Get WebKit r44544.

7 files changed, 477 insertions, 118 deletions

diff --git a/JavaScriptCore/bytecode/CodeBlock.cpp b/JavaScriptCore/bytecode/CodeBlock.cpp
index be060d0..d2b122a 100644
--- a/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -55,7 +55,7 @@ static UString escapeQuotes(const UString& str)
     return result;
 }
 
-static UString valueToSourceString(ExecState* exec, JSValuePtr val)
+static UString valueToSourceString(ExecState* exec, JSValue val)
 {
     if (val.isString()) {
         UString result("\"");
@@ -74,7 +74,7 @@ static CString registerName(int r)
     return (UString("r") + UString::from(r)).UTF8String();
 }
 
-static CString constantName(ExecState* exec, int k, JSValuePtr value)
+static CString constantName(ExecState* exec, int k, JSValue value)
 {
     return (valueToSourceString(exec, value) + "(@k" + UString::from(k) + ")").UTF8String();
 }
@@ -357,7 +357,7 @@ void CodeBlock::dump(ExecState* exec) const
         unsigned registerIndex = m_numVars;
         size_t i = 0;
         do {
-            printf("   r%u = %s\n", registerIndex, valueToSourceString(exec, m_constantRegisters[i].jsValue(exec)).ascii());
+            printf("   r%u = %s\n", registerIndex, valueToSourceString(exec, m_constantRegisters[i].jsValue()).ascii());
             ++i;
             ++registerIndex;
         } while (i < m_constantRegisters.size());
@@ -497,6 +497,10 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printf("[%4d] create_arguments\n", location);
             break;
         }
+        case op_init_arguments: {
+            printf("[%4d] init_arguments\n", location);
+            break;
+        }
         case op_convert_this: {
             int r0 = (++it)->u.operand;
             printf("[%4d] convert_this %s\n", location, registerName(r0).c_str());
@@ -703,7 +707,7 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
         }
         case op_resolve_global: {
             int r0 = (++it)->u.operand;
-            JSValuePtr scope = JSValuePtr((++it)->u.jsCell);
+            JSValue scope = JSValue((++it)->u.jsCell);
             int id0 = (++it)->u.operand;
             printf("[%4d] resolve_global\t %s, %s, %s\n", location, registerName(r0).c_str(), valueToSourceString(exec, scope).ascii(), idName(id0, m_identifiers[id0]).c_str());
             it += 2;
@@ -725,13 +729,13 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
         }
         case op_get_global_var: {
             int r0 = (++it)->u.operand;
-            JSValuePtr scope = JSValuePtr((++it)->u.jsCell);
+            JSValue scope = JSValue((++it)->u.jsCell);
             int index = (++it)->u.operand;
             printf("[%4d] get_global_var\t %s, %s, %d\n", location, registerName(r0).c_str(), valueToSourceString(exec, scope).ascii(), index);
             break;
         }
         case op_put_global_var: {
-            JSValuePtr scope = JSValuePtr((++it)->u.jsCell);
+            JSValue scope = JSValue((++it)->u.jsCell);
             int index = (++it)->u.operand;
             int r0 = (++it)->u.operand;
             printf("[%4d] put_global_var\t %s, %d, %s\n", location, valueToSourceString(exec, scope).ascii(), index, registerName(r0).c_str());
@@ -823,6 +827,10 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printf("[%4d] put_setter\t %s, %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
             break;
         }
+        case op_method_check: {
+            printf("[%4d] op_method_check\n", location);
+            break;
+        }
         case op_del_by_id: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
@@ -888,6 +896,13 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printConditionalJump(begin, it, location, "jneq_null");
             break;
         }
+        case op_jneq_ptr: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printf("[%4d] jneq_ptr\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            break;
+        }
         case op_jnless: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
@@ -895,6 +910,13 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printf("[%4d] jnless\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
             break;
         }
+        case op_jnlesseq: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int offset = (++it)->u.operand;
+            printf("[%4d] jnlesseq\t\t %s, %s, %d(->%d)\n", location, registerName(r0).c_str(), registerName(r1).c_str(), offset, locationForOffset(begin, it, offset));
+            break;
+        }
         case op_loop_if_less: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
@@ -958,6 +980,18 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printf("[%4d] call_eval\t %s, %s, %d, %d\n", location, registerName(dst).c_str(), registerName(func).c_str(), argCount, registerOffset);
             break;
         }
+        case op_call_varargs: {
+            int dst = (++it)->u.operand;
+            int func = (++it)->u.operand;
+            int argCount = (++it)->u.operand;
+            int registerOffset = (++it)->u.operand;
+            printf("[%4d] call_varargs\t %s, %s, %s, %d\n", location, registerName(dst).c_str(), registerName(func).c_str(), registerName(argCount).c_str(), registerOffset);
+            break;
+        }
+        case op_load_varargs: {
+            printUnaryOp(location, it, "load_varargs");
+            break;
+        }
         case op_tear_off_activation: {
             int r0 = (++it)->u.operand;
             printf("[%4d] tear_off_activation\t %s\n", location, registerName(r0).c_str());
@@ -988,6 +1022,19 @@ void CodeBlock::dump(ExecState* exec, const Vector<Instruction>::const_iterator&
             printf("[%4d] construct_verify\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
             break;
         }
+        case op_strcat: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            int count = (++it)->u.operand;
+            printf("[%4d] op_strcat\t %s, %s, %d\n", location, registerName(r0).c_str(), registerName(r1).c_str(), count);
+            break;
+        }
+        case op_to_primitive: {
+            int r0 = (++it)->u.operand;
+            int r1 = (++it)->u.operand;
+            printf("[%4d] op_to_primitive\t %s, %s\n", location, registerName(r0).c_str(), registerName(r1).c_str());
+            break;
+        }
         case op_get_pnames: {
             int r0 = (++it)->u.operand;
             int r1 = (++it)->u.operand;
@@ -1267,6 +1314,11 @@ CodeBlock::~CodeBlock()
             callLinkInfo->callee->removeCaller(callLinkInfo);
     }
 
