat == DataFormatCell || registerFormat == DataFormatStorage)
379             spillAction = StorePtr;
380         else if (registerFormat == DataFormatInt52 || registerFormat == DataFormatStrictInt52)
381             spillAction = Store64;
382         else {
383             ASSERT(registerFormat & DataFormatJS);
384             spillAction = Store64;
385         }
386 #elif USE(JSVALUE32_64)
387         if (registerFormat & DataFormatJS) {
388             ASSERT(info.tagGPR() == source || info.payloadGPR() == source);
389             spillAction = source == info.tagGPR() ? Store32Tag : Store32Payload;
390         } else {
391             ASSERT(info.gpr() == source);
392             spillAction = Store32Payload;
393         }
394 #endif
395     }
396         
397     if (registerFormat == DataFormatInt32) {
398         ASSERT(info.gpr() == source);
399         ASSERT(isJSInt32(info.registerFormat()));
400         if (node->hasConstant()) {
401             ASSERT(node->isInt32Constant());
402             fillAction = SetInt32Constant;
403         } else
404             fillAction = Load32Payload;
405     } else if (registerFormat == DataFormatBoolean) {
406 #if USE(JSVALUE64)
407         RELEASE_ASSERT_NOT_REACHED();
408 #if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
409         fillAction = DoNothingForFill;
410 #endif
411 #elif USE(JSVALUE32_64)
412         ASSERT(info.gpr() == source);
413         if (node->hasConstant()) {
414             ASSERT(node->isBooleanConstant());
415             fillAction = SetBooleanConstant;
416         } else
417             fillAction = Load32Payload;
418 #endif
419     } else if (registerFormat == DataFormatCell) {
420         ASSERT(info.gpr() == source);
421         if (node->hasConstant()) {
422             DFG_ASSERT(m_jit.graph(), m_currentNode, node->isCellConstant());
423             node->asCell(); // To get the assertion.
424             fillAction = SetCellConstant;
425         } else {
426 #if USE(JSVALUE64)
427             fillAction = LoadPtr;
428 #else
429             fillAction = Load32Payload;
430 #endif
431         }
432     } else if (registerFormat == DataFormatStorage) {
433         ASSERT(info.gpr() == source);
434         fillAction = LoadPtr;
435     } else if (registerFormat == DataFormatInt52) {
436         if (node->hasConstant())
437             fillAction = SetInt52Constant;
438         else if (info.spillFormat() == DataFormatInt52)
439             fillAction = Load64;
440         else if (info.spillFormat() == DataFormatStrictInt52)
441             fillAction = Load64ShiftInt52Left;
442         else if (info.spillFormat() == DataFormatNone)
443             fillAction = Load64;
444         else {
445             RELEASE_ASSERT_NOT_REACHED();
446 #if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
447             fillAction = Load64; // Make GCC happy.
448 #endif
449         }
450     } else if (registerFormat == DataFormatStrictInt52) {
451         if (node->hasConstant())
452             fillAction = SetStrictInt52Constant;
453         else if (info.spillFormat() == DataFormatInt52)
454             fillAction = Load64ShiftInt52Right;
455         else if (info.spillFormat() == DataFormatStrictInt52)
456             fillAction = Load64;
457         else if (info.spillFormat() == DataFormatNone)
458             fillAction = Load64;
459         else {
460             RELEASE_ASSERT_NOT_REACHED();
461 #if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
462             fillAction = Load64; // Make GCC happy.
463 #endif
464         }
465     } else {
466         ASSERT(registerFormat & DataFormatJS);
467 #if USE(JSVALUE64)
468         ASSERT(info.gpr() == source);
469         if (node->hasConstant()) {
470             if (node->isCellConstant())
471                 fillAction = SetTrustedJSConstant;
472             else
473                 fillAction = SetJSConstant;
474         } else if (info.spillFormat() == DataFormatInt32) {
475             ASSERT(registerFormat == DataFormatJSInt32);
476             fillAction = Load32PayloadBoxInt;
477         } else
478             fillAction = Load64;
479 #else
480         ASSERT(info.tagGPR() == source || info.payloadGPR() == source);
481         if (node->hasConstant())
482             fillAction = info.tagGPR() == source ? SetJSConstantTag : SetJSConstantPayload;
483         else if (info.payloadGPR() == source)
484             fillAction = Load32Payload;
485         else { // Fill the Tag
486             switch (info.spillFormat()) {
487             case DataFormatInt32:
488                 ASSERT(registerFormat == DataFormatJSInt32);
489                 fillAction = SetInt32Tag;
490                 break;
491             case DataFormatCell:
492                 ASSERT(registerFormat == DataFormatJSCell);
493                 fillAction = SetCellTag;
494                 break;
495             case DataFormatBoolean:
496                 ASSERT(registerFormat == DataFormatJSBoolean);
497                 fillAction = SetBooleanTag;
498                 break;
499             default:
500                 fillAction = Load32Tag;
501                 break;
502             }
503         }
504 #endif
505     }
506         
507     return SilentRegisterSavePlan(spillAction, fillAction, node, source);
508 }
509     
510 SilentRegisterSavePlan SpeculativeJIT::silentSavePlanForFPR(VirtualRegister spillMe, FPRReg source)
511 {
512     GenerationInfo& info = generationInfoFromVirtualRegister(spillMe);
513     Node* node = info.node();
514     ASSERT(info.registerFormat() == DataFormatDouble);
515
516     SilentSpillAction spillAction;
517     SilentFillAction fillAction;
518         
519     if (!info.needsSpill())
520         spillAction = DoNothingForSpill;
521     else {
522         ASSERT(!node->hasConstant());
523         ASSERT(info.spillFormat() == DataFormatNone);
524         ASSERT(info.fpr() == source);
525         spillAction = StoreDouble;
526     }
527         
528 #if USE(JSVALUE64)
529     if (node->hasConstant()) {
530         node->asNumber(); // To get the assertion.
531         fillAction = SetDoubleConstant;
532     } else {
533         ASSERT(info.spillFormat() == DataFormatNone || info.spillFormat() == DataFormatDouble);
534         fillAction = LoadDouble;
535     }
536 #elif USE(JSVALUE32_64)
537     ASSERT(info.registerFormat() == DataFormatDouble);
538     if (node->hasConstant()) {
539         node->asNumber(); // To get the assertion.
540         fillAction = SetDoubleConstant;
541     } else
542         fillAction = LoadDouble;
543 #endif
544
545     return SilentRegisterSavePlan(spillAction, fillAction, node, source);
546 }
547     
548 void SpeculativeJIT::silentSpill(const SilentRegisterSavePlan& plan)
549 {
550     switch (plan.spillAction()) {
551     case DoNothingForSpill:
552         break;
553     case Store32Tag:
554         m_jit.store32(plan.gpr(), JITCompiler::tagFor(plan.node()->virtualRegister()));
555         break;
556     case Store32Payload:
557         m_jit.store32(plan.gpr(), JITCompiler::payloadFor(plan.node()->virtualRegister()));
558         break;
559     case StorePtr:
560         m_jit.storePtr(plan.gpr(), JITCompiler::addressFor(plan.node()->virtualRegister()));
561         break;
562 #if USE(JSVALUE64)
563     case Store64:
564         m_jit.store64(plan.gpr(), JITCompiler::addressFor(plan.node()->virtualRegister()));
565         break;
566 #endif
567     case StoreDouble:
568         m_jit.storeDouble(plan.fpr(), JITCompiler::addressFor(plan.node()->virtualRegister()));
569         break;
570     default:
571         RELEASE_ASSERT_NOT_REACHED();
572     }
573 }
574     
575 void SpeculativeJIT::silentFill(const SilentRegisterSavePlan& plan, GPRReg canTrample)
576 {
577 #if USE(JSVALUE32_64)
578     UNUSED_PARAM(canTrample);
579 #endif
580     switch (plan.fillAction()) {
581     case DoNothingForFill:
582         break;
583     case SetInt32Constant:
584         m_jit.move(Imm32(plan.node()->asInt32()), plan.gpr());
585         break;
586 #if USE(JSVALUE64)
587     case SetInt52Constant:
588         m_jit.move(Imm64(plan.node()->asMachineInt() << JSValue::int52ShiftAmount), plan.gpr());
589         break;
590     case SetStrictInt52Constant:
591         m_jit.move(Imm64(plan.node()->asMachineInt()), plan.gpr());
592         break;
593 #endif // USE(JSVALUE64)
594     case SetBooleanConstant:
595         m_jit.move(TrustedImm32(plan.node()->asBoolean()), plan.gpr());
596         break;
597     case SetCellConstant:
598         m_jit.move(TrustedImmPtr(plan.node()->asCell()), plan.gpr());
599         break;
600 #if USE(JSVALUE64)
601     case SetTrustedJSConstant:
602         m_jit.move(valueOfJSConstantAsImm64(plan.node()).asTrustedImm64(), plan.gpr());
603         break;
604     case SetJSConstant:
605         m_jit.move(valueOfJSConstantAsImm64(plan.node()), plan.gpr());
606         break;
607     case SetDoubleConstant:
608         m_jit.move(Imm64(reinterpretDoubleToInt64(plan.node()->asNumber())), canTrample);
609         m_jit.move64ToDouble(canTrample, plan.fpr());
610         break;
611     case Load32PayloadBoxInt:
612         m_jit.load32(JITCompiler::payloadFor(plan.node()->virtualRegister()), plan.gpr());
613         m_jit.or64(GPRInfo::tagTypeNumberRegister, plan.gpr());
614         break;
615     case Load32PayloadConvertToInt52:
616         m_jit.load32(JITCompiler::payloadFor(plan.node()->virtualRegister()), plan.gpr());
617         m_jit.signExtend32ToPtr(plan.gpr(), plan.gpr());
618         m_jit.lshift64(TrustedImm32(JSValue::int52ShiftAmount), plan.gpr());
619         break;
620     case Load32PayloadSignExtend:
621         m_jit.load32(JITCompiler::payloadFor(plan.node()->virtualRegister()), plan.gpr());
622         m_jit.signExtend32ToPtr(plan.gpr(), plan.gpr());
623         break;
624 #else
625     case SetJSConstantTag:
626         m_jit.move(Imm32(plan.node()->asJSValue().tag()), plan.gpr());
627         break;
628     case SetJSConstantPayload:
629         m_jit.move(Imm32(plan.node()->asJSValue().payload()), plan.gpr());
630         break;
631     case SetInt32Tag:
632         m_jit.move(TrustedImm32(JSValue::Int32Tag), plan.gpr());
633         break;
634     case SetCellTag:
635         m_jit.move(TrustedImm32(JSValue::CellTag), plan.gpr());
636         break;
637     case SetBooleanTag:
638         m_jit.move(TrustedImm32(JSValue::BooleanTag), plan.gpr());
639         break;
640     case SetDoubleConstant:
641         m_jit.loadDouble(TrustedImmPtr(m_jit.addressOfDoubleConstant(plan.node())), plan.fpr());
642         break;
643 #endif
644     case Load32Tag:
645         m_jit.load32(JITCompiler::tagFor(plan.node()->virtualRegister()), plan.gpr());
646         break;
647     case Load32Payload:
648         m_jit.load32(JITCompiler::payloadFor(plan.node()->virtualRegister()), plan.gpr());
649         break;
650     case LoadPtr:
651         m_jit.loadPtr(JITCompiler::addressFor(plan.node()->virtualRegister()), plan.gpr());
652         break;
653 #if USE(JSVALUE64)
654     case Load64:
655         m_jit.load64(JITCompiler::addressFor(plan.node()->virtualRegister()), plan.gpr());
656         break;
657     case Load64ShiftInt52Right:
658         m_jit.load64(JITCompiler::addressFor(plan.node()->virtualRegister()), plan.gpr());
659         m_jit.rshift64(TrustedImm32(JSValue::int52ShiftAmount), plan.gpr());
660         break;
661     case Load64ShiftInt52Left:
662         m_jit.load64(JITCompiler::addressFor(plan.node()->virtualRegister()), plan.gpr());
663         m_jit.lshift64(TrustedImm32(JSValue::int52ShiftAmount), plan.gpr());
664         break;
665 #endif
666     case LoadDouble:
667         m_jit.loadDouble(JITCompiler::addressFor(plan.node()->virtualRegister()), plan.fpr());
668         break;
669     default:
670         RELEASE_ASSERT_NOT_REACHED();
671     }
672 }
673     
674 JITCompiler::Jump SpeculativeJIT::jumpSlowForUnwantedArrayMode(GPRReg tempGPR, ArrayMode arrayMode, IndexingType shape)
675 {
676     switch (arrayMode.arrayClass()) {
677     case Array::OriginalArray: {
678         CRASH();
679 #if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
680         JITCompiler::Jump result; // I already know that VC++ takes unkindly to the expression "return Jump()", so I'm doing it this way in anticipation of someone eventually using VC++ to compile the DFG.
681         return result;
682 #endif
683     }
684         
685     case Array::Array:
686         m_jit.and32(TrustedImm32(IsArray | IndexingShapeMask), tempGPR);
687         return m_jit.branch32(
688             MacroAssembler::NotEqual, tempGPR, TrustedImm32(IsArray | shape));
689         
690     case Array::NonArray:
691     case Array::OriginalNonArray:
692         m_jit.and32(TrustedImm32(IsArray | IndexingShapeMask), tempGPR);
693         return m_jit.branch32(
694             MacroAssembler::NotEqual, tempGPR, TrustedImm32(shape));
695         
696     case Array::PossiblyArray:
697         m_jit.and32(TrustedImm32(IndexingShapeMask), tempGPR);
698         return m_jit.branch32(MacroAssembler::NotEqual, tempGPR, TrustedImm32(shape));
699     }
700     
701     RELEASE_ASSERT_NOT_REACHED();
702     return JITCompiler::Jump();
703 }
704
705 JITCompiler::JumpList SpeculativeJIT::jumpSlowForUnwantedArrayMode(GPRReg tempGPR, ArrayMode arrayMode)
706 {
707     JITCompiler::JumpList result;
708     
709     switch (arrayMode.type()) {
710     case Array::Int32:
711         return jumpSlowForUnwantedArrayMode(tempGPR, arrayMode, Int32Shape);
712
713     case Array::Double:
714         return jumpSlowForUnwantedArrayMode(tempGPR, arrayMode, DoubleShape);
715
716     case Array::Contiguous:
717         return jumpSlowForUnwantedArrayMode(tempGPR, arrayMode, ContiguousShape);
718
719     case Array::ArrayStorage:
720     case Array::SlowPutArrayStorage: {
721         ASSERT(!arrayMode.isJSArrayWithOriginalStructure());
722         
723         if (arrayMode.isJSArray()) {
724             if (arrayMode.isSlowPut()) {
725                 result.append(
726                     m_jit.branchTest32(
727                         MacroAssembler::Zero, tempGPR, MacroAssembler::TrustedImm32(IsArray)));
728                 m_jit.and32(TrustedImm32(IndexingShapeMask), tempGPR);
729                 m_jit.sub32(TrustedImm32(ArrayStorageShape), tempGPR);
730                 result.append(
731                     m_jit.branch32(
732                         MacroAssembler::Above, tempGPR,
733                         TrustedImm32(SlowPutArrayStorageShape - ArrayStorageShape)));
734                 break;
735             }
736             m_jit.and32(TrustedImm32(IsArray | IndexingShapeMask), tempGPR);
737             result.append(
738                 m_jit.branch32(MacroAssembler::NotEqual, tempGPR, TrustedImm32(IsArray | ArrayStorageShape)));
739             break;
740         }
741         m_jit.and32(TrustedImm32(IndexingShapeMask), tempGPR);
742         if (arrayMode.isSlowPut()) {
743             m_jit.sub32(TrustedImm32(ArrayStorageShape), tempGPR);
744             result.append(
745                 m_jit.branch32(
746                     MacroAssembler::Above, tempGPR,
747                     TrustedImm32(SlowPutArrayStorageShape - ArrayStorageShape)));
748             break;
749         }
750         result.append(
751             m_jit.branch32(MacroAssembler::NotEqual, tempGPR, TrustedImm32(ArrayStorageShape)));
752         break;
753     }
754     default:
755         CRASH();
756         break;
757     }
758     
759     return result;
760 }
761
762 void SpeculativeJIT::checkArray(Node* node)
763 {
764     ASSERT(node->arrayMode().isSpecific());
765     ASSERT(!node->arrayMode().doesConversion());
766     
767     SpeculateCellOperand base(this, node->child1());
768     GPRReg baseReg = base.gpr();
769     
770     if (node->arrayMode().alreadyChecked(m_jit.graph(), node, m_state.forNode(node->child1()))) {
771         noResult(m_currentNode);
772         return;
773     }
774     
775     const ClassInfo* expectedClassInfo = 0;
776     
777     switch (node->arrayMode().type()) {
778     case Array::String:
779         RELEASE_ASSERT_NOT_REACHED(); // Should have been a Phantom(String:)
780         break;
781     case Array::Int32:
782     case Array::Double:
783     case Array::Contiguous:
784     case Array::ArrayStorage:
785     case Array::SlowPutArrayStorage: {
786         GPRTemporary temp(this);
787         GPRReg tempGPR = temp.gpr();
788         m_jit.load8(MacroAssembler::Address(baseReg, JSCell::indexingTypeOffset()), tempGPR);
789         speculationCheck(
790             BadIndexingType, JSValueSource::unboxedCell(baseReg), 0,
791             jumpSlowForUnwantedArrayMode(tempGPR, node->arrayMode()));
792         
793         noResult(m_currentNode);
794         return;
795     }
796     case Array::DirectArguments:
797         speculateCellTypeWithoutTypeFiltering(node->child1(), baseReg, DirectArgumentsType);
798         noResult(m_currentNode);
799         return;
800     case Array::ScopedArguments:
801         speculateCellTypeWithoutTypeFiltering(node->child1(), baseReg, ScopedArgumentsType);
802         noResult(m_currentNode);
803         return;
804     default:
805         speculateCellTypeWithoutTypeFiltering(
806             node->child1(), baseReg,
807             typeForTypedArrayType(node->arrayMode().typedArrayType()));
808         noResult(m_currentNode);
809         return;
810     }
811     
812     RELEASE_ASSERT(expectedClassInfo);
813     
814     GPRTemporary temp(this);
815     GPRTemporary temp2(this);
816     m_jit.emitLoadStructure(baseReg, temp.gpr(), temp2.gpr());
817     speculationCheck(
818         BadType, JSValueSource::unboxedCell(baseReg), node,
819         m_jit.branchPtr(
820             MacroAssembler::NotEqual,
821             MacroAssembler::Address(temp.gpr(), Structure::classInfoOffset()),
822             MacroAssembler::TrustedImmPtr(expectedClassInfo)));
823     
824     noResult(m_currentNode);
825 }
826
827 void SpeculativeJIT::arrayify(Node* node, GPRReg baseReg, GPRReg propertyReg)
828 {
829     ASSERT(node->arrayMode().doesConversion());
830     
831     GPRTemporary temp(this);
832     GPRTemporary structure;
833     GPRReg tempGPR = temp.gpr();
834     GPRReg structureGPR = InvalidGPRReg;
835     
836     if (node->op() != ArrayifyToStructure) {
837         GPRTemporary realStructure(this);
838         structure.adopt(realStructure);
839         structureGPR = structure.gpr();
840     }
841         
842     // We can skip all that comes next if we already have array storage.
