3ad75276e2cc9d8bfa745ae193d3fb46ec8b5b6d
[WebKit-https.git] / Source / JavaScriptCore / bytecode / CodeBlock.cpp
1 /*
2  * Copyright (C) 2008-2010, 2012-2015 Apple Inc. All rights reserved.
3  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1.  Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  * 2.  Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
15  *     its contributors may be used to endorse or promote products derived
16  *     from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29
30 #include "config.h"
31 #include "CodeBlock.h"
32
33 #include "BasicBlockLocation.h"
34 #include "BytecodeGenerator.h"
35 #include "BytecodeUseDef.h"
36 #include "CallLinkStatus.h"
37 #include "DFGCapabilities.h"
38 #include "DFGCommon.h"
39 #include "DFGDriver.h"
40 #include "DFGJITCode.h"
41 #include "DFGWorklist.h"
42 #include "Debugger.h"
43 #include "FunctionExecutableDump.h"
44 #include "Interpreter.h"
45 #include "JIT.h"
46 #include "JITStubs.h"
47 #include "JSCJSValue.h"
48 #include "JSFunction.h"
49 #include "JSLexicalEnvironment.h"
50 #include "JSNameScope.h"
51 #include "LLIntEntrypoint.h"
52 #include "LowLevelInterpreter.h"
53 #include "JSCInlines.h"
54 #include "PolymorphicGetByIdList.h"
55 #include "PolymorphicPutByIdList.h"
56 #include "ProfilerDatabase.h"
57 #include "ReduceWhitespace.h"
58 #include "Repatch.h"
59 #include "RepatchBuffer.h"
60 #include "SlotVisitorInlines.h"
61 #include "StackVisitor.h"
62 #include "TypeLocationCache.h"
63 #include "TypeProfiler.h"
64 #include "UnlinkedInstructionStream.h"
65 #include <wtf/BagToHashMap.h>
66 #include <wtf/CommaPrinter.h>
67 #include <wtf/StringExtras.h>
68 #include <wtf/StringPrintStream.h>
69 #include <wtf/text/UniquedStringImpl.h>
70
71 #if ENABLE(DFG_JIT)
72 #include "DFGOperations.h"
73 #endif
74
75 #if ENABLE(FTL_JIT)
76 #include "FTLJITCode.h"
77 #endif
78
79 namespace JSC {
80
81 CString CodeBlock::inferredName() const
82 {
83     switch (codeType()) {
84     case GlobalCode:
85         return "<global>";
86     case EvalCode:
87         return "<eval>";
88     case FunctionCode:
89         return jsCast<FunctionExecutable*>(ownerExecutable())->inferredName().utf8();
90     default:
91         CRASH();
92         return CString("", 0);
93     }
94 }
95
96 bool CodeBlock::hasHash() const
97 {
98     return !!m_hash;
99 }
100
101 bool CodeBlock::isSafeToComputeHash() const
102 {
103     return !isCompilationThread();
104 }
105
106 CodeBlockHash CodeBlock::hash() const
107 {
108     if (!m_hash) {
109         RELEASE_ASSERT(isSafeToComputeHash());
110         m_hash = CodeBlockHash(ownerExecutable()->source(), specializationKind());
111     }
112     return m_hash;
113 }
114
115 CString CodeBlock::sourceCodeForTools() const
116 {
117     if (codeType() != FunctionCode)
118         return ownerExecutable()->source().toUTF8();
119     
120     SourceProvider* provider = source();
121     FunctionExecutable* executable = jsCast<FunctionExecutable*>(ownerExecutable());
122     UnlinkedFunctionExecutable* unlinked = executable->unlinkedExecutable();
123     unsigned unlinkedStartOffset = unlinked->startOffset();
124     unsigned linkedStartOffset = executable->source().startOffset();
125     int delta = linkedStartOffset - unlinkedStartOffset;
126     unsigned rangeStart = delta + unlinked->unlinkedFunctionNameStart();
127     unsigned rangeEnd = delta + unlinked->startOffset() + unlinked->sourceLength();
128     return toCString(
129         "function ",
130         provider->source().impl()->utf8ForRange(rangeStart, rangeEnd - rangeStart));
131 }
132
133 CString CodeBlock::sourceCodeOnOneLine() const
134 {
135     return reduceWhitespace(sourceCodeForTools());
136 }
137
138 CString CodeBlock::hashAsStringIfPossible() const
139 {
140     if (hasHash() || isSafeToComputeHash())
141         return toCString(hash());
142     return "<no-hash>";
143 }
144
145 void CodeBlock::dumpAssumingJITType(PrintStream& out, JITCode::JITType jitType) const
146 {
147     out.print(inferredName(), "#", hashAsStringIfPossible());
148     out.print(":[", RawPointer(this), "->");
149     if (!!m_alternative)
150         out.print(RawPointer(m_alternative.get()), "->");
151     out.print(RawPointer(ownerExecutable()), ", ", jitType, codeType());
152
153     if (codeType() == FunctionCode)
154         out.print(specializationKind());
155     out.print(", ", instructionCount());
156     if (this->jitType() == JITCode::BaselineJIT && m_shouldAlwaysBeInlined)
157         out.print(" (ShouldAlwaysBeInlined)");
158     if (ownerExecutable()->neverInline())
159         out.print(" (NeverInline)");
160     if (ownerExecutable()->didTryToEnterInLoop())
161         out.print(" (DidTryToEnterInLoop)");
162     if (ownerExecutable()->isStrictMode())
163         out.print(" (StrictMode)");
164     if (this->jitType() == JITCode::BaselineJIT && m_didFailFTLCompilation)
165         out.print(" (FTLFail)");
166     if (this->jitType() == JITCode::BaselineJIT && m_hasBeenCompiledWithFTL)
167         out.print(" (HadFTLReplacement)");
168     out.print("]");
169 }
170
171 void CodeBlock::dump(PrintStream& out) const
172 {
173     dumpAssumingJITType(out, jitType());
174 }
175
176 static CString idName(int id0, const Identifier& ident)
177 {
178     return toCString(ident.impl(), "(@id", id0, ")");
179 }
180
181 CString CodeBlock::registerName(int r) const
182 {
183     if (isConstantRegisterIndex(r))
184         return constantName(r);
185
186     return toCString(VirtualRegister(r));
187 }
188
189 CString CodeBlock::constantName(int index) const
190 {
191     JSValue value = getConstant(index);
192     return toCString(value, "(", VirtualRegister(index), ")");
193 }
194
195 static CString regexpToSourceString(RegExp* regExp)
196 {
197     char postfix[5] = { '/', 0, 0, 0, 0 };
198     int index = 1;
199     if (regExp->global())
200         postfix[index++] = 'g';
201     if (regExp->ignoreCase())
202         postfix[index++] = 'i';
203     if (regExp->multiline())
204         postfix[index] = 'm';
205
206     return toCString("/", regExp->pattern().impl(), postfix);
207 }
208
209 static CString regexpName(int re, RegExp* regexp)
210 {
211     return toCString(regexpToSourceString(regexp), "(@re", re, ")");
212 }
213
214 NEVER_INLINE static const char* debugHookName(int debugHookID)
215 {
216     switch (static_cast<DebugHookID>(debugHookID)) {
217         case DidEnterCallFrame:
218             return "didEnterCallFrame";
219         case WillLeaveCallFrame:
220             return "willLeaveCallFrame";
221         case WillExecuteStatement:
222             return "willExecuteStatement";
223         case WillExecuteProgram:
224             return "willExecuteProgram";
225         case DidExecuteProgram:
226             return "didExecuteProgram";
227         case DidReachBreakpoint:
228             return "didReachBreakpoint";
229     }
230
231     RELEASE_ASSERT_NOT_REACHED();
232     return "";
233 }
234
235 void CodeBlock::printUnaryOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
236 {
237     int r0 = (++it)->u.operand;
238     int r1 = (++it)->u.operand;
239
240     printLocationAndOp(out, exec, location, it, op);
241     out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
242 }
243
244 void CodeBlock::printBinaryOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
245 {
246     int r0 = (++it)->u.operand;
247     int r1 = (++it)->u.operand;
248     int r2 = (++it)->u.operand;
249     printLocationAndOp(out, exec, location, it, op);
250     out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
251 }
252
253 void CodeBlock::printConditionalJump(PrintStream& out, ExecState* exec, const Instruction*, const Instruction*& it, int location, const char* op)
254 {
255     int r0 = (++it)->u.operand;
256     int offset = (++it)->u.operand;
257     printLocationAndOp(out, exec, location, it, op);
258     out.printf("%s, %d(->%d)", registerName(r0).data(), offset, location + offset);
259 }
260
261 void CodeBlock::printGetByIdOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it)
262 {
263     const char* op;
264     switch (exec->interpreter()->getOpcodeID(it->u.opcode)) {
265     case op_get_by_id:
266         op = "get_by_id";
267         break;
268     case op_get_by_id_out_of_line:
269         op = "get_by_id_out_of_line";
270         break;
271     case op_get_array_length:
272         op = "array_length";
273         break;
274     default:
275         RELEASE_ASSERT_NOT_REACHED();
276 #if COMPILER_QUIRK(CONSIDERS_UNREACHABLE_CODE)
277         op = 0;
278 #endif
279     }
280     int r0 = (++it)->u.operand;
281     int r1 = (++it)->u.operand;
282     int id0 = (++it)->u.operand;
283     printLocationAndOp(out, exec, location, it, op);
284     out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), idName(id0, identifier(id0)).data());
285     it += 4; // Increment up to the value profiler.
286 }
287
288 static void dumpStructure(PrintStream& out, const char* name, Structure* structure, const Identifier& ident)
289 {
290     if (!structure)
291         return;
292     
293     out.printf("%s = %p", name, structure);
294     
295     PropertyOffset offset = structure->getConcurrently(ident.impl());
296     if (offset != invalidOffset)
297         out.printf(" (offset = %d)", offset);
298 }
299
300 static void dumpChain(PrintStream& out, StructureChain* chain, const Identifier& ident)
301 {
302     out.printf("chain = %p: [", chain);
303     bool first = true;
304     for (WriteBarrier<Structure>* currentStructure = chain->head();
305          *currentStructure;
306          ++currentStructure) {
307         if (first)
308             first = false;
309         else
310             out.printf(", ");
311         dumpStructure(out, "struct", currentStructure->get(), ident);
312     }
313     out.printf("]");
314 }
315
316 void CodeBlock::printGetByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
317 {
318     Instruction* instruction = instructions().begin() + location;
319
320     const Identifier& ident = identifier(instruction[3].u.operand);
321     
322     UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
323     
324     if (exec->interpreter()->getOpcodeID(instruction[0].u.opcode) == op_get_array_length)
325         out.printf(" llint(array_length)");
326     else if (Structure* structure = instruction[4].u.structure.get()) {
327         out.printf(" llint(");
328         dumpStructure(out, "struct", structure, ident);
329         out.printf(")");
330     }
331
332 #if ENABLE(JIT)
333     if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
334         StructureStubInfo& stubInfo = *stubPtr;
335         if (stubInfo.resetByGC)
336             out.print(" (Reset By GC)");
337         
338         if (stubInfo.seen) {
339             out.printf(" jit(");
340             
341             Structure* baseStructure = 0;
342             Structure* prototypeStructure = 0;
343             StructureChain* chain = 0;
344             PolymorphicGetByIdList* list = 0;
345             
346             switch (stubInfo.accessType) {
347             case access_get_by_id_self:
348                 out.printf("self");
349                 baseStructure = stubInfo.u.getByIdSelf.baseObjectStructure.get();
350                 break;
351             case access_get_by_id_list:
352                 out.printf("list");
353                 list = stubInfo.u.getByIdList.list;
354                 break;
355             case access_unset:
356                 out.printf("unset");
357                 break;
358             default:
359                 RELEASE_ASSERT_NOT_REACHED();
360                 break;
361             }
362             
363             if (baseStructure) {
364                 out.printf(", ");
365                 dumpStructure(out, "struct", baseStructure, ident);
366             }
367             
368             if (prototypeStructure) {
369                 out.printf(", ");
370                 dumpStructure(out, "prototypeStruct", baseStructure, ident);
371             }
372             
373             if (chain) {
374                 out.printf(", ");
375                 dumpChain(out, chain, ident);
376             }
377             
378             if (list) {
379                 out.printf(", list = %p: [", list);
380                 for (unsigned i = 0; i < list->size(); ++i) {
381                     if (i)
382                         out.printf(", ");
383                     out.printf("(");
384                     dumpStructure(out, "base", list->at(i).structure(), ident);
385                     if (list->at(i).chain()) {
386                         out.printf(", ");
387                         dumpChain(out, list->at(i).chain(), ident);
388                     }
389                     out.printf(")");
390                 }
391                 out.printf("]");
392             }
393             out.printf(")");
394         }
395     }
396 #else
397     UNUSED_PARAM(map);
398 #endif
399 }
400
401 void CodeBlock::printPutByIdCacheStatus(PrintStream& out, ExecState* exec, int location, const StubInfoMap& map)
402 {
403     Instruction* instruction = instructions().begin() + location;
404
405     const Identifier& ident = identifier(instruction[2].u.operand);
406     
407     UNUSED_PARAM(ident); // tell the compiler to shut up in certain platform configurations.
408     
409     if (Structure* structure = instruction[4].u.structure.get()) {
410         switch (exec->interpreter()->getOpcodeID(instruction[0].u.opcode)) {
411         case op_put_by_id:
412         case op_put_by_id_out_of_line:
413             out.print(" llint(");
414             dumpStructure(out, "struct", structure, ident);
415             out.print(")");
416             break;
417             
418         case op_put_by_id_transition_direct:
419         case op_put_by_id_transition_normal:
420         case op_put_by_id_transition_direct_out_of_line:
421         case op_put_by_id_transition_normal_out_of_line:
422             out.print(" llint(");
423             dumpStructure(out, "prev", structure, ident);
424             out.print(", ");
425             dumpStructure(out, "next", instruction[6].u.structure.get(), ident);
426             if (StructureChain* chain = instruction[7].u.structureChain.get()) {
427                 out.print(", ");
428                 dumpChain(out, chain, ident);
429             }
430             out.print(")");
431             break;
432             
433         default:
434             out.print(" llint(unknown)");
435             break;
436         }
437     }
438
439 #if ENABLE(JIT)
440     if (StructureStubInfo* stubPtr = map.get(CodeOrigin(location))) {
441         StructureStubInfo& stubInfo = *stubPtr;
442         if (stubInfo.resetByGC)
443             out.print(" (Reset By GC)");
444         
445         if (stubInfo.seen) {
446             out.printf(" jit(");
447             
448             switch (stubInfo.accessType) {
449             case access_put_by_id_replace:
450                 out.print("replace, ");
451                 dumpStructure(out, "struct", stubInfo.u.putByIdReplace.baseObjectStructure.get(), ident);
452                 break;
453             case access_put_by_id_transition_normal:
454             case access_put_by_id_transition_direct:
455                 out.print("transition, ");
456                 dumpStructure(out, "prev", stubInfo.u.putByIdTransition.previousStructure.get(), ident);
457                 out.print(", ");
458                 dumpStructure(out, "next", stubInfo.u.putByIdTransition.structure.get(), ident);
459                 if (StructureChain* chain = stubInfo.u.putByIdTransition.chain.get()) {
460                     out.print(", ");
461                     dumpChain(out, chain, ident);
462                 }
463                 break;
464             case access_put_by_id_list: {
465                 out.printf("list = [");
466                 PolymorphicPutByIdList* list = stubInfo.u.putByIdList.list;
467                 CommaPrinter comma;
468                 for (unsigned i = 0; i < list->size(); ++i) {
469                     out.print(comma, "(");
470                     const PutByIdAccess& access = list->at(i);
471                     
472                     if (access.isReplace()) {
473                         out.print("replace, ");
474                         dumpStructure(out, "struct", access.oldStructure(), ident);
475                     } else if (access.isSetter()) {
476                         out.print("setter, ");
477                         dumpStructure(out, "struct", access.oldStructure(), ident);
478                     } else if (access.isCustom()) {
479                         out.print("custom, ");
480                         dumpStructure(out, "struct", access.oldStructure(), ident);
481                     } else if (access.isTransition()) {
482                         out.print("transition, ");
483                         dumpStructure(out, "prev", access.oldStructure(), ident);
484                         out.print(", ");
485                         dumpStructure(out, "next", access.newStructure(), ident);
486                         if (access.chain()) {
487                             out.print(", ");
488                             dumpChain(out, access.chain(), ident);
489                         }
490                     } else
491                         out.print("unknown");
492                     
493                     out.print(")");
494                 }
495                 out.print("]");
496                 break;
497             }
498             case access_unset:
499                 out.printf("unset");
500                 break;
501             default:
502                 RELEASE_ASSERT_NOT_REACHED();
503                 break;
504             }
505             out.printf(")");
506         }
507     }
508 #else
509     UNUSED_PARAM(map);
510 #endif
511 }
512
513 void CodeBlock::printCallOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, CacheDumpMode cacheDumpMode, bool& hasPrintedProfiling, const CallLinkInfoMap& map)
514 {
515     int dst = (++it)->u.operand;
516     int func = (++it)->u.operand;
517     int argCount = (++it)->u.operand;
518     int registerOffset = (++it)->u.operand;
519     printLocationAndOp(out, exec, location, it, op);
520     out.printf("%s, %s, %d, %d", registerName(dst).data(), registerName(func).data(), argCount, registerOffset);
521     if (cacheDumpMode == DumpCaches) {
522         LLIntCallLinkInfo* callLinkInfo = it[1].u.callLinkInfo;
523         if (callLinkInfo->lastSeenCallee) {
524             out.printf(
525                 " llint(%p, exec %p)",
526                 callLinkInfo->lastSeenCallee.get(),
527                 callLinkInfo->lastSeenCallee->executable());
528         }
529 #if ENABLE(JIT)
530         if (CallLinkInfo* info = map.get(CodeOrigin(location))) {
531             JSFunction* target = info->lastSeenCallee();
532             if (target)
533                 out.printf(" jit(%p, exec %p)", target, target->executable());
534         }
535         
536         if (jitType() != JITCode::FTLJIT)
537             out.print(" status(", CallLinkStatus::computeFor(this, location, map), ")");
538 #else
539         UNUSED_PARAM(map);
540 #endif
541     }
542     ++it;
543     ++it;
544     dumpArrayProfiling(out, it, hasPrintedProfiling);
545     dumpValueProfiling(out, it, hasPrintedProfiling);
546 }
547
548 void CodeBlock::printPutByIdOp(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op)
549 {
550     int r0 = (++it)->u.operand;
551     int id0 = (++it)->u.operand;
552     int r1 = (++it)->u.operand;
553     printLocationAndOp(out, exec, location, it, op);
554     out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
555     it += 5;
556 }
557
558 void CodeBlock::dumpSource()
559 {
560     dumpSource(WTF::dataFile());
561 }
562
563 void CodeBlock::dumpSource(PrintStream& out)
564 {
565     ScriptExecutable* executable = ownerExecutable();
566     if (executable->isFunctionExecutable()) {
567         FunctionExecutable* functionExecutable = reinterpret_cast<FunctionExecutable*>(executable);
568         String source = functionExecutable->source().provider()->getRange(
569             functionExecutable->parametersStartOffset(),
570             functionExecutable->typeProfilingEndOffset() + 1); // Type profiling end offset is the character before the '}'.