+    for (size_t size = m_methodCallLinkInfos.size(), i = 0; i < size; ++i) {
+        if (Structure* structure = m_methodCallLinkInfos[i].cachedStructure)
+            structure->deref();
+    }
+
     unlinkCallers();
 #endif
 
@@ -1420,7 +1472,7 @@ void CodeBlock::reparseForExceptionInfoIfNecessary(CallFrame* callFrame)
 
 #if ENABLE(JIT)
             JIT::compile(m_globalData, &newCodeBlock);
-            ASSERT(newCodeBlock.m_jitCode.codeSize == m_jitCode.codeSize);
+            ASSERT(newFunctionBody->generatedJITCode().size() == ownerNode()->generatedJITCode().size());
 #endif
 
             m_exceptionInfo.set(newCodeBlock.m_exceptionInfo.release());
@@ -1441,7 +1493,7 @@ void CodeBlock::reparseForExceptionInfoIfNecessary(CallFrame* callFrame)
 
 #if ENABLE(JIT)
             JIT::compile(m_globalData, &newCodeBlock);
-            ASSERT(newCodeBlock.m_jitCode.codeSize == m_jitCode.codeSize);
+            ASSERT(newEvalBody->generatedJITCode().size() == ownerNode()->generatedJITCode().size());
 #endif
 
             m_exceptionInfo.set(newCodeBlock.m_exceptionInfo.release());
@@ -1635,9 +1687,9 @@ bool CodeBlock::hasGlobalResolveInfoAtBytecodeOffset(unsigned bytecodeOffset)
 #endif
 
 #if ENABLE(JIT)
-void CodeBlock::setJITCode(JITCodeRef& jitCode)
+void CodeBlock::setJITCode(JITCode jitCode)
 {
-    m_jitCode = jitCode;
+    ownerNode()->setJITCode(jitCode);
 #if !ENABLE(OPCODE_SAMPLING)
     if (!BytecodeGenerator::dumpsGeneratedCode())
         m_instructions.clear();
diff --git a/JavaScriptCore/bytecode/CodeBlock.h b/JavaScriptCore/bytecode/CodeBlock.h
index 9bd4090..ac29c6c 100644
--- a/JavaScriptCore/bytecode/CodeBlock.h
+++ b/JavaScriptCore/bytecode/CodeBlock.h
@@ -63,34 +63,6 @@ namespace JSC {
 #endif
     };
 
-#if ENABLE(JIT)
-    // The code, and the associated pool from which it was allocated.
-    struct JITCodeRef {
-        JITCode code;
-#ifndef NDEBUG
-        unsigned codeSize;
-#endif
-        RefPtr<ExecutablePool> executablePool;
-
-        JITCodeRef()
-            : code(0)
-#ifndef NDEBUG
-            , codeSize(0)
-#endif
-        {
-        }
-        
-        JITCodeRef(void* code, PassRefPtr<ExecutablePool> executablePool)
-            : code(code)
-#ifndef NDEBUG
-            , codeSize(0)
-#endif
-            , executablePool(executablePool)
-        {
-        }
-    };
-#endif
-
     struct ExpressionRangeInfo {
         enum {
             MaxOffset = (1 << 7) - 1, 
@@ -134,6 +106,17 @@ namespace JSC {
         bool isLinked() { return callee; }
     };
 
+    struct MethodCallLinkInfo {
+        MethodCallLinkInfo()
+            : cachedStructure(0)
+        {
+        }
+
+        MacroAssembler::CodeLocationCall callReturnLocation;
+        MacroAssembler::CodeLocationDataLabelPtr structureLabel;
+        Structure* cachedStructure;
+    };
+
     struct FunctionRegisterInfo {
         FunctionRegisterInfo(unsigned bytecodeOffset, int functionRegisterIndex)
             : bytecodeOffset(bytecodeOffset)
@@ -185,6 +168,11 @@ namespace JSC {
         return callLinkInfo->callReturnLocation.calleeReturnAddressValue();
     }
 