843     MacroAssembler::JumpList slowPath;
844     
845     if (node->op() == ArrayifyToStructure) {
846         slowPath.append(m_jit.branchWeakStructure(
847             JITCompiler::NotEqual,
848             JITCompiler::Address(baseReg, JSCell::structureIDOffset()),
849             node->structure()));
850     } else {
851         m_jit.load8(
852             MacroAssembler::Address(baseReg, JSCell::indexingTypeOffset()), tempGPR);
853         
854         slowPath.append(jumpSlowForUnwantedArrayMode(tempGPR, node->arrayMode()));
855     }
856     
857     addSlowPathGenerator(std::make_unique<ArrayifySlowPathGenerator>(
858         slowPath, this, node, baseReg, propertyReg, tempGPR, structureGPR));
859     
860     noResult(m_currentNode);
861 }
862
863 void SpeculativeJIT::arrayify(Node* node)
864 {
865     ASSERT(node->arrayMode().isSpecific());
866     
867     SpeculateCellOperand base(this, node->child1());
868     
869     if (!node->child2()) {
870         arrayify(node, base.gpr(), InvalidGPRReg);
871         return;
872     }
873     
874     SpeculateInt32Operand property(this, node->child2());
875     
876     arrayify(node, base.gpr(), property.gpr());
877 }
878
879 GPRReg SpeculativeJIT::fillStorage(Edge edge)
880 {
881     VirtualRegister virtualRegister = edge->virtualRegister();
882     GenerationInfo& info = generationInfoFromVirtualRegister(virtualRegister);
883     
884     switch (info.registerFormat()) {
885     case DataFormatNone: {
886         if (info.spillFormat() == DataFormatStorage) {
887             GPRReg gpr = allocate();
888             m_gprs.retain(gpr, virtualRegister, SpillOrderSpilled);
889             m_jit.loadPtr(JITCompiler::addressFor(virtualRegister), gpr);
890             info.fillStorage(*m_stream, gpr);
891             return gpr;
892         }
893         
894         // Must be a cell; fill it as a cell and then return the pointer.
895         return fillSpeculateCell(edge);
896     }
897         
898     case DataFormatStorage: {
899         GPRReg gpr = info.gpr();
900         m_gprs.lock(gpr);
901         return gpr;
902     }
903         
904     default:
905         return fillSpeculateCell(edge);
906     }
907 }
908
909 void SpeculativeJIT::useChildren(Node* node)
910 {
911     if (node->flags() & NodeHasVarArgs) {
912         for (unsigned childIdx = node->firstChild(); childIdx < node->firstChild() + node->numChildren(); childIdx++) {
913             if (!!m_jit.graph().m_varArgChildren[childIdx])
914                 use(m_jit.graph().m_varArgChildren[childIdx]);
915         }
916     } else {
917         Edge child1 = node->child1();
918         if (!child1) {
919             ASSERT(!node->child2() && !node->child3());
920             return;
921         }
922         use(child1);
923         
924         Edge child2 = node->child2();
925         if (!child2) {
926             ASSERT(!node->child3());
927             return;
928         }
929         use(child2);
930         
931         Edge child3 = node->child3();
932         if (!child3)
933             return;
934         use(child3);
935     }
936 }
937
938 void SpeculativeJIT::compileIn(Node* node)
939 {
940     SpeculateCellOperand base(this, node->child2());
941     GPRReg baseGPR = base.gpr();
942     
943     if (JSString* string = node->child1()->dynamicCastConstant<JSString*>()) {
944         if (string->tryGetValueImpl() && string->tryGetValueImpl()->isAtomic()) {
945             StructureStubInfo* stubInfo = m_jit.codeBlock()->addStubInfo();
946             
947             GPRTemporary result(this);
948             GPRReg resultGPR = result.gpr();
949
950             use(node->child1());
951             
952             MacroAssembler::PatchableJump jump = m_jit.patchableJump();
953             MacroAssembler::Label done = m_jit.label();
954             
955             // Since this block is executed only when the result of string->tryGetValueImpl() is atomic,
956             // we can cast it to const AtomicStringImpl* safely.
957             auto slowPath = slowPathCall(
958                 jump.m_jump, this, operationInOptimize,
959                 JSValueRegs::payloadOnly(resultGPR), stubInfo, baseGPR,
960                 static_cast<const AtomicStringImpl*>(string->tryGetValueImpl()));
961             
962             stubInfo->codeOrigin = node->origin.semantic;
963             stubInfo->patch.baseGPR = static_cast<int8_t>(baseGPR);
964             stubInfo->patch.valueGPR = static_cast<int8_t>(resultGPR);
965             stubInfo->patch.usedRegisters = usedRegisters();
966             stubInfo->patch.spillMode = NeedToSpill;
967
968             m_jit.addIn(InRecord(jump, done, slowPath.get(), stubInfo));
969             addSlowPathGenerator(WTF::move(slowPath));
970
971             base.use();
972
973             blessedBooleanResult(resultGPR, node, UseChildrenCalledExplicitly);
974             return;
975         }
976     }
977
978     JSValueOperand key(this, node->child1());
979     JSValueRegs regs = key.jsValueRegs();
980         
981     GPRFlushedCallResult result(this);
982     GPRReg resultGPR = result.gpr();
983         
984     base.use();
985     key.use();
986         
987     flushRegisters();
988     callOperation(
989         operationGenericIn, extractResult(JSValueRegs::payloadOnly(resultGPR)),
990         baseGPR, regs);
991     blessedBooleanResult(resultGPR, node, UseChildrenCalledExplicitly);
992 }
993
994 bool SpeculativeJIT::nonSpeculativeCompare(Node* node, MacroAssembler::RelationalCondition cond, S_JITOperation_EJJ helperFunction)
995 {
996     unsigned branchIndexInBlock = detectPeepHoleBranch();
997     if (branchIndexInBlock != UINT_MAX) {
998         Node* branchNode = m_block->at(branchIndexInBlock);
999
1000         ASSERT(node->adjustedRefCount() == 1);
1001         
1002         nonSpeculativePeepholeBranch(node, branchNode, cond, helperFunction);
1003     
1004         m_indexInBlock = branchIndexInBlock;
1005         m_currentNode = branchNode;
1006         
1007         return true;
1008     }
1009     
1010     nonSpeculativeNonPeepholeCompare(node, cond, helperFunction);
1011     
1012     return false;
1013 }
1014
1015 bool SpeculativeJIT::nonSpeculativeStrictEq(Node* node, bool invert)
1016 {
1017     unsigned branchIndexInBlock = detectPeepHoleBranch();
1018     if (branchIndexInBlock != UINT_MAX) {
1019         Node* branchNode = m_block->at(branchIndexInBlock);
1020
1021         ASSERT(node->adjustedRefCount() == 1);
1022         
1023         nonSpeculativePeepholeStrictEq(node, branchNode, invert);
1024     
1025         m_indexInBlock = branchIndexInBlock;
1026         m_currentNode = branchNode;
1027         
1028         return true;
1029     }
1030     
1031     nonSpeculativeNonPeepholeStrictEq(node, invert);
1032     
1033     return false;
1034 }
1035
1036 static const char* dataFormatString(DataFormat format)
1037 {
1038     // These values correspond to the DataFormat enum.
1039     const char* strings[] = {
1040         "[  ]",
1041         "[ i]",
1042         "[ d]",
1043         "[ c]",
1044         "Err!",
1045         "Err!",
1046         "Err!",
1047         "Err!",
1048         "[J ]",
1049         "[Ji]",
1050         "[Jd]",
1051         "[Jc]",
1052         "Err!",
1053         "Err!",
1054         "Err!",
1055         "Err!",
1056     };
1057     return strings[format];
1058 }
1059
1060 void SpeculativeJIT::dump(const char* label)
1061 {
1062     if (label)
1063         dataLogF("<%s>\n", label);
1064
1065     dataLogF("  gprs:\n");
1066     m_gprs.dump();
1067     dataLogF("  fprs:\n");
1068     m_fprs.dump();
1069     dataLogF("  VirtualRegisters:\n");
1070     for (unsigned i = 0; i < m_generationInfo.size(); ++i) {
1071         GenerationInfo& info = m_generationInfo[i];
1072         if (info.alive())
1073             dataLogF("    % 3d:%s%s", i, dataFormatString(info.registerFormat()), dataFormatString(info.spillFormat()));
1074         else
1075             dataLogF("    % 3d:[__][__]", i);
1076         if (info.registerFormat() == DataFormatDouble)
1077             dataLogF(":fpr%d\n", info.fpr());
1078         else if (info.registerFormat() != DataFormatNone
1079 #if USE(JSVALUE32_64)
1080             && !(info.registerFormat() & DataFormatJS)
1081 #endif
1082             ) {
1083             ASSERT(info.gpr() != InvalidGPRReg);
1084             dataLogF(":%s\n", GPRInfo::debugName(info.gpr()));
1085         } else
1086             dataLogF("\n");
1087     }
1088     if (label)
1089         dataLogF("</%s>\n", label);
1090 }
1091
1092 GPRTemporary::GPRTemporary()
1093     : m_jit(0)
1094     , m_gpr(InvalidGPRReg)
1095 {
1096 }
1097
1098 GPRTemporary::GPRTemporary(SpeculativeJIT* jit)
1099     : m_jit(jit)
1100     , m_gpr(InvalidGPRReg)
1101 {
1102     m_gpr = m_jit->allocate();
1103 }
1104
1105 GPRTemporary::GPRTemporary(SpeculativeJIT* jit, GPRReg specific)
1106     : m_jit(jit)
1107     , m_gpr(InvalidGPRReg)
1108 {
1109     m_gpr = m_jit->allocate(specific);
1110 }
1111
1112 #if USE(JSVALUE32_64)
1113 GPRTemporary::GPRTemporary(
1114     SpeculativeJIT* jit, ReuseTag, JSValueOperand& op1, WhichValueWord which)
1115     : m_jit(jit)
1116     , m_gpr(InvalidGPRReg)
1117 {
1118     if (!op1.isDouble() && m_jit->canReuse(op1.node()))
1119         m_gpr = m_jit->reuse(op1.gpr(which));
1120     else
1121         m_gpr = m_jit->allocate();
1122 }
1123 #endif // USE(JSVALUE32_64)
1124
1125 JSValueRegsTemporary::JSValueRegsTemporary() { }
1126
1127 JSValueRegsTemporary::JSValueRegsTemporary(SpeculativeJIT* jit)
1128 #if USE(JSVALUE64)
1129     : m_gpr(jit)
1130 #else
1131     : m_payloadGPR(jit)
1132     , m_tagGPR(jit)
1133 #endif
1134 {
1135 }
1136
1137 JSValueRegsTemporary::~JSValueRegsTemporary() { }
1138
1139 JSValueRegs JSValueRegsTemporary::regs()
1140 {
1141 #if USE(JSVALUE64)
1142     return JSValueRegs(m_gpr.gpr());
1143 #else
1144     return JSValueRegs(m_tagGPR.gpr(), m_payloadGPR.gpr());
1145 #endif
1146 }
1147
1148 void GPRTemporary::adopt(GPRTemporary& other)
1149 {
1150     ASSERT(!m_jit);
1151     ASSERT(m_gpr == InvalidGPRReg);
1152     ASSERT(other.m_jit);
1153     ASSERT(other.m_gpr != InvalidGPRReg);
1154     m_jit = other.m_jit;
1155     m_gpr = other.m_gpr;
1156     other.m_jit = 0;
1157     other.m_gpr = InvalidGPRReg;
1158 }
1159
1160 FPRTemporary::FPRTemporary(SpeculativeJIT* jit)
1161     : m_jit(jit)
1162     , m_fpr(InvalidFPRReg)
1163 {
1164     m_fpr = m_jit->fprAllocate();
1165 }
1166
1167 FPRTemporary::FPRTemporary(SpeculativeJIT* jit, SpeculateDoubleOperand& op1)
1168     : m_jit(jit)
1169     , m_fpr(InvalidFPRReg)
1170 {
1171     if (m_jit->canReuse(op1.node()))
1172         m_fpr = m_jit->reuse(op1.fpr());
1173     else
1174         m_fpr = m_jit->fprAllocate();
1175 }
1176
1177 FPRTemporary::FPRTemporary(SpeculativeJIT* jit, SpeculateDoubleOperand& op1, SpeculateDoubleOperand& op2)
1178     : m_jit(jit)
1179     , m_fpr(InvalidFPRReg)
1180 {
1181     if (m_jit->canReuse(op1.node()))
1182         m_fpr = m_jit->reuse(op1.fpr());
1183     else if (m_jit->canReuse(op2.node()))
1184         m_fpr = m_jit->reuse(op2.fpr());
1185     else
1186         m_fpr = m_jit->fprAllocate();
1187 }
1188
1189 #if USE(JSVALUE32_64)
1190 FPRTemporary::FPRTemporary(SpeculativeJIT* jit, JSValueOperand& op1)
1191     : m_jit(jit)
1192     , m_fpr(InvalidFPRReg)
1193 {
1194     if (op1.isDouble() && m_jit->canReuse(op1.node()))
1195         m_fpr = m_jit->reuse(op1.fpr());
1196     else
1197         m_fpr = m_jit->fprAllocate();
1198 }
1199 #endif
1200
1201 void SpeculativeJIT::compilePeepHoleDoubleBranch(Node* node, Node* branchNode, JITCompiler::DoubleCondition condition)
1202 {
1203     BasicBlock* taken = branchNode->branchData()->taken.block;
1204     BasicBlock* notTaken = branchNode->branchData()->notTaken.block;
1205     
1206     SpeculateDoubleOperand op1(this, node->child1());
1207     SpeculateDoubleOperand op2(this, node->child2());
1208     
1209     branchDouble(condition, op1.fpr(), op2.fpr(), taken);
1210     jump(notTaken);
1211 }
1212
1213 void SpeculativeJIT::compilePeepHoleObjectEquality(Node* node, Node* branchNode)
1214 {
1215     BasicBlock* taken = branchNode->branchData()->taken.block;
1216     BasicBlock* notTaken = branchNode->branchData()->notTaken.block;
1217
1218     MacroAssembler::RelationalCondition condition = MacroAssembler::Equal;
1219     
1220     if (taken == nextBlock()) {
1221         condition = MacroAssembler::NotEqual;
1222         BasicBlock* tmp = taken;
1223         taken = notTaken;
1224         notTaken = tmp;
1225     }
1226
1227     SpeculateCellOperand op1(this, node->child1());
1228     SpeculateCellOperand op2(this, node->child2());
1229     
1230     GPRReg op1GPR = op1.gpr();
1231     GPRReg op2GPR = op2.gpr();
1232     
1233     if (masqueradesAsUndefinedWatchpointIsStillValid()) {
1234         if (m_state.forNode(node->child1()).m_type & ~SpecObject) {
1235             speculationCheck(
1236                 BadType, JSValueSource::unboxedCell(op1GPR), node->child1(), m_jit.branchIfNotObject(op1GPR));
1237         }
1238         if (m_state.forNode(node->child2()).m_type & ~SpecObject) {
1239             speculationCheck(
1240                 BadType, JSValueSource::unboxedCell(op2GPR), node->child2(), m_jit.branchIfNotObject(op2GPR));
1241         }
1242     } else {
1243         if (m_state.forNode(node->child1()).m_type & ~SpecObject) {
1244             speculationCheck(
1245                 BadType, JSValueSource::unboxedCell(op1GPR), node->child1(),
1246                 m_jit.branchIfNotObject(op1GPR));
1247         }
1248         speculationCheck(BadType, JSValueSource::unboxedCell(op1GPR), node->child1(),
1249             m_jit.branchTest8(
1250                 MacroAssembler::NonZero, 
1251                 MacroAssembler::Address(op1GPR, JSCell::typeInfoFlagsOffset()), 
1252                 MacroAssembler::TrustedImm32(MasqueradesAsUndefined)));
1253
1254         if (m_state.forNode(node->child2()).m_type & ~SpecObject) {
1255             speculationCheck(
1256                 BadType, JSValueSource::unboxedCell(op2GPR), node->child2(),
1257                 m_jit.branchIfNotObject(op2GPR));
1258         }
1259         speculationCheck(BadType, JSValueSource::unboxedCell(op2GPR), node->child2(),
1260             m_jit.branchTest8(
1261                 MacroAssembler::NonZero, 
1262                 MacroAssembler::Address(op2GPR, JSCell::typeInfoFlagsOffset()), 
1263                 MacroAssembler::TrustedImm32(MasqueradesAsUndefined)));
1264     }
1265
1266     branchPtr(condition, op1GPR, op2GPR, taken);
1267     jump(notTaken);
1268 }
1269
1270 void SpeculativeJIT::compilePeepHoleBooleanBranch(Node* node, Node* branchNode, JITCompiler::RelationalCondition condition)
1271 {
1272     BasicBlock* taken = branchNode->branchData()->taken.block;
1273     BasicBlock* notTaken = branchNode->branchData()->notTaken.block;
1274
1275     // The branch instruction will branch to the taken block.
1276     // If taken is next, switch taken with notTaken & invert the branch condition so we can fall through.
1277     if (taken == nextBlock()) {
1278         condition = JITCompiler::invert(condition);
1279         BasicBlock* tmp = taken;
1280         taken = notTaken;
1281         notTaken = tmp;
1282     }
1283
1284     if (node->child1()->isBooleanConstant()) {
1285         bool imm = node->child1()->asBoolean();
1286         SpeculateBooleanOperand op2(this, node->child2());
1287         branch32(condition, JITCompiler::Imm32(static_cast<int32_t>(JSValue::encode(jsBoolean(imm)))), op2.gpr(), taken);
1288     } else if (node->child2()->isBooleanConstant()) {
1289         SpeculateBooleanOperand op1(this, node->child1());
1290         bool imm = node->child2()->asBoolean();
1291         branch32(condition, op1.gpr(), JITCompiler::Imm32(static_cast<int32_t>(JSValue::encode(jsBoolean(imm)))), taken);
1292     } else {
1293         SpeculateBooleanOperand op1(this, node->child1());
1294         SpeculateBooleanOperand op2(this, node->child2());
1295         branch32(condition, op1.gpr(), op2.gpr(), taken);
1296     }
1297
1298     jump(notTaken);
1299 }
1300
1301 void SpeculativeJIT::compilePeepHoleInt32Branch(Node* node, Node* branchNode, JITCompiler::RelationalCondition condition)
1302 {
1303     BasicBlock* taken = branchNode->branchData()->taken.block;
1304     BasicBlock* notTaken = branchNode->branchData()->notTaken.block;
1305
1306     // The branch instruction will branch to the taken block.