571         
572         out.print("function ", inferredName(), source);
573         return;
574     }
575     out.print(executable->source().toString());
576 }
577
578 void CodeBlock::dumpBytecode()
579 {
580     dumpBytecode(WTF::dataFile());
581 }
582
583 void CodeBlock::dumpBytecode(PrintStream& out)
584 {
585     // We only use the ExecState* for things that don't actually lead to JS execution,
586     // like converting a JSString to a String. Hence the globalExec is appropriate.
587     ExecState* exec = m_globalObject->globalExec();
588     
589     size_t instructionCount = 0;
590
591     for (size_t i = 0; i < instructions().size(); i += opcodeLengths[exec->interpreter()->getOpcodeID(instructions()[i].u.opcode)])
592         ++instructionCount;
593
594     out.print(*this);
595     out.printf(
596         ": %lu m_instructions; %lu bytes; %d parameter(s); %d callee register(s); %d variable(s)",
597         static_cast<unsigned long>(instructions().size()),
598         static_cast<unsigned long>(instructions().size() * sizeof(Instruction)),
599         m_numParameters, m_numCalleeRegisters, m_numVars);
600     if (needsActivation() && codeType() == FunctionCode)
601         out.printf("; lexical environment in r%d", activationRegister().offset());
602     out.printf("\n");
603     
604     StubInfoMap stubInfos;
605     CallLinkInfoMap callLinkInfos;
606     getStubInfoMap(stubInfos);
607     getCallLinkInfoMap(callLinkInfos);
608     
609     const Instruction* begin = instructions().begin();
610     const Instruction* end = instructions().end();
611     for (const Instruction* it = begin; it != end; ++it)
612         dumpBytecode(out, exec, begin, it, stubInfos, callLinkInfos);
613     
614     if (numberOfIdentifiers()) {
615         out.printf("\nIdentifiers:\n");
616         size_t i = 0;
617         do {
618             out.printf("  id%u = %s\n", static_cast<unsigned>(i), identifier(i).string().utf8().data());
619             ++i;
620         } while (i != numberOfIdentifiers());
621     }
622
623     if (!m_constantRegisters.isEmpty()) {
624         out.printf("\nConstants:\n");
625         size_t i = 0;
626         do {
627             const char* sourceCodeRepresentationDescription = nullptr;
628             switch (m_constantsSourceCodeRepresentation[i]) {
629             case SourceCodeRepresentation::Double:
630                 sourceCodeRepresentationDescription = ": in source as double";
631                 break;
632             case SourceCodeRepresentation::Integer:
633                 sourceCodeRepresentationDescription = ": in source as integer";
634                 break;
635             case SourceCodeRepresentation::Other:
636                 sourceCodeRepresentationDescription = "";
637                 break;
638             }
639             out.printf("   k%u = %s%s\n", static_cast<unsigned>(i), toCString(m_constantRegisters[i].get()).data(), sourceCodeRepresentationDescription);
640             ++i;
641         } while (i < m_constantRegisters.size());
642     }
643
644     if (size_t count = m_unlinkedCode->numberOfRegExps()) {
645         out.printf("\nm_regexps:\n");
646         size_t i = 0;
647         do {
648             out.printf("  re%u = %s\n", static_cast<unsigned>(i), regexpToSourceString(m_unlinkedCode->regexp(i)).data());
649             ++i;
650         } while (i < count);
651     }
652
653     if (m_rareData && !m_rareData->m_exceptionHandlers.isEmpty()) {
654         out.printf("\nException Handlers:\n");
655         unsigned i = 0;
656         do {
657             HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
658             out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] depth: [%4d] } %s\n",
659                 i + 1, handler.start, handler.end, handler.target, handler.scopeDepth, handler.typeName());
660             ++i;
661         } while (i < m_rareData->m_exceptionHandlers.size());
662     }
663     
664     if (m_rareData && !m_rareData->m_switchJumpTables.isEmpty()) {
665         out.printf("Switch Jump Tables:\n");
666         unsigned i = 0;
667         do {
668             out.printf("  %1d = {\n", i);
669             int entry = 0;
670             Vector<int32_t>::const_iterator end = m_rareData->m_switchJumpTables[i].branchOffsets.end();
671             for (Vector<int32_t>::const_iterator iter = m_rareData->m_switchJumpTables[i].branchOffsets.begin(); iter != end; ++iter, ++entry) {
672                 if (!*iter)
673                     continue;
674                 out.printf("\t\t%4d => %04d\n", entry + m_rareData->m_switchJumpTables[i].min, *iter);
675             }
676             out.printf("      }\n");
677             ++i;
678         } while (i < m_rareData->m_switchJumpTables.size());
679     }
680     
681     if (m_rareData && !m_rareData->m_stringSwitchJumpTables.isEmpty()) {
682         out.printf("\nString Switch Jump Tables:\n");
683         unsigned i = 0;
684         do {
685             out.printf("  %1d = {\n", i);
686             StringJumpTable::StringOffsetTable::const_iterator end = m_rareData->m_stringSwitchJumpTables[i].offsetTable.end();
687             for (StringJumpTable::StringOffsetTable::const_iterator iter = m_rareData->m_stringSwitchJumpTables[i].offsetTable.begin(); iter != end; ++iter)
688                 out.printf("\t\t\"%s\" => %04d\n", iter->key->utf8().data(), iter->value.branchOffset);
689             out.printf("      }\n");
690             ++i;
691         } while (i < m_rareData->m_stringSwitchJumpTables.size());
692     }
693
694     out.printf("\n");
695 }
696
697 void CodeBlock::beginDumpProfiling(PrintStream& out, bool& hasPrintedProfiling)
698 {
699     if (hasPrintedProfiling) {
700         out.print("; ");
701         return;
702     }
703     
704     out.print("    ");
705     hasPrintedProfiling = true;
706 }
707
708 void CodeBlock::dumpValueProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
709 {
710     ConcurrentJITLocker locker(m_lock);
711     
712     ++it;
713     CString description = it->u.profile->briefDescription(locker);
714     if (!description.length())
715         return;
716     beginDumpProfiling(out, hasPrintedProfiling);
717     out.print(description);
718 }
719
720 void CodeBlock::dumpArrayProfiling(PrintStream& out, const Instruction*& it, bool& hasPrintedProfiling)
721 {
722     ConcurrentJITLocker locker(m_lock);
723     
724     ++it;
725     if (!it->u.arrayProfile)
726         return;
727     CString description = it->u.arrayProfile->briefDescription(locker, this);
728     if (!description.length())
729         return;
730     beginDumpProfiling(out, hasPrintedProfiling);
731     out.print(description);
732 }
733
734 void CodeBlock::dumpRareCaseProfile(PrintStream& out, const char* name, RareCaseProfile* profile, bool& hasPrintedProfiling)
735 {
736     if (!profile || !profile->m_counter)
737         return;
738
739     beginDumpProfiling(out, hasPrintedProfiling);
740     out.print(name, profile->m_counter);
741 }
742
743 void CodeBlock::printLocationAndOp(PrintStream& out, ExecState*, int location, const Instruction*&, const char* op)
744 {
745     out.printf("[%4d] %-17s ", location, op);
746 }
747
748 void CodeBlock::printLocationOpAndRegisterOperand(PrintStream& out, ExecState* exec, int location, const Instruction*& it, const char* op, int operand)
749 {
750     printLocationAndOp(out, exec, location, it, op);
751     out.printf("%s", registerName(operand).data());
752 }
753
754 void CodeBlock::dumpBytecode(
755     PrintStream& out, ExecState* exec, const Instruction* begin, const Instruction*& it,
756     const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
757 {
758     int location = it - begin;
759     bool hasPrintedProfiling = false;
760     OpcodeID opcode = exec->interpreter()->getOpcodeID(it->u.opcode);
761     switch (opcode) {
762         case op_enter: {
763             printLocationAndOp(out, exec, location, it, "enter");
764             break;
765         }
766         case op_create_lexical_environment: {
767             int r0 = (++it)->u.operand;
768             int r1 = (++it)->u.operand;
769             printLocationAndOp(out, exec, location, it, "create_lexical_environment");
770             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
771             break;
772         }
773         case op_get_scope: {
774             int r0 = (++it)->u.operand;
775             printLocationOpAndRegisterOperand(out, exec, location, it, "get_scope", r0);
776             break;
777         }
778         case op_create_direct_arguments: {
779             int r0 = (++it)->u.operand;
780             printLocationAndOp(out, exec, location, it, "create_direct_arguments");
781             out.printf("%s", registerName(r0).data());
782             break;
783         }
784         case op_create_scoped_arguments: {
785             int r0 = (++it)->u.operand;
786             int r1 = (++it)->u.operand;
787             printLocationAndOp(out, exec, location, it, "create_scoped_arguments");
788             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
789             break;
790         }
791         case op_create_out_of_band_arguments: {
792             int r0 = (++it)->u.operand;
793             printLocationAndOp(out, exec, location, it, "create_out_of_band_arguments");
794             out.printf("%s", registerName(r0).data());
795             break;
796         }
797         case op_create_this: {
798             int r0 = (++it)->u.operand;
799             int r1 = (++it)->u.operand;
800             unsigned inferredInlineCapacity = (++it)->u.operand;
801             unsigned cachedFunction = (++it)->u.operand;
802             printLocationAndOp(out, exec, location, it, "create_this");
803             out.printf("%s, %s, %u, %u", registerName(r0).data(), registerName(r1).data(), inferredInlineCapacity, cachedFunction);
804             break;
805         }
806         case op_to_this: {
807             int r0 = (++it)->u.operand;
808             printLocationOpAndRegisterOperand(out, exec, location, it, "to_this", r0);
809             Structure* structure = (++it)->u.structure.get();
810             if (structure)
811                 out.print(", cache(struct = ", RawPointer(structure), ")");
812             out.print(", ", (++it)->u.toThisStatus);
813             break;
814         }
815         case op_check_tdz: {
816             int r0 = (++it)->u.operand;
817             printLocationOpAndRegisterOperand(out, exec, location, it, "op_check_tdz", r0);
818             break;
819         }
820         case op_new_object: {
821             int r0 = (++it)->u.operand;
822             unsigned inferredInlineCapacity = (++it)->u.operand;
823             printLocationAndOp(out, exec, location, it, "new_object");
824             out.printf("%s, %u", registerName(r0).data(), inferredInlineCapacity);
825             ++it; // Skip object allocation profile.
826             break;
827         }
828         case op_new_array: {
829             int dst = (++it)->u.operand;
830             int argv = (++it)->u.operand;
831             int argc = (++it)->u.operand;
832             printLocationAndOp(out, exec, location, it, "new_array");
833             out.printf("%s, %s, %d", registerName(dst).data(), registerName(argv).data(), argc);
834             ++it; // Skip array allocation profile.
835             break;
836         }
837         case op_new_array_with_size: {
838             int dst = (++it)->u.operand;
839             int length = (++it)->u.operand;
840             printLocationAndOp(out, exec, location, it, "new_array_with_size");
841             out.printf("%s, %s", registerName(dst).data(), registerName(length).data());
842             ++it; // Skip array allocation profile.
843             break;
844         }
845         case op_new_array_buffer: {
846             int dst = (++it)->u.operand;
847             int argv = (++it)->u.operand;
848             int argc = (++it)->u.operand;
849             printLocationAndOp(out, exec, location, it, "new_array_buffer");
850             out.printf("%s, %d, %d", registerName(dst).data(), argv, argc);
851             ++it; // Skip array allocation profile.
852             break;
853         }
854         case op_new_regexp: {
855             int r0 = (++it)->u.operand;
856             int re0 = (++it)->u.operand;
857             printLocationAndOp(out, exec, location, it, "new_regexp");
858             out.printf("%s, ", registerName(r0).data());
859             if (r0 >=0 && r0 < (int)m_unlinkedCode->numberOfRegExps())
860                 out.printf("%s", regexpName(re0, regexp(re0)).data());
861             else
862                 out.printf("bad_regexp(%d)", re0);
863             break;
864         }
865         case op_mov: {
866             int r0 = (++it)->u.operand;
867             int r1 = (++it)->u.operand;
868             printLocationAndOp(out, exec, location, it, "mov");
869             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
870             break;
871         }
872         case op_profile_type: {
873             int r0 = (++it)->u.operand;
874             ++it;
875             ++it;
876             ++it;
877             ++it;
878             printLocationAndOp(out, exec, location, it, "op_profile_type");
879             out.printf("%s", registerName(r0).data());
880             break;
881         }
882         case op_profile_control_flow: {
883             BasicBlockLocation* basicBlockLocation = (++it)->u.basicBlockLocation;
884             printLocationAndOp(out, exec, location, it, "profile_control_flow");
885             out.printf("[%d, %d]", basicBlockLocation->startOffset(), basicBlockLocation->endOffset());
886             break;
887         }
888         case op_not: {
889             printUnaryOp(out, exec, location, it, "not");
890             break;
891         }
892         case op_eq: {
893             printBinaryOp(out, exec, location, it, "eq");
894             break;
895         }
896         case op_eq_null: {
897             printUnaryOp(out, exec, location, it, "eq_null");
898             break;
899         }
900         case op_neq: {
901             printBinaryOp(out, exec, location, it, "neq");
902             break;
903         }
904         case op_neq_null: {
905             printUnaryOp(out, exec, location, it, "neq_null");
906             break;
907         }
908         case op_stricteq: {
909             printBinaryOp(out, exec, location, it, "stricteq");
910             break;
911         }
912         case op_nstricteq: {
913             printBinaryOp(out, exec, location, it, "nstricteq");
914             break;
915         }
916         case op_less: {
917             printBinaryOp(out, exec, location, it, "less");
918             break;
919         }
920         case op_lesseq: {
921             printBinaryOp(out, exec, location, it, "lesseq");
922             break;
923         }
924         case op_greater: {
925             printBinaryOp(out, exec, location, it, "greater");
926             break;
927         }
928         case op_greatereq: {
929             printBinaryOp(out, exec, location, it, "greatereq");
930             break;
931         }
932         case op_inc: {
933             int r0 = (++it)->u.operand;
934             printLocationOpAndRegisterOperand(out, exec, location, it, "inc", r0);
935             break;
936         }
937         case op_dec: {
938             int r0 = (++it)->u.operand;
939             printLocationOpAndRegisterOperand(out, exec, location, it, "dec", r0);
940             break;
941         }
942         case op_to_number: {
943             printUnaryOp(out, exec, location, it, "to_number");
944             break;
945         }
946         case op_to_string: {
947             printUnaryOp(out, exec, location, it, "to_string");
948             break;
949         }
950         case op_negate: {
951             printUnaryOp(out, exec, location, it, "negate");
952             break;
953         }
954         case op_add: {
955             printBinaryOp(out, exec, location, it, "add");
956             ++it;
957             break;
958         }
959         case op_mul: {
960             printBinaryOp(out, exec, location, it, "mul");
961             ++it;
962             break;
963         }
964         case op_div: {
965             printBinaryOp(out, exec, location, it, "div");
966             ++it;
967             break;
968         }
969         case op_mod: {
970             printBinaryOp(out, exec, location, it, "mod");
971             break;
972         }
973         case op_sub: {
974             printBinaryOp(out, exec, location, it, "sub");
975             ++it;
976             break;
977         }
978         case op_lshift: {
979             printBinaryOp(out, exec, location, it, "lshift");
980             break;            
981         }
982         case op_rshift: {
983             printBinaryOp(out, exec, location, it, "rshift");
984             break;
985         }
986         case op_urshift: {
987             printBinaryOp(out, exec, location, it, "urshift");
988             break;
989         }
990         case op_bitand: {
991             printBinaryOp(out, exec, location, it, "bitand");
992             ++it;
993             break;
994         }
995         case op_bitxor: {
996             printBinaryOp(out, exec, location, it, "bitxor");
997             ++it;
998             break;
999         }
1000         case op_bitor: {
1001             printBinaryOp(out, exec, location, it, "bitor");
1002             ++it;
1003             break;
1004         }
1005         case op_check_has_instance: {
1006             int r0 = (++it)->u.operand;
1007             int r1 = (++it)->u.operand;
1008             int r2 = (++it)->u.operand;
1009             int offset = (++it)->u.operand;
1010             printLocationAndOp(out, exec, location, it, "check_has_instance");
1011             out.printf("%s, %s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), registerName(r2).data(), offset, location + offset);
1012             break;
1013         }
1014         case op_instanceof: {
1015             int r0 = (++it)->u.operand;
1016             int r1 = (++it)->u.operand;
1017             int r2 = (++it)->u.operand;
1018             printLocationAndOp(out, exec, location, it, "instanceof");
1019             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
1020             break;
1021         }
1022         case op_unsigned: {
1023             printUnaryOp(out, exec, location, it, "unsigned");
1024             break;
1025         }
1026         case op_typeof: {
1027             printUnaryOp(out, exec, location, it, "typeof");
1028             break;
1029         }
1030         case op_is_undefined: {
1031             printUnaryOp(out, exec, location, it, "is_undefined");
1032             break;
1033         }
1034         case op_is_boolean: {
1035             printUnaryOp(out, exec, location, it, "is_boolean");
1036             break;
1037         }
1038         case op_is_number: {
1039             printUnaryOp(out, exec, location, it, "is_number");
1040             break;
1041         }
1042         case op_is_string: {
1043             printUnaryOp(out, exec, location, it, "is_string");
1044             break;
1045         }
1046         case op_is_object: {
1047             printUnaryOp(out, exec, location, it, "is_object");
1048             break;
1049         }
1050         case op_is_object_or_null: {
1051             printUnaryOp(out, exec, location, it, "is_object_or_null");
1052             break;
1053         }
1054         case op_is_function: {
1055             printUnaryOp(out, exec, location, it, "is_function");
1056             break;
1057         }
1058         case op_in: {
1059             printBinaryOp(out, exec, location, it, "in");
1060             break;
1061         }
1062         case op_init_global_const_nop: {
1063             printLocationAndOp(out, exec, location, it, "init_global_const_nop");
1064             it++;
1065             it++;
1066             it++;
1067             it++;
1068             break;
1069         }
1070         case op_init_global_const: {
1071             WriteBarrier<Unknown>* variablePointer = (++it)->u.variablePointer;
1072             int r0 = (++it)->u.operand;
1073             printLocationAndOp(out, exec, location, it, "init_global_const");
1074             out.printf("g%d(%p), %s", m_globalObject->findVariableIndex(variablePointer).offset(), variablePointer, registerName(r0).data());
1075             it++;
1076             it++;
1077             break;
1078         }
1079         case op_get_by_id:
1080         case op_get_by_id_out_of_line:
1081         case op_get_array_length: {
1082             printGetByIdOp(out, exec, location, it);
1083             printGetByIdCacheStatus(out, exec, location, stubInfos);
1084             dumpValueProfiling(out, it, hasPrintedProfiling);
1085             break;
1086         }
1087         case op_put_by_id: {
1088             printPutByIdOp(out, exec, location, it, "put_by_id");
1089             printPutByIdCacheStatus(out, exec, location, stubInfos);
1090             break;
1091         }
1092         case op_put_by_id_out_of_line: {
1093             printPutByIdOp(out, exec, location, it, "put_by_id_out_of_line");
1094             printPutByIdCacheStatus(out, exec, location, stubInfos);
1095             break;
1096         }
1097         case op_put_by_id_transition_direct: {
1098             printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct");
1099             printPutByIdCacheStatus(out, exec, location, stubInfos);
1100             break;
1101         }
1102         case op_put_by_id_transition_direct_out_of_line: {
1103             printPutByIdOp(out, exec, location, it, "put_by_id_transition_direct_out_of_line");
1104             printPutByIdCacheStatus(out, exec, location, stubInfos);
1105             break;
1106         }
1107         case op_put_by_id_transition_normal: {
1108             printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal");
1109             printPutByIdCacheStatus(out, exec, location, stubInfos);
1110             break;
1111         }
1112         case op_put_by_id_transition_normal_out_of_line: {
1113             printPutByIdOp(out, exec, location, it, "put_by_id_transition_normal_out_of_line");