+    inline void* getMethodCallLinkInfoReturnLocation(MethodCallLinkInfo* methodCallLinkInfo)
+    {
+        return methodCallLinkInfo->callReturnLocation.calleeReturnAddressValue();
+    }
+
     inline unsigned getCallReturnOffset(CallReturnOffsetToBytecodeIndex* pc)
     {
         return pc->callReturnOffset;
@@ -264,9 +252,9 @@ namespace JSC {
             return index >= m_numVars && index < m_numVars + m_numConstants;
         }
 
-        ALWAYS_INLINE JSValuePtr getConstant(int index)
+        ALWAYS_INLINE JSValue getConstant(int index)
         {
-            return m_constantRegisters[index - m_numVars].getJSValue();
+            return m_constantRegisters[index - m_numVars].jsValue();
         }
 
         ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
@@ -309,10 +297,15 @@ namespace JSC {
             return *(binaryChop<CallLinkInfo, void*, getCallLinkInfoReturnLocation>(m_callLinkInfos.begin(), m_callLinkInfos.size(), returnAddress));
         }
 
+        MethodCallLinkInfo& getMethodCallLinkInfo(void* returnAddress)
+        {
+            return *(binaryChop<MethodCallLinkInfo, void*, getMethodCallLinkInfoReturnLocation>(m_methodCallLinkInfos.begin(), m_methodCallLinkInfos.size(), returnAddress));
+        }
+
         unsigned getBytecodeIndex(CallFrame* callFrame, void* nativePC)
         {
             reparseForExceptionInfoIfNecessary(callFrame);
-            return binaryChop<CallReturnOffsetToBytecodeIndex, unsigned, getCallReturnOffset>(m_exceptionInfo->m_callReturnIndexVector.begin(), m_exceptionInfo->m_callReturnIndexVector.size(), m_jitCode.code.offsetOf(nativePC))->bytecodeIndex;
+            return binaryChop<CallReturnOffsetToBytecodeIndex, unsigned, getCallReturnOffset>(m_exceptionInfo->m_callReturnIndexVector.begin(), m_exceptionInfo->m_callReturnIndexVector.size(), ownerNode()->generatedJITCode().offsetOf(nativePC))->bytecodeIndex;
         }
         
         bool functionRegisterForBytecodeOffset(unsigned bytecodeOffset, int& functionRegisterIndex);
@@ -327,9 +320,8 @@ namespace JSC {
 #endif
 
 #if ENABLE(JIT)
-        void setJITCode(JITCodeRef& jitCode);
-        JITCode jitCode() { return m_jitCode.code; }
-        ExecutablePool* executablePool() { return m_jitCode.executablePool.get(); }
+        void setJITCode(JITCode);
+        ExecutablePool* executablePool() { return ownerNode()->getExecutablePool(); }
 #endif
 
         ScopeNode* ownerNode() const { return m_ownerNode; }
@@ -373,6 +365,9 @@ namespace JSC {
         void addCallLinkInfo() { m_callLinkInfos.append(CallLinkInfo()); }
         CallLinkInfo& callLinkInfo(int index) { return m_callLinkInfos[index]; }
 
+        void addMethodCallLinkInfos(unsigned n) { m_methodCallLinkInfos.grow(n); }
+        MethodCallLinkInfo& methodCallLinkInfo(int index) { return m_methodCallLinkInfos[index]; }
+
         void addFunctionRegisterInfo(unsigned bytecodeOffset, int functionIndex) { createRareDataIfNecessary(); m_rareData->m_functionRegisterInfos.append(FunctionRegisterInfo(bytecodeOffset, functionIndex)); }
 #endif
 
@@ -414,8 +409,8 @@ namespace JSC {
 
         bool hasFunctions() const { return m_functionExpressions.size() || (m_rareData && m_rareData->m_functions.size()); }
 
-        unsigned addUnexpectedConstant(JSValuePtr v) { createRareDataIfNecessary(); unsigned size = m_rareData->m_unexpectedConstants.size(); m_rareData->m_unexpectedConstants.append(v); return size; }
-        JSValuePtr unexpectedConstant(int index) const { ASSERT(m_rareData); return m_rareData->m_unexpectedConstants[index]; }
+        unsigned addUnexpectedConstant(JSValue v) { createRareDataIfNecessary(); unsigned size = m_rareData->m_unexpectedConstants.size(); m_rareData->m_unexpectedConstants.append(v); return size; }
+        JSValue unexpectedConstant(int index) const { ASSERT(m_rareData); return m_rareData->m_unexpectedConstants[index]; }
 
         unsigned addRegExp(RegExp* r) { createRareDataIfNecessary(); unsigned size = m_rareData->m_regexps.size(); m_rareData->m_regexps.append(r); return size; }
         RegExp* regexp(int index) const { ASSERT(m_rareData); return m_rareData->m_regexps[index].get(); }
@@ -473,9 +468,6 @@ namespace JSC {
 #ifndef NDEBUG
         unsigned m_instructionCount;
 #endif
-#if ENABLE(JIT)
-        JITCodeRef m_jitCode;
-#endif
 
         int m_thisRegister;
 