1307     // If taken is next, switch taken with notTaken & invert the branch condition so we can fall through.
1308     if (taken == nextBlock()) {
1309         condition = JITCompiler::invert(condition);
1310         BasicBlock* tmp = taken;
1311         taken = notTaken;
1312         notTaken = tmp;
1313     }
1314
1315     if (node->child1()->isInt32Constant()) {
1316         int32_t imm = node->child1()->asInt32();
1317         SpeculateInt32Operand op2(this, node->child2());
1318         branch32(condition, JITCompiler::Imm32(imm), op2.gpr(), taken);
1319     } else if (node->child2()->isInt32Constant()) {
1320         SpeculateInt32Operand op1(this, node->child1());
1321         int32_t imm = node->child2()->asInt32();
1322         branch32(condition, op1.gpr(), JITCompiler::Imm32(imm), taken);
1323     } else {
1324         SpeculateInt32Operand op1(this, node->child1());
1325         SpeculateInt32Operand op2(this, node->child2());
1326         branch32(condition, op1.gpr(), op2.gpr(), taken);
1327     }
1328
1329     jump(notTaken);
1330 }
1331
1332 // Returns true if the compare is fused with a subsequent branch.
1333 bool SpeculativeJIT::compilePeepHoleBranch(Node* node, MacroAssembler::RelationalCondition condition, MacroAssembler::DoubleCondition doubleCondition, S_JITOperation_EJJ operation)
1334 {
1335     // Fused compare & branch.
1336     unsigned branchIndexInBlock = detectPeepHoleBranch();
1337     if (branchIndexInBlock != UINT_MAX) {
1338         Node* branchNode = m_block->at(branchIndexInBlock);
1339
1340         // detectPeepHoleBranch currently only permits the branch to be the very next node,
1341         // so can be no intervening nodes to also reference the compare. 
1342         ASSERT(node->adjustedRefCount() == 1);
1343
1344         if (node->isBinaryUseKind(Int32Use))
1345             compilePeepHoleInt32Branch(node, branchNode, condition);
1346 #if USE(JSVALUE64)
1347         else if (node->isBinaryUseKind(Int52RepUse))
1348             compilePeepHoleInt52Branch(node, branchNode, condition);
1349 #endif // USE(JSVALUE64)
1350         else if (node->isBinaryUseKind(DoubleRepUse))
1351             compilePeepHoleDoubleBranch(node, branchNode, doubleCondition);
1352         else if (node->op() == CompareEq) {
1353             if (node->isBinaryUseKind(StringUse) || node->isBinaryUseKind(StringIdentUse)) {
1354                 // Use non-peephole comparison, for now.
1355                 return false;
1356             }
1357             if (node->isBinaryUseKind(BooleanUse))
1358                 compilePeepHoleBooleanBranch(node, branchNode, condition);
1359             else if (node->isBinaryUseKind(ObjectUse))
1360                 compilePeepHoleObjectEquality(node, branchNode);
1361             else if (node->isBinaryUseKind(ObjectUse, ObjectOrOtherUse))
1362                 compilePeepHoleObjectToObjectOrOtherEquality(node->child1(), node->child2(), branchNode);
1363             else if (node->isBinaryUseKind(ObjectOrOtherUse, ObjectUse))
1364                 compilePeepHoleObjectToObjectOrOtherEquality(node->child2(), node->child1(), branchNode);
1365             else {
1366                 nonSpeculativePeepholeBranch(node, branchNode, condition, operation);
1367                 return true;
1368             }
1369         } else {
1370             nonSpeculativePeepholeBranch(node, branchNode, condition, operation);
1371             return true;
1372         }
1373
1374         use(node->child1());
1375         use(node->child2());
1376         m_indexInBlock = branchIndexInBlock;
1377         m_currentNode = branchNode;
1378         return true;
1379     }
1380     return false;
1381 }
1382
1383 void SpeculativeJIT::noticeOSRBirth(Node* node)
1384 {
1385     if (!node->hasVirtualRegister())
1386         return;
1387     
1388     VirtualRegister virtualRegister = node->virtualRegister();
1389     GenerationInfo& info = generationInfoFromVirtualRegister(virtualRegister);
1390     
1391     info.noticeOSRBirth(*m_stream, node, virtualRegister);
1392 }
1393
1394 void SpeculativeJIT::compileMovHint(Node* node)
1395 {
1396     ASSERT(node->containsMovHint() && node->op() != ZombieHint);
1397     
1398     Node* child = node->child1().node();
1399     noticeOSRBirth(child);
1400     
1401     m_stream->appendAndLog(VariableEvent::movHint(MinifiedID(child), node->unlinkedLocal()));
1402 }
1403
1404 void SpeculativeJIT::bail(AbortReason reason)
1405 {
1406     if (verboseCompilationEnabled())
1407         dataLog("Bailing compilation.\n");
1408     m_compileOkay = true;
1409     m_jit.abortWithReason(reason, m_lastGeneratedNode);
1410     clearGenerationInfo();
1411 }
1412
1413 void SpeculativeJIT::compileCurrentBlock()
1414 {
1415     ASSERT(m_compileOkay);
1416     
1417     if (!m_block)
1418         return;
1419     
1420     ASSERT(m_block->isReachable);
1421     
1422     m_jit.blockHeads()[m_block->index] = m_jit.label();
1423
1424     if (!m_block->intersectionOfCFAHasVisited) {
1425         // Don't generate code for basic blocks that are unreachable according to CFA.
1426         // But to be sure that nobody has generated a jump to this block, drop in a
1427         // breakpoint here.
1428         m_jit.abortWithReason(DFGUnreachableBasicBlock);
1429         return;
1430     }
1431
1432     m_stream->appendAndLog(VariableEvent::reset());
1433     
1434     m_jit.jitAssertHasValidCallFrame();
1435     m_jit.jitAssertTagsInPlace();
1436     m_jit.jitAssertArgumentCountSane();
1437
1438     m_state.reset();
1439     m_state.beginBasicBlock(m_block);
1440     
1441     for (size_t i = m_block->variablesAtHead.size(); i--;) {
1442         int operand = m_block->variablesAtHead.operandForIndex(i);
1443         Node* node = m_block->variablesAtHead[i];
1444         if (!node)
1445             continue; // No need to record dead SetLocal's.
1446         
1447         VariableAccessData* variable = node->variableAccessData();
1448         DataFormat format;
1449         if (!node->refCount())
1450             continue; // No need to record dead SetLocal's.
1451         format = dataFormatFor(variable->flushFormat());
1452         m_stream->appendAndLog(
1453             VariableEvent::setLocal(
1454                 VirtualRegister(operand),
1455                 variable->machineLocal(),
1456                 format));
1457     }
1458     
1459     m_codeOriginForExitTarget = CodeOrigin();
1460     m_codeOriginForExitProfile = CodeOrigin();
1461     
1462     for (m_indexInBlock = 0; m_indexInBlock < m_block->size(); ++m_indexInBlock) {
1463         m_currentNode = m_block->at(m_indexInBlock);
1464         
1465         // We may have hit a contradiction that the CFA was aware of but that the JIT
1466         // didn't cause directly.
1467         if (!m_state.isValid()) {
1468             bail(DFGBailedAtTopOfBlock);
1469             return;
1470         }
1471
1472         if (ASSERT_DISABLED)
1473             m_canExit = true; // Essentially disable the assertions.
1474         else
1475             m_canExit = mayExit(m_jit.graph(), m_currentNode);
1476         
1477         m_interpreter.startExecuting();
1478         m_jit.setForNode(m_currentNode);
1479         m_codeOriginForExitTarget = m_currentNode->origin.forExit;
1480         m_codeOriginForExitProfile = m_currentNode->origin.semantic;
1481         m_lastGeneratedNode = m_currentNode->op();
1482         
1483         ASSERT(m_currentNode->shouldGenerate());
1484         
1485         if (verboseCompilationEnabled()) {
1486             dataLogF(
1487                 "SpeculativeJIT generating Node @%d (bc#%u) at JIT offset 0x%x",
1488                 (int)m_currentNode->index(),
1489                 m_currentNode->origin.semantic.bytecodeIndex, m_jit.debugOffset());
1490             dataLog("\n");
1491         }
1492         
1493         compile(m_currentNode);
1494         
1495         if (belongsInMinifiedGraph(m_currentNode->op()))
1496             m_minifiedGraph->append(MinifiedNode::fromNode(m_currentNode));
1497         
1498 #if ENABLE(DFG_REGISTER_ALLOCATION_VALIDATION)
1499         m_jit.clearRegisterAllocationOffsets();
1500 #endif
1501         
1502         if (!m_compileOkay) {
1503             bail(DFGBailedAtEndOfNode);
1504             return;
1505         }
1506         
1507         // Make sure that the abstract state is rematerialized for the next node.
1508         m_interpreter.executeEffects(m_indexInBlock);
1509     }
1510     
1511     // Perform the most basic verification that children have been used correctly.
1512     if (!ASSERT_DISABLED) {
1513         for (unsigned index = 0; index < m_generationInfo.size(); ++index) {
1514             GenerationInfo& info = m_generationInfo[index];
1515             RELEASE_ASSERT(!info.alive());
1516         }
1517     }
1518 }
1519
1520 // If we are making type predictions about our arguments then
1521 // we need to check that they are correct on function entry.
1522 void SpeculativeJIT::checkArgumentTypes()
1523 {
1524     ASSERT(!m_currentNode);
1525     m_isCheckingArgumentTypes = true;
1526     m_codeOriginForExitTarget = CodeOrigin(0);
1527     m_codeOriginForExitProfile = CodeOrigin(0);
1528
1529     for (int i = 0; i < m_jit.codeBlock()->numParameters(); ++i) {
1530         Node* node = m_jit.graph().m_arguments[i];
1531         if (!node) {
1532             // The argument is dead. We don't do any checks for such arguments.
1533             continue;
1534         }
1535         
1536         ASSERT(node->op() == SetArgument);
1537         ASSERT(node->shouldGenerate());
1538
1539         VariableAccessData* variableAccessData = node->variableAccessData();
1540         FlushFormat format = variableAccessData->flushFormat();
1541         
1542         if (format == FlushedJSValue)
1543             continue;
1544         
1545         VirtualRegister virtualRegister = variableAccessData->local();
1546
1547         JSValueSource valueSource = JSValueSource(JITCompiler::addressFor(virtualRegister));
1548         
1549 #if USE(JSVALUE64)
1550         switch (format) {
1551         case FlushedInt32: {
1552             speculationCheck(BadType, valueSource, node, m_jit.branch64(MacroAssembler::Below, JITCompiler::addressFor(virtualRegister), GPRInfo::tagTypeNumberRegister));
1553             break;
1554         }
1555         case FlushedBoolean: {
1556             GPRTemporary temp(this);
1557             m_jit.load64(JITCompiler::addressFor(virtualRegister), temp.gpr());
1558             m_jit.xor64(TrustedImm32(static_cast<int32_t>(ValueFalse)), temp.gpr());
1559             speculationCheck(BadType, valueSource, node, m_jit.branchTest64(MacroAssembler::NonZero, temp.gpr(), TrustedImm32(static_cast<int32_t>(~1))));
1560             break;
1561         }
1562         case FlushedCell: {
1563             speculationCheck(BadType, valueSource, node, m_jit.branchTest64(MacroAssembler::NonZero, JITCompiler::addressFor(virtualRegister), GPRInfo::tagMaskRegister));
1564             break;
1565         }
1566         default:
1567             RELEASE_ASSERT_NOT_REACHED();
1568             break;
1569         }
1570 #else
1571         switch (format) {
1572         case FlushedInt32: {
1573             speculationCheck(BadType, valueSource, node, m_jit.branch32(MacroAssembler::NotEqual, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::Int32Tag)));
1574             break;
1575         }
1576         case FlushedBoolean: {
1577             speculationCheck(BadType, valueSource, node, m_jit.branch32(MacroAssembler::NotEqual, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::BooleanTag)));
1578             break;
1579         }
1580         case FlushedCell: {
1581             speculationCheck(BadType, valueSource, node, m_jit.branch32(MacroAssembler::NotEqual, JITCompiler::tagFor(virtualRegister), TrustedImm32(JSValue::CellTag)));
1582             break;
1583         }
1584         default:
1585             RELEASE_ASSERT_NOT_REACHED();
1586             break;
1587         }
1588 #endif
1589     }
1590     m_isCheckingArgumentTypes = false;
1591 }
1592
1593 bool SpeculativeJIT::compile()
1594 {
1595     checkArgumentTypes();
1596     
1597     ASSERT(!m_currentNode);
1598     for (BlockIndex blockIndex = 0; blockIndex < m_jit.graph().numBlocks(); ++blockIndex) {
1599         m_jit.setForBlockIndex(blockIndex);
1600         m_block = m_jit.graph().block(blockIndex);
1601         compileCurrentBlock();
1602     }
1603     linkBranches();
1604     return true;
1605 }
1606
1607 void SpeculativeJIT::createOSREntries()
1608 {
1609     for (BlockIndex blockIndex = 0; blockIndex < m_jit.graph().numBlocks(); ++blockIndex) {
1610         BasicBlock* block = m_jit.graph().block(blockIndex);
1611         if (!block)
1612             continue;
1613         if (!block->isOSRTarget)
1614             continue;
1615         
1616         // Currently we don't have OSR entry trampolines. We could add them
1617         // here if need be.
1618         m_osrEntryHeads.append(m_jit.blockHeads()[blockIndex]);
1619     }
1620 }
1621
1622 void SpeculativeJIT::linkOSREntries(LinkBuffer& linkBuffer)
1623 {
1624     unsigned osrEntryIndex = 0;
1625     for (BlockIndex blockIndex = 0; blockIndex < m_jit.graph().numBlocks(); ++blockIndex) {
1626         BasicBlock* block = m_jit.graph().block(blockIndex);
1627         if (!block)
1628             continue;
1629         if (!block->isOSRTarget)
1630             continue;
1631         m_jit.noticeOSREntry(*block, m_osrEntryHeads[osrEntryIndex++], linkBuffer);
1632     }
1633     ASSERT(osrEntryIndex == m_osrEntryHeads.size());
1634     
1635     if (verboseCompilationEnabled()) {
1636         DumpContext dumpContext;
1637         dataLog("OSR Entries:\n");
1638         for (OSREntryData& entryData : m_jit.jitCode()->osrEntry)
1639             dataLog("    ", inContext(entryData, &dumpContext), "\n");
1640         if (!dumpContext.isEmpty())
1641             dumpContext.dump(WTF::dataFile());
1642     }
1643 }
1644
1645 void SpeculativeJIT::compileDoublePutByVal(Node* node, SpeculateCellOperand& base, SpeculateStrictInt32Operand& property)
1646 {
1647     Edge child3 = m_jit.graph().varArgChild(node, 2);
1648     Edge child4 = m_jit.graph().varArgChild(node, 3);
1649
1650     ArrayMode arrayMode = node->arrayMode();
1651     
1652     GPRReg baseReg = base.gpr();
1653     GPRReg propertyReg = property.gpr();
1654     
1655     SpeculateDoubleOperand value(this, child3);
1656
1657     FPRReg valueReg = value.fpr();
1658     
1659     DFG_TYPE_CHECK(
1660         JSValueRegs(), child3, SpecFullRealNumber,
1661         m_jit.branchDouble(
1662             MacroAssembler::DoubleNotEqualOrUnordered, valueReg, valueReg));
1663     
1664     if (!m_compileOkay)
1665         return;
1666     
1667     StorageOperand storage(this, child4);
1668     GPRReg storageReg = storage.gpr();
1669
1670     if (node->op() == PutByValAlias) {
1671         // Store the value to the array.
1672         GPRReg propertyReg = property.gpr();
1673         FPRReg valueReg = value.fpr();
1674         m_jit.storeDouble(valueReg, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesEight));
1675         
1676         noResult(m_currentNode);
1677         return;
1678     }
1679     
1680     GPRTemporary temporary;
1681     GPRReg temporaryReg = temporaryRegisterForPutByVal(temporary, node);
1682
1683     MacroAssembler::Jump slowCase;
1684     
1685     if (arrayMode.isInBounds()) {
1686         speculationCheck(
1687             OutOfBounds, JSValueRegs(), 0,
1688             m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(storageReg, Butterfly::offsetOfPublicLength())));
1689     } else {
1690         MacroAssembler::Jump inBounds = m_jit.branch32(MacroAssembler::Below, propertyReg, MacroAssembler::Address(storageReg, Butterfly::offsetOfPublicLength()));
1691         
1692         slowCase = m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, MacroAssembler::Address(storageReg, Butterfly::offsetOfVectorLength()));
1693         
1694         if (!arrayMode.isOutOfBounds())
1695             speculationCheck(OutOfBounds, JSValueRegs(), 0, slowCase);
1696         
1697         m_jit.add32(TrustedImm32(1), propertyReg, temporaryReg);
1698         m_jit.store32(temporaryReg, MacroAssembler::Address(storageReg, Butterfly::offsetOfPublicLength()));
1699         
1700         inBounds.link(&m_jit);
1701     }
1702     
1703     m_jit.storeDouble(valueReg, MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesEight));
1704
1705     base.use();
1706     property.use();
1707     value.use();
1708     storage.use();
1709     
1710     if (arrayMode.isOutOfBounds()) {
1711         addSlowPathGenerator(
1712             slowPathCall(
1713                 slowCase, this,
1714                 m_jit.codeBlock()->isStrictMode() ? operationPutDoubleByValBeyondArrayBoundsStrict : operationPutDoubleByValBeyondArrayBoundsNonStrict,
1715                 NoResult, baseReg, propertyReg, valueReg));
1716     }
1717
1718     noResult(m_currentNode, UseChildrenCalledExplicitly);
1719 }
1720
1721 void SpeculativeJIT::compileGetCharCodeAt(Node* node)
1722 {
1723     SpeculateCellOperand string(this, node->child1());
1724     SpeculateStrictInt32Operand index(this, node->child2());
1725     StorageOperand storage(this, node->child3());
1726
1727     GPRReg stringReg = string.gpr();
1728     GPRReg indexReg = index.gpr();
1729     GPRReg storageReg = storage.gpr();
1730     
1731     ASSERT(speculationChecked(m_state.forNode(node->child1()).m_type, SpecString));
1732
1733     // unsigned comparison so we can filter out negative indices and indices that are too large
1734     speculationCheck(Uncountable, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::AboveOrEqual, indexReg, MacroAssembler::Address(stringReg, JSString::offsetOfLength())));
1735
1736     GPRTemporary scratch(this);
1737     GPRReg scratchReg = scratch.gpr();
1738
1739     m_jit.loadPtr(MacroAssembler::Address(stringReg, JSString::offsetOfValue()), scratchReg);
1740
1741     // Load the character into scratchReg
1742     JITCompiler::Jump is16Bit = m_jit.branchTest32(MacroAssembler::Zero, MacroAssembler::Address(scratchReg, StringImpl::flagsOffset()), TrustedImm32(StringImpl::flagIs8Bit()));
1743
1744     m_jit.load8(MacroAssembler::BaseIndex(storageReg, indexReg, MacroAssembler::TimesOne, 0), scratchReg);
1745     JITCompiler::Jump cont8Bit = m_jit.jump();
1746
1747     is16Bit.link(&m_jit);
1748
1749     m_jit.load16(MacroAssembler::BaseIndex(storageReg, indexReg, MacroAssembler::TimesTwo, 0), scratchReg);
1750
1751     cont8Bit.link(&m_jit);
1752
1753     int32Result(scratchReg, m_currentNode);
1754 }
1755
1756 void SpeculativeJIT::compileGetByValOnString(Node* node)
1757 {
1758     SpeculateCellOperand base(this, node->child1());
1759     SpeculateStrictInt32Operand property(this, node->child2());
1760     StorageOperand storage(this, node->child3());
1761     GPRReg baseReg = base.gpr();
1762     GPRReg propertyReg = property.gpr();
1763     GPRReg storageReg = storage.gpr();
1764
1765     GPRTemporary scratch(this);
1766     GPRReg scratchReg = scratch.gpr();
1767 #if USE(JSVALUE32_64)
1768     GPRTemporary resultTag;
1769     GPRReg resultTagReg = InvalidGPRReg;
1770     if (node->arrayMode().isOutOfBounds()) {
1771         GPRTemporary realResultTag(this);
1772         resultTag.adopt(realResultTag);
1773         resultTagReg = resultTag.gpr();
1774     }
1775 #endif
1776
1777     ASSERT(ArrayMode(Array::String).alreadyChecked(m_jit.graph(), node, m_state.forNode(node->child1())));
1778
1779     // unsigned comparison so we can filter out negative indices and indices that are too large
1780     JITCompiler::Jump outOfBounds = m_jit.branch32(
1781         MacroAssembler::AboveOrEqual, propertyReg,
1782         MacroAssembler::Address(baseReg, JSString::offsetOfLength()));
1783     if (node->arrayMode().isInBounds())
1784         speculationCheck(OutOfBounds, JSValueRegs(), 0, outOfBounds);
1785
1786     m_jit.loadPtr(MacroAssembler::Address(baseReg, JSString::offsetOfValue()), scratchReg);
1787
1788     // Load the character into scratchReg
1789     JITCompiler::Jump is16Bit = m_jit.branchTest32(MacroAssembler::Zero, MacroAssembler::Address(scratchReg, StringImpl::flagsOffset()), TrustedImm32(StringImpl::flagIs8Bit()));
1790
1791     m_jit.load8(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesOne, 0), scratchReg);
1792     JITCompiler::Jump cont8Bit = m_jit.jump();
1793
1794     is16Bit.link(&m_jit);
1795
1796     m_jit.load16(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesTwo, 0), scratchReg);
1797
1798     JITCompiler::Jump bigCharacter =
1799         m_jit.branch32(MacroAssembler::AboveOrEqual, scratchReg, TrustedImm32(0x100));
1800
1801     // 8 bit string values don't need the isASCII check.