1114             printPutByIdCacheStatus(out, exec, location, stubInfos);
1115             break;
1116         }
1117         case op_put_getter_by_id: {
1118             int r0 = (++it)->u.operand;
1119             int id0 = (++it)->u.operand;
1120             int r1 = (++it)->u.operand;
1121             printLocationAndOp(out, exec, location, it, "put_getter_by_id");
1122             out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
1123             break;
1124         }
1125         case op_put_setter_by_id: {
1126             int r0 = (++it)->u.operand;
1127             int id0 = (++it)->u.operand;
1128             int r1 = (++it)->u.operand;
1129             printLocationAndOp(out, exec, location, it, "put_setter_by_id");
1130             out.printf("%s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data());
1131             break;
1132         }
1133         case op_put_getter_setter: {
1134             int r0 = (++it)->u.operand;
1135             int id0 = (++it)->u.operand;
1136             int r1 = (++it)->u.operand;
1137             int r2 = (++it)->u.operand;
1138             printLocationAndOp(out, exec, location, it, "put_getter_setter");
1139             out.printf("%s, %s, %s, %s", registerName(r0).data(), idName(id0, identifier(id0)).data(), registerName(r1).data(), registerName(r2).data());
1140             break;
1141         }
1142         case op_del_by_id: {
1143             int r0 = (++it)->u.operand;
1144             int r1 = (++it)->u.operand;
1145             int id0 = (++it)->u.operand;
1146             printLocationAndOp(out, exec, location, it, "del_by_id");
1147             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), idName(id0, identifier(id0)).data());
1148             break;
1149         }
1150         case op_get_by_val: {
1151             int r0 = (++it)->u.operand;
1152             int r1 = (++it)->u.operand;
1153             int r2 = (++it)->u.operand;
1154             printLocationAndOp(out, exec, location, it, "get_by_val");
1155             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
1156             dumpArrayProfiling(out, it, hasPrintedProfiling);
1157             dumpValueProfiling(out, it, hasPrintedProfiling);
1158             break;
1159         }
1160         case op_put_by_val: {
1161             int r0 = (++it)->u.operand;
1162             int r1 = (++it)->u.operand;
1163             int r2 = (++it)->u.operand;
1164             printLocationAndOp(out, exec, location, it, "put_by_val");
1165             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
1166             dumpArrayProfiling(out, it, hasPrintedProfiling);
1167             break;
1168         }
1169         case op_put_by_val_direct: {
1170             int r0 = (++it)->u.operand;
1171             int r1 = (++it)->u.operand;
1172             int r2 = (++it)->u.operand;
1173             printLocationAndOp(out, exec, location, it, "put_by_val_direct");
1174             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
1175             dumpArrayProfiling(out, it, hasPrintedProfiling);
1176             break;
1177         }
1178         case op_del_by_val: {
1179             int r0 = (++it)->u.operand;
1180             int r1 = (++it)->u.operand;
1181             int r2 = (++it)->u.operand;
1182             printLocationAndOp(out, exec, location, it, "del_by_val");
1183             out.printf("%s, %s, %s", registerName(r0).data(), registerName(r1).data(), registerName(r2).data());
1184             break;
1185         }
1186         case op_put_by_index: {
1187             int r0 = (++it)->u.operand;
1188             unsigned n0 = (++it)->u.operand;
1189             int r1 = (++it)->u.operand;
1190             printLocationAndOp(out, exec, location, it, "put_by_index");
1191             out.printf("%s, %u, %s", registerName(r0).data(), n0, registerName(r1).data());
1192             break;
1193         }
1194         case op_jmp: {
1195             int offset = (++it)->u.operand;
1196             printLocationAndOp(out, exec, location, it, "jmp");
1197             out.printf("%d(->%d)", offset, location + offset);
1198             break;
1199         }
1200         case op_jtrue: {
1201             printConditionalJump(out, exec, begin, it, location, "jtrue");
1202             break;
1203         }
1204         case op_jfalse: {
1205             printConditionalJump(out, exec, begin, it, location, "jfalse");
1206             break;
1207         }
1208         case op_jeq_null: {
1209             printConditionalJump(out, exec, begin, it, location, "jeq_null");
1210             break;
1211         }
1212         case op_jneq_null: {
1213             printConditionalJump(out, exec, begin, it, location, "jneq_null");
1214             break;
1215         }
1216         case op_jneq_ptr: {
1217             int r0 = (++it)->u.operand;
1218             Special::Pointer pointer = (++it)->u.specialPointer;
1219             int offset = (++it)->u.operand;
1220             printLocationAndOp(out, exec, location, it, "jneq_ptr");
1221             out.printf("%s, %d (%p), %d(->%d)", registerName(r0).data(), pointer, m_globalObject->actualPointerFor(pointer), offset, location + offset);
1222             break;
1223         }
1224         case op_jless: {
1225             int r0 = (++it)->u.operand;
1226             int r1 = (++it)->u.operand;
1227             int offset = (++it)->u.operand;
1228             printLocationAndOp(out, exec, location, it, "jless");
1229             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1230             break;
1231         }
1232         case op_jlesseq: {
1233             int r0 = (++it)->u.operand;
1234             int r1 = (++it)->u.operand;
1235             int offset = (++it)->u.operand;
1236             printLocationAndOp(out, exec, location, it, "jlesseq");
1237             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1238             break;
1239         }
1240         case op_jgreater: {
1241             int r0 = (++it)->u.operand;
1242             int r1 = (++it)->u.operand;
1243             int offset = (++it)->u.operand;
1244             printLocationAndOp(out, exec, location, it, "jgreater");
1245             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1246             break;
1247         }
1248         case op_jgreatereq: {
1249             int r0 = (++it)->u.operand;
1250             int r1 = (++it)->u.operand;
1251             int offset = (++it)->u.operand;
1252             printLocationAndOp(out, exec, location, it, "jgreatereq");
1253             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1254             break;
1255         }
1256         case op_jnless: {
1257             int r0 = (++it)->u.operand;
1258             int r1 = (++it)->u.operand;
1259             int offset = (++it)->u.operand;
1260             printLocationAndOp(out, exec, location, it, "jnless");
1261             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1262             break;
1263         }
1264         case op_jnlesseq: {
1265             int r0 = (++it)->u.operand;
1266             int r1 = (++it)->u.operand;
1267             int offset = (++it)->u.operand;
1268             printLocationAndOp(out, exec, location, it, "jnlesseq");
1269             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1270             break;
1271         }
1272         case op_jngreater: {
1273             int r0 = (++it)->u.operand;
1274             int r1 = (++it)->u.operand;
1275             int offset = (++it)->u.operand;
1276             printLocationAndOp(out, exec, location, it, "jngreater");
1277             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1278             break;
1279         }
1280         case op_jngreatereq: {
1281             int r0 = (++it)->u.operand;
1282             int r1 = (++it)->u.operand;
1283             int offset = (++it)->u.operand;
1284             printLocationAndOp(out, exec, location, it, "jngreatereq");
1285             out.printf("%s, %s, %d(->%d)", registerName(r0).data(), registerName(r1).data(), offset, location + offset);
1286             break;
1287         }
1288         case op_loop_hint: {
1289             printLocationAndOp(out, exec, location, it, "loop_hint");
1290             break;
1291         }
1292         case op_switch_imm: {
1293             int tableIndex = (++it)->u.operand;
1294             int defaultTarget = (++it)->u.operand;
1295             int scrutineeRegister = (++it)->u.operand;
1296             printLocationAndOp(out, exec, location, it, "switch_imm");
1297             out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
1298             break;
1299         }
1300         case op_switch_char: {
1301             int tableIndex = (++it)->u.operand;
1302             int defaultTarget = (++it)->u.operand;
1303             int scrutineeRegister = (++it)->u.operand;
1304             printLocationAndOp(out, exec, location, it, "switch_char");
1305             out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
1306             break;
1307         }
1308         case op_switch_string: {
1309             int tableIndex = (++it)->u.operand;
1310             int defaultTarget = (++it)->u.operand;
1311             int scrutineeRegister = (++it)->u.operand;
1312             printLocationAndOp(out, exec, location, it, "switch_string");
1313             out.printf("%d, %d(->%d), %s", tableIndex, defaultTarget, location + defaultTarget, registerName(scrutineeRegister).data());
1314             break;
1315         }
1316         case op_new_func: {
1317             int r0 = (++it)->u.operand;
1318             int r1 = (++it)->u.operand;
1319             int f0 = (++it)->u.operand;
1320             printLocationAndOp(out, exec, location, it, "new_func");
1321             out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
1322             break;
1323         }
1324         case op_new_func_exp: {
1325             int r0 = (++it)->u.operand;
1326             int r1 = (++it)->u.operand;
1327             int f0 = (++it)->u.operand;
1328             printLocationAndOp(out, exec, location, it, "new_func_exp");
1329             out.printf("%s, %s, f%d", registerName(r0).data(), registerName(r1).data(), f0);
1330             break;
1331         }
1332         case op_call: {
1333             printCallOp(out, exec, location, it, "call", DumpCaches, hasPrintedProfiling, callLinkInfos);
1334             break;
1335         }
1336         case op_call_eval: {
1337             printCallOp(out, exec, location, it, "call_eval", DontDumpCaches, hasPrintedProfiling, callLinkInfos);
1338             break;
1339         }
1340             
1341         case op_construct_varargs:
1342         case op_call_varargs: {
1343             int result = (++it)->u.operand;
1344             int callee = (++it)->u.operand;
1345             int thisValue = (++it)->u.operand;
1346             int arguments = (++it)->u.operand;
1347             int firstFreeRegister = (++it)->u.operand;
1348             int varArgOffset = (++it)->u.operand;
1349             ++it;
1350             printLocationAndOp(out, exec, location, it, opcode == op_call_varargs ? "call_varargs" : "construct_varargs");
1351             out.printf("%s, %s, %s, %s, %d, %d", registerName(result).data(), registerName(callee).data(), registerName(thisValue).data(), registerName(arguments).data(), firstFreeRegister, varArgOffset);
1352             dumpValueProfiling(out, it, hasPrintedProfiling);
1353             break;
1354         }
1355
1356         case op_ret: {
1357             int r0 = (++it)->u.operand;
1358             printLocationOpAndRegisterOperand(out, exec, location, it, "ret", r0);
1359             break;
1360         }
1361         case op_construct: {
1362             printCallOp(out, exec, location, it, "construct", DumpCaches, hasPrintedProfiling, callLinkInfos);
1363             break;
1364         }
1365         case op_strcat: {
1366             int r0 = (++it)->u.operand;
1367             int r1 = (++it)->u.operand;
1368             int count = (++it)->u.operand;
1369             printLocationAndOp(out, exec, location, it, "strcat");
1370             out.printf("%s, %s, %d", registerName(r0).data(), registerName(r1).data(), count);
1371             break;
1372         }
1373         case op_to_primitive: {
1374             int r0 = (++it)->u.operand;
1375             int r1 = (++it)->u.operand;
1376             printLocationAndOp(out, exec, location, it, "to_primitive");
1377             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
1378             break;
1379         }
1380         case op_get_enumerable_length: {
1381             int dst = it[1].u.operand;
1382             int base = it[2].u.operand;
1383             printLocationAndOp(out, exec, location, it, "op_get_enumerable_length");
1384             out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
1385             it += OPCODE_LENGTH(op_get_enumerable_length) - 1;
1386             break;
1387         }
1388         case op_has_indexed_property: {
1389             int dst = it[1].u.operand;
1390             int base = it[2].u.operand;
1391             int propertyName = it[3].u.operand;
1392             ArrayProfile* arrayProfile = it[4].u.arrayProfile;
1393             printLocationAndOp(out, exec, location, it, "op_has_indexed_property");
1394             out.printf("%s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), arrayProfile);
1395             it += OPCODE_LENGTH(op_has_indexed_property) - 1;
1396             break;
1397         }
1398         case op_has_structure_property: {
1399             int dst = it[1].u.operand;
1400             int base = it[2].u.operand;
1401             int propertyName = it[3].u.operand;
1402             int enumerator = it[4].u.operand;
1403             printLocationAndOp(out, exec, location, it, "op_has_structure_property");
1404             out.printf("%s, %s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(enumerator).data());
1405             it += OPCODE_LENGTH(op_has_structure_property) - 1;
1406             break;
1407         }
1408         case op_has_generic_property: {
1409             int dst = it[1].u.operand;
1410             int base = it[2].u.operand;
1411             int propertyName = it[3].u.operand;
1412             printLocationAndOp(out, exec, location, it, "op_has_generic_property");
1413             out.printf("%s, %s, %s", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data());
1414             it += OPCODE_LENGTH(op_has_generic_property) - 1;
1415             break;
1416         }
1417         case op_get_direct_pname: {
1418             int dst = it[1].u.operand;
1419             int base = it[2].u.operand;
1420             int propertyName = it[3].u.operand;
1421             int index = it[4].u.operand;
1422             int enumerator = it[5].u.operand;
1423             ValueProfile* profile = it[6].u.profile;
1424             printLocationAndOp(out, exec, location, it, "op_get_direct_pname");
1425             out.printf("%s, %s, %s, %s, %s, %p", registerName(dst).data(), registerName(base).data(), registerName(propertyName).data(), registerName(index).data(), registerName(enumerator).data(), profile);
1426             it += OPCODE_LENGTH(op_get_direct_pname) - 1;
1427             break;
1428
1429         }
1430         case op_get_property_enumerator: {
1431             int dst = it[1].u.operand;
1432             int base = it[2].u.operand;
1433             printLocationAndOp(out, exec, location, it, "op_get_property_enumerator");
1434             out.printf("%s, %s", registerName(dst).data(), registerName(base).data());
1435             it += OPCODE_LENGTH(op_get_property_enumerator) - 1;
1436             break;
1437         }
1438         case op_enumerator_structure_pname: {
1439             int dst = it[1].u.operand;
1440             int enumerator = it[2].u.operand;
1441             int index = it[3].u.operand;
1442             printLocationAndOp(out, exec, location, it, "op_enumerator_structure_pname");
1443             out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
1444             it += OPCODE_LENGTH(op_enumerator_structure_pname) - 1;
1445             break;
1446         }
1447         case op_enumerator_generic_pname: {
1448             int dst = it[1].u.operand;
1449             int enumerator = it[2].u.operand;
1450             int index = it[3].u.operand;
1451             printLocationAndOp(out, exec, location, it, "op_enumerator_generic_pname");
1452             out.printf("%s, %s, %s", registerName(dst).data(), registerName(enumerator).data(), registerName(index).data());
1453             it += OPCODE_LENGTH(op_enumerator_generic_pname) - 1;
1454             break;
1455         }
1456         case op_to_index_string: {
1457             int dst = it[1].u.operand;
1458             int index = it[2].u.operand;
1459             printLocationAndOp(out, exec, location, it, "op_to_index_string");
1460             out.printf("%s, %s", registerName(dst).data(), registerName(index).data());
1461             it += OPCODE_LENGTH(op_to_index_string) - 1;
1462             break;
1463         }
1464         case op_push_with_scope: {
1465             int dst = (++it)->u.operand;
1466             int newScope = (++it)->u.operand;
1467             printLocationAndOp(out, exec, location, it, "push_with_scope");
1468             out.printf("%s, %s", registerName(dst).data(), registerName(newScope).data());
1469             break;
1470         }
1471         case op_pop_scope: {
1472             int r0 = (++it)->u.operand;
1473             printLocationOpAndRegisterOperand(out, exec, location, it, "pop_scope", r0);
1474             break;
1475         }
1476         case op_push_name_scope: {
1477             int dst = (++it)->u.operand;
1478             int r1 = (++it)->u.operand;
1479             int k0 = (++it)->u.operand;
1480             JSNameScope::Type scopeType = (JSNameScope::Type)(++it)->u.operand;
1481             printLocationAndOp(out, exec, location, it, "push_name_scope");
1482             out.printf("%s, %s, %s, %s", registerName(dst).data(), registerName(r1).data(), constantName(k0).data(), (scopeType == JSNameScope::FunctionNameScope) ? "functionScope" : ((scopeType == JSNameScope::CatchScope) ? "catchScope" : "unknownScopeType"));
1483             break;
1484         }
1485         case op_catch: {
1486             int r0 = (++it)->u.operand;
1487             int r1 = (++it)->u.operand;
1488             printLocationAndOp(out, exec, location, it, "catch");
1489             out.printf("%s, %s", registerName(r0).data(), registerName(r1).data());
1490             break;
1491         }
1492         case op_throw: {
1493             int r0 = (++it)->u.operand;
1494             printLocationOpAndRegisterOperand(out, exec, location, it, "throw", r0);
1495             break;
1496         }
1497         case op_throw_static_error: {
1498             int k0 = (++it)->u.operand;
1499             int k1 = (++it)->u.operand;
1500             printLocationAndOp(out, exec, location, it, "throw_static_error");
1501             out.printf("%s, %s", constantName(k0).data(), k1 ? "true" : "false");
1502             break;
1503         }
1504         case op_debug: {
1505             int debugHookID = (++it)->u.operand;
1506             int hasBreakpointFlag = (++it)->u.operand;
1507             printLocationAndOp(out, exec, location, it, "debug");
1508             out.printf("%s %d", debugHookName(debugHookID), hasBreakpointFlag);
1509             break;
1510         }
1511         case op_profile_will_call: {
1512             int function = (++it)->u.operand;
1513             printLocationOpAndRegisterOperand(out, exec, location, it, "profile_will_call", function);
1514             break;
1515         }
1516         case op_profile_did_call: {
1517             int function = (++it)->u.operand;
1518             printLocationOpAndRegisterOperand(out, exec, location, it, "profile_did_call", function);
1519             break;
1520         }
1521         case op_end: {
1522             int r0 = (++it)->u.operand;
1523             printLocationOpAndRegisterOperand(out, exec, location, it, "end", r0);
1524             break;
1525         }
1526         case op_resolve_scope: {
1527             int r0 = (++it)->u.operand;
1528             int scope = (++it)->u.operand;
1529             int id0 = (++it)->u.operand;
1530             ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
1531             int depth = (++it)->u.operand;
1532             printLocationAndOp(out, exec, location, it, "resolve_scope");
1533             out.printf("%s, %s, %s, %u<%s|%s>, %d", registerName(r0).data(), registerName(scope).data(), idName(id0, identifier(id0)).data(),
1534                 modeAndType.operand(), resolveModeName(modeAndType.mode()), resolveTypeName(modeAndType.type()),
1535                 depth);
1536             ++it;
1537             break;
1538         }
1539         case op_get_from_scope: {
1540             int r0 = (++it)->u.operand;
1541             int r1 = (++it)->u.operand;
1542             int id0 = (++it)->u.operand;
1543             ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
1544             ++it; // Structure
1545             int operand = (++it)->u.operand; // Operand
1546             printLocationAndOp(out, exec, location, it, "get_from_scope");
1547             out.print(registerName(r0), ", ", registerName(r1));
1548             if (static_cast<unsigned>(id0) == UINT_MAX)
1549                 out.print(", anonymous");
1550             else
1551                 out.print(", ", idName(id0, identifier(id0)));
1552             out.print(", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, ", operand);
1553             dumpValueProfiling(out, it, hasPrintedProfiling);
1554             break;
1555         }
1556         case op_put_to_scope: {
1557             int r0 = (++it)->u.operand;
1558             int id0 = (++it)->u.operand;
1559             int r1 = (++it)->u.operand;
1560             ResolveModeAndType modeAndType = ResolveModeAndType((++it)->u.operand);
1561             ++it; // Structure
1562             int operand = (++it)->u.operand; // Operand
1563             printLocationAndOp(out, exec, location, it, "put_to_scope");
1564             out.print(registerName(r0));