@@ -496,6 +488,7 @@ namespace JSC {
         Vector<StructureStubInfo> m_structureStubInfos;
         Vector<GlobalResolveInfo> m_globalResolveInfos;
         Vector<CallLinkInfo> m_callLinkInfos;
+        Vector<MethodCallLinkInfo> m_methodCallLinkInfos;
         Vector<CallLinkInfo*> m_linkedCallerList;
 #endif
 
@@ -524,7 +517,7 @@ namespace JSC {
 
             // Rare Constants
             Vector<RefPtr<FuncDeclNode> > m_functions;
-            Vector<JSValuePtr> m_unexpectedConstants;
+            Vector<JSValue> m_unexpectedConstants;
             Vector<RefPtr<RegExp> > m_regexps;
 
             // Jump Tables
diff --git a/JavaScriptCore/bytecode/EvalCodeCache.h b/JavaScriptCore/bytecode/EvalCodeCache.h
index 2d6f7dc..f0ce73e 100644
--- a/JavaScriptCore/bytecode/EvalCodeCache.h
+++ b/JavaScriptCore/bytecode/EvalCodeCache.h
@@ -41,7 +41,7 @@ namespace JSC {
 
     class EvalCodeCache {
     public:
-        PassRefPtr<EvalNode> get(ExecState* exec, const UString& evalSource, ScopeChainNode* scopeChain, JSValuePtr& exceptionValue)
+        PassRefPtr<EvalNode> get(ExecState* exec, const UString& evalSource, ScopeChainNode* scopeChain, JSValue& exceptionValue)
         {
             RefPtr<EvalNode> evalNode;
 
diff --git a/JavaScriptCore/bytecode/Instruction.h b/JavaScriptCore/bytecode/Instruction.h
index 314fda4..24ba490 100644
--- a/JavaScriptCore/bytecode/Instruction.h
+++ b/JavaScriptCore/bytecode/Instruction.h
@@ -34,7 +34,7 @@
 #include "Structure.h"
 #include <wtf/VectorTraits.h>
 
-#define POLYMORPHIC_LIST_CACHE_SIZE 4
+#define POLYMORPHIC_LIST_CACHE_SIZE 8
 
 namespace JSC {
 
diff --git a/JavaScriptCore/bytecode/Opcode.h b/JavaScriptCore/bytecode/Opcode.h
index d00178b..f4421df 100644
--- a/JavaScriptCore/bytecode/Opcode.h
+++ b/JavaScriptCore/bytecode/Opcode.h
@@ -40,6 +40,7 @@ namespace JSC {
     #define FOR_EACH_OPCODE_ID(macro) \
         macro(op_enter, 1) \
         macro(op_enter_with_activation, 2) \
+        macro(op_init_arguments, 1) \
         macro(op_create_arguments, 1) \
         macro(op_convert_this, 2) \
         \
@@ -125,7 +126,9 @@ namespace JSC {
         macro(op_jfalse, 3) \
         macro(op_jeq_null, 3) \
         macro(op_jneq_null, 3) \
+        macro(op_jneq_ptr, 4) \
         macro(op_jnless, 4) \
+        macro(op_jnlesseq, 4) \
         macro(op_jmp_scopes, 3) \
         macro(op_loop, 2) \
         macro(op_loop_if_true, 3) \
@@ -139,12 +142,17 @@ namespace JSC {
         macro(op_new_func_exp, 3) \
         macro(op_call, 5) \
         macro(op_call_eval, 5) \
+        macro(op_call_varargs, 5) \
+        macro(op_load_varargs, 3) \
         macro(op_tear_off_activation, 2) \
         macro(op_tear_off_arguments, 1) \
         macro(op_ret, 2) \
+        macro(op_method_check, 1) \
         \
         macro(op_construct, 7) \
         macro(op_construct_verify, 3) \
+        macro(op_strcat, 4) \
+        macro(op_to_primitive, 3) \
         \
         macro(op_get_pnames, 3) \
         macro(op_next_pname, 4) \
diff --git a/JavaScriptCore/bytecode/SamplingTool.cpp b/JavaScriptCore/bytecode/SamplingTool.cpp
index 215ebe5..8651723 100644
--- a/JavaScriptCore/bytecode/SamplingTool.cpp
+++ b/JavaScriptCore/bytecode/SamplingTool.cpp
@@ -39,24 +39,57 @@
 
 namespace JSC {
 
-void ScopeSampleRecord::sample(CodeBlock* codeBlock, Instruction* vPC)
+#if ENABLE(SAMPLING_FLAGS)
+
+void SamplingFlags::sample()
 {
-    if (!m_samples) {
-        m_size = codeBlock->instructions().size();
-        m_samples = static_cast<int*>(calloc(m_size, sizeof(int)));
-        m_codeBlock = codeBlock;
+    uint32_t mask = 1 << 31;
+    unsigned index;
+
+    for (index = 0; index < 32; ++index) {
+        if (mask & s_flags)
+            break;
+        mask >>= 1;
     }
 