1802     cont8Bit.link(&m_jit);
1803
1804     m_jit.lshift32(MacroAssembler::TrustedImm32(sizeof(void*) == 4 ? 2 : 3), scratchReg);
1805     m_jit.addPtr(MacroAssembler::TrustedImmPtr(m_jit.vm()->smallStrings.singleCharacterStrings()), scratchReg);
1806     m_jit.loadPtr(scratchReg, scratchReg);
1807
1808     addSlowPathGenerator(
1809         slowPathCall(
1810             bigCharacter, this, operationSingleCharacterString, scratchReg, scratchReg));
1811
1812     if (node->arrayMode().isOutOfBounds()) {
1813 #if USE(JSVALUE32_64)
1814         m_jit.move(TrustedImm32(JSValue::CellTag), resultTagReg);
1815 #endif
1816
1817         JSGlobalObject* globalObject = m_jit.globalObjectFor(node->origin.semantic);
1818         if (globalObject->stringPrototypeChainIsSane()) {
1819             // FIXME: This could be captured using a Speculation mode that means "out-of-bounds
1820             // loads return a trivial value". Something like SaneChainOutOfBounds. This should
1821             // speculate that we don't take negative out-of-bounds, or better yet, it should rely
1822             // on a stringPrototypeChainIsSane() guaranteeing that the prototypes have no negative
1823             // indexed properties either.
1824             // https://bugs.webkit.org/show_bug.cgi?id=144668
1825             m_jit.graph().watchpoints().addLazily(globalObject->stringPrototype()->structure()->transitionWatchpointSet());
1826             m_jit.graph().watchpoints().addLazily(globalObject->objectPrototype()->structure()->transitionWatchpointSet());
1827             
1828 #if USE(JSVALUE64)
1829             addSlowPathGenerator(std::make_unique<SaneStringGetByValSlowPathGenerator>(
1830                 outOfBounds, this, JSValueRegs(scratchReg), baseReg, propertyReg));
1831 #else
1832             addSlowPathGenerator(std::make_unique<SaneStringGetByValSlowPathGenerator>(
1833                 outOfBounds, this, JSValueRegs(resultTagReg, scratchReg),
1834                 baseReg, propertyReg));
1835 #endif
1836         } else {
1837 #if USE(JSVALUE64)
1838             addSlowPathGenerator(
1839                 slowPathCall(
1840                     outOfBounds, this, operationGetByValStringInt,
1841                     scratchReg, baseReg, propertyReg));
1842 #else
1843             addSlowPathGenerator(
1844                 slowPathCall(
1845                     outOfBounds, this, operationGetByValStringInt,
1846                     resultTagReg, scratchReg, baseReg, propertyReg));
1847 #endif
1848         }
1849         
1850 #if USE(JSVALUE64)
1851         jsValueResult(scratchReg, m_currentNode);
1852 #else
1853         jsValueResult(resultTagReg, scratchReg, m_currentNode);
1854 #endif
1855     } else
1856         cellResult(scratchReg, m_currentNode);
1857 }
1858
1859 void SpeculativeJIT::compileFromCharCode(Node* node)
1860 {
1861     SpeculateStrictInt32Operand property(this, node->child1());
1862     GPRReg propertyReg = property.gpr();
1863     GPRTemporary smallStrings(this);
1864     GPRTemporary scratch(this);
1865     GPRReg scratchReg = scratch.gpr();
1866     GPRReg smallStringsReg = smallStrings.gpr();
1867
1868     JITCompiler::JumpList slowCases;
1869     slowCases.append(m_jit.branch32(MacroAssembler::AboveOrEqual, propertyReg, TrustedImm32(0xff)));
1870     m_jit.move(MacroAssembler::TrustedImmPtr(m_jit.vm()->smallStrings.singleCharacterStrings()), smallStringsReg);
1871     m_jit.loadPtr(MacroAssembler::BaseIndex(smallStringsReg, propertyReg, MacroAssembler::ScalePtr, 0), scratchReg);
1872
1873     slowCases.append(m_jit.branchTest32(MacroAssembler::Zero, scratchReg));
1874     addSlowPathGenerator(slowPathCall(slowCases, this, operationStringFromCharCode, scratchReg, propertyReg));
1875     cellResult(scratchReg, m_currentNode);
1876 }
1877
1878 GeneratedOperandType SpeculativeJIT::checkGeneratedTypeForToInt32(Node* node)
1879 {
1880     VirtualRegister virtualRegister = node->virtualRegister();
1881     GenerationInfo& info = generationInfoFromVirtualRegister(virtualRegister);
1882
1883     switch (info.registerFormat()) {
1884     case DataFormatStorage:
1885         RELEASE_ASSERT_NOT_REACHED();
1886
1887     case DataFormatBoolean:
1888     case DataFormatCell:
1889         terminateSpeculativeExecution(Uncountable, JSValueRegs(), 0);
1890         return GeneratedOperandTypeUnknown;
1891
1892     case DataFormatNone:
1893     case DataFormatJSCell:
1894     case DataFormatJS:
1895     case DataFormatJSBoolean:
1896     case DataFormatJSDouble:
1897         return GeneratedOperandJSValue;
1898
1899     case DataFormatJSInt32:
1900     case DataFormatInt32:
1901         return GeneratedOperandInteger;
1902
1903     default:
1904         RELEASE_ASSERT_NOT_REACHED();
1905         return GeneratedOperandTypeUnknown;
1906     }
1907 }
1908
1909 void SpeculativeJIT::compileValueToInt32(Node* node)
1910 {
1911     switch (node->child1().useKind()) {
1912 #if USE(JSVALUE64)
1913     case Int52RepUse: {
1914         SpeculateStrictInt52Operand op1(this, node->child1());
1915         GPRTemporary result(this, Reuse, op1);
1916         GPRReg op1GPR = op1.gpr();
1917         GPRReg resultGPR = result.gpr();
1918         m_jit.zeroExtend32ToPtr(op1GPR, resultGPR);
1919         int32Result(resultGPR, node, DataFormatInt32);
1920         return;
1921     }
1922 #endif // USE(JSVALUE64)
1923         
1924     case DoubleRepUse: {
1925         GPRTemporary result(this);
1926         SpeculateDoubleOperand op1(this, node->child1());
1927         FPRReg fpr = op1.fpr();
1928         GPRReg gpr = result.gpr();
1929         JITCompiler::Jump notTruncatedToInteger = m_jit.branchTruncateDoubleToInt32(fpr, gpr, JITCompiler::BranchIfTruncateFailed);
1930         
1931         addSlowPathGenerator(slowPathCall(notTruncatedToInteger, this, toInt32, gpr, fpr));
1932         
1933         int32Result(gpr, node);
1934         return;
1935     }
1936     
1937     case NumberUse:
1938     case NotCellUse: {
1939         switch (checkGeneratedTypeForToInt32(node->child1().node())) {
1940         case GeneratedOperandInteger: {
1941             SpeculateInt32Operand op1(this, node->child1(), ManualOperandSpeculation);
1942             GPRTemporary result(this, Reuse, op1);
1943             m_jit.move(op1.gpr(), result.gpr());
1944             int32Result(result.gpr(), node, op1.format());
1945             return;
1946         }
1947         case GeneratedOperandJSValue: {
1948             GPRTemporary result(this);
1949 #if USE(JSVALUE64)
1950             JSValueOperand op1(this, node->child1(), ManualOperandSpeculation);
1951
1952             GPRReg gpr = op1.gpr();
1953             GPRReg resultGpr = result.gpr();
1954             FPRTemporary tempFpr(this);
1955             FPRReg fpr = tempFpr.fpr();
1956
1957             JITCompiler::Jump isInteger = m_jit.branch64(MacroAssembler::AboveOrEqual, gpr, GPRInfo::tagTypeNumberRegister);
1958             JITCompiler::JumpList converted;
1959
1960             if (node->child1().useKind() == NumberUse) {
1961                 DFG_TYPE_CHECK(
1962                     JSValueRegs(gpr), node->child1(), SpecBytecodeNumber,
1963                     m_jit.branchTest64(
1964                         MacroAssembler::Zero, gpr, GPRInfo::tagTypeNumberRegister));
1965             } else {
1966                 JITCompiler::Jump isNumber = m_jit.branchTest64(MacroAssembler::NonZero, gpr, GPRInfo::tagTypeNumberRegister);
1967                 
1968                 DFG_TYPE_CHECK(
1969                     JSValueRegs(gpr), node->child1(), ~SpecCell, m_jit.branchIfCell(JSValueRegs(gpr)));
1970                 
1971                 // It's not a cell: so true turns into 1 and all else turns into 0.
1972                 m_jit.compare64(JITCompiler::Equal, gpr, TrustedImm32(ValueTrue), resultGpr);
1973                 converted.append(m_jit.jump());
1974                 
1975                 isNumber.link(&m_jit);
1976             }
1977
1978             // First, if we get here we have a double encoded as a JSValue
1979             m_jit.move(gpr, resultGpr);
1980             unboxDouble(resultGpr, fpr);
1981
1982             silentSpillAllRegisters(resultGpr);
1983             callOperation(toInt32, resultGpr, fpr);
1984             silentFillAllRegisters(resultGpr);
1985
1986             converted.append(m_jit.jump());
1987
1988             isInteger.link(&m_jit);
1989             m_jit.zeroExtend32ToPtr(gpr, resultGpr);
1990
1991             converted.link(&m_jit);
1992 #else
1993             Node* childNode = node->child1().node();
1994             VirtualRegister virtualRegister = childNode->virtualRegister();
1995             GenerationInfo& info = generationInfoFromVirtualRegister(virtualRegister);
1996
1997             JSValueOperand op1(this, node->child1(), ManualOperandSpeculation);
1998
1999             GPRReg payloadGPR = op1.payloadGPR();
2000             GPRReg resultGpr = result.gpr();
2001         
2002             JITCompiler::JumpList converted;
2003
2004             if (info.registerFormat() == DataFormatJSInt32)
2005                 m_jit.move(payloadGPR, resultGpr);
2006             else {
2007                 GPRReg tagGPR = op1.tagGPR();
2008                 FPRTemporary tempFpr(this);
2009                 FPRReg fpr = tempFpr.fpr();
2010                 FPRTemporary scratch(this);
2011
2012                 JITCompiler::Jump isInteger = m_jit.branch32(MacroAssembler::Equal, tagGPR, TrustedImm32(JSValue::Int32Tag));
2013
2014                 if (node->child1().useKind() == NumberUse) {
2015                     DFG_TYPE_CHECK(
2016                         op1.jsValueRegs(), node->child1(), SpecBytecodeNumber,
2017                         m_jit.branch32(
2018                             MacroAssembler::AboveOrEqual, tagGPR,
2019                             TrustedImm32(JSValue::LowestTag)));
2020                 } else {
2021                     JITCompiler::Jump isNumber = m_jit.branch32(MacroAssembler::Below, tagGPR, TrustedImm32(JSValue::LowestTag));
2022                     
2023                     DFG_TYPE_CHECK(
2024                         op1.jsValueRegs(), node->child1(), ~SpecCell,
2025                         m_jit.branchIfCell(op1.jsValueRegs()));
2026                     
2027                     // It's not a cell: so true turns into 1 and all else turns into 0.
2028                     JITCompiler::Jump isBoolean = m_jit.branch32(JITCompiler::Equal, tagGPR, TrustedImm32(JSValue::BooleanTag));
2029                     m_jit.move(TrustedImm32(0), resultGpr);
2030                     converted.append(m_jit.jump());
2031                     
2032                     isBoolean.link(&m_jit);
2033                     m_jit.move(payloadGPR, resultGpr);
2034                     converted.append(m_jit.jump());
2035                     
2036                     isNumber.link(&m_jit);
2037                 }
2038
2039                 unboxDouble(tagGPR, payloadGPR, fpr, scratch.fpr());
2040
2041                 silentSpillAllRegisters(resultGpr);
2042                 callOperation(toInt32, resultGpr, fpr);
2043                 silentFillAllRegisters(resultGpr);
2044
2045                 converted.append(m_jit.jump());
2046
2047                 isInteger.link(&m_jit);
2048                 m_jit.move(payloadGPR, resultGpr);
2049
2050                 converted.link(&m_jit);
2051             }
2052 #endif
2053             int32Result(resultGpr, node);
2054             return;
2055         }
2056         case GeneratedOperandTypeUnknown:
2057             RELEASE_ASSERT(!m_compileOkay);
2058             return;
2059         }
2060         RELEASE_ASSERT_NOT_REACHED();
2061         return;
2062     }
2063     
2064     default:
2065         ASSERT(!m_compileOkay);
2066         return;
2067     }
2068 }
2069
2070 void SpeculativeJIT::compileUInt32ToNumber(Node* node)
2071 {
2072     if (doesOverflow(node->arithMode())) {
2073         // We know that this sometimes produces doubles. So produce a double every
2074         // time. This at least allows subsequent code to not have weird conditionals.
2075             
2076         SpeculateInt32Operand op1(this, node->child1());
2077         FPRTemporary result(this);
2078             
2079         GPRReg inputGPR = op1.gpr();
2080         FPRReg outputFPR = result.fpr();
2081             
2082         m_jit.convertInt32ToDouble(inputGPR, outputFPR);
2083             
2084         JITCompiler::Jump positive = m_jit.branch32(MacroAssembler::GreaterThanOrEqual, inputGPR, TrustedImm32(0));
2085         m_jit.addDouble(JITCompiler::AbsoluteAddress(&AssemblyHelpers::twoToThe32), outputFPR);
2086         positive.link(&m_jit);
2087             
2088         doubleResult(outputFPR, node);
2089         return;
2090     }
2091     
2092     RELEASE_ASSERT(node->arithMode() == Arith::CheckOverflow);
2093
2094     SpeculateInt32Operand op1(this, node->child1());
2095     GPRTemporary result(this);
2096
2097     m_jit.move(op1.gpr(), result.gpr());
2098
2099     speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, result.gpr(), TrustedImm32(0)));
2100
2101     int32Result(result.gpr(), node, op1.format());
2102 }
2103
2104 void SpeculativeJIT::compileDoubleAsInt32(Node* node)
2105 {
2106     SpeculateDoubleOperand op1(this, node->child1());
2107     FPRTemporary scratch(this);
2108     GPRTemporary result(this);
2109     
2110     FPRReg valueFPR = op1.fpr();
2111     FPRReg scratchFPR = scratch.fpr();
2112     GPRReg resultGPR = result.gpr();
2113
2114     JITCompiler::JumpList failureCases;
2115     RELEASE_ASSERT(shouldCheckOverflow(node->arithMode()));
2116     m_jit.branchConvertDoubleToInt32(
2117         valueFPR, resultGPR, failureCases, scratchFPR,
2118         shouldCheckNegativeZero(node->arithMode()));
2119     speculationCheck(Overflow, JSValueRegs(), 0, failureCases);
2120
2121     int32Result(resultGPR, node);
2122 }
2123
2124 void SpeculativeJIT::compileDoubleRep(Node* node)
2125 {
2126     switch (node->child1().useKind()) {
2127     case RealNumberUse: {
2128         JSValueOperand op1(this, node->child1(), ManualOperandSpeculation);
2129         FPRTemporary result(this);
2130         
2131         JSValueRegs op1Regs = op1.jsValueRegs();
2132         FPRReg resultFPR = result.fpr();
2133         
2134 #if USE(JSVALUE64)
2135         GPRTemporary temp(this);
2136         GPRReg tempGPR = temp.gpr();
2137         m_jit.move(op1Regs.gpr(), tempGPR);
2138         m_jit.unboxDoubleWithoutAssertions(tempGPR, resultFPR);
2139 #else
2140         FPRTemporary temp(this);
2141         FPRReg tempFPR = temp.fpr();
2142         unboxDouble(op1Regs.tagGPR(), op1Regs.payloadGPR(), resultFPR, tempFPR);
2143 #endif
2144         
2145         JITCompiler::Jump done = m_jit.branchDouble(
2146             JITCompiler::DoubleEqual, resultFPR, resultFPR);
2147         
2148         DFG_TYPE_CHECK(
2149             op1Regs, node->child1(), SpecBytecodeRealNumber, m_jit.branchIfNotInt32(op1Regs));
2150         m_jit.convertInt32ToDouble(op1Regs.payloadGPR(), resultFPR);
2151         
2152         done.link(&m_jit);
2153         
2154         doubleResult(resultFPR, node);
2155         return;
2156     }
2157     
2158     case NotCellUse:
2159     case NumberUse: {
2160         ASSERT(!node->child1()->isNumberConstant()); // This should have been constant folded.
2161
2162         SpeculatedType possibleTypes = m_state.forNode(node->child1()).m_type;
2163         if (isInt32Speculation(possibleTypes)) {
2164             SpeculateInt32Operand op1(this, node->child1(), ManualOperandSpeculation);
2165             FPRTemporary result(this);
2166             m_jit.convertInt32ToDouble(op1.gpr(), result.fpr());
2167             doubleResult(result.fpr(), node);
2168             return;
2169         }
2170
2171         JSValueOperand op1(this, node->child1(), ManualOperandSpeculation);
2172         FPRTemporary result(this);
2173
2174 #if USE(JSVALUE64)
2175         GPRTemporary temp(this);
2176
2177         GPRReg op1GPR = op1.gpr();
2178         GPRReg tempGPR = temp.gpr();
2179         FPRReg resultFPR = result.fpr();
2180         JITCompiler::JumpList done;
2181
2182         JITCompiler::Jump isInteger = m_jit.branch64(
2183             MacroAssembler::AboveOrEqual, op1GPR, GPRInfo::tagTypeNumberRegister);
2184
2185         if (node->child1().useKind() == NotCellUse) {
2186             JITCompiler::Jump isNumber = m_jit.branchTest64(MacroAssembler::NonZero, op1GPR, GPRInfo::tagTypeNumberRegister);
2187             JITCompiler::Jump isUndefined = m_jit.branch64(JITCompiler::Equal, op1GPR, TrustedImm64(ValueUndefined));
2188
2189             static const double zero = 0;
2190             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&zero), resultFPR);
2191
2192             JITCompiler::Jump isNull = m_jit.branch64(JITCompiler::Equal, op1GPR, TrustedImm64(ValueNull));
2193             done.append(isNull);
2194
2195             DFG_TYPE_CHECK(JSValueRegs(op1GPR), node->child1(), ~SpecCell,
2196                 m_jit.branchTest64(JITCompiler::NonZero, op1GPR, TrustedImm32(static_cast<int32_t>(~1))));
2197
2198             JITCompiler::Jump isFalse = m_jit.branch64(JITCompiler::Equal, op1GPR, TrustedImm64(ValueFalse));
2199             static const double one = 1;
2200             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&one), resultFPR);
2201             done.append(isFalse);
2202
2203             isUndefined.link(&m_jit);
2204             static const double NaN = PNaN;
2205             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&NaN), resultFPR);
2206             done.append(m_jit.jump());
2207
2208             isNumber.link(&m_jit);
2209         } else if (needsTypeCheck(node->child1(), SpecBytecodeNumber)) {
2210             typeCheck(
2211                 JSValueRegs(op1GPR), node->child1(), SpecBytecodeNumber,
2212                 m_jit.branchTest64(MacroAssembler::Zero, op1GPR, GPRInfo::tagTypeNumberRegister));
2213         }
2214     
2215         m_jit.move(op1GPR, tempGPR);
2216         unboxDouble(tempGPR, resultFPR);
2217         done.append(m_jit.jump());
2218     
2219         isInteger.link(&m_jit);
2220         m_jit.convertInt32ToDouble(op1GPR, resultFPR);
2221         done.link(&m_jit);
2222 #else // USE(JSVALUE64) -> this is the 32_64 case
2223         FPRTemporary temp(this);
2224     
2225         GPRReg op1TagGPR = op1.tagGPR();
2226         GPRReg op1PayloadGPR = op1.payloadGPR();
2227         FPRReg tempFPR = temp.fpr();
2228         FPRReg resultFPR = result.fpr();
2229         JITCompiler::JumpList done;
2230     
2231         JITCompiler::Jump isInteger = m_jit.branch32(
2232             MacroAssembler::Equal, op1TagGPR, TrustedImm32(JSValue::Int32Tag));
2233
2234         if (node->child1().useKind() == NotCellUse) {
2235             JITCompiler::Jump isNumber = m_jit.branch32(JITCompiler::Below, op1TagGPR, JITCompiler::TrustedImm32(JSValue::LowestTag + 1));
2236             JITCompiler::Jump isUndefined = m_jit.branch32(JITCompiler::Equal, op1TagGPR, TrustedImm32(JSValue::UndefinedTag));
2237
2238             static const double zero = 0;
2239             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&zero), resultFPR);
2240
2241             JITCompiler::Jump isNull = m_jit.branch32(JITCompiler::Equal, op1TagGPR, TrustedImm32(JSValue::NullTag));
2242             done.append(isNull);
2243
2244             DFG_TYPE_CHECK(JSValueRegs(op1TagGPR, op1PayloadGPR), node->child1(), ~SpecCell, m_jit.branch32(JITCompiler::NotEqual, op1TagGPR, TrustedImm32(JSValue::BooleanTag)));
2245
2246             JITCompiler::Jump isFalse = m_jit.branchTest32(JITCompiler::Zero, op1PayloadGPR, TrustedImm32(1));
2247             static const double one = 1;
2248             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&one), resultFPR);
2249             done.append(isFalse);
2250
2251             isUndefined.link(&m_jit);
2252             static const double NaN = PNaN;
2253             m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&NaN), resultFPR);
2254             done.append(m_jit.jump());
2255
2256             isNumber.link(&m_jit);
2257         } else if (needsTypeCheck(node->child1(), SpecBytecodeNumber)) {
2258             typeCheck(
2259                 JSValueRegs(op1TagGPR, op1PayloadGPR), node->child1(), SpecBytecodeNumber,
2260                 m_jit.branch32(MacroAssembler::AboveOrEqual, op1TagGPR, TrustedImm32(JSValue::LowestTag)));
2261         }
2262
2263         unboxDouble(op1TagGPR, op1PayloadGPR, resultFPR, tempFPR);
2264         done.append(m_jit.jump());
2265     
2266         isInteger.link(&m_jit);
2267         m_jit.convertInt32ToDouble(op1PayloadGPR, resultFPR);
2268         done.link(&m_jit);
2269 #endif // USE(JSVALUE64)
2270     
2271         doubleResult(resultFPR, node);
2272         return;
2273     }
2274         
2275 #if USE(JSVALUE64)
2276     case Int52RepUse: {
2277         SpeculateStrictInt52Operand value(this, node->child1());
2278         FPRTemporary result(this);
2279         
2280         GPRReg valueGPR = value.gpr();
2281         FPRReg resultFPR = result.fpr();
2282
2283         m_jit.convertInt64ToDouble(valueGPR, resultFPR);
2284         
2285         doubleResult(resultFPR, node);
2286         return;
2287     }
2288 #endif // USE(JSVALUE64)
2289         
2290     default:
2291         RELEASE_ASSERT_NOT_REACHED();
2292         return;
2293     }
2294 }
2295
2296 void SpeculativeJIT::compileValueRep(Node* node)
2297 {
2298     switch (node->child1().useKind()) {
2299     case DoubleRepUse: {
2300         SpeculateDoubleOperand value(this, node->child1());
2301         JSValueRegsTemporary result(this);
2302         
2303         FPRReg valueFPR = value.fpr();
2304         JSValueRegs resultRegs = result.regs();
2305         
2306         // It's very tempting to in-place filter the value to indicate that it's not impure NaN
2307         // anymore. Unfortunately, this would be unsound. If it's a GetLocal or if the value was
2308         // subject to a prior SetLocal, filtering the value would imply that the corresponding
2309         // local was purified.
2310         if (needsTypeCheck(node->child1(), ~SpecDoubleImpureNaN))
2311             m_jit.purifyNaN(valueFPR);
2312
2313         boxDouble(valueFPR, resultRegs);
2314         
2315         jsValueResult(resultRegs, node);
2316         return;
2317     }
2318         
2319 #if USE(JSVALUE64)
2320     case Int52RepUse: {
2321         SpeculateStrictInt52Operand value(this, node->child1());
2322         GPRTemporary result(this);
2323         
2324         GPRReg valueGPR = value.gpr();
2325         GPRReg resultGPR = result.gpr();
2326         
2327         boxInt52(valueGPR, resultGPR, DataFormatStrictInt52);
2328         
2329         jsValueResult(resultGPR, node);
2330         return;
2331     }
2332 #endif // USE(JSVALUE64)
2333         
2334     default:
2335         RELEASE_ASSERT_NOT_REACHED();
2336         return;
2337     }
2338 }
2339
2340 static double clampDoubleToByte(double d)
2341 {
2342     d += 0.5;
2343     if (!(d > 0))
2344         d = 0;
2345     else if (d > 255)
2346         d = 255;
2347     return d;
2348 }
2349
2350 static void compileClampIntegerToByte(JITCompiler& jit, GPRReg result)
2351 {
2352     MacroAssembler::Jump inBounds = jit.branch32(MacroAssembler::BelowOrEqual, result, JITCompiler::TrustedImm32(0xff));
2353     MacroAssembler::Jump tooBig = jit.branch32(MacroAssembler::GreaterThan, result, JITCompiler::TrustedImm32(0xff));
2354     jit.xorPtr(result, result);
2355     MacroAssembler::Jump clamped = jit.jump();
2356     tooBig.link(&jit);
2357     jit.move(JITCompiler::TrustedImm32(255), result);
2358     clamped.link(&jit);
2359     inBounds.link(&jit);
2360 }
2361
2362 static void compileClampDoubleToByte(JITCompiler& jit, GPRReg result, FPRReg source, FPRReg scratch)
2363 {
2364     // Unordered compare so we pick up NaN
2365     static const double zero = 0;
2366     static const double byteMax = 255;
2367     static const double half = 0.5;
2368     jit.loadDouble(MacroAssembler::TrustedImmPtr(&zero), scratch);
2369     MacroAssembler::Jump tooSmall = jit.branchDouble(MacroAssembler::DoubleLessThanOrEqualOrUnordered, source, scratch);
2370     jit.loadDouble(MacroAssembler::TrustedImmPtr(&byteMax), scratch);
2371     MacroAssembler::Jump tooBig = jit.branchDouble(MacroAssembler::DoubleGreaterThan, source, scratch);
2372     
2373     jit.loadDouble(MacroAssembler::TrustedImmPtr(&half), scratch);
2374     // FIXME: This should probably just use a floating point round!
2375     // https://bugs.webkit.org/show_bug.cgi?id=72054
2376     jit.addDouble(source, scratch);
2377     jit.truncateDoubleToInt32(scratch, result);   
2378     MacroAssembler::Jump truncatedInt = jit.jump();
2379     
2380     tooSmall.link(&jit);
2381     jit.xorPtr(result, result);
2382     MacroAssembler::Jump zeroed = jit.jump();
2383     
2384     tooBig.link(&jit);
2385     jit.move(JITCompiler::TrustedImm32(255), result);
2386     
2387     truncatedInt.link(&jit);
2388     zeroed.link(&jit);
2389
2390 }
2391
2392 JITCompiler::Jump SpeculativeJIT::jumpForTypedArrayOutOfBounds(Node* node, GPRReg baseGPR, GPRReg indexGPR)
2393 {
2394     if (node->op() == PutByValAlias)
2395         return JITCompiler::Jump();
2396     JSArrayBufferView* view = m_jit.graph().tryGetFoldableView(
2397         m_state.forNode(m_jit.graph().child(node, 0)).m_value, node->arrayMode());
2398     if (view) {
2399         uint32_t length = view->length();
2400         Node* indexNode = m_jit.graph().child(node, 1).node();
2401         if (indexNode->isInt32Constant() && indexNode->asUInt32() < length)
2402             return JITCompiler::Jump();
2403         return m_jit.branch32(
2404             MacroAssembler::AboveOrEqual, indexGPR, MacroAssembler::Imm32(length));
2405     }
2406     return m_jit.branch32(
2407         MacroAssembler::AboveOrEqual, indexGPR,
2408         MacroAssembler::Address(baseGPR, JSArrayBufferView::offsetOfLength()));
2409 }
2410
2411 void SpeculativeJIT::emitTypedArrayBoundsCheck(Node* node, GPRReg baseGPR, GPRReg indexGPR)
2412 {
2413     JITCompiler::Jump jump = jumpForTypedArrayOutOfBounds(node, baseGPR, indexGPR);
2414     if (!jump.isSet())
2415         return;
2416     speculationCheck(OutOfBounds, JSValueRegs(), 0, jump);
2417 }
2418
2419 void SpeculativeJIT::compileGetByValOnIntTypedArray(Node* node, TypedArrayType type)
2420 {
2421     ASSERT(isInt(type));
2422     
2423     SpeculateCellOperand base(this, node->child1());
2424     SpeculateStrictInt32Operand property(this, node->child2());
2425     StorageOperand storage(this, node->child3());
2426
2427     GPRReg baseReg = base.gpr();
2428     GPRReg propertyReg = property.gpr();
2429     GPRReg storageReg = storage.gpr();
2430
2431     GPRTemporary result(this);
2432     GPRReg resultReg = result.gpr();
2433
2434     ASSERT(node->arrayMode().alreadyChecked(m_jit.graph(), node, m_state.forNode(node->child1())));
2435
2436     emitTypedArrayBoundsCheck(node, baseReg, propertyReg);
2437     switch (elementSize(type)) {
2438     case 1:
2439         if (isSigned(type))
2440             m_jit.load8SignedExtendTo32(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesOne), resultReg);
2441         else
2442             m_jit.load8(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesOne), resultReg);
2443         break;
2444     case 2:
2445         if (isSigned(type))
2446             m_jit.load16SignedExtendTo32(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesTwo), resultReg);
2447         else
2448             m_jit.load16(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesTwo), resultReg);
2449         break;
2450     case 4:
2451         m_jit.load32(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesFour), resultReg);
2452         break;
2453     default:
2454         CRASH();
2455     }
2456     if (elementSize(type) < 4 || isSigned(type)) {
2457         int32Result(resultReg, node);
2458         return;
2459     }
2460     
2461     ASSERT(elementSize(type) == 4 && !isSigned(type));
2462     if (node->shouldSpeculateInt32()) {
2463         speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, resultReg, TrustedImm32(0)));
2464         int32Result(resultReg, node);
2465         return;
2466     }
2467     
2468 #if USE(JSVALUE64)
2469     if (node->shouldSpeculateMachineInt()) {
2470         m_jit.zeroExtend32ToPtr(resultReg, resultReg);
2471         strictInt52Result(resultReg, node);
2472         return;
2473     }
2474 #endif
2475     
2476     FPRTemporary fresult(this);
2477     m_jit.convertInt32ToDouble(resultReg, fresult.fpr());
2478     JITCompiler::Jump positive = m_jit.branch32(MacroAssembler::GreaterThanOrEqual, resultReg, TrustedImm32(0));
2479     m_jit.addDouble(JITCompiler::AbsoluteAddress(&AssemblyHelpers::twoToThe32), fresult.fpr());
2480     positive.link(&m_jit);
2481     doubleResult(fresult.fpr(), node);
2482 }
2483
2484 void SpeculativeJIT::compilePutByValForIntTypedArray(GPRReg base, GPRReg property, Node* node, TypedArrayType type)
2485 {
2486     ASSERT(isInt(type));
2487     
2488     StorageOperand storage(this, m_jit.graph().varArgChild(node, 3));
2489     GPRReg storageReg = storage.gpr();
2490     
2491     Edge valueUse = m_jit.graph().varArgChild(node, 2);
2492     
2493     GPRTemporary value;
2494     GPRReg valueGPR = InvalidGPRReg;
2495     
2496     if (valueUse->isConstant()) {
2497         JSValue jsValue = valueUse->asJSValue();
2498         if (!jsValue.isNumber()) {
2499             terminateSpeculativeExecution(Uncountable, JSValueRegs(), 0);
2500             noResult(node);
2501             return;
2502         }
2503         double d = jsValue.asNumber();
2504         if (isClamped(type)) {
2505             ASSERT(elementSize(type) == 1);
2506             d = clampDoubleToByte(d);
2507         }
2508         GPRTemporary scratch(this);
2509         GPRReg scratchReg = scratch.gpr();
2510         m_jit.move(Imm32(toInt32(d)), scratchReg);
2511         value.adopt(scratch);
2512         valueGPR = scratchReg;
2513     } else {
2514         switch (valueUse.useKind()) {
2515         case Int32Use: {
2516             SpeculateInt32Operand valueOp(this, valueUse);
2517             GPRTemporary scratch(this);
2518             GPRReg scratchReg = scratch.gpr();
2519             m_jit.move(valueOp.gpr(), scratchReg);
2520             if (isClamped(type)) {
2521                 ASSERT(elementSize(type) == 1);
2522                 compileClampIntegerToByte(m_jit, scratchReg);
2523             }
2524             value.adopt(scratch);
2525             valueGPR = scratchReg;
2526             break;
2527         }
2528             
2529 #if USE(JSVALUE64)
2530         case Int52RepUse: {
2531             SpeculateStrictInt52Operand valueOp(this, valueUse);
2532             GPRTemporary scratch(this);
2533             GPRReg scratchReg = scratch.gpr();
2534             m_jit.move(valueOp.gpr(), scratchReg);
2535             if (isClamped(type)) {
2536                 ASSERT(elementSize(type) == 1);
2537                 MacroAssembler::Jump inBounds = m_jit.branch64(
2538                     MacroAssembler::BelowOrEqual, scratchReg, JITCompiler::TrustedImm64(0xff));
2539                 MacroAssembler::Jump tooBig = m_jit.branch64(
2540                     MacroAssembler::GreaterThan, scratchReg, JITCompiler::TrustedImm64(0xff));
2541                 m_jit.move(TrustedImm32(0), scratchReg);
2542                 MacroAssembler::Jump clamped = m_jit.jump();
2543                 tooBig.link(&m_jit);
2544                 m_jit.move(JITCompiler::TrustedImm32(255), scratchReg);
2545                 clamped.link(&m_jit);
2546                 inBounds.link(&m_jit);
2547             }
2548             value.adopt(scratch);
2549             valueGPR = scratchReg;
2550             break;
2551         }
2552 #endif // USE(JSVALUE64)
2553             
2554         case DoubleRepUse: {
2555             if (isClamped(type)) {
2556                 ASSERT(elementSize(type) == 1);
2557                 SpeculateDoubleOperand valueOp(this, valueUse);
2558                 GPRTemporary result(this);
2559                 FPRTemporary floatScratch(this);
2560                 FPRReg fpr = valueOp.fpr();
2561                 GPRReg gpr = result.gpr();
2562                 compileClampDoubleToByte(m_jit, gpr, fpr, floatScratch.fpr());
2563                 value.adopt(result);
2564                 valueGPR = gpr;
2565             } else {
2566                 SpeculateDoubleOperand valueOp(this, valueUse);
2567                 GPRTemporary result(this);
2568                 FPRReg fpr = valueOp.fpr();
2569                 GPRReg gpr = result.gpr();
2570                 MacroAssembler::Jump notNaN = m_jit.branchDouble(MacroAssembler::DoubleEqual, fpr, fpr);
2571                 m_jit.xorPtr(gpr, gpr);
2572                 MacroAssembler::Jump fixed = m_jit.jump();
2573                 notNaN.link(&m_jit);
2574                 
2575                 MacroAssembler::Jump failed = m_jit.branchTruncateDoubleToInt32(
2576                     fpr, gpr, MacroAssembler::BranchIfTruncateFailed);
2577                 
2578                 addSlowPathGenerator(slowPathCall(failed, this, toInt32, gpr, fpr));
2579                 
2580                 fixed.link(&m_jit);
2581                 value.adopt(result);
2582                 valueGPR = gpr;
2583             }
2584             break;
2585         }
2586             
2587         default:
2588             RELEASE_ASSERT_NOT_REACHED();
2589             break;
2590         }
2591     }
2592     
2593     ASSERT_UNUSED(valueGPR, valueGPR != property);
2594     ASSERT(valueGPR != base);
2595     ASSERT(valueGPR != storageReg);
2596     MacroAssembler::Jump outOfBounds = jumpForTypedArrayOutOfBounds(node, base, property);
2597     if (node->arrayMode().isInBounds() && outOfBounds.isSet()) {
2598         speculationCheck(OutOfBounds, JSValueSource(), 0, outOfBounds);
2599         outOfBounds = MacroAssembler::Jump();
2600     }
2601
2602     switch (elementSize(type)) {
2603     case 1:
2604         m_jit.store8(value.gpr(), MacroAssembler::BaseIndex(storageReg, property, MacroAssembler::TimesOne));
2605         break;
2606     case 2:
2607         m_jit.store16(value.gpr(), MacroAssembler::BaseIndex(storageReg, property, MacroAssembler::TimesTwo));
2608         break;
2609     case 4:
2610         m_jit.store32(value.gpr(), MacroAssembler::BaseIndex(storageReg, property, MacroAssembler::TimesFour));
2611         break;
2612     default:
2613         CRASH();
2614     }
2615     if (outOfBounds.isSet())
2616         outOfBounds.link(&m_jit);
2617     noResult(node);
2618 }
2619
2620 void SpeculativeJIT::compileGetByValOnFloatTypedArray(Node* node, TypedArrayType type)
2621 {
2622     ASSERT(isFloat(type));
2623     
2624     SpeculateCellOperand base(this, node->child1());
2625     SpeculateStrictInt32Operand property(this, node->child2());
2626     StorageOperand storage(this, node->child3());
2627
2628     GPRReg baseReg = base.gpr();
2629     GPRReg propertyReg = property.gpr();
2630     GPRReg storageReg = storage.gpr();
2631
2632     ASSERT(node->arrayMode().alreadyChecked(m_jit.graph(), node, m_state.forNode(node->child1())));
2633
2634     FPRTemporary result(this);
2635     FPRReg resultReg = result.fpr();
2636     emitTypedArrayBoundsCheck(node, baseReg, propertyReg);
2637     switch (elementSize(type)) {
2638     case 4:
2639         m_jit.loadFloat(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesFour), resultReg);
2640         m_jit.convertFloatToDouble(resultReg, resultReg);
2641         break;
2642     case 8: {
2643         m_jit.loadDouble(MacroAssembler::BaseIndex(storageReg, propertyReg, MacroAssembler::TimesEight), resultReg);
2644         break;
2645     }
2646     default:
2647         RELEASE_ASSERT_NOT_REACHED();
2648     }
2649     
2650     doubleResult(resultReg, node);
2651 }
2652
2653 void SpeculativeJIT::compilePutByValForFloatTypedArray(GPRReg base, GPRReg property, Node* node, TypedArrayType type)
2654 {
2655     ASSERT(isFloat(type));
2656     
2657     StorageOperand storage(this, m_jit.graph().varArgChild(node, 3));
2658     GPRReg storageReg = storage.gpr();
2659     
2660     Edge baseUse = m_jit.graph().varArgChild(node, 0);
2661     Edge valueUse = m_jit.graph().varArgChild(node, 2);
2662
2663     SpeculateDoubleOperand valueOp(this, valueUse);
2664     FPRTemporary scratch(this);
2665     FPRReg valueFPR = valueOp.fpr();
2666     FPRReg scratchFPR = scratch.fpr();
2667
2668     ASSERT_UNUSED(baseUse, node->arrayMode().alreadyChecked(m_jit.graph(), node, m_state.forNode(baseUse)));
2669     
2670     MacroAssembler::Jump outOfBounds = jumpForTypedArrayOutOfBounds(node, base, property);
2671     if (node->arrayMode().isInBounds() && outOfBounds.isSet()) {
2672         speculationCheck(OutOfBounds, JSValueSource(), 0, outOfBounds);
2673         outOfBounds = MacroAssembler::Jump();
2674     }
2675     
2676     switch (elementSize(type)) {
2677     case 4: {
2678         m_jit.moveDouble(valueFPR, scratchFPR);
2679         m_jit.convertDoubleToFloat(valueFPR, scratchFPR);
2680         m_jit.storeFloat(scratchFPR, MacroAssembler::BaseIndex(storageReg, property, MacroAssembler::TimesFour));
2681         break;
2682     }
2683     case 8:
2684         m_jit.storeDouble(valueFPR, MacroAssembler::BaseIndex(storageReg, property, MacroAssembler::TimesEight));
2685         break;
2686     default:
2687         RELEASE_ASSERT_NOT_REACHED();
2688     }
2689     if (outOfBounds.isSet())
2690         outOfBounds.link(&m_jit);
2691     noResult(node);
2692 }
2693
2694 void SpeculativeJIT::compileInstanceOfForObject(Node*, GPRReg valueReg, GPRReg prototypeReg, GPRReg scratchReg, GPRReg scratch2Reg)
2695 {
2696     // Check that prototype is an object.
2697     speculationCheck(BadType, JSValueRegs(), 0, m_jit.branchIfNotObject(prototypeReg));
2698     
2699     // Initialize scratchReg with the value being checked.
2700     m_jit.move(valueReg, scratchReg);
2701     
2702     // Walk up the prototype chain of the value (in scratchReg), comparing to prototypeReg.
2703     MacroAssembler::Label loop(&m_jit);
2704     m_jit.emitLoadStructure(scratchReg, scratchReg, scratch2Reg);
2705     m_jit.loadPtr(MacroAssembler::Address(scratchReg, Structure::prototypeOffset() + CellPayloadOffset), scratchReg);
2706     MacroAssembler::Jump isInstance = m_jit.branchPtr(MacroAssembler::Equal, scratchReg, prototypeReg);
2707 #if USE(JSVALUE64)
2708     m_jit.branchIfCell(JSValueRegs(scratchReg)).linkTo(loop, &m_jit);
2709 #else
2710     m_jit.branchTestPtr(MacroAssembler::NonZero, scratchReg).linkTo(loop, &m_jit);
2711 #endif
2712     
2713     // No match - result is false.
2714 #if USE(JSVALUE64)
2715     m_jit.move(MacroAssembler::TrustedImm64(JSValue::encode(jsBoolean(false))), scratchReg);
2716 #else
2717     m_jit.move(MacroAssembler::TrustedImm32(0), scratchReg);
2718 #endif
2719     MacroAssembler::Jump putResult = m_jit.jump();
2720     
2721     isInstance.link(&m_jit);
2722 #if USE(JSVALUE64)
2723     m_jit.move(MacroAssembler::TrustedImm64(JSValue::encode(jsBoolean(true))), scratchReg);
2724 #else
2725     m_jit.move(MacroAssembler::TrustedImm32(1), scratchReg);
2726 #endif
2727     
2728     putResult.link(&m_jit);
2729 }
2730
2731 void SpeculativeJIT::compileInstanceOf(Node* node)
2732 {
2733     if (node->child1().useKind() == UntypedUse) {
2734         // It might not be a cell. Speculate less aggressively.
2735         // Or: it might only be used once (i.e. by us), so we get zero benefit
2736         // from speculating any more aggressively than we absolutely need to.
2737         
2738         JSValueOperand value(this, node->child1());
2739         SpeculateCellOperand prototype(this, node->child2());
2740         GPRTemporary scratch(this);
2741         GPRTemporary scratch2(this);
2742         
2743         GPRReg prototypeReg = prototype.gpr();
2744         GPRReg scratchReg = scratch.gpr();
2745         GPRReg scratch2Reg = scratch2.gpr();
2746         
2747         MacroAssembler::Jump isCell = m_jit.branchIfCell(value.jsValueRegs());
2748         GPRReg valueReg = value.jsValueRegs().payloadGPR();
2749         moveFalseTo(scratchReg);
2750
2751         MacroAssembler::Jump done = m_jit.jump();
2752         
2753         isCell.link(&m_jit);
2754         
2755         compileInstanceOfForObject(node, valueReg, prototypeReg, scratchReg, scratch2Reg);
2756         
2757         done.link(&m_jit);
2758
2759         blessedBooleanResult(scratchReg, node);
2760         return;
2761     }
2762     
2763     SpeculateCellOperand value(this, node->child1());
2764     SpeculateCellOperand prototype(this, node->child2());
2765     
2766     GPRTemporary scratch(this);
2767     GPRTemporary scratch2(this);
2768     
2769     GPRReg valueReg = value.gpr();
2770     GPRReg prototypeReg = prototype.gpr();
2771     GPRReg scratchReg = scratch.gpr();
2772     GPRReg scratch2Reg = scratch2.gpr();
2773     
2774     compileInstanceOfForObject(node, valueReg, prototypeReg, scratchReg, scratch2Reg);
2775
2776     blessedBooleanResult(scratchReg, node);
2777 }
2778
2779 void SpeculativeJIT::compileAdd(Node* node)
2780 {
2781     switch (node->binaryUseKind()) {
2782     case Int32Use: {
2783         ASSERT(!shouldCheckNegativeZero(node->arithMode()));
2784         
2785         if (node->child1()->isInt32Constant()) {
2786             int32_t imm1 = node->child1()->asInt32();
2787             SpeculateInt32Operand op2(this, node->child2());
2788             GPRTemporary result(this);
2789
2790             if (!shouldCheckOverflow(node->arithMode())) {
2791                 m_jit.move(op2.gpr(), result.gpr());
2792                 m_jit.add32(Imm32(imm1), result.gpr());
2793             } else
2794                 speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchAdd32(MacroAssembler::Overflow, op2.gpr(), Imm32(imm1), result.gpr()));
2795
2796             int32Result(result.gpr(), node);
2797             return;
2798         }
2799         
2800         if (node->child2()->isInt32Constant()) {
2801             SpeculateInt32Operand op1(this, node->child1());
2802             int32_t imm2 = node->child2()->asInt32();
2803             GPRTemporary result(this);
2804                 
2805             if (!shouldCheckOverflow(node->arithMode())) {
2806                 m_jit.move(op1.gpr(), result.gpr());
2807                 m_jit.add32(Imm32(imm2), result.gpr());
2808             } else
2809                 speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchAdd32(MacroAssembler::Overflow, op1.gpr(), Imm32(imm2), result.gpr()));
2810
2811             int32Result(result.gpr(), node);
2812             return;
2813         }
2814                 
2815         SpeculateInt32Operand op1(this, node->child1());
2816         SpeculateInt32Operand op2(this, node->child2());
2817         GPRTemporary result(this, Reuse, op1, op2);
2818
2819         GPRReg gpr1 = op1.gpr();
2820         GPRReg gpr2 = op2.gpr();
2821         GPRReg gprResult = result.gpr();
2822
2823         if (!shouldCheckOverflow(node->arithMode())) {
2824             if (gpr1 == gprResult)
2825                 m_jit.add32(gpr2, gprResult);
2826             else {
2827                 m_jit.move(gpr2, gprResult);
2828                 m_jit.add32(gpr1, gprResult);
2829             }
2830         } else {
2831             MacroAssembler::Jump check = m_jit.branchAdd32(MacroAssembler::Overflow, gpr1, gpr2, gprResult);
2832                 
2833             if (gpr1 == gprResult)
2834                 speculationCheck(Overflow, JSValueRegs(), 0, check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr2));
2835             else if (gpr2 == gprResult)
2836                 speculationCheck(Overflow, JSValueRegs(), 0, check, SpeculationRecovery(SpeculativeAdd, gprResult, gpr1));
2837             else
2838                 speculationCheck(Overflow, JSValueRegs(), 0, check);
2839         }
2840
2841         int32Result(gprResult, node);
2842         return;
2843     }
2844         
2845 #if USE(JSVALUE64)
2846     case Int52RepUse: {
2847         ASSERT(shouldCheckOverflow(node->arithMode()));
2848         ASSERT(!shouldCheckNegativeZero(node->arithMode()));
2849
2850         // Will we need an overflow check? If we can prove that neither input can be
2851         // Int52 then the overflow check will not be necessary.
2852         if (!m_state.forNode(node->child1()).couldBeType(SpecInt52)
2853             && !m_state.forNode(node->child2()).couldBeType(SpecInt52)) {
2854             SpeculateWhicheverInt52Operand op1(this, node->child1());
2855             SpeculateWhicheverInt52Operand op2(this, node->child2(), op1);
2856             GPRTemporary result(this, Reuse, op1);
2857             m_jit.move(op1.gpr(), result.gpr());
2858             m_jit.add64(op2.gpr(), result.gpr());
2859             int52Result(result.gpr(), node, op1.format());
2860             return;
2861         }
2862         
2863         SpeculateInt52Operand op1(this, node->child1());
2864         SpeculateInt52Operand op2(this, node->child2());
2865         GPRTemporary result(this);
2866         m_jit.move(op1.gpr(), result.gpr());
2867         speculationCheck(
2868             Int52Overflow, JSValueRegs(), 0,
2869             m_jit.branchAdd64(MacroAssembler::Overflow, op2.gpr(), result.gpr()));
2870         int52Result(result.gpr(), node);
2871         return;
2872     }
2873 #endif // USE(JSVALUE64)
2874     
2875     case DoubleRepUse: {
2876         SpeculateDoubleOperand op1(this, node->child1());
2877         SpeculateDoubleOperand op2(this, node->child2());
2878         FPRTemporary result(this, op1, op2);
2879
2880         FPRReg reg1 = op1.fpr();
2881         FPRReg reg2 = op2.fpr();
2882         m_jit.addDouble(reg1, reg2, result.fpr());
2883
2884         doubleResult(result.fpr(), node);
2885         return;
2886     }
2887         
2888     default:
2889         RELEASE_ASSERT_NOT_REACHED();
2890         break;
2891     }
2892 }
2893
2894 void SpeculativeJIT::compileMakeRope(Node* node)
2895 {
2896     ASSERT(node->child1().useKind() == KnownStringUse);
2897     ASSERT(node->child2().useKind() == KnownStringUse);
2898     ASSERT(!node->child3() || node->child3().useKind() == KnownStringUse);
2899     
2900     SpeculateCellOperand op1(this, node->child1());
2901     SpeculateCellOperand op2(this, node->child2());
2902     SpeculateCellOperand op3(this, node->child3());
2903     GPRTemporary result(this);
2904     GPRTemporary allocator(this);
2905     GPRTemporary scratch(this);
2906     
2907     GPRReg opGPRs[3];
2908     unsigned numOpGPRs;
2909     opGPRs[0] = op1.gpr();
2910     opGPRs[1] = op2.gpr();
2911     if (node->child3()) {
2912         opGPRs[2] = op3.gpr();
2913         numOpGPRs = 3;
2914     } else {
2915         opGPRs[2] = InvalidGPRReg;
2916         numOpGPRs = 2;
2917     }
2918     GPRReg resultGPR = result.gpr();
2919     GPRReg allocatorGPR = allocator.gpr();
2920     GPRReg scratchGPR = scratch.gpr();
2921     
2922     JITCompiler::JumpList slowPath;
2923     MarkedAllocator& markedAllocator = m_jit.vm()->heap.allocatorForObjectWithDestructor(sizeof(JSRopeString));
2924     m_jit.move(TrustedImmPtr(&markedAllocator), allocatorGPR);
2925     emitAllocateJSCell(resultGPR, allocatorGPR, TrustedImmPtr(m_jit.vm()->stringStructure.get()), scratchGPR, slowPath);
2926         
2927     m_jit.storePtr(TrustedImmPtr(0), JITCompiler::Address(resultGPR, JSString::offsetOfValue()));
2928     for (unsigned i = 0; i < numOpGPRs; ++i)
2929         m_jit.storePtr(opGPRs[i], JITCompiler::Address(resultGPR, JSRopeString::offsetOfFibers() + sizeof(WriteBarrier<JSString>) * i));
2930     for (unsigned i = numOpGPRs; i < JSRopeString::s_maxInternalRopeLength; ++i)
2931         m_jit.storePtr(TrustedImmPtr(0), JITCompiler::Address(resultGPR, JSRopeString::offsetOfFibers() + sizeof(WriteBarrier<JSString>) * i));
2932     m_jit.load32(JITCompiler::Address(opGPRs[0], JSString::offsetOfFlags()), scratchGPR);
2933     m_jit.load32(JITCompiler::Address(opGPRs[0], JSString::offsetOfLength()), allocatorGPR);
2934     if (!ASSERT_DISABLED) {
2935         JITCompiler::Jump ok = m_jit.branch32(
2936             JITCompiler::GreaterThanOrEqual, allocatorGPR, TrustedImm32(0));
2937         m_jit.abortWithReason(DFGNegativeStringLength);
2938         ok.link(&m_jit);
2939     }
2940     for (unsigned i = 1; i < numOpGPRs; ++i) {
2941         m_jit.and32(JITCompiler::Address(opGPRs[i], JSString::offsetOfFlags()), scratchGPR);
2942         speculationCheck(
2943             Uncountable, JSValueSource(), nullptr,
2944             m_jit.branchAdd32(
2945                 JITCompiler::Overflow,
2946                 JITCompiler::Address(opGPRs[i], JSString::offsetOfLength()), allocatorGPR));
2947     }
2948     m_jit.and32(JITCompiler::TrustedImm32(JSString::Is8Bit), scratchGPR);
2949     m_jit.store32(scratchGPR, JITCompiler::Address(resultGPR, JSString::offsetOfFlags()));
2950     if (!ASSERT_DISABLED) {
2951         JITCompiler::Jump ok = m_jit.branch32(
2952             JITCompiler::GreaterThanOrEqual, allocatorGPR, TrustedImm32(0));
2953         m_jit.abortWithReason(DFGNegativeStringLength);
2954         ok.link(&m_jit);
2955     }
2956     m_jit.store32(allocatorGPR, JITCompiler::Address(resultGPR, JSString::offsetOfLength()));
2957     
2958     switch (numOpGPRs) {
2959     case 2:
2960         addSlowPathGenerator(slowPathCall(
2961             slowPath, this, operationMakeRope2, resultGPR, opGPRs[0], opGPRs[1]));
2962         break;
2963     case 3:
2964         addSlowPathGenerator(slowPathCall(
2965             slowPath, this, operationMakeRope3, resultGPR, opGPRs[0], opGPRs[1], opGPRs[2]));
2966         break;
2967     default:
2968         RELEASE_ASSERT_NOT_REACHED();
2969         break;
2970     }
2971         
2972     cellResult(resultGPR, node);
2973 }
2974
2975 void SpeculativeJIT::compileArithClz32(Node* node)
2976 {
2977     ASSERT_WITH_MESSAGE(node->child1().useKind() == Int32Use || node->child1().useKind() == KnownInt32Use, "The Fixup phase should have enforced a Int32 operand.");
2978     SpeculateInt32Operand value(this, node->child1());
2979     GPRTemporary result(this, Reuse, value);
2980     GPRReg valueReg = value.gpr();
2981     GPRReg resultReg = result.gpr();
2982     m_jit.countLeadingZeros32(valueReg, resultReg);
2983     int32Result(resultReg, node);
2984 }
2985
2986 void SpeculativeJIT::compileArithSub(Node* node)
2987 {
2988     switch (node->binaryUseKind()) {
2989     case Int32Use: {
2990         ASSERT(!shouldCheckNegativeZero(node->arithMode()));
2991         
2992         if (node->child2()->isInt32Constant()) {
2993             SpeculateInt32Operand op1(this, node->child1());
2994             int32_t imm2 = node->child2()->asInt32();
2995             GPRTemporary result(this);
2996
2997             if (!shouldCheckOverflow(node->arithMode())) {
2998                 m_jit.move(op1.gpr(), result.gpr());
2999                 m_jit.sub32(Imm32(imm2), result.gpr());
3000             } else {
3001                 GPRTemporary scratch(this);
3002                 speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchSub32(MacroAssembler::Overflow, op1.gpr(), Imm32(imm2), result.gpr(), scratch.gpr()));
3003             }
3004
3005             int32Result(result.gpr(), node);
3006             return;
3007         }
3008             
3009         if (node->child1()->isInt32Constant()) {
3010             int32_t imm1 = node->child1()->asInt32();
3011             SpeculateInt32Operand op2(this, node->child2());
3012             GPRTemporary result(this);
3013                 
3014             m_jit.move(Imm32(imm1), result.gpr());
3015             if (!shouldCheckOverflow(node->arithMode()))
3016                 m_jit.sub32(op2.gpr(), result.gpr());
3017             else
3018                 speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchSub32(MacroAssembler::Overflow, op2.gpr(), result.gpr()));
3019                 
3020             int32Result(result.gpr(), node);
3021             return;
3022         }
3023             
3024         SpeculateInt32Operand op1(this, node->child1());
3025         SpeculateInt32Operand op2(this, node->child2());
3026         GPRTemporary result(this);
3027
3028         if (!shouldCheckOverflow(node->arithMode())) {
3029             m_jit.move(op1.gpr(), result.gpr());
3030             m_jit.sub32(op2.gpr(), result.gpr());
3031         } else
3032             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchSub32(MacroAssembler::Overflow, op1.gpr(), op2.gpr(), result.gpr()));
3033
3034         int32Result(result.gpr(), node);
3035         return;
3036     }
3037         
3038 #if USE(JSVALUE64)
3039     case Int52RepUse: {
3040         ASSERT(shouldCheckOverflow(node->arithMode()));
3041         ASSERT(!shouldCheckNegativeZero(node->arithMode()));
3042
3043         // Will we need an overflow check? If we can prove that neither input can be
3044         // Int52 then the overflow check will not be necessary.