1565             if (static_cast<unsigned>(id0) == UINT_MAX)
1566                 out.print(", anonymous");
1567             else
1568                 out.print(", ", idName(id0, identifier(id0)));
1569             out.print(", ", registerName(r1), ", ", modeAndType.operand(), "<", resolveModeName(modeAndType.mode()), "|", resolveTypeName(modeAndType.type()), ">, <structure>, ", operand);
1570             break;
1571         }
1572         case op_get_from_arguments: {
1573             int r0 = (++it)->u.operand;
1574             int r1 = (++it)->u.operand;
1575             int offset = (++it)->u.operand;
1576             printLocationAndOp(out, exec, location, it, "get_from_arguments");
1577             out.printf("%s, %s, %d", registerName(r0).data(), registerName(r1).data(), offset);
1578             dumpValueProfiling(out, it, hasPrintedProfiling);
1579             break;
1580         }
1581         case op_put_to_arguments: {
1582             int r0 = (++it)->u.operand;
1583             int offset = (++it)->u.operand;
1584             int r1 = (++it)->u.operand;
1585             printLocationAndOp(out, exec, location, it, "put_to_arguments");
1586             out.printf("%s, %d, %s", registerName(r0).data(), offset, registerName(r1).data());
1587             break;
1588         }
1589         default:
1590             RELEASE_ASSERT_NOT_REACHED();
1591     }
1592
1593     dumpRareCaseProfile(out, "rare case: ", rareCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
1594     dumpRareCaseProfile(out, "special fast case: ", specialFastCaseProfileForBytecodeOffset(location), hasPrintedProfiling);
1595     
1596 #if ENABLE(DFG_JIT)
1597     Vector<DFG::FrequentExitSite> exitSites = exitProfile().exitSitesFor(location);
1598     if (!exitSites.isEmpty()) {
1599         out.print(" !! frequent exits: ");
1600         CommaPrinter comma;
1601         for (unsigned i = 0; i < exitSites.size(); ++i)
1602             out.print(comma, exitSites[i].kind(), " ", exitSites[i].jitType());
1603     }
1604 #else // ENABLE(DFG_JIT)
1605     UNUSED_PARAM(location);
1606 #endif // ENABLE(DFG_JIT)
1607     out.print("\n");
1608 }
1609
1610 void CodeBlock::dumpBytecode(
1611     PrintStream& out, unsigned bytecodeOffset,
1612     const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
1613 {
1614     ExecState* exec = m_globalObject->globalExec();
1615     const Instruction* it = instructions().begin() + bytecodeOffset;
1616     dumpBytecode(out, exec, instructions().begin(), it, stubInfos, callLinkInfos);
1617 }
1618
1619 #define FOR_EACH_MEMBER_VECTOR(macro) \
1620     macro(instructions) \
1621     macro(callLinkInfos) \
1622     macro(linkedCallerList) \
1623     macro(identifiers) \
1624     macro(functionExpressions) \
1625     macro(constantRegisters)
1626
1627 #define FOR_EACH_MEMBER_VECTOR_RARE_DATA(macro) \
1628     macro(regexps) \
1629     macro(functions) \
1630     macro(exceptionHandlers) \
1631     macro(switchJumpTables) \
1632     macro(stringSwitchJumpTables) \
1633     macro(evalCodeCache) \
1634     macro(expressionInfo) \
1635     macro(lineInfo) \
1636     macro(callReturnIndexVector)
1637
1638 template<typename T>
1639 static size_t sizeInBytes(const Vector<T>& vector)
1640 {
1641     return vector.capacity() * sizeof(T);
1642 }
1643
1644 namespace {
1645
1646 class PutToScopeFireDetail : public FireDetail {
1647 public:
1648     PutToScopeFireDetail(CodeBlock* codeBlock, const Identifier& ident)
1649         : m_codeBlock(codeBlock)
1650         , m_ident(ident)
1651     {
1652     }
1653     
1654     virtual void dump(PrintStream& out) const override
1655     {
1656         out.print("Linking put_to_scope in ", FunctionExecutableDump(jsCast<FunctionExecutable*>(m_codeBlock->ownerExecutable())), " for ", m_ident);
1657     }
1658     
1659 private:
1660     CodeBlock* m_codeBlock;
1661     const Identifier& m_ident;
1662 };
1663
1664 } // anonymous namespace
1665
1666 CodeBlock::CodeBlock(CopyParsedBlockTag, CodeBlock& other)
1667     : m_globalObject(other.m_globalObject)
1668     , m_heap(other.m_heap)
1669     , m_numCalleeRegisters(other.m_numCalleeRegisters)
1670     , m_numVars(other.m_numVars)
1671     , m_isConstructor(other.m_isConstructor)
1672     , m_shouldAlwaysBeInlined(true)
1673     , m_didFailFTLCompilation(false)
1674     , m_hasBeenCompiledWithFTL(false)
1675     , m_unlinkedCode(*other.m_vm, other.m_ownerExecutable.get(), other.m_unlinkedCode.get())
1676     , m_hasDebuggerStatement(false)
1677     , m_steppingMode(SteppingModeDisabled)
1678     , m_numBreakpoints(0)
1679     , m_ownerExecutable(*other.m_vm, other.m_ownerExecutable.get(), other.m_ownerExecutable.get())
1680     , m_vm(other.m_vm)
1681     , m_instructions(other.m_instructions)
1682     , m_thisRegister(other.m_thisRegister)
1683     , m_scopeRegister(other.m_scopeRegister)
1684     , m_lexicalEnvironmentRegister(other.m_lexicalEnvironmentRegister)
1685     , m_isStrictMode(other.m_isStrictMode)
1686     , m_needsActivation(other.m_needsActivation)
1687     , m_mayBeExecuting(false)
1688     , m_source(other.m_source)
1689     , m_sourceOffset(other.m_sourceOffset)
1690     , m_firstLineColumnOffset(other.m_firstLineColumnOffset)
1691     , m_codeType(other.m_codeType)
1692     , m_constantRegisters(other.m_constantRegisters)
1693     , m_constantsSourceCodeRepresentation(other.m_constantsSourceCodeRepresentation)
1694     , m_functionDecls(other.m_functionDecls)
1695     , m_functionExprs(other.m_functionExprs)
1696     , m_osrExitCounter(0)
1697     , m_optimizationDelayCounter(0)
1698     , m_reoptimizationRetryCounter(0)
1699     , m_hash(other.m_hash)
1700 #if ENABLE(JIT)
1701     , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
1702 #endif
1703 {
1704     m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
1705
1706     ASSERT(m_heap->isDeferred());
1707     ASSERT(m_scopeRegister.isLocal());
1708
1709     if (SymbolTable* symbolTable = other.symbolTable())
1710         m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable);
1711     
1712     setNumParameters(other.numParameters());
1713     optimizeAfterWarmUp();
1714     jitAfterWarmUp();
1715
1716     if (other.m_rareData) {
1717         createRareDataIfNecessary();
1718         
1719         m_rareData->m_exceptionHandlers = other.m_rareData->m_exceptionHandlers;
1720         m_rareData->m_constantBuffers = other.m_rareData->m_constantBuffers;
1721         m_rareData->m_switchJumpTables = other.m_rareData->m_switchJumpTables;
1722         m_rareData->m_stringSwitchJumpTables = other.m_rareData->m_stringSwitchJumpTables;
1723     }
1724     
1725     m_heap->m_codeBlocks.add(this);
1726     m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock));
1727 }
1728
1729 CodeBlock::CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1730     : m_globalObject(scope->globalObject()->vm(), ownerExecutable, scope->globalObject())
1731     , m_heap(&m_globalObject->vm().heap)
1732     , m_numCalleeRegisters(unlinkedCodeBlock->m_numCalleeRegisters)
1733     , m_numVars(unlinkedCodeBlock->m_numVars)
1734     , m_isConstructor(unlinkedCodeBlock->isConstructor())
1735     , m_shouldAlwaysBeInlined(true)
1736     , m_didFailFTLCompilation(false)
1737     , m_hasBeenCompiledWithFTL(false)
1738     , m_unlinkedCode(m_globalObject->vm(), ownerExecutable, unlinkedCodeBlock)
1739     , m_hasDebuggerStatement(false)
1740     , m_steppingMode(SteppingModeDisabled)
1741     , m_numBreakpoints(0)
1742     , m_ownerExecutable(m_globalObject->vm(), ownerExecutable, ownerExecutable)
1743     , m_vm(unlinkedCodeBlock->vm())
1744     , m_thisRegister(unlinkedCodeBlock->thisRegister())
1745     , m_scopeRegister(unlinkedCodeBlock->scopeRegister())
1746     , m_lexicalEnvironmentRegister(unlinkedCodeBlock->activationRegister())
1747     , m_isStrictMode(unlinkedCodeBlock->isStrictMode())
1748     , m_needsActivation(unlinkedCodeBlock->hasActivationRegister() && unlinkedCodeBlock->codeType() == FunctionCode)
1749     , m_mayBeExecuting(false)
1750     , m_source(sourceProvider)
1751     , m_sourceOffset(sourceOffset)
1752     , m_firstLineColumnOffset(firstLineColumnOffset)
1753     , m_codeType(unlinkedCodeBlock->codeType())
1754     , m_osrExitCounter(0)
1755     , m_optimizationDelayCounter(0)
1756     , m_reoptimizationRetryCounter(0)
1757 #if ENABLE(JIT)
1758     , m_capabilityLevelState(DFG::CapabilityLevelNotSet)
1759 #endif
1760 {
1761     m_visitAggregateHasBeenCalled.store(false, std::memory_order_relaxed);
1762
1763     ASSERT(m_heap->isDeferred());
1764     ASSERT(m_scopeRegister.isLocal());
1765
1766     bool didCloneSymbolTable = false;
1767     
1768     if (SymbolTable* symbolTable = unlinkedCodeBlock->symbolTable()) {
1769         if (m_vm->typeProfiler()) {
1770             ConcurrentJITLocker locker(symbolTable->m_lock);
1771             symbolTable->prepareForTypeProfiling(locker);
1772         }
1773
1774         if (codeType() == FunctionCode && symbolTable->scopeSize()) {
1775             m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable->cloneScopePart(*m_vm));
1776             didCloneSymbolTable = true;
1777         } else
1778             m_symbolTable.set(*m_vm, m_ownerExecutable.get(), symbolTable);
1779     }
1780     
1781     ASSERT(m_source);
1782     setNumParameters(unlinkedCodeBlock->numParameters());
1783
1784     if (vm()->typeProfiler() || vm()->controlFlowProfiler())
1785         vm()->functionHasExecutedCache()->removeUnexecutedRange(m_ownerExecutable->sourceID(), m_ownerExecutable->typeProfilingStartOffset(), m_ownerExecutable->typeProfilingEndOffset());
1786
1787     setConstantRegisters(unlinkedCodeBlock->constantRegisters(), unlinkedCodeBlock->constantsSourceCodeRepresentation());
1788     if (unlinkedCodeBlock->usesGlobalObject())
1789         m_constantRegisters[unlinkedCodeBlock->globalObjectRegister().toConstantIndex()].set(*m_vm, ownerExecutable, m_globalObject.get());
1790
1791     for (unsigned i = 0; i < LinkTimeConstantCount; i++) {
1792         LinkTimeConstant type = static_cast<LinkTimeConstant>(i);
1793         if (unsigned registerIndex = unlinkedCodeBlock->registerIndexForLinkTimeConstant(type))
1794             m_constantRegisters[registerIndex].set(*m_vm, ownerExecutable, m_globalObject->jsCellForLinkTimeConstant(type));
1795     }
1796
1797     m_functionDecls.resizeToFit(unlinkedCodeBlock->numberOfFunctionDecls());
1798     for (size_t count = unlinkedCodeBlock->numberOfFunctionDecls(), i = 0; i < count; ++i) {
1799         UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionDecl(i);
1800         if (vm()->typeProfiler() || vm()->controlFlowProfiler())
1801             vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
1802         m_functionDecls[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
1803     }
1804
1805     m_functionExprs.resizeToFit(unlinkedCodeBlock->numberOfFunctionExprs());
1806     for (size_t count = unlinkedCodeBlock->numberOfFunctionExprs(), i = 0; i < count; ++i) {
1807         UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionExpr(i);
1808         if (vm()->typeProfiler() || vm()->controlFlowProfiler())
1809             vm()->functionHasExecutedCache()->insertUnexecutedRange(m_ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
1810         m_functionExprs[i].set(*m_vm, ownerExecutable, unlinkedExecutable->link(*m_vm, ownerExecutable->source()));
1811     }
1812
1813     if (unlinkedCodeBlock->hasRareData()) {
1814         createRareDataIfNecessary();
1815         if (size_t count = unlinkedCodeBlock->constantBufferCount()) {
1816             m_rareData->m_constantBuffers.grow(count);
1817             for (size_t i = 0; i < count; i++) {
1818                 const UnlinkedCodeBlock::ConstantBuffer& buffer = unlinkedCodeBlock->constantBuffer(i);
1819                 m_rareData->m_constantBuffers[i] = buffer;
1820             }
1821         }
1822         if (size_t count = unlinkedCodeBlock->numberOfExceptionHandlers()) {
1823             m_rareData->m_exceptionHandlers.resizeToFit(count);
1824             size_t nonLocalScopeDepth = scope->depth();
1825             for (size_t i = 0; i < count; i++) {
1826                 const UnlinkedHandlerInfo& unlinkedHandler = unlinkedCodeBlock->exceptionHandler(i);
1827                 HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
1828 #if ENABLE(JIT)
1829                 handler.initialize(unlinkedHandler, nonLocalScopeDepth,
1830                     CodeLocationLabel(MacroAssemblerCodePtr::createFromExecutableAddress(LLInt::getCodePtr(op_catch))));
1831 #else
1832                 handler.initialize(unlinkedHandler, nonLocalScopeDepth);
1833 #endif
1834             }
1835         }
1836
1837         if (size_t count = unlinkedCodeBlock->numberOfStringSwitchJumpTables()) {
1838             m_rareData->m_stringSwitchJumpTables.grow(count);
1839             for (size_t i = 0; i < count; i++) {
1840                 UnlinkedStringJumpTable::StringOffsetTable::iterator ptr = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.begin();
1841                 UnlinkedStringJumpTable::StringOffsetTable::iterator end = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.end();
1842                 for (; ptr != end; ++ptr) {
1843                     OffsetLocation offset;
1844                     offset.branchOffset = ptr->value;
1845                     m_rareData->m_stringSwitchJumpTables[i].offsetTable.add(ptr->key, offset);
1846                 }
1847             }
1848         }
1849
1850         if (size_t count = unlinkedCodeBlock->numberOfSwitchJumpTables()) {
1851             m_rareData->m_switchJumpTables.grow(count);
1852             for (size_t i = 0; i < count; i++) {
1853                 UnlinkedSimpleJumpTable& sourceTable = unlinkedCodeBlock->switchJumpTable(i);
1854                 SimpleJumpTable& destTable = m_rareData->m_switchJumpTables[i];
1855                 destTable.branchOffsets = sourceTable.branchOffsets;
1856                 destTable.min = sourceTable.min;
1857             }
1858         }
1859     }
1860
1861     // Allocate metadata buffers for the bytecode
1862     if (size_t size = unlinkedCodeBlock->numberOfLLintCallLinkInfos())
1863         m_llintCallLinkInfos.resizeToFit(size);
1864     if (size_t size = unlinkedCodeBlock->numberOfArrayProfiles())
1865         m_arrayProfiles.grow(size);
1866     if (size_t size = unlinkedCodeBlock->numberOfArrayAllocationProfiles())
1867         m_arrayAllocationProfiles.resizeToFit(size);
1868     if (size_t size = unlinkedCodeBlock->numberOfValueProfiles())
1869         m_valueProfiles.resizeToFit(size);
1870     if (size_t size = unlinkedCodeBlock->numberOfObjectAllocationProfiles())
1871         m_objectAllocationProfiles.resizeToFit(size);
1872
1873     // Copy and translate the UnlinkedInstructions
1874     unsigned instructionCount = unlinkedCodeBlock->instructions().count();
1875     UnlinkedInstructionStream::Reader instructionReader(unlinkedCodeBlock->instructions());
1876
1877     Vector<Instruction, 0, UnsafeVectorOverflow> instructions(instructionCount);
1878     for (unsigned i = 0; !instructionReader.atEnd(); ) {
1879         const UnlinkedInstruction* pc = instructionReader.next();
1880
1881         unsigned opLength = opcodeLength(pc[0].u.opcode);
1882
1883         instructions[i] = vm()->interpreter->getOpcode(pc[0].u.opcode);
1884         for (size_t j = 1; j < opLength; ++j) {
1885             if (sizeof(int32_t) != sizeof(intptr_t))
1886                 instructions[i + j].u.pointer = 0;
1887             instructions[i + j].u.operand = pc[j].u.operand;
1888         }
1889         switch (pc[0].u.opcode) {
1890         case op_has_indexed_property: {
1891             int arrayProfileIndex = pc[opLength - 1].u.operand;
1892             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
1893
1894             instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
1895             break;
1896         }
1897         case op_call_varargs:
1898         case op_construct_varargs:
1899         case op_get_by_val: {
1900             int arrayProfileIndex = pc[opLength - 2].u.operand;
1901             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
1902
1903             instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
1904             FALLTHROUGH;
1905         }
1906         case op_get_direct_pname:
1907         case op_get_by_id:
1908         case op_get_from_arguments: {
1909             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
1910             ASSERT(profile->m_bytecodeOffset == -1);
1911             profile->m_bytecodeOffset = i;
1912             instructions[i + opLength - 1] = profile;
1913             break;
1914         }
1915         case op_put_by_val: {
1916             int arrayProfileIndex = pc[opLength - 1].u.operand;
1917             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
1918             instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
1919             break;
1920         }
1921         case op_put_by_val_direct: {
1922             int arrayProfileIndex = pc[opLength - 1].u.operand;
1923             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
1924             instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
1925             break;
1926         }
1927
1928         case op_new_array:
1929         case op_new_array_buffer:
1930         case op_new_array_with_size: {
1931             int arrayAllocationProfileIndex = pc[opLength - 1].u.operand;
1932             instructions[i + opLength - 1] = &m_arrayAllocationProfiles[arrayAllocationProfileIndex];
1933             break;
1934         }
1935         case op_new_object: {
1936             int objectAllocationProfileIndex = pc[opLength - 1].u.operand;
1937             ObjectAllocationProfile* objectAllocationProfile = &m_objectAllocationProfiles[objectAllocationProfileIndex];
1938             int inferredInlineCapacity = pc[opLength - 2].u.operand;
1939
1940             instructions[i + opLength - 1] = objectAllocationProfile;
1941             objectAllocationProfile->initialize(*vm(),
1942                 m_ownerExecutable.get(), m_globalObject->objectPrototype(), inferredInlineCapacity);
1943             break;
1944         }
1945
1946         case op_call:
1947         case op_call_eval: {
1948             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
1949             ASSERT(profile->m_bytecodeOffset == -1);
1950             profile->m_bytecodeOffset = i;
1951             instructions[i + opLength - 1] = profile;
1952             int arrayProfileIndex = pc[opLength - 2].u.operand;
1953             m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
1954             instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
1955             instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
1956             break;
1957         }
1958         case op_construct: {
1959             instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
1960             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
1961             ASSERT(profile->m_bytecodeOffset == -1);
1962             profile->m_bytecodeOffset = i;
1963             instructions[i + opLength - 1] = profile;
1964             break;
1965         }
1966         case op_get_by_id_out_of_line:
1967         case op_get_array_length:
1968             CRASH();
1969
1970         case op_init_global_const_nop: {
1971             ASSERT(codeType() == GlobalCode);
1972             Identifier ident = identifier(pc[4].u.operand);
1973             SymbolTableEntry entry = m_globalObject->symbolTable()->get(ident.impl());
1974             if (entry.isNull())
1975                 break;
1976
1977             instructions[i + 0] = vm()->interpreter->getOpcode(op_init_global_const);
1978             instructions[i + 1] = &m_globalObject->variableAt(entry.varOffset().scopeOffset());
1979             break;
1980         }
1981
1982         case op_resolve_scope: {
1983             const Identifier& ident = identifier(pc[3].u.operand);
1984             ResolveType type = static_cast<ResolveType>(pc[4].u.operand);
1985             RELEASE_ASSERT(type != LocalClosureVar);
1986
1987             ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), needsActivation(), scope, ident, Get, type);
1988             instructions[i + 4].u.operand = op.type;
1989             instructions[i + 5].u.operand = op.depth;
1990             if (op.lexicalEnvironment)
1991                 instructions[i + 6].u.symbolTable.set(*vm(), ownerExecutable, op.lexicalEnvironment->symbolTable());
1992             break;
1993         }
1994
1995         case op_get_from_scope: {
1996             ValueProfile* profile = &m_valueProfiles[pc[opLength - 1].u.operand];
1997             ASSERT(profile->m_bytecodeOffset == -1);
1998             profile->m_bytecodeOffset = i;
1999             instructions[i + opLength - 1] = profile;
2000
2001             // get_from_scope dst, scope, id, ResolveModeAndType, Structure, Operand
2002
2003             ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
2004             if (modeAndType.type() == LocalClosureVar) {
2005                 instructions[i + 4] = ResolveModeAndType(modeAndType.mode(), ClosureVar).operand();
2006                 break;
2007             }
2008
2009             const Identifier& ident = identifier(pc[3].u.operand);
2010
2011             ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), needsActivation(), scope, ident, Get, modeAndType.type());
2012
2013             instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
2014             if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
2015                 instructions[i + 5].u.watchpointSet = op.watchpointSet;
2016             else if (op.structure)
2017                 instructions[i + 5].u.structure.set(*vm(), ownerExecutable, op.structure);
2018             instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
2019             break;
2020         }
2021
2022         case op_put_to_scope: {
2023             // put_to_scope scope, id, value, ResolveModeAndType, Structure, Operand
2024             ResolveModeAndType modeAndType = ResolveModeAndType(pc[4].u.operand);
2025             if (modeAndType.type() == LocalClosureVar) {
2026                 // Only do watching if the property we're putting to is not anonymous.