-    ++m_sampleCount;
+    s_flagCounts[32 - index]++;
+}
 
-    unsigned offest = vPC - codeBlock->instructions().begin();
-    // Since we don't read and write codeBlock and vPC atomically, this check
-    // can fail if we sample mid op_call / op_ret.
-    if (offest < m_size) {
-        m_samples[offest]++;
-        m_opcodeSampleCount++;
-    }
+void SamplingFlags::start()
+{
+    for (unsigned i = 0; i <= 32; ++i)
+        s_flagCounts[i] = 0;
 }
+void SamplingFlags::stop()
+{
+    uint64_t total = 0;
+    for (unsigned i = 0; i <= 32; ++i)
+        total += s_flagCounts[i];
+
+    if (total) {
+        printf("\nSamplingFlags: sample counts with flags set: (%lld total)\n", total);
+        for (unsigned i = 0; i <= 32; ++i) {
+            if (s_flagCounts[i])
+                printf("  [ %02d ] : %lld\t\t(%03.2f%%)\n", i, s_flagCounts[i], (100.0 * s_flagCounts[i]) / total);
+        }
+        printf("\n");
+    } else
+    printf("\nSamplingFlags: no samples.\n\n");
+}
+uint64_t SamplingFlags::s_flagCounts[33];
+
+#else
+void SamplingFlags::start() {}
+void SamplingFlags::stop() {}
+#endif
+
+/*
+  Start with flag 16 set.
+  By doing this the monitoring of lower valued flags will be masked out
+  until flag 16 is explictly cleared.
+*/
+uint32_t SamplingFlags::s_flags = 1 << 15;
+
 
 #if PLATFORM(WIN_OS)
 
@@ -82,62 +115,113 @@ static inline unsigned hertz2us(unsigned hertz)
     return 1000000 / hertz;
 }
 
-void SamplingTool::run()
+
+SamplingTool* SamplingTool::s_samplingTool = 0;
+
+
+bool SamplingThread::s_running = false;
+unsigned SamplingThread::s_hertz = 10000;
+ThreadIdentifier SamplingThread::s_samplingThread;
+
+void* SamplingThread::threadStartFunc(void*)
 {
-    while (m_running) {
-        sleepForMicroseconds(hertz2us(m_hertz));
+    while (s_running) {
+        sleepForMicroseconds(hertz2us(s_hertz));
 
-        Sample sample(m_sample, m_codeBlock);
-        ++m_sampleCount;
+#if ENABLE(SAMPLING_FLAGS)
+        SamplingFlags::sample();
+#endif
+#if ENABLE(OPCODE_SAMPLING)
+        SamplingTool::sample();
+#endif
+    }
 
-        if (sample.isNull())
-            continue;
+    return 0;
+}
 
-        if (!sample.inHostFunction()) {
-            unsigned opcodeID = m_interpreter->getOpcodeID(sample.vPC()[0].u.opcode);
 
-            ++m_opcodeSampleCount;
-            ++m_opcodeSamples[opcodeID];
+void SamplingThread::start(unsigned hertz)
+{
+    ASSERT(!s_running);
+    s_running = true;
+    s_hertz = hertz;
 
-            if (sample.inCTIFunction())
-                m_opcodeSamplesInCTIFunctions[opcodeID]++;
-        }
+    s_samplingThread = createThread(threadStartFunc, 0, "JavaScriptCore::Sampler");
+}
+
+void SamplingThread::stop()
+{
+    ASSERT(s_running);
+    s_running = false;
+    waitForThreadCompletion(s_samplingThread, 0);
+}
+
+
+void ScopeSampleRecord::sample(CodeBlock* codeBlock, Instruction* vPC)
+{
+    if (!m_samples) {
+        m_size = codeBlock->instructions().size();
+        m_samples = static_cast<int*>(calloc(m_size, sizeof(int)));
+        m_codeBlock = codeBlock;
+    }
+
+    ++m_sampleCount;
+
+    unsigned offest = vPC - codeBlock->instructions().begin();
+    // Since we don't read and write codeBlock and vPC atomically, this check
+    // can fail if we sample mid op_call / op_ret.
+    if (offest < m_size) {
+        m_samples[offest]++;
+        m_opcodeSampleCount++;
+    }
+}
+
+void SamplingTool::doRun()
+{
+    Sample sample(m_sample, m_codeBlock);
+    ++m_sampleCount;
+
+    if (sample.isNull())
+        return;
+
+    if (!sample.inHostFunction()) {
+        unsigned opcodeID = m_interpreter->getOpcodeID(sample.vPC()[0].u.opcode);
+
+        ++m_opcodeSampleCount;
+        ++m_opcodeSamples[opcodeID];
+
+        if (sample.inCTIFunction())
+            m_opcodeSamplesInCTIFunctions[opcodeID]++;
+    }
 
 #if ENABLE(CODEBLOCK_SAMPLING)
+    if (CodeBlock* codeBlock = sample.codeBlock()) {
         MutexLocker locker(m_scopeSampleMapMutex);
-        ScopeSampleRecord* record = m_scopeSampleMap->get(sample.codeBlock()->ownerNode());
+        ScopeSampleRecord* record = m_scopeSampleMap->get(codeBlock->ownerNode());
         ASSERT(record);
-        record->sample(sample.codeBlock(), sample.vPC());
-#endif
+        record->sample(codeBlock, sample.vPC());
     }
+#endif
 }
 
