diff --git a/Source/JavaScriptCore/CMakeLists.txt b/Source/JavaScriptCore/CMakeLists.txt
index fb6210c..fde79e2 100644
--- a/Source/JavaScriptCore/CMakeLists.txt
+++ b/Source/JavaScriptCore/CMakeLists.txt
@@ -963,6 +963,7 @@
     runtime/Symbol.h
     runtime/SymbolPrototype.h
     runtime/SymbolTable.h
+    runtime/SymbolTableOrScopeDepth.h
     runtime/TemplateObjectDescriptor.h
     runtime/TestRunnerUtils.h
     runtime/ThrowScope.h
diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index b3ecb66..adea1fc 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,43 @@
+2019-05-12  Yusuke Suzuki  <ysuzuki@apple.com>
+
+        [JSC] Compact generator code's bytecode size
+        https://bugs.webkit.org/show_bug.cgi?id=197822
+
+        Reviewed by Michael Saboff.
+
+        op_put_to_scope's symbolTableOrScopeDepth is represented as int. This was OK for the old bytecode format since
+        VirtualRegister / scope depth can be represented by int anyway. But it is problematic now since only int8_t range
+        will be represented in narrow bytecode. When this field is used for symbol table constant index, it is always
+        larger than FirstConstantRegisterIndex. So it always exceeds the range of int8_t, and results in wide bytecode.
+        It makes all generator's op_put_to_scope wide bytecode.
+
+        In this patch, we introduce a new (logically) union type SymbolTableOrScopeDepth. It holds unsigned value, and we store the
+        SymbolTableConstantIndex - FirstConstantRegisterIndex in this unsigned value to make op_put_to_scope narrow bytecode.
+
+        * CMakeLists.txt:
+        * JavaScriptCore.xcodeproj/project.pbxproj:
+        * bytecode/BytecodeGeneratorification.cpp:
+        (JSC::BytecodeGeneratorification::run):
+        * bytecode/BytecodeList.rb:
+        * bytecode/CodeBlock.cpp:
+        (JSC::CodeBlock::finishCreation):
+        * bytecode/Fits.h:
+        * bytecompiler/BytecodeGenerator.cpp:
+        (JSC::BytecodeGenerator::BytecodeGenerator):
+        (JSC::BytecodeGenerator::emitProfileType):
+        (JSC::BytecodeGenerator::emitPutToScope):
+        (JSC::BytecodeGenerator::localScopeDepth const):
+        * bytecompiler/BytecodeGenerator.h:
+        * runtime/SymbolTableOrScopeDepth.h: Added.
+        (JSC::SymbolTableOrScopeDepth::symbolTable):
+        (JSC::SymbolTableOrScopeDepth::scopeDepth):
+        (JSC::SymbolTableOrScopeDepth::raw):
+        (JSC::SymbolTableOrScopeDepth::symbolTable const):
+        (JSC::SymbolTableOrScopeDepth::scopeDepth const):
+        (JSC::SymbolTableOrScopeDepth::raw const):
+        (JSC::SymbolTableOrScopeDepth::dump const):
+        (JSC::SymbolTableOrScopeDepth::SymbolTableOrScopeDepth):
+
 2019-05-10  Saam barati  <sbarati@apple.com>
 