2027                 if (static_cast<unsigned>(pc[2].u.operand) != UINT_MAX) {
2028                     RELEASE_ASSERT(didCloneSymbolTable);
2029                     const Identifier& ident = identifier(pc[2].u.operand);
2030                     ConcurrentJITLocker locker(m_symbolTable->m_lock);
2031                     SymbolTable::Map::iterator iter = m_symbolTable->find(locker, ident.impl());
2032                     ASSERT(iter != m_symbolTable->end(locker));
2033                     iter->value.prepareToWatch();
2034                     instructions[i + 5].u.watchpointSet = iter->value.watchpointSet();
2035                 } else
2036                     instructions[i + 5].u.watchpointSet = nullptr;
2037                 break;
2038             }
2039
2040             const Identifier& ident = identifier(pc[2].u.operand);
2041
2042             ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), needsActivation(), scope, ident, Put, modeAndType.type());
2043
2044             instructions[i + 4].u.operand = ResolveModeAndType(modeAndType.mode(), op.type).operand();
2045             if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks)
2046                 instructions[i + 5].u.watchpointSet = op.watchpointSet;
2047             else if (op.type == ClosureVar || op.type == ClosureVarWithVarInjectionChecks) {
2048                 if (op.watchpointSet)
2049                     op.watchpointSet->invalidate(PutToScopeFireDetail(this, ident));
2050             } else if (op.structure)
2051                 instructions[i + 5].u.structure.set(*vm(), ownerExecutable, op.structure);
2052             instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
2053
2054             break;
2055         }
2056
2057         case op_profile_type: {
2058             RELEASE_ASSERT(vm()->typeProfiler());
2059             // The format of this instruction is: op_profile_type regToProfile, TypeLocation*, flag, identifier?, resolveType?
2060             size_t instructionOffset = i + opLength - 1;
2061             unsigned divotStart, divotEnd;
2062             GlobalVariableID globalVariableID = 0;
2063             RefPtr<TypeSet> globalTypeSet;
2064             bool shouldAnalyze = m_unlinkedCode->typeProfilerExpressionInfoForBytecodeOffset(instructionOffset, divotStart, divotEnd);
2065             VirtualRegister profileRegister(pc[1].u.operand);
2066             ProfileTypeBytecodeFlag flag = static_cast<ProfileTypeBytecodeFlag>(pc[3].u.operand);
2067             SymbolTable* symbolTable = nullptr;
2068
2069             switch (flag) {
2070             case ProfileTypeBytecodePutToScope:
2071             case ProfileTypeBytecodeGetFromScope: {
2072                 const Identifier& ident = identifier(pc[4].u.operand);
2073                 ResolveType type = static_cast<ResolveType>(pc[5].u.operand);
2074                 ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), needsActivation(), scope, ident, (flag == ProfileTypeBytecodeGetFromScope ? Get : Put), type);
2075
2076                 // FIXME: handle other values for op.type here, and also consider what to do when we can't statically determine the globalID
2077                 // https://bugs.webkit.org/show_bug.cgi?id=135184
2078                 if (op.type == ClosureVar)
2079                     symbolTable = op.lexicalEnvironment->symbolTable();
2080                 else if (op.type == GlobalVar)
2081                     symbolTable = m_globalObject.get()->symbolTable();
2082                 
2083                 if (symbolTable) {
2084                     ConcurrentJITLocker locker(symbolTable->m_lock);
2085                     // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
2086                     symbolTable->prepareForTypeProfiling(locker);
2087                     globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
2088                     globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
2089                 } else
2090                     globalVariableID = TypeProfilerNoGlobalIDExists;
2091
2092                 break;
2093             }
2094             case ProfileTypeBytecodePutToLocalScope:
2095             case ProfileTypeBytecodeGetFromLocalScope: {
2096                 const Identifier& ident = identifier(pc[4].u.operand);
2097                 symbolTable = m_symbolTable.get();
2098                 ConcurrentJITLocker locker(symbolTable->m_lock);
2099                 // If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
2100                 symbolTable->prepareForTypeProfiling(locker);
2101                 globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), *vm());
2102                 globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), *vm());
2103
2104                 break;
2105             }
2106
2107             case ProfileTypeBytecodeHasGlobalID: {
2108                 symbolTable = m_symbolTable.get();
2109                 ConcurrentJITLocker locker(symbolTable->m_lock);
2110                 globalVariableID = symbolTable->uniqueIDForOffset(locker, VarOffset(profileRegister), *vm());
2111                 globalTypeSet = symbolTable->globalTypeSetForOffset(locker, VarOffset(profileRegister), *vm());
2112                 break;
2113             }
2114             case ProfileTypeBytecodeDoesNotHaveGlobalID: 
2115             case ProfileTypeBytecodeFunctionArgument: {
2116                 globalVariableID = TypeProfilerNoGlobalIDExists;
2117                 break;
2118             }
2119             case ProfileTypeBytecodeFunctionReturnStatement: {
2120                 RELEASE_ASSERT(ownerExecutable->isFunctionExecutable());
2121                 globalTypeSet = jsCast<FunctionExecutable*>(ownerExecutable)->returnStatementTypeSet();
2122                 globalVariableID = TypeProfilerReturnStatement;
2123                 if (!shouldAnalyze) {
2124                     // Because a return statement can be added implicitly to return undefined at the end of a function,
2125                     // and these nodes don't emit expression ranges because they aren't in the actual source text of
2126                     // the user's program, give the type profiler some range to identify these return statements.
2127                     // Currently, the text offset that is used as identification is on the open brace of the function 
2128                     // and is stored on TypeLocation's m_divotForFunctionOffsetIfReturnStatement member variable.
2129                     divotStart = divotEnd = m_sourceOffset;
2130                     shouldAnalyze = true;
2131                 }
2132                 break;
2133             }
2134             }
2135
2136             std::pair<TypeLocation*, bool> locationPair = vm()->typeProfiler()->typeLocationCache()->getTypeLocation(globalVariableID,
2137                 m_ownerExecutable->sourceID(), divotStart, divotEnd, globalTypeSet, vm());
2138             TypeLocation* location = locationPair.first;
2139             bool isNewLocation = locationPair.second;
2140
2141             if (flag == ProfileTypeBytecodeFunctionReturnStatement)
2142                 location->m_divotForFunctionOffsetIfReturnStatement = m_sourceOffset;
2143
2144             if (shouldAnalyze && isNewLocation)
2145                 vm()->typeProfiler()->insertNewLocation(location);
2146
2147             instructions[i + 2].u.location = location;
2148             break;
2149         }
2150
2151         case op_debug: {
2152             if (pc[1].u.index == DidReachBreakpoint)
2153                 m_hasDebuggerStatement = true;
2154             break;
2155         }
2156
2157         default:
2158             break;
2159         }
2160         i += opLength;
2161     }
2162
2163     if (vm()->controlFlowProfiler())
2164         insertBasicBlockBoundariesForControlFlowProfiler(instructions);
2165
2166     m_instructions = WTF::RefCountedArray<Instruction>(instructions);
2167
2168     // Set optimization thresholds only after m_instructions is initialized, since these
2169     // rely on the instruction count (and are in theory permitted to also inspect the
2170     // instruction stream to more accurate assess the cost of tier-up).
2171     optimizeAfterWarmUp();
2172     jitAfterWarmUp();
2173
2174     // If the concurrent thread will want the code block's hash, then compute it here
2175     // synchronously.
2176     if (Options::alwaysComputeHash())
2177         hash();
2178
2179     if (Options::dumpGeneratedBytecodes())
2180         dumpBytecode();
2181     
2182     m_heap->m_codeBlocks.add(this);
2183     m_heap->reportExtraMemoryAllocated(sizeof(CodeBlock) + m_instructions.size() * sizeof(Instruction));
2184 }
2185
2186 CodeBlock::~CodeBlock()
2187 {
2188     if (m_vm->m_perBytecodeProfiler)
2189         m_vm->m_perBytecodeProfiler->notifyDestruction(this);
2190     
2191 #if ENABLE(VERBOSE_VALUE_PROFILE)
2192     dumpValueProfiles();
2193 #endif
2194     while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
2195         m_incomingLLIntCalls.begin()->remove();
2196 #if ENABLE(JIT)
2197     // We may be destroyed before any CodeBlocks that refer to us are destroyed.
2198     // Consider that two CodeBlocks become unreachable at the same time. There
2199     // is no guarantee about the order in which the CodeBlocks are destroyed.
2200     // So, if we don't remove incoming calls, and get destroyed before the
2201     // CodeBlock(s) that have calls into us, then the CallLinkInfo vector's
2202     // destructor will try to remove nodes from our (no longer valid) linked list.
2203     while (m_incomingCalls.begin() != m_incomingCalls.end())
2204         m_incomingCalls.begin()->remove();
2205     while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
2206         m_incomingPolymorphicCalls.begin()->remove();
2207     
2208     // Note that our outgoing calls will be removed from other CodeBlocks'
2209     // m_incomingCalls linked lists through the execution of the ~CallLinkInfo
2210     // destructors.
2211
2212     for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter)
2213         (*iter)->deref();
2214 #endif // ENABLE(JIT)
2215 }
2216
2217 void CodeBlock::setNumParameters(int newValue)
2218 {
2219     m_numParameters = newValue;
2220
2221     m_argumentValueProfiles.resizeToFit(newValue);
2222 }
2223
2224 void EvalCodeCache::visitAggregate(SlotVisitor& visitor)
2225 {
2226     EvalCacheMap::iterator end = m_cacheMap.end();
2227     for (EvalCacheMap::iterator ptr = m_cacheMap.begin(); ptr != end; ++ptr)
2228         visitor.append(&ptr->value);
2229 }
2230
2231 CodeBlock* CodeBlock::specialOSREntryBlockOrNull()
2232 {
2233 #if ENABLE(FTL_JIT)
2234     if (jitType() != JITCode::DFGJIT)
2235         return 0;
2236     DFG::JITCode* jitCode = m_jitCode->dfg();
2237     return jitCode->osrEntryBlock.get();
2238 #else // ENABLE(FTL_JIT)
2239     return 0;
2240 #endif // ENABLE(FTL_JIT)
2241 }
2242
2243 void CodeBlock::visitAggregate(SlotVisitor& visitor)
2244 {
2245 #if ENABLE(PARALLEL_GC)
2246     // I may be asked to scan myself more than once, and it may even happen concurrently.
2247     // To this end, use an atomic operation to check (and set) if I've been called already.
2248     // Only one thread may proceed past this point - whichever one wins the atomic set race.
2249     bool setByMe = m_visitAggregateHasBeenCalled.compareExchangeStrong(false, true);
2250     if (!setByMe)
2251         return;
2252 #endif // ENABLE(PARALLEL_GC)
2253     
2254     if (!!m_alternative)
2255         m_alternative->visitAggregate(visitor);
2256     
2257     if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
2258         otherBlock->visitAggregate(visitor);
2259
2260     visitor.reportExtraMemoryVisited(ownerExecutable(), sizeof(CodeBlock));
2261     if (m_jitCode)
2262         visitor.reportExtraMemoryVisited(ownerExecutable(), m_jitCode->size());
2263     if (m_instructions.size()) {
2264         // Divide by refCount() because m_instructions points to something that is shared
2265         // by multiple CodeBlocks, and we only want to count it towards the heap size once.
2266         // Having each CodeBlock report only its proportional share of the size is one way
2267         // of accomplishing this.
2268         visitor.reportExtraMemoryVisited(ownerExecutable(), m_instructions.size() * sizeof(Instruction) / m_instructions.refCount());
2269     }
2270
2271     visitor.append(&m_unlinkedCode);
2272
2273     // There are three things that may use unconditional finalizers: lazy bytecode freeing,
2274     // inline cache clearing, and jettisoning. The probability of us wanting to do at
2275     // least one of those things is probably quite close to 1. So we add one no matter what
2276     // and when it runs, it figures out whether it has any work to do.
2277     visitor.addUnconditionalFinalizer(this);
2278     
2279     m_allTransitionsHaveBeenMarked = false;
2280     
2281     if (shouldImmediatelyAssumeLivenessDuringScan()) {
2282         // This code block is live, so scan all references strongly and return.
2283         stronglyVisitStrongReferences(visitor);
2284         stronglyVisitWeakReferences(visitor);
2285         propagateTransitions(visitor);
2286         return;
2287     }
2288     
2289     // There are two things that we use weak reference harvesters for: DFG fixpoint for
2290     // jettisoning, and trying to find structures that would be live based on some
2291     // inline cache. So it makes sense to register them regardless.
2292     visitor.addWeakReferenceHarvester(this);
2293
2294 #if ENABLE(DFG_JIT)
2295     // We get here if we're live in the sense that our owner executable is live,
2296     // but we're not yet live for sure in another sense: we may yet decide that this
2297     // code block should be jettisoned based on its outgoing weak references being
2298     // stale. Set a flag to indicate that we're still assuming that we're dead, and
2299     // perform one round of determining if we're live. The GC may determine, based on
2300     // either us marking additional objects, or by other objects being marked for
2301     // other reasons, that this iteration should run again; it will notify us of this
2302     // decision by calling harvestWeakReferences().
2303     
2304     m_jitCode->dfgCommon()->livenessHasBeenProved = false;
2305     
2306     propagateTransitions(visitor);
2307     determineLiveness(visitor);
2308 #else // ENABLE(DFG_JIT)
2309     RELEASE_ASSERT_NOT_REACHED();
2310 #endif // ENABLE(DFG_JIT)
2311 }
2312
2313 bool CodeBlock::shouldImmediatelyAssumeLivenessDuringScan()
2314 {
2315 #if ENABLE(DFG_JIT)
2316     // Interpreter and Baseline JIT CodeBlocks don't need to be jettisoned when
2317     // their weak references go stale. So if a basline JIT CodeBlock gets
2318     // scanned, we can assume that this means that it's live.
2319     if (!JITCode::isOptimizingJIT(jitType()))
2320         return true;
2321
2322     // For simplicity, we don't attempt to jettison code blocks during GC if
2323     // they are executing. Instead we strongly mark their weak references to
2324     // allow them to continue to execute soundly.