-void* SamplingTool::threadStartFunc(void* samplingTool)
+void SamplingTool::sample()
 {
-    reinterpret_cast<SamplingTool*>(samplingTool)->run();
-    return 0;
+    s_samplingTool->doRun();
 }
 
 void SamplingTool::notifyOfScope(ScopeNode* scope)
 {
+#if ENABLE(CODEBLOCK_SAMPLING)
     MutexLocker locker(m_scopeSampleMapMutex);
     m_scopeSampleMap->set(scope, new ScopeSampleRecord(scope));
+#else
+    UNUSED_PARAM(scope);
+#endif
 }
 
-void SamplingTool::start(unsigned hertz)
-{
-    ASSERT(!m_running);
-    m_running = true;
-    m_hertz = hertz;
-
-    m_samplingThread = createThread(threadStartFunc, this, "JavaScriptCore::Sampler");
-}
-
-void SamplingTool::stop()
+void SamplingTool::setup()
 {
-    ASSERT(m_running);
-    m_running = false;
-    waitForThreadCompletion(m_samplingThread, 0);
+    s_samplingTool = this;
 }
 
 #if ENABLE(OPCODE_SAMPLING)
@@ -153,14 +237,6 @@ struct LineCountInfo {
     unsigned count;
 };
 
-static int compareLineCountInfoSampling(const void* left, const void* right)
-{
-    const LineCountInfo* leftLineCount = reinterpret_cast<const LineCountInfo*>(left);
-    const LineCountInfo* rightLineCount = reinterpret_cast<const LineCountInfo*>(right);
-
-    return (leftLineCount->line > rightLineCount->line) ? 1 : (leftLineCount->line < rightLineCount->line) ? -1 : 0;
-}
-
 static int compareOpcodeIndicesSampling(const void* left, const void* right)
 {
     const OpcodeSampleInfo* leftSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(left);
@@ -169,6 +245,15 @@ static int compareOpcodeIndicesSampling(const void* left, const void* right)
     return (leftSampleInfo->count < rightSampleInfo->count) ? 1 : (leftSampleInfo->count > rightSampleInfo->count) ? -1 : 0;
 }
 
+#if ENABLE(CODEBLOCK_SAMPLING)
+static int compareLineCountInfoSampling(const void* left, const void* right)
+{
+    const LineCountInfo* leftLineCount = reinterpret_cast<const LineCountInfo*>(left);
+    const LineCountInfo* rightLineCount = reinterpret_cast<const LineCountInfo*>(right);
+
+    return (leftLineCount->line > rightLineCount->line) ? 1 : (leftLineCount->line < rightLineCount->line) ? -1 : 0;
+}
+
 static int compareScopeSampleRecords(const void* left, const void* right)
 {
     const ScopeSampleRecord* const leftValue = *static_cast<const ScopeSampleRecord* const *>(left);
@@ -176,6 +261,7 @@ static int compareScopeSampleRecords(const void* left, const void* right)
 
     return (leftValue->m_sampleCount < rightValue->m_sampleCount) ? 1 : (leftValue->m_sampleCount > rightValue->m_sampleCount) ? -1 : 0;
 }
+#endif
 
 void SamplingTool::dump(ExecState* exec)
 {
@@ -227,6 +313,8 @@ void SamplingTool::dump(ExecState* exec)
     printf("\tcti count:\tsamples inside a CTI function called by this opcode\n");
     printf("\tcti %% of self:\tcti count / sample count\n");
     
+#if ENABLE(CODEBLOCK_SAMPLING)
+
     // (3) Build and sort 'codeBlockSamples' array.
 
     int scopeCount = m_scopeSampleMap->size();
@@ -285,6 +373,9 @@ void SamplingTool::dump(ExecState* exec)
             }
         }
     }
+#else
+    UNUSED_PARAM(exec);
+#endif
 }
 
 #else
@@ -295,4 +386,21 @@ void SamplingTool::dump(ExecState*)
 
 #endif
 
+void AbstractSamplingCounter::dump()
+{
+#if ENABLE(SAMPLING_COUNTERS)
+    if (s_abstractSamplingCounterChain != &s_abstractSamplingCounterChainEnd) {
+        printf("\nSampling Counter Values:\n");
+        for (AbstractSamplingCounter* currCounter = s_abstractSamplingCounterChain; (currCounter != &s_abstractSamplingCounterChainEnd); currCounter = currCounter->m_next)
+            printf("\t%s\t: %lld\n", currCounter->m_name, currCounter->m_counter);
+        printf("\n\n");
+    }
+    s_completed = true;
+#endif
+}
+
+AbstractSamplingCounter AbstractSamplingCounter::s_abstractSamplingCounterChainEnd;
+AbstractSamplingCounter* AbstractSamplingCounter::s_abstractSamplingCounterChain = &s_abstractSamplingCounterChainEnd;
+bool AbstractSamplingCounter::s_completed = false;
+
 } // namespace JSC
diff --git a/JavaScriptCore/bytecode/SamplingTool.h b/JavaScriptCore/bytecode/SamplingTool.h
index d1cf2e88..7d7dc9c 100644
--- a/JavaScriptCore/bytecode/SamplingTool.h
+++ b/JavaScriptCore/bytecode/SamplingTool.h
@@ -38,6 +38,54 @@
 