         Call to JSToWasmICCallee::createStructure passes in wrong prototype value
diff --git a/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj b/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
index e7dc887..fa0c844 100644
--- a/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
+++ b/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
@@ -1742,6 +1742,7 @@
 		DE26E9031CB5DD0500D2BE82 /* BuiltinExecutableCreator.h in Headers */ = {isa = PBXBuildFile; fileRef = DE26E9021CB5DD0500D2BE82 /* BuiltinExecutableCreator.h */; };
 		DEA7E2451BBC677F00D78440 /* JSTypedArrayViewPrototype.h in Headers */ = {isa = PBXBuildFile; fileRef = 53917E7C1B791106000EBD33 /* JSTypedArrayViewPrototype.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E124A8F70E555775003091F1 /* OpaqueJSString.h in Headers */ = {isa = PBXBuildFile; fileRef = E124A8F50E555775003091F1 /* OpaqueJSString.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		E31179AA2288386100514B2C /* SymbolTableOrScopeDepth.h in Headers */ = {isa = PBXBuildFile; fileRef = E31179A92288385D00514B2C /* SymbolTableOrScopeDepth.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E31618131EC5FE170006A218 /* DOMAnnotation.h in Headers */ = {isa = PBXBuildFile; fileRef = E31618101EC5FE080006A218 /* DOMAnnotation.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E31618151EC5FE270006A218 /* DOMAttributeGetterSetter.h in Headers */ = {isa = PBXBuildFile; fileRef = E31618121EC5FE080006A218 /* DOMAttributeGetterSetter.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		E318CBC11B8AEF5100A2929D /* JSModuleNamespaceObject.h in Headers */ = {isa = PBXBuildFile; fileRef = E318CBBF1B8AEF5100A2929D /* JSModuleNamespaceObject.h */; settings = {ATTRIBUTES = (Private, ); }; };
@@ -4721,6 +4722,7 @@
 		E18E3A560DF9278C00D90B34 /* VM.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; lineEnding = 0; path = VM.h; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.objcpp; };
 		E18E3A570DF9278C00D90B34 /* VM.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; lineEnding = 0; path = VM.cpp; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.cpp; };
 		E30677971B8BC6F5003F87F0 /* ModuleLoader.js */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.javascript; path = ModuleLoader.js; sourceTree = "<group>"; };
+		E31179A92288385D00514B2C /* SymbolTableOrScopeDepth.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = SymbolTableOrScopeDepth.h; sourceTree = "<group>"; };
 		E31618101EC5FE080006A218 /* DOMAnnotation.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DOMAnnotation.h; sourceTree = "<group>"; };
 		E31618111EC5FE080006A218 /* DOMAttributeGetterSetter.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = DOMAttributeGetterSetter.cpp; sourceTree = "<group>"; };
 		E31618121EC5FE080006A218 /* DOMAttributeGetterSetter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = DOMAttributeGetterSetter.h; sourceTree = "<group>"; };
@@ -7299,6 +7301,7 @@
 				705B41AA1A6E501E00716757 /* SymbolPrototype.h */,
 				0F919D2715856770004A4E7D /* SymbolTable.cpp */,
 				14A396A60CD2933100B5B4FF /* SymbolTable.h */,
+				E31179A92288385D00514B2C /* SymbolTableOrScopeDepth.h */,
 				BDB4B5E099CD4C1BB3C1CF05 /* TemplateObjectDescriptor.cpp */,
 				70ECA6041AFDBEA200449739 /* TemplateObjectDescriptor.h */,
 				0FA2C17917D7CF84009D015F /* TestRunnerUtils.cpp */,
@@ -9857,6 +9860,7 @@
 				705B41B21A6E501E00716757 /* SymbolPrototype.h in Headers */,
 				996B73281BDA08EF00331B84 /* SymbolPrototype.lut.h in Headers */,
 				BC18C46B0E16F5CD00B34460 /* SymbolTable.h in Headers */,
+				E31179AA2288386100514B2C /* SymbolTableOrScopeDepth.h in Headers */,
 				0FD79A2D1EBBBDBB00DA88D3 /* Synchronousness.h in Headers */,
 				0F1FB38F1E173A6700A9BE50 /* SynchronousStopTheWorldMutatorScheduler.h in Headers */,
 				A784A26411D16622005776AC /* SyntaxChecker.h in Headers */,
diff --git a/Source/JavaScriptCore/bytecode/BytecodeGeneratorification.cpp b/Source/JavaScriptCore/bytecode/BytecodeGeneratorification.cpp
index 2e6dcc8..81ab758 100644
--- a/Source/JavaScriptCore/bytecode/BytecodeGeneratorification.cpp
+++ b/Source/JavaScriptCore/bytecode/BytecodeGeneratorification.cpp
@@ -252,7 +252,7 @@
                     storage.identifierIndex, // identifier
                     operand, // value
                     GetPutInfo(DoNotThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization), // info
-                    m_generatorFrameSymbolTableIndex, // symbol table constant index
+                    SymbolTableOrScopeDepth::symbolTable(VirtualRegister { m_generatorFrameSymbolTableIndex }), // symbol table constant index
                     storage.scopeOffset.offset() // scope offset
                 );
             });
diff --git a/Source/JavaScriptCore/bytecode/BytecodeList.rb b/Source/JavaScriptCore/bytecode/BytecodeList.rb
index 8ca0da9..0695a25 100644
--- a/Source/JavaScriptCore/bytecode/BytecodeList.rb
+++ b/Source/JavaScriptCore/bytecode/BytecodeList.rb
@@ -50,6 +50,7 @@
     :StructureID,
     :StructureChain,
     :SymbolTable,
+    :SymbolTableOrScopeDepth,
     :ToThisStatus,
     :TypeLocation,
     :WatchpointSet,
@@ -881,7 +882,7 @@
         value: VirtualRegister, # offset 3
         # $begin: :private,
         getPutInfo: GetPutInfo,
-        symbolTableOrScopeDepth: int,
+        symbolTableOrScopeDepth: SymbolTableOrScopeDepth,
         offset: unsigned,
     },
     metadata: {
@@ -977,7 +978,7 @@
 op :profile_type,
     args: {
         targetVirtualRegister: VirtualRegister,
-        symbolTableOrScopeDepth: int,
+        symbolTableOrScopeDepth: SymbolTableOrScopeDepth,
         flag: ProfileTypeBytecodeFlag,
         identifier?: unsigned,
         resolveType: ResolveType,
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
index db28f67..ecc1a95 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -643,7 +643,7 @@
             if (bytecode.m_getPutInfo.resolveType() == LocalClosureVar) {
                 // Only do watching if the property we're putting to is not anonymous.
                 if (bytecode.m_var != UINT_MAX) {
-                    SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(bytecode.m_symbolTableOrScopeDepth));
+                    SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(bytecode.m_symbolTableOrScopeDepth.symbolTable().offset()));
                     const Identifier& ident = identifier(bytecode.m_var);
                     ConcurrentJSLocker locker(symbolTable->m_lock);
                     auto iter = symbolTable->find(locker, ident.impl());
@@ -657,7 +657,7 @@
 