2325     if (m_mayBeExecuting)
2326         return true;
2327
2328     if (Options::forceDFGCodeBlockLiveness())
2329         return true;
2330
2331     return false;
2332 #else
2333     return true;
2334 #endif
2335 }
2336
2337 bool CodeBlock::isKnownToBeLiveDuringGC()
2338 {
2339 #if ENABLE(DFG_JIT)
2340     // This should return true for:
2341     // - Code blocks that behave like normal objects - i.e. if they are referenced then they
2342     //   are live.
2343     // - Code blocks that were running on the stack.
2344     // - Code blocks that survived the last GC if the current GC is an Eden GC. This is
2345     //   because either livenessHasBeenProved would have survived as true or m_mayBeExecuting
2346     //   would survive as true.
2347     // - Code blocks that don't have any dead weak references.
2348     
2349     return shouldImmediatelyAssumeLivenessDuringScan()
2350         || m_jitCode->dfgCommon()->livenessHasBeenProved;
2351 #else
2352     return true;
2353 #endif
2354 }
2355
2356 #if ENABLE(DFG_JIT)
2357 static bool shouldMarkTransition(DFG::WeakReferenceTransition& transition)
2358 {
2359     if (transition.m_codeOrigin && !Heap::isMarked(transition.m_codeOrigin.get()))
2360         return false;
2361     
2362     if (!Heap::isMarked(transition.m_from.get()))
2363         return false;
2364     
2365     return true;
2366 }
2367 #endif // ENABLE(DFG_JIT)
2368
2369 void CodeBlock::propagateTransitions(SlotVisitor& visitor)
2370 {
2371     UNUSED_PARAM(visitor);
2372
2373     if (m_allTransitionsHaveBeenMarked)
2374         return;
2375
2376     bool allAreMarkedSoFar = true;
2377         
2378     Interpreter* interpreter = m_vm->interpreter;
2379     if (jitType() == JITCode::InterpreterThunk) {
2380         const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
2381         for (size_t i = 0; i < propertyAccessInstructions.size(); ++i) {
2382             Instruction* instruction = &instructions()[propertyAccessInstructions[i]];
2383             switch (interpreter->getOpcodeID(instruction[0].u.opcode)) {
2384             case op_put_by_id_transition_direct:
2385             case op_put_by_id_transition_normal:
2386             case op_put_by_id_transition_direct_out_of_line:
2387             case op_put_by_id_transition_normal_out_of_line: {
2388                 if (Heap::isMarked(instruction[4].u.structure.get()))
2389                     visitor.append(&instruction[6].u.structure);
2390                 else
2391                     allAreMarkedSoFar = false;
2392                 break;
2393             }
2394             default:
2395                 break;
2396             }
2397         }
2398     }
2399
2400 #if ENABLE(JIT)
2401     if (JITCode::isJIT(jitType())) {
2402         for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter) {
2403             StructureStubInfo& stubInfo = **iter;
2404             switch (stubInfo.accessType) {
2405             case access_put_by_id_transition_normal:
2406             case access_put_by_id_transition_direct: {
2407                 JSCell* origin = stubInfo.codeOrigin.codeOriginOwner();
2408                 if ((!origin || Heap::isMarked(origin))
2409                     && Heap::isMarked(stubInfo.u.putByIdTransition.previousStructure.get()))
2410                     visitor.append(&stubInfo.u.putByIdTransition.structure);
2411                 else
2412                     allAreMarkedSoFar = false;
2413                 break;
2414             }
2415
2416             case access_put_by_id_list: {
2417                 PolymorphicPutByIdList* list = stubInfo.u.putByIdList.list;
2418                 JSCell* origin = stubInfo.codeOrigin.codeOriginOwner();
2419                 if (origin && !Heap::isMarked(origin)) {
2420                     allAreMarkedSoFar = false;
2421                     break;
2422                 }
2423                 for (unsigned j = list->size(); j--;) {
2424                     PutByIdAccess& access = list->m_list[j];
2425                     if (!access.isTransition())
2426                         continue;
2427                     if (Heap::isMarked(access.oldStructure()))
2428                         visitor.append(&access.m_newStructure);
2429                     else
2430                         allAreMarkedSoFar = false;
2431                 }
2432                 break;
2433             }
2434             
2435             default:
2436                 break;
2437             }
2438         }
2439     }
2440 #endif // ENABLE(JIT)
2441     
2442 #if ENABLE(DFG_JIT)
2443     if (JITCode::isOptimizingJIT(jitType())) {
2444         DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
2445         
2446         for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
2447             if (shouldMarkTransition(dfgCommon->transitions[i])) {
2448                 // If the following three things are live, then the target of the
2449                 // transition is also live:
2450                 //
2451                 // - This code block. We know it's live already because otherwise
2452                 //   we wouldn't be scanning ourselves.
2453                 //
2454                 // - The code origin of the transition. Transitions may arise from
2455                 //   code that was inlined. They are not relevant if the user's
2456                 //   object that is required for the inlinee to run is no longer
2457                 //   live.
2458                 //
2459                 // - The source of the transition. The transition checks if some
2460                 //   heap location holds the source, and if so, stores the target.
2461                 //   Hence the source must be live for the transition to be live.
2462                 //
2463                 // We also short-circuit the liveness if the structure is harmless
2464                 // to mark (i.e. its global object and prototype are both already
2465                 // live).
2466                 
2467                 visitor.append(&dfgCommon->transitions[i].m_to);
2468             } else
2469                 allAreMarkedSoFar = false;
2470         }
2471     }
2472 #endif // ENABLE(DFG_JIT)
2473     
2474     if (allAreMarkedSoFar)
2475         m_allTransitionsHaveBeenMarked = true;
2476 }
2477
2478 void CodeBlock::determineLiveness(SlotVisitor& visitor)
2479 {
2480     UNUSED_PARAM(visitor);
2481     
2482     if (shouldImmediatelyAssumeLivenessDuringScan())
2483         return;
2484     
2485 #if ENABLE(DFG_JIT)
2486     // Check if we have any remaining work to do.
2487     DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
2488     if (dfgCommon->livenessHasBeenProved)
2489         return;
2490     
2491     // Now check all of our weak references. If all of them are live, then we
2492     // have proved liveness and so we scan our strong references. If at end of
2493     // GC we still have not proved liveness, then this code block is toast.
2494     bool allAreLiveSoFar = true;
2495     for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
2496         if (!Heap::isMarked(dfgCommon->weakReferences[i].get())) {
2497             allAreLiveSoFar = false;
2498             break;
2499         }
2500     }
2501     if (allAreLiveSoFar) {
2502         for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i) {
2503             if (!Heap::isMarked(dfgCommon->weakStructureReferences[i].get())) {
2504                 allAreLiveSoFar = false;
2505                 break;
2506             }
2507         }
2508     }
2509     
2510     // If some weak references are dead, then this fixpoint iteration was
2511     // unsuccessful.
2512     if (!allAreLiveSoFar)
2513         return;
2514     
2515     // All weak references are live. Record this information so we don't
2516     // come back here again, and scan the strong references.
2517     dfgCommon->livenessHasBeenProved = true;
2518     stronglyVisitStrongReferences(visitor);
2519 #endif // ENABLE(DFG_JIT)
2520 }
2521
2522 void CodeBlock::visitWeakReferences(SlotVisitor& visitor)
2523 {
2524     propagateTransitions(visitor);
2525     determineLiveness(visitor);
2526 }
2527
2528 void CodeBlock::finalizeUnconditionally()
2529 {
2530     Interpreter* interpreter = m_vm->interpreter;
2531     if (JITCode::couldBeInterpreted(jitType())) {
2532         const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
2533         for (size_t size = propertyAccessInstructions.size(), i = 0; i < size; ++i) {
2534             Instruction* curInstruction = &instructions()[propertyAccessInstructions[i]];
2535             switch (interpreter->getOpcodeID(curInstruction[0].u.opcode)) {
2536             case op_get_by_id:
2537             case op_get_by_id_out_of_line:
2538             case op_put_by_id:
2539             case op_put_by_id_out_of_line:
2540                 if (!curInstruction[4].u.structure || Heap::isMarked(curInstruction[4].u.structure.get()))
2541                     break;
2542                 if (Options::verboseOSR())
2543                     dataLogF("Clearing LLInt property access with structure %p.\n", curInstruction[4].u.structure.get());
2544                 curInstruction[4].u.structure.clear();
2545                 curInstruction[5].u.operand = 0;
2546                 break;
2547             case op_put_by_id_transition_direct:
2548             case op_put_by_id_transition_normal:
2549             case op_put_by_id_transition_direct_out_of_line:
2550             case op_put_by_id_transition_normal_out_of_line:
2551                 if (Heap::isMarked(curInstruction[4].u.structure.get())
2552                     && Heap::isMarked(curInstruction[6].u.structure.get())
2553                     && Heap::isMarked(curInstruction[7].u.structureChain.get()))
2554                     break;
2555                 if (Options::verboseOSR()) {
2556                     dataLogF("Clearing LLInt put transition with structures %p -> %p, chain %p.\n",
2557                             curInstruction[4].u.structure.get(),
2558                             curInstruction[6].u.structure.get(),
2559                             curInstruction[7].u.structureChain.get());
2560                 }
2561                 curInstruction[4].u.structure.clear();
2562                 curInstruction[6].u.structure.clear();
2563                 curInstruction[7].u.structureChain.clear();
2564                 curInstruction[0].u.opcode = interpreter->getOpcode(op_put_by_id);
2565                 break;
2566             case op_get_array_length:
2567                 break;
2568             case op_to_this:
2569                 if (!curInstruction[2].u.structure || Heap::isMarked(curInstruction[2].u.structure.get()))
2570                     break;
2571                 if (Options::verboseOSR())
2572                     dataLogF("Clearing LLInt to_this with structure %p.\n", curInstruction[2].u.structure.get());
2573                 curInstruction[2].u.structure.clear();
2574                 curInstruction[3].u.toThisStatus = merge(
2575                     curInstruction[3].u.toThisStatus, ToThisClearedByGC);
2576                 break;
2577             case op_create_this: {
2578                 auto& cacheWriteBarrier = curInstruction[4].u.jsCell;
2579                 if (!cacheWriteBarrier || cacheWriteBarrier.unvalidatedGet() == JSCell::seenMultipleCalleeObjects())
2580                     break;
2581                 JSCell* cachedFunction = cacheWriteBarrier.get();
2582                 if (Heap::isMarked(cachedFunction))
2583                     break;
2584                 if (Options::verboseOSR())
2585                     dataLogF("Clearing LLInt create_this with cached callee %p.\n", cachedFunction);
2586                 cacheWriteBarrier.clear();
2587                 break;
2588             }
2589             case op_resolve_scope: {
2590                 // Right now this isn't strictly necessary. Any symbol tables that this will refer to
2591                 // are for outer functions, and we refer to those functions strongly, and they refer
2592                 // to the symbol table strongly. But it's nice to be on the safe side.
2593                 WriteBarrierBase<SymbolTable>& symbolTable = curInstruction[6].u.symbolTable;
2594                 if (!symbolTable || Heap::isMarked(symbolTable.get()))
2595                     break;
2596                 if (Options::verboseOSR())
2597                     dataLogF("Clearing dead symbolTable %p.\n", symbolTable.get());
2598                 symbolTable.clear();
2599                 break;
2600             }
2601             case op_get_from_scope:
2602             case op_put_to_scope: {
2603                 ResolveModeAndType modeAndType =
2604                     ResolveModeAndType(curInstruction[4].u.operand);
2605                 if (modeAndType.type() == GlobalVar || modeAndType.type() == GlobalVarWithVarInjectionChecks || modeAndType.type() == LocalClosureVar)
2606                     continue;
2607                 WriteBarrierBase<Structure>& structure = curInstruction[5].u.structure;
2608                 if (!structure || Heap::isMarked(structure.get()))
2609                     break;
2610                 if (Options::verboseOSR())
2611                     dataLogF("Clearing scope access with structure %p.\n", structure.get());
2612                 structure.clear();
2613                 break;
2614             }
2615             default:
2616                 OpcodeID opcodeID = interpreter->getOpcodeID(curInstruction[0].u.opcode);
2617                 ASSERT_WITH_MESSAGE_UNUSED(opcodeID, false, "Unhandled opcode in CodeBlock::finalizeUnconditionally, %s(%d) at bc %u", opcodeNames[opcodeID], opcodeID, propertyAccessInstructions[i]);
2618             }
2619         }
2620
2621         for (unsigned i = 0; i < m_llintCallLinkInfos.size(); ++i) {
2622             if (m_llintCallLinkInfos[i].isLinked() && !Heap::isMarked(m_llintCallLinkInfos[i].callee.get())) {
2623                 if (Options::verboseOSR())
2624                     dataLog("Clearing LLInt call from ", *this, "\n");
2625                 m_llintCallLinkInfos[i].unlink();
2626             }
2627             if (!!m_llintCallLinkInfos[i].lastSeenCallee && !Heap::isMarked(m_llintCallLinkInfos[i].lastSeenCallee.get()))
2628                 m_llintCallLinkInfos[i].lastSeenCallee.clear();
2629         }
2630     }
2631
2632 #if ENABLE(DFG_JIT)
2633     // Check if we're not live. If we are, then jettison.
2634     if (!isKnownToBeLiveDuringGC()) {
2635         if (Options::verboseOSR())
2636             dataLog(*this, " has dead weak references, jettisoning during GC.\n");
2637
2638         if (DFG::shouldShowDisassembly()) {
2639             dataLog(*this, " will be jettisoned because of the following dead references:\n");
2640             DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
2641             for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
2642                 DFG::WeakReferenceTransition& transition = dfgCommon->transitions[i];
2643                 JSCell* origin = transition.m_codeOrigin.get();
2644                 JSCell* from = transition.m_from.get();
2645                 JSCell* to = transition.m_to.get();
2646                 if ((!origin || Heap::isMarked(origin)) && Heap::isMarked(from))
2647                     continue;
2648                 dataLog("    Transition under ", RawPointer(origin), ", ", RawPointer(from), " -> ", RawPointer(to), ".\n");
2649             }
2650             for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
2651                 JSCell* weak = dfgCommon->weakReferences[i].get();
2652                 if (Heap::isMarked(weak))
2653                     continue;
2654                 dataLog("    Weak reference ", RawPointer(weak), ".\n");
2655             }
2656         }
2657         
2658         jettison(Profiler::JettisonDueToWeakReference);
2659         return;
2660     }
2661 #endif // ENABLE(DFG_JIT)
2662
2663 #if ENABLE(JIT)
2664     // Handle inline caches.
2665     if (!!jitCode()) {
2666         RepatchBuffer repatchBuffer(this);
2667         
2668         for (auto iter = callLinkInfosBegin(); !!iter; ++iter)
2669             (*iter)->visitWeak(repatchBuffer);
2670
2671         for (Bag<StructureStubInfo>::iterator iter = m_stubInfos.begin(); !!iter; ++iter) {
2672             StructureStubInfo& stubInfo = **iter;
2673             
2674             if (stubInfo.visitWeakReferences(repatchBuffer))
2675                 continue;
2676             
2677             resetStubDuringGCInternal(repatchBuffer, stubInfo);
2678         }
2679     }
2680 #endif
2681 }
2682
2683 void CodeBlock::getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result)
2684 {
2685 #if ENABLE(JIT)
2686     toHashMap(m_stubInfos, getStructureStubInfoCodeOrigin, result);
2687 #else
2688     UNUSED_PARAM(result);
2689 #endif
2690 }
2691
2692 void CodeBlock::getStubInfoMap(StubInfoMap& result)
2693 {
2694     ConcurrentJITLocker locker(m_lock);
2695     getStubInfoMap(locker, result);
2696 }
2697
2698 void CodeBlock::getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result)
2699 {
2700 #if ENABLE(JIT)
2701     toHashMap(m_callLinkInfos, getCallLinkInfoCodeOrigin, result);
2702 #else
2703     UNUSED_PARAM(result);
2704 #endif
2705 }
2706
2707 void CodeBlock::getCallLinkInfoMap(CallLinkInfoMap& result)
2708 {
2709     ConcurrentJITLocker locker(m_lock);
2710     getCallLinkInfoMap(locker, result);
2711 }
2712
2713 #if ENABLE(JIT)
2714 StructureStubInfo* CodeBlock::addStubInfo()
2715 {
2716     ConcurrentJITLocker locker(m_lock);
2717     return m_stubInfos.add();
2718 }
2719
2720 StructureStubInfo* CodeBlock::findStubInfo(CodeOrigin codeOrigin)
2721 {
2722     for (StructureStubInfo* stubInfo : m_stubInfos) {
2723         if (stubInfo->codeOrigin == codeOrigin)
2724             return stubInfo;
2725     }
2726     return nullptr;
2727 }
2728
2729 CallLinkInfo* CodeBlock::addCallLinkInfo()
2730 {
2731     ConcurrentJITLocker locker(m_lock);
2732     return m_callLinkInfos.add();
2733 }
2734
2735 void CodeBlock::resetStub(StructureStubInfo& stubInfo)
2736 {
2737     if (stubInfo.accessType == access_unset)
2738         return;
2739     
2740     ConcurrentJITLocker locker(m_lock);
2741     
2742     RepatchBuffer repatchBuffer(this);
2743     resetStubInternal(repatchBuffer, stubInfo);
2744 }
2745
2746 void CodeBlock::resetStubInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
2747 {
2748     AccessType accessType = static_cast<AccessType>(stubInfo.accessType);
2749     
2750     if (Options::verboseOSR()) {
2751         // This can be called from GC destructor calls, so we don't try to do a full dump
2752         // of the CodeBlock.
2753         dataLog("Clearing structure cache (kind ", static_cast<int>(stubInfo.accessType), ") in ", RawPointer(this), ".\n");
2754     }
2755     
2756     RELEASE_ASSERT(JITCode::isJIT(jitType()));
2757     
2758     if (isGetByIdAccess(accessType))
2759         resetGetByID(repatchBuffer, stubInfo);
2760     else if (isPutByIdAccess(accessType))
2761         resetPutByID(repatchBuffer, stubInfo);
2762     else {
2763         RELEASE_ASSERT(isInAccess(accessType));
2764         resetIn(repatchBuffer, stubInfo);
2765     }
2766     
2767     stubInfo.reset();
2768 }
2769
2770 void CodeBlock::resetStubDuringGCInternal(RepatchBuffer& repatchBuffer, StructureStubInfo& stubInfo)
2771 {
2772     resetStubInternal(repatchBuffer, stubInfo);
2773     stubInfo.resetByGC = true;
2774 }
2775
2776 CallLinkInfo* CodeBlock::getCallLinkInfoForBytecodeIndex(unsigned index)
2777 {
2778     for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
2779         if ((*iter)->codeOrigin() == CodeOrigin(index))
2780             return *iter;
2781     }
2782     return nullptr;
2783 }
2784 #endif
2785
2786 void CodeBlock::stronglyVisitStrongReferences(SlotVisitor& visitor)
2787 {
2788     visitor.append(&m_globalObject);
2789     visitor.append(&m_ownerExecutable);
2790     visitor.append(&m_symbolTable);
2791     visitor.append(&m_unlinkedCode);
2792     if (m_rareData)
2793         m_rareData->m_evalCodeCache.visitAggregate(visitor);
2794     visitor.appendValues(m_constantRegisters.data(), m_constantRegisters.size());
2795     for (size_t i = 0; i < m_functionExprs.size(); ++i)
2796         visitor.append(&m_functionExprs[i]);
2797     for (size_t i = 0; i < m_functionDecls.size(); ++i)
2798         visitor.append(&m_functionDecls[i]);
2799     for (unsigned i = 0; i < m_objectAllocationProfiles.size(); ++i)
2800         m_objectAllocationProfiles[i].visitAggregate(visitor);
2801
2802 #if ENABLE(DFG_JIT)
2803     if (JITCode::isOptimizingJIT(jitType())) {
2804         // FIXME: This is an antipattern for two reasons. References introduced by the DFG
2805         // that aren't in the original CodeBlock being compiled should be weakly referenced.