 namespace JSC {
 
+    class SamplingFlags {
+        friend class JIT;
+    public:
+        static void start();
+        static void stop();
+
+#if ENABLE(SAMPLING_FLAGS)
+        static void setFlag(unsigned flag)
+        {
+            ASSERT(flag >= 1);
+            ASSERT(flag <= 32);
+            s_flags |= 1u << (flag - 1);
+        }
+
+        static void clearFlag(unsigned flag)
+        {
+            ASSERT(flag >= 1);
+            ASSERT(flag <= 32);
+            s_flags &= ~(1u << (flag - 1));
+        }
+
+        static void sample();
+
+        class ScopedFlag {
+        public:
+            ScopedFlag(int flag)
+                : m_flag(flag)
+            {
+                setFlag(flag);
+            }
+
+            ~ScopedFlag()
+            {
+                clearFlag(m_flag);
+            }
+
+        private:
+            int m_flag;
+        };
+    
+#endif
+    private:
+        static uint32_t s_flags;
+#if ENABLE(SAMPLING_FLAGS)
+        static uint64_t s_flagCounts[33];
+#endif
+    };
+
     class CodeBlock;
     class ExecState;
     class Interpreter;
@@ -73,6 +121,19 @@ namespace JSC {
 
     typedef WTF::HashMap<ScopeNode*, ScopeSampleRecord*> ScopeSampleRecordMap;
 
+    class SamplingThread {
+    public:
+        // Sampling thread state.
+        static bool s_running;
+        static unsigned s_hertz;
+        static ThreadIdentifier s_samplingThread;
+
+        static void start(unsigned hertz=10000);
+        static void stop();
+
+        static void* threadStartFunc(void*);
+    };
+
     class SamplingTool {
     public:
         friend class CallRecord;
@@ -127,12 +188,13 @@ namespace JSC {
 
         SamplingTool(Interpreter* interpreter)
             : m_interpreter(interpreter)
-            , m_running(false)
             , m_codeBlock(0)
             , m_sample(0)
             , m_sampleCount(0)
             , m_opcodeSampleCount(0)
+#if ENABLE(CODEBLOCK_SAMPLING)
             , m_scopeSampleMap(new ScopeSampleRecordMap())
+#endif
         {
             memset(m_opcodeSamples, 0, sizeof(m_opcodeSamples));
             memset(m_opcodeSamplesInCTIFunctions, 0, sizeof(m_opcodeSamplesInCTIFunctions));
@@ -140,11 +202,12 @@ namespace JSC {
 
         ~SamplingTool()
         {
+#if ENABLE(CODEBLOCK_SAMPLING)
             deleteAllValues(*m_scopeSampleMap);
+#endif
         }
 
-        void start(unsigned hertz=10000);
-        void stop();
+        void setup();
         void dump(ExecState*);
 
         void notifyOfScope(ScopeNode* scope);
@@ -165,6 +228,8 @@ namespace JSC {
             return reinterpret_cast<void*>(reinterpret_cast<intptr_t>(vPC) | (static_cast<intptr_t>(inCTIFunction) << 1) | static_cast<intptr_t>(inHostFunction));
         }
 
+        static void sample();
+
     private:
         class Sample {
         public:
@@ -174,7 +239,7 @@ namespace JSC {
             {
             }
             
-            bool isNull() { return !m_sample || !m_codeBlock; }
+            bool isNull() { return !m_sample; }
             CodeBlock* codeBlock() { return m_codeBlock; }
             Instruction* vPC() { return reinterpret_cast<Instruction*>(m_sample & ~0x3); }
             bool inHostFunction() { return m_sample & 0x1; }
@@ -184,17 +249,12 @@ namespace JSC {
             intptr_t m_sample;
             CodeBlock* m_codeBlock;
         };
-        
-        static void* threadStartFunc(void*);
-        void run();
+
+        void doRun();
+        static SamplingTool* s_samplingTool;
         
         Interpreter* m_interpreter;
         
-        // Sampling thread state.
-        bool m_running;
-        unsigned m_hertz;
-        ThreadIdentifier m_samplingThread;
-
         // State tracked by the main thread, used by the sampling thread.
         CodeBlock* m_codeBlock;
         intptr_t m_sample;
@@ -205,9 +265,147 @@ namespace JSC {
         unsigned m_opcodeSamples[numOpcodeIDs];
         unsigned m_opcodeSamplesInCTIFunctions[numOpcodeIDs];
         