3045         if (!m_state.forNode(node->child1()).couldBeType(SpecInt52)
3046             && !m_state.forNode(node->child2()).couldBeType(SpecInt52)) {
3047             SpeculateWhicheverInt52Operand op1(this, node->child1());
3048             SpeculateWhicheverInt52Operand op2(this, node->child2(), op1);
3049             GPRTemporary result(this, Reuse, op1);
3050             m_jit.move(op1.gpr(), result.gpr());
3051             m_jit.sub64(op2.gpr(), result.gpr());
3052             int52Result(result.gpr(), node, op1.format());
3053             return;
3054         }
3055         
3056         SpeculateInt52Operand op1(this, node->child1());
3057         SpeculateInt52Operand op2(this, node->child2());
3058         GPRTemporary result(this);
3059         m_jit.move(op1.gpr(), result.gpr());
3060         speculationCheck(
3061             Int52Overflow, JSValueRegs(), 0,
3062             m_jit.branchSub64(MacroAssembler::Overflow, op2.gpr(), result.gpr()));
3063         int52Result(result.gpr(), node);
3064         return;
3065     }
3066 #endif // USE(JSVALUE64)
3067
3068     case DoubleRepUse: {
3069         SpeculateDoubleOperand op1(this, node->child1());
3070         SpeculateDoubleOperand op2(this, node->child2());
3071         FPRTemporary result(this, op1);
3072
3073         FPRReg reg1 = op1.fpr();
3074         FPRReg reg2 = op2.fpr();
3075         m_jit.subDouble(reg1, reg2, result.fpr());
3076
3077         doubleResult(result.fpr(), node);
3078         return;
3079     }
3080         
3081     default:
3082         RELEASE_ASSERT_NOT_REACHED();
3083         return;
3084     }
3085 }
3086
3087 void SpeculativeJIT::compileArithNegate(Node* node)
3088 {
3089     switch (node->child1().useKind()) {
3090     case Int32Use: {
3091         SpeculateInt32Operand op1(this, node->child1());
3092         GPRTemporary result(this);
3093
3094         m_jit.move(op1.gpr(), result.gpr());
3095
3096         // Note: there is no notion of being not used as a number, but someone
3097         // caring about negative zero.
3098         
3099         if (!shouldCheckOverflow(node->arithMode()))
3100             m_jit.neg32(result.gpr());
3101         else if (!shouldCheckNegativeZero(node->arithMode()))
3102             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchNeg32(MacroAssembler::Overflow, result.gpr()));
3103         else {
3104             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(MacroAssembler::Zero, result.gpr(), TrustedImm32(0x7fffffff)));
3105             m_jit.neg32(result.gpr());
3106         }
3107
3108         int32Result(result.gpr(), node);
3109         return;
3110     }
3111
3112 #if USE(JSVALUE64)
3113     case Int52RepUse: {
3114         ASSERT(shouldCheckOverflow(node->arithMode()));
3115         
3116         if (!m_state.forNode(node->child1()).couldBeType(SpecInt52)) {
3117             SpeculateWhicheverInt52Operand op1(this, node->child1());
3118             GPRTemporary result(this);
3119             GPRReg op1GPR = op1.gpr();
3120             GPRReg resultGPR = result.gpr();
3121             m_jit.move(op1GPR, resultGPR);
3122             m_jit.neg64(resultGPR);
3123             if (shouldCheckNegativeZero(node->arithMode())) {
3124                 speculationCheck(
3125                     NegativeZero, JSValueRegs(), 0,
3126                     m_jit.branchTest64(MacroAssembler::Zero, resultGPR));
3127             }
3128             int52Result(resultGPR, node, op1.format());
3129             return;
3130         }
3131         
3132         SpeculateInt52Operand op1(this, node->child1());
3133         GPRTemporary result(this);
3134         GPRReg op1GPR = op1.gpr();
3135         GPRReg resultGPR = result.gpr();
3136         m_jit.move(op1GPR, resultGPR);
3137         speculationCheck(
3138             Int52Overflow, JSValueRegs(), 0,
3139             m_jit.branchNeg64(MacroAssembler::Overflow, resultGPR));
3140         if (shouldCheckNegativeZero(node->arithMode())) {
3141             speculationCheck(
3142                 NegativeZero, JSValueRegs(), 0,
3143                 m_jit.branchTest64(MacroAssembler::Zero, resultGPR));
3144         }
3145         int52Result(resultGPR, node);
3146         return;
3147     }
3148 #endif // USE(JSVALUE64)
3149         
3150     case DoubleRepUse: {
3151         SpeculateDoubleOperand op1(this, node->child1());
3152         FPRTemporary result(this);
3153         
3154         m_jit.negateDouble(op1.fpr(), result.fpr());
3155         
3156         doubleResult(result.fpr(), node);
3157         return;
3158     }
3159         
3160     default:
3161         RELEASE_ASSERT_NOT_REACHED();
3162         return;
3163     }
3164 }
3165 void SpeculativeJIT::compileArithMul(Node* node)
3166 {
3167     switch (node->binaryUseKind()) {
3168     case Int32Use: {
3169         SpeculateInt32Operand op1(this, node->child1());
3170         SpeculateInt32Operand op2(this, node->child2());
3171         GPRTemporary result(this);
3172
3173         GPRReg reg1 = op1.gpr();
3174         GPRReg reg2 = op2.gpr();
3175
3176         // We can perform truncated multiplications if we get to this point, because if the
3177         // fixup phase could not prove that it would be safe, it would have turned us into
3178         // a double multiplication.
3179         if (!shouldCheckOverflow(node->arithMode())) {
3180             m_jit.move(reg1, result.gpr());
3181             m_jit.mul32(reg2, result.gpr());
3182         } else {
3183             speculationCheck(
3184                 Overflow, JSValueRegs(), 0,
3185                 m_jit.branchMul32(MacroAssembler::Overflow, reg1, reg2, result.gpr()));
3186         }
3187             
3188         // Check for negative zero, if the users of this node care about such things.
3189         if (shouldCheckNegativeZero(node->arithMode())) {
3190             MacroAssembler::Jump resultNonZero = m_jit.branchTest32(MacroAssembler::NonZero, result.gpr());
3191             speculationCheck(NegativeZero, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, reg1, TrustedImm32(0)));
3192             speculationCheck(NegativeZero, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, reg2, TrustedImm32(0)));
3193             resultNonZero.link(&m_jit);
3194         }
3195
3196         int32Result(result.gpr(), node);
3197         return;
3198     }
3199     
3200 #if USE(JSVALUE64)   
3201     case Int52RepUse: {
3202         ASSERT(shouldCheckOverflow(node->arithMode()));
3203         
3204         // This is super clever. We want to do an int52 multiplication and check the
3205         // int52 overflow bit. There is no direct hardware support for this, but we do
3206         // have the ability to do an int64 multiplication and check the int64 overflow
3207         // bit. We leverage that. Consider that a, b are int52 numbers inside int64
3208         // registers, with the high 12 bits being sign-extended. We can do:
3209         //
3210         //     (a * (b << 12))
3211         //
3212         // This will give us a left-shifted int52 (value is in high 52 bits, low 16
3213         // bits are zero) plus the int52 overflow bit. I.e. whether this 64-bit
3214         // multiplication overflows is identical to whether the 'a * b' 52-bit
3215         // multiplication overflows.
3216         //
3217         // In our nomenclature, this is:
3218         //
3219         //     strictInt52(a) * int52(b) => int52
3220         //
3221         // That is "strictInt52" means unshifted and "int52" means left-shifted by 16
3222         // bits.
3223         //
3224         // We don't care which of op1 or op2 serves as the left-shifted operand, so
3225         // we just do whatever is more convenient for op1 and have op2 do the
3226         // opposite. This ensures that we do at most one shift.
3227
3228         SpeculateWhicheverInt52Operand op1(this, node->child1());
3229         SpeculateWhicheverInt52Operand op2(this, node->child2(), OppositeShift, op1);
3230         GPRTemporary result(this);
3231         
3232         GPRReg op1GPR = op1.gpr();
3233         GPRReg op2GPR = op2.gpr();
3234         GPRReg resultGPR = result.gpr();
3235         
3236         m_jit.move(op1GPR, resultGPR);
3237         speculationCheck(
3238             Int52Overflow, JSValueRegs(), 0,
3239             m_jit.branchMul64(MacroAssembler::Overflow, op2GPR, resultGPR));
3240         
3241         if (shouldCheckNegativeZero(node->arithMode())) {
3242             MacroAssembler::Jump resultNonZero = m_jit.branchTest64(
3243                 MacroAssembler::NonZero, resultGPR);
3244             speculationCheck(
3245                 NegativeZero, JSValueRegs(), 0,
3246                 m_jit.branch64(MacroAssembler::LessThan, op1GPR, TrustedImm64(0)));
3247             speculationCheck(
3248                 NegativeZero, JSValueRegs(), 0,
3249                 m_jit.branch64(MacroAssembler::LessThan, op2GPR, TrustedImm64(0)));
3250             resultNonZero.link(&m_jit);
3251         }
3252         
3253         int52Result(resultGPR, node);
3254         return;
3255     }
3256 #endif // USE(JSVALUE64)
3257         
3258     case DoubleRepUse: {
3259         SpeculateDoubleOperand op1(this, node->child1());
3260         SpeculateDoubleOperand op2(this, node->child2());
3261         FPRTemporary result(this, op1, op2);
3262         
3263         FPRReg reg1 = op1.fpr();
3264         FPRReg reg2 = op2.fpr();
3265         
3266         m_jit.mulDouble(reg1, reg2, result.fpr());
3267         
3268         doubleResult(result.fpr(), node);
3269         return;
3270     }
3271         
3272     default:
3273         RELEASE_ASSERT_NOT_REACHED();
3274         return;
3275     }
3276 }
3277
3278 void SpeculativeJIT::compileArithDiv(Node* node)
3279 {
3280     switch (node->binaryUseKind()) {
3281     case Int32Use: {
3282 #if CPU(X86) || CPU(X86_64)
3283         SpeculateInt32Operand op1(this, node->child1());
3284         SpeculateInt32Operand op2(this, node->child2());
3285         GPRTemporary eax(this, X86Registers::eax);
3286         GPRTemporary edx(this, X86Registers::edx);
3287         GPRReg op1GPR = op1.gpr();
3288         GPRReg op2GPR = op2.gpr();
3289     
3290         GPRReg op2TempGPR;
3291         GPRReg temp;
3292         if (op2GPR == X86Registers::eax || op2GPR == X86Registers::edx) {
3293             op2TempGPR = allocate();
3294             temp = op2TempGPR;
3295         } else {
3296             op2TempGPR = InvalidGPRReg;
3297             if (op1GPR == X86Registers::eax)
3298                 temp = X86Registers::edx;
3299             else
3300                 temp = X86Registers::eax;
3301         }
3302     
3303         ASSERT(temp != op1GPR);
3304         ASSERT(temp != op2GPR);
3305     
3306         m_jit.add32(JITCompiler::TrustedImm32(1), op2GPR, temp);
3307     
3308         JITCompiler::Jump safeDenominator = m_jit.branch32(JITCompiler::Above, temp, JITCompiler::TrustedImm32(1));
3309     
3310         JITCompiler::JumpList done;
3311         if (shouldCheckOverflow(node->arithMode())) {
3312             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, op2GPR));
3313             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branch32(JITCompiler::Equal, op1GPR, TrustedImm32(-2147483647-1)));
3314         } else {
3315             // This is the case where we convert the result to an int after we're done, and we
3316             // already know that the denominator is either -1 or 0. So, if the denominator is
3317             // zero, then the result should be zero. If the denominator is not zero (i.e. it's
3318             // -1) and the numerator is -2^31 then the result should be -2^31. Otherwise we
3319             // are happy to fall through to a normal division, since we're just dividing
3320             // something by negative 1.
3321         
3322             JITCompiler::Jump notZero = m_jit.branchTest32(JITCompiler::NonZero, op2GPR);
3323             m_jit.move(TrustedImm32(0), eax.gpr());
3324             done.append(m_jit.jump());
3325         
3326             notZero.link(&m_jit);
3327             JITCompiler::Jump notNeg2ToThe31 =
3328                 m_jit.branch32(JITCompiler::NotEqual, op1GPR, TrustedImm32(-2147483647-1));
3329             m_jit.zeroExtend32ToPtr(op1GPR, eax.gpr());
3330             done.append(m_jit.jump());
3331         
3332             notNeg2ToThe31.link(&m_jit);
3333         }
3334     
3335         safeDenominator.link(&m_jit);
3336     
3337         // If the user cares about negative zero, then speculate that we're not about
3338         // to produce negative zero.
3339         if (shouldCheckNegativeZero(node->arithMode())) {
3340             MacroAssembler::Jump numeratorNonZero = m_jit.branchTest32(MacroAssembler::NonZero, op1GPR);
3341             speculationCheck(NegativeZero, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, op2GPR, TrustedImm32(0)));
3342             numeratorNonZero.link(&m_jit);
3343         }
3344     
3345         if (op2TempGPR != InvalidGPRReg) {
3346             m_jit.move(op2GPR, op2TempGPR);
3347             op2GPR = op2TempGPR;
3348         }
3349             
3350         m_jit.move(op1GPR, eax.gpr());
3351         m_jit.assembler().cdq();
3352         m_jit.assembler().idivl_r(op2GPR);
3353             
3354         if (op2TempGPR != InvalidGPRReg)
3355             unlock(op2TempGPR);
3356
3357         // Check that there was no remainder. If there had been, then we'd be obligated to
3358         // produce a double result instead.
3359         if (shouldCheckOverflow(node->arithMode()))
3360             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::NonZero, edx.gpr()));
3361         
3362         done.link(&m_jit);
3363         int32Result(eax.gpr(), node);
3364 #elif HAVE(ARM_IDIV_INSTRUCTIONS) || CPU(ARM64)
3365         SpeculateInt32Operand op1(this, node->child1());
3366         SpeculateInt32Operand op2(this, node->child2());
3367         GPRReg op1GPR = op1.gpr();
3368         GPRReg op2GPR = op2.gpr();
3369         GPRTemporary quotient(this);
3370         GPRTemporary multiplyAnswer(this);
3371
3372         // If the user cares about negative zero, then speculate that we're not about
3373         // to produce negative zero.
3374         if (shouldCheckNegativeZero(node->arithMode())) {
3375             MacroAssembler::Jump numeratorNonZero = m_jit.branchTest32(MacroAssembler::NonZero, op1GPR);
3376             speculationCheck(NegativeZero, JSValueRegs(), 0, m_jit.branch32(MacroAssembler::LessThan, op2GPR, TrustedImm32(0)));
3377             numeratorNonZero.link(&m_jit);
3378         }
3379
3380         m_jit.assembler().sdiv<32>(quotient.gpr(), op1GPR, op2GPR);
3381
3382         // Check that there was no remainder. If there had been, then we'd be obligated to
3383         // produce a double result instead.