2806         // Inline call frames aren't in the original CodeBlock, so they qualify as weak. Also,
2807         // those weak references should already be tracked in the DFG as weak FrozenValues. So,
2808         // there is probably no need for this. We already have assertions that this should be
2809         // unnecessary.
2810         // https://bugs.webkit.org/show_bug.cgi?id=146613
2811         DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
2812         if (dfgCommon->inlineCallFrames.get())
2813             dfgCommon->inlineCallFrames->visitAggregate(visitor);
2814     }
2815 #endif
2816
2817     updateAllPredictions();
2818 }
2819
2820 void CodeBlock::stronglyVisitWeakReferences(SlotVisitor& visitor)
2821 {
2822     UNUSED_PARAM(visitor);
2823
2824 #if ENABLE(DFG_JIT)
2825     if (!JITCode::isOptimizingJIT(jitType()))
2826         return;
2827     
2828     DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
2829
2830     for (unsigned i = 0; i < dfgCommon->transitions.size(); ++i) {
2831         if (!!dfgCommon->transitions[i].m_codeOrigin)
2832             visitor.append(&dfgCommon->transitions[i].m_codeOrigin); // Almost certainly not necessary, since the code origin should also be a weak reference. Better to be safe, though.
2833         visitor.append(&dfgCommon->transitions[i].m_from);
2834         visitor.append(&dfgCommon->transitions[i].m_to);
2835     }
2836     
2837     for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i)
2838         visitor.append(&dfgCommon->weakReferences[i]);
2839
2840     for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i)
2841         visitor.append(&dfgCommon->weakStructureReferences[i]);
2842 #endif    
2843 }
2844
2845 CodeBlock* CodeBlock::baselineAlternative()
2846 {
2847 #if ENABLE(JIT)
2848     CodeBlock* result = this;
2849     while (result->alternative())
2850         result = result->alternative();
2851     RELEASE_ASSERT(result);
2852     RELEASE_ASSERT(JITCode::isBaselineCode(result->jitType()) || result->jitType() == JITCode::None);
2853     return result;
2854 #else
2855     return this;
2856 #endif
2857 }
2858
2859 CodeBlock* CodeBlock::baselineVersion()
2860 {
2861 #if ENABLE(JIT)
2862     if (JITCode::isBaselineCode(jitType()))
2863         return this;
2864     CodeBlock* result = replacement();
2865     if (!result) {
2866         // This can happen if we're creating the original CodeBlock for an executable.
2867         // Assume that we're the baseline CodeBlock.
2868         RELEASE_ASSERT(jitType() == JITCode::None);
2869         return this;
2870     }
2871     result = result->baselineAlternative();
2872     return result;
2873 #else
2874     return this;
2875 #endif
2876 }
2877
2878 #if ENABLE(JIT)
2879 bool CodeBlock::hasOptimizedReplacement(JITCode::JITType typeToReplace)
2880 {
2881     return JITCode::isHigherTier(replacement()->jitType(), typeToReplace);
2882 }
2883
2884 bool CodeBlock::hasOptimizedReplacement()
2885 {
2886     return hasOptimizedReplacement(jitType());
2887 }
2888 #endif
2889
2890 HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler requiredHandler)
2891 {
2892     RELEASE_ASSERT(bytecodeOffset < instructions().size());
2893
2894     if (!m_rareData)
2895         return 0;
2896     
2897     Vector<HandlerInfo>& exceptionHandlers = m_rareData->m_exceptionHandlers;
2898     for (size_t i = 0; i < exceptionHandlers.size(); ++i) {
2899         HandlerInfo& handler = exceptionHandlers[i];
2900         if ((requiredHandler == RequiredHandler::CatchHandler) && !handler.isCatchHandler())
2901             continue;
2902
2903         // Handlers are ordered innermost first, so the first handler we encounter
2904         // that contains the source address is the correct handler to use.
2905         if (handler.start <= bytecodeOffset && handler.end > bytecodeOffset)
2906             return &handler;
2907     }
2908
2909     return 0;
2910 }
2911
2912 unsigned CodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
2913 {
2914     RELEASE_ASSERT(bytecodeOffset < instructions().size());
2915     return m_ownerExecutable->firstLine() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
2916 }
2917
2918 unsigned CodeBlock::columnNumberForBytecodeOffset(unsigned bytecodeOffset)
2919 {
2920     int divot;
2921     int startOffset;
2922     int endOffset;
2923     unsigned line;
2924     unsigned column;
2925     expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
2926     return column;
2927 }
2928
2929 void CodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset, unsigned& line, unsigned& column)
2930 {
2931     m_unlinkedCode->expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
2932     divot += m_sourceOffset;
2933     column += line ? 1 : firstLineColumnOffset();
2934     line += m_ownerExecutable->firstLine();
2935 }
2936
2937 bool CodeBlock::hasOpDebugForLineAndColumn(unsigned line, unsigned column)
2938 {
2939     Interpreter* interpreter = vm()->interpreter;
2940     const Instruction* begin = instructions().begin();
2941     const Instruction* end = instructions().end();
2942     for (const Instruction* it = begin; it != end;) {
2943         OpcodeID opcodeID = interpreter->getOpcodeID(it->u.opcode);
2944         if (opcodeID == op_debug) {
2945             unsigned bytecodeOffset = it - begin;
2946             int unused;
2947             unsigned opDebugLine;
2948             unsigned opDebugColumn;
2949             expressionRangeForBytecodeOffset(bytecodeOffset, unused, unused, unused, opDebugLine, opDebugColumn);
2950             if (line == opDebugLine && (column == Breakpoint::unspecifiedColumn || column == opDebugColumn))
2951                 return true;
2952         }
2953         it += opcodeLengths[opcodeID];
2954     }
2955     return false;
2956 }
2957
2958 void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
2959 {
2960     m_rareCaseProfiles.shrinkToFit();
2961     m_specialFastCaseProfiles.shrinkToFit();
2962     
2963     if (shrinkMode == EarlyShrink) {
2964         m_constantRegisters.shrinkToFit();
2965         m_constantsSourceCodeRepresentation.shrinkToFit();
2966         
2967         if (m_rareData) {
2968             m_rareData->m_switchJumpTables.shrinkToFit();
2969             m_rareData->m_stringSwitchJumpTables.shrinkToFit();
2970         }
2971     } // else don't shrink these, because we would have already pointed pointers into these tables.
2972 }
2973
2974 #if ENABLE(JIT)
2975 void CodeBlock::unlinkCalls()
2976 {
2977     if (!!m_alternative)
2978         m_alternative->unlinkCalls();
2979     for (size_t i = 0; i < m_llintCallLinkInfos.size(); ++i) {
2980         if (m_llintCallLinkInfos[i].isLinked())
2981             m_llintCallLinkInfos[i].unlink();
2982     }
2983     if (m_callLinkInfos.isEmpty())
2984         return;
2985     if (!m_vm->canUseJIT())
2986         return;
2987     RepatchBuffer repatchBuffer(this);
2988     for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
2989         CallLinkInfo& info = **iter;
2990         if (!info.isLinked())
2991             continue;
2992         info.unlink(repatchBuffer);
2993     }
2994 }
2995
2996 void CodeBlock::linkIncomingCall(ExecState* callerFrame, CallLinkInfo* incoming)
2997 {
2998     noticeIncomingCall(callerFrame);
2999     m_incomingCalls.push(incoming);
3000 }
3001
3002 void CodeBlock::linkIncomingPolymorphicCall(ExecState* callerFrame, PolymorphicCallNode* incoming)
3003 {
3004     noticeIncomingCall(callerFrame);
3005     m_incomingPolymorphicCalls.push(incoming);
3006 }
3007 #endif // ENABLE(JIT)
3008
3009 void CodeBlock::unlinkIncomingCalls()
3010 {
3011     while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
3012         m_incomingLLIntCalls.begin()->unlink();
3013 #if ENABLE(JIT)
3014     if (m_incomingCalls.isEmpty() && m_incomingPolymorphicCalls.isEmpty())
3015         return;
3016     RepatchBuffer repatchBuffer(this);
3017     while (m_incomingCalls.begin() != m_incomingCalls.end())
3018         m_incomingCalls.begin()->unlink(repatchBuffer);
3019     while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
3020         m_incomingPolymorphicCalls.begin()->unlink(repatchBuffer);
3021 #endif // ENABLE(JIT)
3022 }
3023
3024 void CodeBlock::linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo* incoming)
3025 {
3026     noticeIncomingCall(callerFrame);
3027     m_incomingLLIntCalls.push(incoming);
3028 }
3029
3030 void CodeBlock::clearEvalCache()
3031 {
3032     if (!!m_alternative)
3033         m_alternative->clearEvalCache();
3034     if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
3035         otherBlock->clearEvalCache();
3036     if (!m_rareData)
3037         return;
3038     m_rareData->m_evalCodeCache.clear();
3039 }
3040
3041 void CodeBlock::install()
3042 {
3043     ownerExecutable()->installCode(this);
3044 }
3045
3046 PassRefPtr<CodeBlock> CodeBlock::newReplacement()
3047 {
3048     return ownerExecutable()->newReplacementCodeBlockFor(specializationKind());
3049 }
3050
3051 #if ENABLE(JIT)
3052 CodeBlock* ProgramCodeBlock::replacement()
3053 {
3054     return jsCast<ProgramExecutable*>(ownerExecutable())->codeBlock();
3055 }
3056
3057 CodeBlock* EvalCodeBlock::replacement()
3058 {
3059     return jsCast<EvalExecutable*>(ownerExecutable())->codeBlock();
3060 }
3061
3062 CodeBlock* FunctionCodeBlock::replacement()
3063 {
3064     return jsCast<FunctionExecutable*>(ownerExecutable())->codeBlockFor(m_isConstructor ? CodeForConstruct : CodeForCall);
3065 }
3066
3067 DFG::CapabilityLevel ProgramCodeBlock::capabilityLevelInternal()
3068 {
3069     return DFG::programCapabilityLevel(this);
3070 }
3071
3072 DFG::CapabilityLevel EvalCodeBlock::capabilityLevelInternal()
3073 {
3074     return DFG::evalCapabilityLevel(this);
3075 }
3076
3077 DFG::CapabilityLevel FunctionCodeBlock::capabilityLevelInternal()
3078 {
3079     if (m_isConstructor)
3080         return DFG::functionForConstructCapabilityLevel(this);
3081     return DFG::functionForCallCapabilityLevel(this);
3082 }
3083 #endif
3084
3085 void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mode, const FireDetail* detail)
3086 {
3087     RELEASE_ASSERT(reason != Profiler::NotJettisoned);
3088     
3089 #if ENABLE(DFG_JIT)
3090     if (DFG::shouldShowDisassembly()) {
3091         dataLog("Jettisoning ", *this);
3092         if (mode == CountReoptimization)
3093             dataLog(" and counting reoptimization");
3094         dataLog(" due to ", reason);
3095         if (detail)
3096             dataLog(", ", *detail);
3097         dataLog(".\n");
3098     }
3099     
3100     DeferGCForAWhile deferGC(*m_heap);
3101     RELEASE_ASSERT(JITCode::isOptimizingJIT(jitType()));
3102     
3103     if (Profiler::Compilation* compilation = jitCode()->dfgCommon()->compilation.get())
3104         compilation->setJettisonReason(reason, detail);
3105     
3106     // We want to accomplish two things here:
3107     // 1) Make sure that if this CodeBlock is on the stack right now, then if we return to it
3108     //    we should OSR exit at the top of the next bytecode instruction after the return.
3109     // 2) Make sure that if we call the owner executable, then we shouldn't call this CodeBlock.
3110     
3111     // This accomplishes the OSR-exit-on-return part, and does its own book-keeping about
3112     // whether the invalidation has already happened.
3113     if (!jitCode()->dfgCommon()->invalidate()) {
3114         // Nothing to do since we've already been invalidated. That means that we cannot be
3115         // the optimized replacement.
3116         RELEASE_ASSERT(this != replacement());
3117         return;
3118     }
3119     
3120     if (DFG::shouldShowDisassembly())
3121         dataLog("    Did invalidate ", *this, "\n");
3122     
3123     // Count the reoptimization if that's what the user wanted.
3124     if (mode == CountReoptimization) {
3125         // FIXME: Maybe this should call alternative().
3126         // https://bugs.webkit.org/show_bug.cgi?id=123677
3127         baselineAlternative()->countReoptimization();
3128         if (DFG::shouldShowDisassembly())
3129             dataLog("    Did count reoptimization for ", *this, "\n");
3130     }
3131     
3132     // Now take care of the entrypoint.
3133     if (this != replacement()) {
3134         // This means that we were never the entrypoint. This can happen for OSR entry code
3135         // blocks.
3136         return;
3137     }
3138     alternative()->optimizeAfterWarmUp();
3139     tallyFrequentExitSites();
3140     alternative()->install();
3141     if (DFG::shouldShowDisassembly())
3142         dataLog("    Did install baseline version of ", *this, "\n");
3143 #else // ENABLE(DFG_JIT)
3144     UNUSED_PARAM(mode);
3145     UNUSED_PARAM(detail);
3146     UNREACHABLE_FOR_PLATFORM();
3147 #endif // ENABLE(DFG_JIT)
3148 }
3149
3150 JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
3151 {
3152     if (!codeOrigin.inlineCallFrame)
3153         return globalObject();
3154     return jsCast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())->eitherCodeBlock()->globalObject();
3155 }
3156
3157 class RecursionCheckFunctor {
3158 public:
3159     RecursionCheckFunctor(CallFrame* startCallFrame, CodeBlock* codeBlock, unsigned depthToCheck)
3160         : m_startCallFrame(startCallFrame)
3161         , m_codeBlock(codeBlock)
3162         , m_depthToCheck(depthToCheck)
3163         , m_foundStartCallFrame(false)
3164         , m_didRecurse(false)
3165     { }
3166
3167     StackVisitor::Status operator()(StackVisitor& visitor)
3168     {
3169         CallFrame* currentCallFrame = visitor->callFrame();
3170
3171         if (currentCallFrame == m_startCallFrame)
3172             m_foundStartCallFrame = true;
3173
3174         if (m_foundStartCallFrame) {
3175             if (visitor->callFrame()->codeBlock() == m_codeBlock) {
3176                 m_didRecurse = true;
3177                 return StackVisitor::Done;
3178             }
3179
3180             if (!m_depthToCheck--)
3181                 return StackVisitor::Done;
3182         }
3183
3184         return StackVisitor::Continue;
3185     }
3186
3187     bool didRecurse() const { return m_didRecurse; }
3188
3189 private:
3190     CallFrame* m_startCallFrame;
3191     CodeBlock* m_codeBlock;
3192     unsigned m_depthToCheck;
3193     bool m_foundStartCallFrame;
3194     bool m_didRecurse;
3195 };
3196
3197 void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
3198 {
3199     CodeBlock* callerCodeBlock = callerFrame->codeBlock();
3200     
3201     if (Options::verboseCallLink())
3202         dataLog("Noticing call link from ", pointerDump(callerCodeBlock), " to ", *this, "\n");
3203     
3204 #if ENABLE(DFG_JIT)
3205     if (!m_shouldAlwaysBeInlined)
3206         return;
3207     
3208     if (!callerCodeBlock) {
3209         m_shouldAlwaysBeInlined = false;
3210         if (Options::verboseCallLink())
3211             dataLog("    Clearing SABI because caller is native.\n");
3212         return;
3213     }
3214
3215     if (!hasBaselineJITProfiling())
3216         return;
3217
3218     if (!DFG::mightInlineFunction(this))
3219         return;
3220
3221     if (!canInline(m_capabilityLevelState))
3222         return;
3223     
3224     if (!DFG::isSmallEnoughToInlineCodeInto(callerCodeBlock)) {
3225         m_shouldAlwaysBeInlined = false;
3226         if (Options::verboseCallLink())
3227             dataLog("    Clearing SABI because caller is too large.\n");
3228         return;
3229     }
3230
3231     if (callerCodeBlock->jitType() == JITCode::InterpreterThunk) {
3232         // If the caller is still in the interpreter, then we can't expect inlining to
3233         // happen anytime soon. Assume it's profitable to optimize it separately. This
3234         // ensures that a function is SABI only if it is called no more frequently than
3235         // any of its callers.
3236         m_shouldAlwaysBeInlined = false;
3237         if (Options::verboseCallLink())
3238             dataLog("    Clearing SABI because caller is in LLInt.\n");
3239         return;
3240     }
3241     
3242     if (JITCode::isOptimizingJIT(callerCodeBlock->jitType())) {
3243         m_shouldAlwaysBeInlined = false;
3244         if (Options::verboseCallLink())
3245             dataLog("    Clearing SABI bcause caller was already optimized.\n");
3246         return;
3247     }
3248     
3249     if (callerCodeBlock->codeType() != FunctionCode) {
3250         // If the caller is either eval or global code, assume that that won't be
3251         // optimized anytime soon. For eval code this is particularly true since we
3252         // delay eval optimization by a *lot*.
3253         m_shouldAlwaysBeInlined = false;
3254         if (Options::verboseCallLink())
3255             dataLog("    Clearing SABI because caller is not a function.\n");
3256         return;
3257     }
3258
3259     // Recursive calls won't be inlined.