+#if ENABLE(CODEBLOCK_SAMPLING)
         Mutex m_scopeSampleMapMutex;
         OwnPtr<ScopeSampleRecordMap> m_scopeSampleMap;
+#endif
+    };
+
+    // AbstractSamplingCounter:
+    //
+    // Implements a named set of counters, printed on exit if ENABLE(SAMPLING_COUNTERS).
+    // See subclasses below, SamplingCounter, GlobalSamplingCounter and DeletableSamplingCounter.
+    class AbstractSamplingCounter {
+        friend class JIT;
+        friend class DeletableSamplingCounter;
+    public:
+        void count(uint32_t count = 1)
+        {
+            m_counter += count;
+        }
+
+        static void dump();
+
+    protected:
+        // Effectively the contructor, however called lazily in the case of GlobalSamplingCounter.
+        void init(const char* name)
+        {
+            m_counter = 0;
+            m_name = name;
+
+            // Set m_next to point to the head of the chain, and inform whatever is
+            // currently at the head that this node will now hold the pointer to it.
+            m_next = s_abstractSamplingCounterChain;
+            s_abstractSamplingCounterChain->m_referer = &m_next;
+            // Add this node to the head of the list.
+            s_abstractSamplingCounterChain = this;
+            m_referer = &s_abstractSamplingCounterChain;
+        }
+
+        int64_t m_counter;
+        const char* m_name;
+        AbstractSamplingCounter* m_next;
+        // This is a pointer to the pointer to this node in the chain; used to
+        // allow fast linked list deletion.
+        AbstractSamplingCounter** m_referer;
+        // Null object used to detect end of static chain.
+        static AbstractSamplingCounter s_abstractSamplingCounterChainEnd;
+        static AbstractSamplingCounter* s_abstractSamplingCounterChain;
+        static bool s_completed;
+    };
+
+#if ENABLE(SAMPLING_COUNTERS)
+    // SamplingCounter:
+    //
+    // This class is suitable and (hopefully!) convenient for cases where a counter is
+    // required within the scope of a single function.  It can be instantiated as a
+    // static variable since it contains a constructor but not a destructor (static
+    // variables in WebKit cannot have destructors).
+    //
+    // For example:
+    //
+    // void someFunction()
+    // {
+    //     static SamplingCounter countMe("This is my counter.  There are many like it, but this one is mine.");
+    //     countMe.count();
+    //     // ...
+    // }
+    //
+    class SamplingCounter : public AbstractSamplingCounter {
+    public:
+        SamplingCounter(const char* name) { init(name); }
+    };
+
+    // GlobalSamplingCounter:
+    //
+    // This class is suitable for use where a counter is to be declared globally,
+    // since it contains neither a constructor nor destructor.  Instead, ensure
+    // that 'name()' is called to provide the counter with a name (and also to
+    // allow it to be printed out on exit).
+    //
+    // GlobalSamplingCounter globalCounter;
+    //
+    // void firstFunction()
+    // {
+    //     // Put this within a function that is definitely called!
+    //     // (Or alternatively alongside all calls to 'count()').
+    //     globalCounter.name("I Name You Destroyer.");
+    //     globalCounter.count();
+    //     // ...
+    // }
+    //
+    // void secondFunction()
+    // {
+    //     globalCounter.count();
+    //     // ...
+    // }
+    //
+    class GlobalSamplingCounter : public AbstractSamplingCounter {
+    public:
+        void name(const char* name)
+        {
+            // Global objects should be mapped in zero filled memory, so this should
+            // be a safe (albeit not necessarily threadsafe) check for 'first call'.
+            if (!m_next)
+                init(name);
+        }
+    };
+
+    // DeletableSamplingCounter:
+    //
+    // The above classes (SamplingCounter, GlobalSamplingCounter), are intended for
+    // use within a global or static scope, and as such cannot have a destructor.
+    // This means there is no convenient way for them to remove themselves from the
+    // static list of counters, and should an instance of either class be freed
+    // before 'dump()' has walked over the list it will potentially walk over an
+    // invalid pointer.
+    //
+    // This class is intended for use where the counter may possibly be deleted before
+    // the program exits.  Should this occur, the counter will print it's value to
+    // stderr, and remove itself from the static list.  Example:
+    //
+    // DeletableSamplingCounter* counter = new DeletableSamplingCounter("The Counter With No Name");
+    // counter->count();
+    // delete counter;
+    //
+    class DeletableSamplingCounter : public AbstractSamplingCounter {
+    public:
+        DeletableSamplingCounter(const char* name) { init(name); }
+
+        ~DeletableSamplingCounter()
+        {
+            if (!s_completed)
+                fprintf(stderr, "DeletableSamplingCounter \"%s\" deleted early (with count %lld)\n", m_name, m_counter);
+            // Our m_referer pointer should know where the pointer to this node is,
+            // and m_next should know that this node is the previous node in the list.
+            ASSERT(*m_referer == this);
+            ASSERT(m_next->m_referer == &m_next);
+            // Remove this node from the list, and inform m_next that we have done so.
+            m_next->m_referer = m_referer;
+            *m_referer = m_next;
+        }
     };
+#endif
 
 } // namespace JSC