3384         if (shouldCheckOverflow(node->arithMode())) {
3385             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchMul32(JITCompiler::Overflow, quotient.gpr(), op2GPR, multiplyAnswer.gpr()));
3386             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branch32(JITCompiler::NotEqual, multiplyAnswer.gpr(), op1GPR));
3387         }
3388
3389         int32Result(quotient.gpr(), node);
3390 #else
3391         RELEASE_ASSERT_NOT_REACHED();
3392 #endif
3393         break;
3394     }
3395         
3396     case DoubleRepUse: {
3397         SpeculateDoubleOperand op1(this, node->child1());
3398         SpeculateDoubleOperand op2(this, node->child2());
3399         FPRTemporary result(this, op1);
3400         
3401         FPRReg reg1 = op1.fpr();
3402         FPRReg reg2 = op2.fpr();
3403         m_jit.divDouble(reg1, reg2, result.fpr());
3404         
3405         doubleResult(result.fpr(), node);
3406         break;
3407     }
3408         
3409     default:
3410         RELEASE_ASSERT_NOT_REACHED();
3411         break;
3412     }
3413 }
3414
3415 void SpeculativeJIT::compileArithMod(Node* node)
3416 {
3417     switch (node->binaryUseKind()) {
3418     case Int32Use: {
3419         // In the fast path, the dividend value could be the final result
3420         // (in case of |dividend| < |divisor|), so we speculate it as strict int32.
3421         SpeculateStrictInt32Operand op1(this, node->child1());
3422         
3423         if (node->child2()->isInt32Constant()) {
3424             int32_t divisor = node->child2()->asInt32();
3425             if (divisor > 1 && hasOneBitSet(divisor)) {
3426                 unsigned logarithm = WTF::fastLog2(divisor);
3427                 GPRReg dividendGPR = op1.gpr();
3428                 GPRTemporary result(this);
3429                 GPRReg resultGPR = result.gpr();
3430
3431                 // This is what LLVM generates. It's pretty crazy. Here's my
3432                 // attempt at understanding it.
3433                 
3434                 // First, compute either divisor - 1, or 0, depending on whether
3435                 // the dividend is negative:
3436                 //
3437                 // If dividend < 0:  resultGPR = divisor - 1
3438                 // If dividend >= 0: resultGPR = 0
3439                 m_jit.move(dividendGPR, resultGPR);
3440                 m_jit.rshift32(TrustedImm32(31), resultGPR);
3441                 m_jit.urshift32(TrustedImm32(32 - logarithm), resultGPR);
3442                 
3443                 // Add in the dividend, so that:
3444                 //
3445                 // If dividend < 0:  resultGPR = dividend + divisor - 1
3446                 // If dividend >= 0: resultGPR = dividend
3447                 m_jit.add32(dividendGPR, resultGPR);
3448                 
3449                 // Mask so as to only get the *high* bits. This rounds down
3450                 // (towards negative infinity) resultGPR to the nearest multiple
3451                 // of divisor, so that:
3452                 //
3453                 // If dividend < 0:  resultGPR = floor((dividend + divisor - 1) / divisor)
3454                 // If dividend >= 0: resultGPR = floor(dividend / divisor)
3455                 //
3456                 // Note that this can be simplified to:
3457                 //
3458                 // If dividend < 0:  resultGPR = ceil(dividend / divisor)
3459                 // If dividend >= 0: resultGPR = floor(dividend / divisor)
3460                 //
3461                 // Note that if the dividend is negative, resultGPR will also be negative.
3462                 // Regardless of the sign of dividend, resultGPR will be rounded towards
3463                 // zero, because of how things are conditionalized.
3464                 m_jit.and32(TrustedImm32(-divisor), resultGPR);
3465                 
3466                 // Subtract resultGPR from dividendGPR, which yields the remainder:
3467                 //
3468                 // resultGPR = dividendGPR - resultGPR
3469                 m_jit.neg32(resultGPR);
3470                 m_jit.add32(dividendGPR, resultGPR);
3471                 
3472                 if (shouldCheckNegativeZero(node->arithMode())) {
3473                     // Check that we're not about to create negative zero.
3474                     JITCompiler::Jump numeratorPositive = m_jit.branch32(JITCompiler::GreaterThanOrEqual, dividendGPR, TrustedImm32(0));
3475                     speculationCheck(NegativeZero, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, resultGPR));
3476                     numeratorPositive.link(&m_jit);
3477                 }
3478
3479                 int32Result(resultGPR, node);
3480                 return;
3481             }
3482         }
3483         
3484 #if CPU(X86) || CPU(X86_64)
3485         if (node->child2()->isInt32Constant()) {
3486             int32_t divisor = node->child2()->asInt32();
3487             if (divisor && divisor != -1) {
3488                 GPRReg op1Gpr = op1.gpr();
3489
3490                 GPRTemporary eax(this, X86Registers::eax);
3491                 GPRTemporary edx(this, X86Registers::edx);
3492                 GPRTemporary scratch(this);
3493                 GPRReg scratchGPR = scratch.gpr();
3494
3495                 GPRReg op1SaveGPR;
3496                 if (op1Gpr == X86Registers::eax || op1Gpr == X86Registers::edx) {
3497                     op1SaveGPR = allocate();
3498                     ASSERT(op1Gpr != op1SaveGPR);
3499                     m_jit.move(op1Gpr, op1SaveGPR);
3500                 } else
3501                     op1SaveGPR = op1Gpr;
3502                 ASSERT(op1SaveGPR != X86Registers::eax);
3503                 ASSERT(op1SaveGPR != X86Registers::edx);
3504
3505                 m_jit.move(op1Gpr, eax.gpr());
3506                 m_jit.move(TrustedImm32(divisor), scratchGPR);
3507                 m_jit.assembler().cdq();
3508                 m_jit.assembler().idivl_r(scratchGPR);
3509                 if (shouldCheckNegativeZero(node->arithMode())) {
3510                     JITCompiler::Jump numeratorPositive = m_jit.branch32(JITCompiler::GreaterThanOrEqual, op1SaveGPR, TrustedImm32(0));
3511                     speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, edx.gpr()));
3512                     numeratorPositive.link(&m_jit);
3513                 }
3514             
3515                 if (op1SaveGPR != op1Gpr)
3516                     unlock(op1SaveGPR);
3517
3518                 int32Result(edx.gpr(), node);
3519                 return;
3520             }
3521         }
3522 #endif
3523
3524         SpeculateInt32Operand op2(this, node->child2());
3525 #if CPU(X86) || CPU(X86_64)
3526         GPRTemporary eax(this, X86Registers::eax);
3527         GPRTemporary edx(this, X86Registers::edx);
3528         GPRReg op1GPR = op1.gpr();
3529         GPRReg op2GPR = op2.gpr();
3530     
3531         GPRReg op2TempGPR;
3532         GPRReg temp;
3533         GPRReg op1SaveGPR;
3534     
3535         if (op2GPR == X86Registers::eax || op2GPR == X86Registers::edx) {
3536             op2TempGPR = allocate();
3537             temp = op2TempGPR;
3538         } else {
3539             op2TempGPR = InvalidGPRReg;
3540             if (op1GPR == X86Registers::eax)
3541                 temp = X86Registers::edx;
3542             else
3543                 temp = X86Registers::eax;
3544         }
3545     
3546         if (op1GPR == X86Registers::eax || op1GPR == X86Registers::edx) {
3547             op1SaveGPR = allocate();
3548             ASSERT(op1GPR != op1SaveGPR);
3549             m_jit.move(op1GPR, op1SaveGPR);
3550         } else
3551             op1SaveGPR = op1GPR;
3552     
3553         ASSERT(temp != op1GPR);
3554         ASSERT(temp != op2GPR);
3555         ASSERT(op1SaveGPR != X86Registers::eax);
3556         ASSERT(op1SaveGPR != X86Registers::edx);
3557     
3558         m_jit.add32(JITCompiler::TrustedImm32(1), op2GPR, temp);
3559     
3560         JITCompiler::Jump safeDenominator = m_jit.branch32(JITCompiler::Above, temp, JITCompiler::TrustedImm32(1));
3561     
3562         JITCompiler::JumpList done;
3563         
3564         // FIXME: -2^31 / -1 will actually yield negative zero, so we could have a
3565         // separate case for that. But it probably doesn't matter so much.
3566         if (shouldCheckOverflow(node->arithMode())) {
3567             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, op2GPR));
3568             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branch32(JITCompiler::Equal, op1GPR, TrustedImm32(-2147483647-1)));
3569         } else {
3570             // This is the case where we convert the result to an int after we're done, and we
3571             // already know that the denominator is either -1 or 0. So, if the denominator is
3572             // zero, then the result should be zero. If the denominator is not zero (i.e. it's
3573             // -1) and the numerator is -2^31 then the result should be 0. Otherwise we are
3574             // happy to fall through to a normal division, since we're just dividing something
3575             // by negative 1.
3576         
3577             JITCompiler::Jump notZero = m_jit.branchTest32(JITCompiler::NonZero, op2GPR);
3578             m_jit.move(TrustedImm32(0), edx.gpr());
3579             done.append(m_jit.jump());
3580         
3581             notZero.link(&m_jit);
3582             JITCompiler::Jump notNeg2ToThe31 =
3583                 m_jit.branch32(JITCompiler::NotEqual, op1GPR, TrustedImm32(-2147483647-1));
3584             m_jit.move(TrustedImm32(0), edx.gpr());
3585             done.append(m_jit.jump());
3586         
3587             notNeg2ToThe31.link(&m_jit);
3588         }
3589         
3590         safeDenominator.link(&m_jit);
3591             
3592         if (op2TempGPR != InvalidGPRReg) {
3593             m_jit.move(op2GPR, op2TempGPR);
3594             op2GPR = op2TempGPR;
3595         }
3596             
3597         m_jit.move(op1GPR, eax.gpr());
3598         m_jit.assembler().cdq();
3599         m_jit.assembler().idivl_r(op2GPR);
3600             
3601         if (op2TempGPR != InvalidGPRReg)
3602             unlock(op2TempGPR);
3603
3604         // Check that we're not about to create negative zero.
3605         if (shouldCheckNegativeZero(node->arithMode())) {
3606             JITCompiler::Jump numeratorPositive = m_jit.branch32(JITCompiler::GreaterThanOrEqual, op1SaveGPR, TrustedImm32(0));
3607             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, edx.gpr()));
3608             numeratorPositive.link(&m_jit);
3609         }
3610     
3611         if (op1SaveGPR != op1GPR)
3612             unlock(op1SaveGPR);
3613             
3614         done.link(&m_jit);
3615         int32Result(edx.gpr(), node);
3616
3617 #elif HAVE(ARM_IDIV_INSTRUCTIONS) || CPU(ARM64)
3618         GPRTemporary temp(this);
3619         GPRTemporary quotientThenRemainder(this);
3620         GPRTemporary multiplyAnswer(this);
3621         GPRReg dividendGPR = op1.gpr();
3622         GPRReg divisorGPR = op2.gpr();
3623         GPRReg quotientThenRemainderGPR = quotientThenRemainder.gpr();
3624         GPRReg multiplyAnswerGPR = multiplyAnswer.gpr();
3625
3626         JITCompiler::JumpList done;
3627     
3628         if (shouldCheckOverflow(node->arithMode()))
3629             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, divisorGPR));
3630         else {
3631             JITCompiler::Jump denominatorNotZero = m_jit.branchTest32(JITCompiler::NonZero, divisorGPR);
3632             m_jit.move(divisorGPR, quotientThenRemainderGPR);
3633             done.append(m_jit.jump());
3634             denominatorNotZero.link(&m_jit);
3635         }
3636
3637         m_jit.assembler().sdiv<32>(quotientThenRemainderGPR, dividendGPR, divisorGPR);
3638         // FIXME: It seems like there are cases where we don't need this? What if we have
3639         // arithMode() == Arith::Unchecked?
3640         // https://bugs.webkit.org/show_bug.cgi?id=126444
3641         speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchMul32(JITCompiler::Overflow, quotientThenRemainderGPR, divisorGPR, multiplyAnswerGPR));
3642 #if HAVE(ARM_IDIV_INSTRUCTIONS)
3643         m_jit.assembler().sub(quotientThenRemainderGPR, dividendGPR, multiplyAnswerGPR);
3644 #else
3645         m_jit.assembler().sub<32>(quotientThenRemainderGPR, dividendGPR, multiplyAnswerGPR);
3646 #endif
3647
3648         // If the user cares about negative zero, then speculate that we're not about
3649         // to produce negative zero.
3650         if (shouldCheckNegativeZero(node->arithMode())) {
3651             // Check that we're not about to create negative zero.
3652             JITCompiler::Jump numeratorPositive = m_jit.branch32(JITCompiler::GreaterThanOrEqual, dividendGPR, TrustedImm32(0));
3653             speculationCheck(Overflow, JSValueRegs(), 0, m_jit.branchTest32(JITCompiler::Zero, quotientThenRemainderGPR));
3654             numeratorPositive.link(&m_jit);
3655         }
3656
3657         done.link(&m_jit);
3658
3659         int32Result(quotientThenRemainderGPR, node);
3660 #else // not architecture that can do integer division
3661         RELEASE_ASSERT_NOT_REACHED();
3662 #endif
3663         return;
3664     }
3665         
3666     case DoubleRepUse: {
3667         SpeculateDoubleOperand op1(this, node->child1());
3668         SpeculateDoubleOperand op2(this, node->child2());
3669         
3670         FPRReg op1FPR = op1.fpr();
3671         FPRReg op2FPR = op2.fpr();
3672         
3673         flushRegisters();
3674         
3675         FPRResult result(this);
3676         
3677         callOperation(fmodAsDFGOperation, result.fpr(), op1FPR, op2FPR);
3678         
3679         doubleResult(result.fpr(), node);
3680         return;
3681     }
3682         
3683     default:
3684         RELEASE_ASSERT_NOT_REACHED();
3685         return;
3686     }
3687 }
3688
3689 void SpeculativeJIT::compileArithRound(Node* node)
3690 {
3691     ASSERT(node->child1().useKind() == DoubleRepUse);
3692
3693     SpeculateDoubleOperand value(this, node->child1());
3694     FPRReg valueFPR = value.fpr();
3695
3696     if (producesInteger(node->arithRoundingMode()) && !shouldCheckNegativeZero(node->arithRoundingMode())) {
3697         FPRTemporary oneHalf(this);
3698         GPRTemporary roundedResultAsInt32(this);
3699         FPRReg oneHalfFPR = oneHalf.fpr();
3700         GPRReg resultGPR = roundedResultAsInt32.gpr();
3701
3702         static const double halfConstant = 0.5;
3703         m_jit.loadDouble(MacroAssembler::TrustedImmPtr(&halfConstant), oneHalfFPR);
3704         m_jit.addDouble(valueFPR, oneHalfFPR);
3705
3706         JITCompiler::Jump truncationFailed = m_jit.branchTruncateDoubleToInt32(oneHalfFPR, resultGPR);
3707         speculationCheck(Overflow, JSValueRegs(), node, truncationFailed);
3708         int32Result(resultGPR, node);
3709         return;
3710     }
3711
3712     flushRegisters();
3713     FPRResult roundedResultAsDouble(this);
3714     FPRReg resultFPR = roundedResultAsDouble.fpr();
3715     callOperation(jsRound, resultFPR, valueFPR);
3716     if (producesInteger(node->arithRoundingMode())) {
3717         GPRTemporary roundedResultAsInt32(this);
3718         FPRTemporary scratch(this);
3719         FPRReg scratchFPR = scratch.fpr();
3720         GPRReg resultGPR = roundedResultAsInt32.gpr();
3721         JITCompiler::JumpList failureCases;
3722         m_jit.branchConvertDoubleToInt32(resultFPR, resultGPR, failureCases, scratchFPR);
3723         speculationCheck(Overflow, JSValueRegs(), node, failureCases);
3724
3725         int32Result(resultGPR, node);
3726     } else
3727         doubleResult(resultFPR, node);
3728 }
3729
3730 void SpeculativeJIT::compileArithSqrt(Node* node)
3731 {
3732     SpeculateDoubleOperand op1(this, node->child1());
3733     FPRReg op1FPR = op1.fpr();
3734
3735     if (!MacroAssembler::supportsFloatingPointSqrt() || !Options::enableArchitectureSpecificOptimizations()) {
3736         flushRegisters();
3737         FPRResult result(this);
3738         callOperation(sqrt, result.fpr(), op1FPR);
3739         doubleResult(result.fpr(), node);
3740     } else {
3741         FPRTemporary result(this, op1);
3742         m_jit.sqrtDouble(op1.fpr(), result.fpr());
3743         doubleResult(result.fpr(), node);
3744     }
3745 }
3746
3747 // For small positive integers , it is worth doing a tiny inline loop to exponentiate the base.
3748 // Every register is clobbered by this helper.
3749 static MacroAssembler::Jump compileArithPowIntegerFastPath(JITCompiler& assembler, FPRReg xOperand, GPRReg yOperand, FPRReg result)
3750 {
3751     MacroAssembler::JumpList skipFastPath;
3752     skipFastPath.append(assembler.branch32(MacroAssembler::LessThan, yOperand, MacroAssembler::TrustedImm32(0)));
3753     skipFastPath.append(assembler.branch32(MacroAssembler::GreaterThan, yOperand, MacroAssembler::TrustedImm32(1000)));
3754
3755     static const double oneConstant = 1.0;
3756     assembler.loadDouble(MacroAssembler::TrustedImmPtr(&oneConstant), result);
3757
3758     MacroAssembler::Label startLoop(assembler.label());
3759     MacroAssembler::Jump exponentIsEven = assembler.branchTest32(MacroAssembler::Zero, yOperand, MacroAssembler::TrustedImm32(1));
3760     assembler.mulDouble(xOperand, result);
3761     exponentIsEven.link(&assembler);
3762     assembler.mulDouble(xOperand, xOperand);
3763     assembler.rshift32(MacroAssembler::TrustedImm32(1), yOperand);
3764     assembler.branchTest32(MacroAssembler::NonZero, yOperand).linkTo(startLoop, &assembler);
3765
3766     MacroAssembler::Jump skipSlowPath = assembler.jump();
3767     skipFastPath.link(&assembler);
3768
3769     return skipSlowPath;
3770 }
3771
3772 void SpeculativeJIT::compileArithPow(Node* node)
3773 {
3774     if (node->child2().useKind() == Int32Use) {
3775         SpeculateDoubleOperand xOperand(this, node->child1());
3776         SpeculateInt32Operand yOperand(this, node->child2());
3777         FPRReg xOperandfpr = xOperand.fpr();
3778         GPRReg yOperandGpr = yOperand.gpr();
3779         FPRTemporary yOperandfpr(this);
3780
3781         flushRegisters();
3782
3783         FPRResult result(this);
3784         FPRReg resultFpr = result.fpr();
3785
3786         FPRTemporary xOperandCopy(this);
3787         FPRReg xOperandCopyFpr = xOperandCopy.fpr();
3788         m_jit.moveDouble(xOperandfpr, xOperandCopyFpr);
3789
3790         GPRTemporary counter(this);
3791         GPRReg counterGpr = counter.gpr();
3792         m_jit.move(yOperandGpr, counterGpr);
3793
3794         MacroAssembler::Jump skipFallback = compileArithPowIntegerFastPath(m_jit, xOperandCopyFpr, counterGpr, resultFpr);
3795         m_jit.convertInt32ToDouble(yOperandGpr, yOperandfpr.fpr());