3260     RecursionCheckFunctor functor(callerFrame, this, Options::maximumInliningDepth());
3261     vm()->topCallFrame->iterate(functor);
3262
3263     if (functor.didRecurse()) {
3264         if (Options::verboseCallLink())
3265             dataLog("    Clearing SABI because recursion was detected.\n");
3266         m_shouldAlwaysBeInlined = false;
3267         return;
3268     }
3269     
3270     if (callerCodeBlock->m_capabilityLevelState == DFG::CapabilityLevelNotSet) {
3271         dataLog("In call from ", *callerCodeBlock, " ", callerFrame->codeOrigin(), " to ", *this, ": caller's DFG capability level is not set.\n");
3272         CRASH();
3273     }
3274     
3275     if (canCompile(callerCodeBlock->m_capabilityLevelState))
3276         return;
3277     
3278     if (Options::verboseCallLink())
3279         dataLog("    Clearing SABI because the caller is not a DFG candidate.\n");
3280     
3281     m_shouldAlwaysBeInlined = false;
3282 #endif
3283 }
3284
3285 unsigned CodeBlock::reoptimizationRetryCounter() const
3286 {
3287 #if ENABLE(JIT)
3288     ASSERT(m_reoptimizationRetryCounter <= Options::reoptimizationRetryCounterMax());
3289     return m_reoptimizationRetryCounter;
3290 #else
3291     return 0;
3292 #endif // ENABLE(JIT)
3293 }
3294
3295 #if ENABLE(JIT)
3296 void CodeBlock::countReoptimization()
3297 {
3298     m_reoptimizationRetryCounter++;
3299     if (m_reoptimizationRetryCounter > Options::reoptimizationRetryCounterMax())
3300         m_reoptimizationRetryCounter = Options::reoptimizationRetryCounterMax();
3301 }
3302
3303 unsigned CodeBlock::numberOfDFGCompiles()
3304 {
3305     ASSERT(JITCode::isBaselineCode(jitType()));
3306     if (Options::testTheFTL()) {
3307         if (m_didFailFTLCompilation)
3308             return 1000000;
3309         return (m_hasBeenCompiledWithFTL ? 1 : 0) + m_reoptimizationRetryCounter;
3310     }
3311     return (JITCode::isOptimizingJIT(replacement()->jitType()) ? 1 : 0) + m_reoptimizationRetryCounter;
3312 }
3313
3314 int32_t CodeBlock::codeTypeThresholdMultiplier() const
3315 {
3316     if (codeType() == EvalCode)
3317         return Options::evalThresholdMultiplier();
3318     
3319     return 1;
3320 }
3321
3322 double CodeBlock::optimizationThresholdScalingFactor()
3323 {
3324     // This expression arises from doing a least-squares fit of
3325     //
3326     // F[x_] =: a * Sqrt[x + b] + Abs[c * x] + d
3327     //
3328     // against the data points:
3329     //
3330     //    x       F[x_]
3331     //    10       0.9          (smallest reasonable code block)
3332     //   200       1.0          (typical small-ish code block)
3333     //   320       1.2          (something I saw in 3d-cube that I wanted to optimize)
3334     //  1268       5.0          (something I saw in 3d-cube that I didn't want to optimize)
3335     //  4000       5.5          (random large size, used to cause the function to converge to a shallow curve of some sort)
3336     // 10000       6.0          (similar to above)
3337     //
3338     // I achieve the minimization using the following Mathematica code:
3339     //
3340     // MyFunctionTemplate[x_, a_, b_, c_, d_] := a*Sqrt[x + b] + Abs[c*x] + d
3341     //
3342     // samples = {{10, 0.9}, {200, 1}, {320, 1.2}, {1268, 5}, {4000, 5.5}, {10000, 6}}
3343     //
3344     // solution = 
3345     //     Minimize[Plus @@ ((MyFunctionTemplate[#[[1]], a, b, c, d] - #[[2]])^2 & /@ samples),
3346     //         {a, b, c, d}][[2]]
3347     //
3348     // And the code below (to initialize a, b, c, d) is generated by:
3349     //
3350     // Print["const double " <> ToString[#[[1]]] <> " = " <>
3351     //     If[#[[2]] < 0.00001, "0.0", ToString[#[[2]]]] <> ";"] & /@ solution
3352     //
3353     // We've long known the following to be true:
3354     // - Small code blocks are cheap to optimize and so we should do it sooner rather
3355     //   than later.
3356     // - Large code blocks are expensive to optimize and so we should postpone doing so,
3357     //   and sometimes have a large enough threshold that we never optimize them.
3358     // - The difference in cost is not totally linear because (a) just invoking the
3359     //   DFG incurs some base cost and (b) for large code blocks there is enough slop
3360     //   in the correlation between instruction count and the actual compilation cost
3361     //   that for those large blocks, the instruction count should not have a strong
3362     //   influence on our threshold.
3363     //
3364     // I knew the goals but I didn't know how to achieve them; so I picked an interesting
3365     // example where the heuristics were right (code block in 3d-cube with instruction
3366     // count 320, which got compiled early as it should have been) and one where they were
3367     // totally wrong (code block in 3d-cube with instruction count 1268, which was expensive
3368     // to compile and didn't run often enough to warrant compilation in my opinion), and
3369     // then threw in additional data points that represented my own guess of what our
3370     // heuristics should do for some round-numbered examples.
3371     //
3372     // The expression to which I decided to fit the data arose because I started with an
3373     // affine function, and then did two things: put the linear part in an Abs to ensure
3374     // that the fit didn't end up choosing a negative value of c (which would result in
3375     // the function turning over and going negative for large x) and I threw in a Sqrt
3376     // term because Sqrt represents my intution that the function should be more sensitive
3377     // to small changes in small values of x, but less sensitive when x gets large.
3378     
3379     // Note that the current fit essentially eliminates the linear portion of the
3380     // expression (c == 0.0).
3381     const double a = 0.061504;
3382     const double b = 1.02406;
3383     const double c = 0.0;
3384     const double d = 0.825914;
3385     
3386     double instructionCount = this->instructionCount();
3387     
3388     ASSERT(instructionCount); // Make sure this is called only after we have an instruction stream; otherwise it'll just return the value of d, which makes no sense.
3389     
3390     double result = d + a * sqrt(instructionCount + b) + c * instructionCount;
3391     
3392     result *= codeTypeThresholdMultiplier();
3393     
3394     if (Options::verboseOSR()) {
3395         dataLog(
3396             *this, ": instruction count is ", instructionCount,
3397             ", scaling execution counter by ", result, " * ", codeTypeThresholdMultiplier(),
3398             "\n");
3399     }
3400     return result;
3401 }
3402
3403 static int32_t clipThreshold(double threshold)
3404 {
3405     if (threshold < 1.0)
3406         return 1;
3407     
3408     if (threshold > static_cast<double>(std::numeric_limits<int32_t>::max()))
3409         return std::numeric_limits<int32_t>::max();
3410     
3411     return static_cast<int32_t>(threshold);
3412 }
3413
3414 int32_t CodeBlock::adjustedCounterValue(int32_t desiredThreshold)
3415 {
3416     return clipThreshold(
3417         static_cast<double>(desiredThreshold) *
3418         optimizationThresholdScalingFactor() *
3419         (1 << reoptimizationRetryCounter()));
3420 }
3421
3422 bool CodeBlock::checkIfOptimizationThresholdReached()
3423 {
3424 #if ENABLE(DFG_JIT)
3425     if (DFG::Worklist* worklist = DFG::existingGlobalDFGWorklistOrNull()) {
3426         if (worklist->compilationState(DFG::CompilationKey(this, DFG::DFGMode))
3427             == DFG::Worklist::Compiled) {
3428             optimizeNextInvocation();
3429             return true;
3430         }
3431     }
3432 #endif
3433     
3434     return m_jitExecuteCounter.checkIfThresholdCrossedAndSet(this);
3435 }
3436
3437 void CodeBlock::optimizeNextInvocation()
3438 {
3439     if (Options::verboseOSR())
3440         dataLog(*this, ": Optimizing next invocation.\n");
3441     m_jitExecuteCounter.setNewThreshold(0, this);
3442 }
3443
3444 void CodeBlock::dontOptimizeAnytimeSoon()
3445 {
3446     if (Options::verboseOSR())
3447         dataLog(*this, ": Not optimizing anytime soon.\n");
3448     m_jitExecuteCounter.deferIndefinitely();
3449 }
3450
3451 void CodeBlock::optimizeAfterWarmUp()
3452 {
3453     if (Options::verboseOSR())
3454         dataLog(*this, ": Optimizing after warm-up.\n");
3455 #if ENABLE(DFG_JIT)
3456     m_jitExecuteCounter.setNewThreshold(
3457         adjustedCounterValue(Options::thresholdForOptimizeAfterWarmUp()), this);
3458 #endif
3459 }
3460
3461 void CodeBlock::optimizeAfterLongWarmUp()
3462 {
3463     if (Options::verboseOSR())
3464         dataLog(*this, ": Optimizing after long warm-up.\n");
3465 #if ENABLE(DFG_JIT)
3466     m_jitExecuteCounter.setNewThreshold(
3467         adjustedCounterValue(Options::thresholdForOptimizeAfterLongWarmUp()), this);
3468 #endif
3469 }
3470
3471 void CodeBlock::optimizeSoon()
3472 {
3473     if (Options::verboseOSR())
3474         dataLog(*this, ": Optimizing soon.\n");
3475 #if ENABLE(DFG_JIT)
3476     m_jitExecuteCounter.setNewThreshold(
3477         adjustedCounterValue(Options::thresholdForOptimizeSoon()), this);
3478 #endif
3479 }
3480
3481 void CodeBlock::forceOptimizationSlowPathConcurrently()
3482 {
3483     if (Options::verboseOSR())
3484         dataLog(*this, ": Forcing slow path concurrently.\n");
3485     m_jitExecuteCounter.forceSlowPathConcurrently();
3486 }
3487
3488 #if ENABLE(DFG_JIT)
3489 void CodeBlock::setOptimizationThresholdBasedOnCompilationResult(CompilationResult result)
3490 {
3491     JITCode::JITType type = jitType();
3492     if (type != JITCode::BaselineJIT) {
3493         dataLog(*this, ": expected to have baseline code but have ", type, "\n");
3494         RELEASE_ASSERT_NOT_REACHED();
3495     }
3496     
3497     CodeBlock* theReplacement = replacement();
3498     if ((result == CompilationSuccessful) != (theReplacement != this)) {
3499         dataLog(*this, ": we have result = ", result, " but ");
3500         if (theReplacement == this)
3501             dataLog("we are our own replacement.\n");
3502         else
3503             dataLog("our replacement is ", pointerDump(theReplacement), "\n");
3504         RELEASE_ASSERT_NOT_REACHED();
3505     }
3506     
3507     switch (result) {
3508     case CompilationSuccessful:
3509         RELEASE_ASSERT(JITCode::isOptimizingJIT(replacement()->jitType()));
3510         optimizeNextInvocation();
3511         return;
3512     case CompilationFailed:
3513         dontOptimizeAnytimeSoon();
3514         return;
3515     case CompilationDeferred:
3516         // We'd like to do dontOptimizeAnytimeSoon() but we cannot because
3517         // forceOptimizationSlowPathConcurrently() is inherently racy. It won't
3518         // necessarily guarantee anything. So, we make sure that even if that
3519         // function ends up being a no-op, we still eventually retry and realize
3520         // that we have optimized code ready.
3521         optimizeAfterWarmUp();
3522         return;
3523     case CompilationInvalidated:
3524         // Retry with exponential backoff.
3525         countReoptimization();
3526         optimizeAfterWarmUp();
3527         return;
3528     }
3529     
3530     dataLog("Unrecognized result: ", static_cast<int>(result), "\n");
3531     RELEASE_ASSERT_NOT_REACHED();
3532 }
3533
3534 #endif
3535     
3536 uint32_t CodeBlock::adjustedExitCountThreshold(uint32_t desiredThreshold)
3537 {
3538     ASSERT(JITCode::isOptimizingJIT(jitType()));
3539     // Compute this the lame way so we don't saturate. This is called infrequently
3540     // enough that this loop won't hurt us.
3541     unsigned result = desiredThreshold;
3542     for (unsigned n = baselineVersion()->reoptimizationRetryCounter(); n--;) {
3543         unsigned newResult = result << 1;
3544         if (newResult < result)
3545             return std::numeric_limits<uint32_t>::max();
3546         result = newResult;
3547     }
3548     return result;
3549 }
3550
3551 uint32_t CodeBlock::exitCountThresholdForReoptimization()
3552 {
3553     return adjustedExitCountThreshold(Options::osrExitCountForReoptimization() * codeTypeThresholdMultiplier());
3554 }
3555
3556 uint32_t CodeBlock::exitCountThresholdForReoptimizationFromLoop()
3557 {
3558     return adjustedExitCountThreshold(Options::osrExitCountForReoptimizationFromLoop() * codeTypeThresholdMultiplier());
3559 }
3560
3561 bool CodeBlock::shouldReoptimizeNow()
3562 {
3563     return osrExitCounter() >= exitCountThresholdForReoptimization();
3564 }
3565
3566 bool CodeBlock::shouldReoptimizeFromLoopNow()
3567 {
3568     return osrExitCounter() >= exitCountThresholdForReoptimizationFromLoop();
3569 }
3570 #endif
3571
3572 ArrayProfile* CodeBlock::getArrayProfile(unsigned bytecodeOffset)
3573 {
3574     for (unsigned i = 0; i < m_arrayProfiles.size(); ++i) {
3575         if (m_arrayProfiles[i].bytecodeOffset() == bytecodeOffset)
3576             return &m_arrayProfiles[i];
3577     }
3578     return 0;
3579 }
3580
3581 ArrayProfile* CodeBlock::getOrAddArrayProfile(unsigned bytecodeOffset)
3582 {
3583     ArrayProfile* result = getArrayProfile(bytecodeOffset);
3584     if (result)
3585         return result;
3586     return addArrayProfile(bytecodeOffset);
3587 }
3588
3589 void CodeBlock::updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles)
3590 {
3591     ConcurrentJITLocker locker(m_lock);
3592     
3593     numberOfLiveNonArgumentValueProfiles = 0;
3594     numberOfSamplesInProfiles = 0; // If this divided by ValueProfile::numberOfBuckets equals numberOfValueProfiles() then value profiles are full.
3595     for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
3596         ValueProfile* profile = getFromAllValueProfiles(i);
3597         unsigned numSamples = profile->totalNumberOfSamples();
3598         if (numSamples > ValueProfile::numberOfBuckets)
3599             numSamples = ValueProfile::numberOfBuckets; // We don't want profiles that are extremely hot to be given more weight.
3600         numberOfSamplesInProfiles += numSamples;
3601         if (profile->m_bytecodeOffset < 0) {
3602             profile->computeUpdatedPrediction(locker);
3603             continue;
3604         }
3605         if (profile->numberOfSamples() || profile->m_prediction != SpecNone)
3606             numberOfLiveNonArgumentValueProfiles++;
3607         profile->computeUpdatedPrediction(locker);
3608     }
3609     
3610 #if ENABLE(DFG_JIT)
3611     m_lazyOperandValueProfiles.computeUpdatedPredictions(locker);
3612 #endif
3613 }
3614
3615 void CodeBlock::updateAllValueProfilePredictions()
3616 {
3617     unsigned ignoredValue1, ignoredValue2;
3618     updateAllPredictionsAndCountLiveness(ignoredValue1, ignoredValue2);
3619 }
3620
3621 void CodeBlock::updateAllArrayPredictions()
3622 {
3623     ConcurrentJITLocker locker(m_lock);
3624     
3625     for (unsigned i = m_arrayProfiles.size(); i--;)
3626         m_arrayProfiles[i].computeUpdatedPrediction(locker, this);
3627     
3628     // Don't count these either, for similar reasons.
3629     for (unsigned i = m_arrayAllocationProfiles.size(); i--;)
3630         m_arrayAllocationProfiles[i].updateIndexingType();
3631 }
3632
3633 void CodeBlock::updateAllPredictions()
3634 {
3635     updateAllValueProfilePredictions();
3636     updateAllArrayPredictions();
3637 }
3638
3639 bool CodeBlock::shouldOptimizeNow()
3640 {
3641     if (Options::verboseOSR())
3642         dataLog("Considering optimizing ", *this, "...\n");
3643
3644     if (m_optimizationDelayCounter >= Options::maximumOptimizationDelay())
3645         return true;
3646     
3647     updateAllArrayPredictions();
3648     
3649     unsigned numberOfLiveNonArgumentValueProfiles;
3650     unsigned numberOfSamplesInProfiles;
3651     updateAllPredictionsAndCountLiveness(numberOfLiveNonArgumentValueProfiles, numberOfSamplesInProfiles);
3652
3653     if (Options::verboseOSR()) {
3654         dataLogF(
3655             "Profile hotness: %lf (%u / %u), %lf (%u / %u)\n",
3656             (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles(),
3657             numberOfLiveNonArgumentValueProfiles, numberOfValueProfiles(),
3658             (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles(),
3659             numberOfSamplesInProfiles, ValueProfile::numberOfBuckets * numberOfValueProfiles());
3660     }
3661
3662     if ((!numberOfValueProfiles() || (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles() >= Options::desiredProfileLivenessRate())
3663         && (!totalNumberOfValueProfiles() || (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / totalNumberOfValueProfiles() >= Options::desiredProfileFullnessRate())
3664         && static_cast<unsigned>(m_optimizationDelayCounter) + 1 >= Options::minimumOptimizationDelay())
3665         return true;
3666     
3667     ASSERT(m_optimizationDelayCounter < std::numeric_limits<uint8_t>::max());
3668     m_optimizationDelayCounter++;
3669     optimizeAfterWarmUp();
3670     return false;
3671 }
3672
3673 #if ENABLE(DFG_JIT)
3674 void CodeBlock::tallyFrequentExitSites()
3675 {
3676     ASSERT(JITCode::isOptimizingJIT(jitType()));
3677     ASSERT(alternative()->jitType() == JITCode::BaselineJIT);
3678     
3679     CodeBlock* profiledBlock = alternative();
3680     
3681     switch (jitType()) {
3682     case JITCode::DFGJIT: {
3683         DFG::JITCode* jitCode = m_jitCode->dfg();
3684         for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
3685             DFG::OSRExit& exit = jitCode->osrExit[i];
3686             exit.considerAddingAsFrequentExitSite(profiledBlock);
3687         }
3688         break;
3689     }
3690
3691 #if ENABLE(FTL_JIT)
3692     case JITCode::FTLJIT: {
3693         // There is no easy way to avoid duplicating this code since the FTL::JITCode::osrExit
3694         // vector contains a totally different type, that just so happens to behave like
3695         // DFG::JITCode::osrExit.
3696         FTL::JITCode* jitCode = m_jitCode->ftl();
3697         for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
3698             FTL::OSRExit& exit = jitCode->osrExit[i];
3699             exit.considerAddingAsFrequentExitSite(profiledBlock);
3700         }
3701         break;
3702     }
3703 #endif
3704         
3705     default:
3706         RELEASE_ASSERT_NOT_REACHED();
3707         break;
3708     }
3709 }
3710 #endif // ENABLE(DFG_JIT)
3711
3712 #if ENABLE(VERBOSE_VALUE_PROFILE)
3713 void CodeBlock::dumpValueProfiles()
3714 {
3715     dataLog("ValueProfile for ", *this, ":\n");
3716     for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
3717         ValueProfile* profile = getFromAllValueProfiles(i);
3718         if (profile->m_bytecodeOffset < 0) {
3719             ASSERT(profile->m_bytecodeOffset == -1);
3720             dataLogF("   arg = %u: ", i);
3721         } else
3722             dataLogF("   bc = %d: ", profile->m_bytecodeOffset);
3723         if (!profile->numberOfSamples() && profile->m_prediction == SpecNone) {
3724             dataLogF("<empty>\n");
3725             continue;
3726         }
3727         profile->dump(WTF::dataFile());
3728         dataLogF("\n");
3729     }
3730     dataLog("RareCaseProfile for ", *this, ":\n");
3731     for (unsigned i = 0; i < numberOfRareCaseProfiles(); ++i) {