             const Identifier& ident = identifier(bytecode.m_var);
             metadata.m_watchpointSet = nullptr;
-            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), bytecode.m_symbolTableOrScopeDepth, scope, ident, Put, bytecode.m_getPutInfo.resolveType(), bytecode.m_getPutInfo.initializationMode());
+            ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), bytecode.m_symbolTableOrScopeDepth.scopeDepth(), scope, ident, Put, bytecode.m_getPutInfo.resolveType(), bytecode.m_getPutInfo.initializationMode());
             RETURN_IF_EXCEPTION(throwScope, false);
 
             metadata.m_getPutInfo = GetPutInfo(bytecode.m_getPutInfo.resolveMode(), op.type, bytecode.m_getPutInfo.initializationMode());
@@ -687,7 +687,7 @@
             switch (bytecode.m_flag) {
             case ProfileTypeBytecodeClosureVar: {
                 const Identifier& ident = identifier(bytecode.m_identifier);
-                unsigned localScopeDepth = bytecode.m_symbolTableOrScopeDepth;
+                unsigned localScopeDepth = bytecode.m_symbolTableOrScopeDepth.scopeDepth();
                 // Even though type profiling may be profiling either a Get or a Put, we can always claim a Get because
                 // we're abstractly "read"ing from a JSScope.
                 ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, bytecode.m_resolveType, InitializationMode::NotInitialization);
@@ -711,7 +711,7 @@
                 break;
             }
             case ProfileTypeBytecodeLocallyResolved: {
-                int symbolTableIndex = bytecode.m_symbolTableOrScopeDepth;
+                int symbolTableIndex = bytecode.m_symbolTableOrScopeDepth.symbolTable().offset();
                 SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
                 const Identifier& ident = identifier(bytecode.m_identifier);
                 ConcurrentJSLocker locker(symbolTable->m_lock);
diff --git a/Source/JavaScriptCore/bytecode/Fits.h b/Source/JavaScriptCore/bytecode/Fits.h
index 207e885..24d7757 100644
--- a/Source/JavaScriptCore/bytecode/Fits.h
+++ b/Source/JavaScriptCore/bytecode/Fits.h
@@ -33,6 +33,7 @@
 #include "PutByIdFlags.h"
 #include "ResultType.h"
 #include "SpecialPointer.h"
+#include "SymbolTableOrScopeDepth.h"
 #include "VirtualRegister.h"
 #include <type_traits>
 
@@ -133,6 +134,25 @@
 };
 
 template<>
+struct Fits<SymbolTableOrScopeDepth, OpcodeSize::Narrow> {
+    static bool check(SymbolTableOrScopeDepth u)
+    {
+        return u.raw() <= UINT8_MAX;
+    }
+
+    static uint8_t convert(SymbolTableOrScopeDepth u)
+    {
+        ASSERT(check(u));
+        return static_cast<uint8_t>(u.raw());
+    }
+
+    static SymbolTableOrScopeDepth convert(uint8_t u)
+    {
+        return SymbolTableOrScopeDepth::raw(u);
+    }
+};
+
+template<>
 struct Fits<Special::Pointer, OpcodeSize::Narrow> : Fits<int, OpcodeSize::Narrow> {
     using Base = Fits<int, OpcodeSize::Narrow>;
     static bool check(Special::Pointer sp) { return Base::check(static_cast<int>(sp)); }
diff --git a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
index 661cb49..667dac0 100644
--- a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
+++ b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
@@ -551,7 +551,7 @@
                     entry.disableWatching(*m_vm);
                     functionSymbolTable->set(NoLockingNecessary, name, entry);
                 }
-                OpPutToScope::emit(this, m_lexicalEnvironmentRegister, UINT_MAX, virtualRegisterForArgument(1 + i), GetPutInfo(ThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization), symbolTableConstantIndex, offset.offset());
+                OpPutToScope::emit(this, m_lexicalEnvironmentRegister, UINT_MAX, virtualRegisterForArgument(1 + i), GetPutInfo(ThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization), SymbolTableOrScopeDepth::symbolTable(VirtualRegister { symbolTableConstantIndex }), offset.offset());
             }
             
             // This creates a scoped arguments object and copies the overflow arguments into the
@@ -589,7 +589,7 @@
                 static_cast<const BindingNode*>(parameters.at(i).first)->boundProperty();
             functionSymbolTable->set(NoLockingNecessary, name, SymbolTableEntry(VarOffset(offset)));
             
-            OpPutToScope::emit(this, m_lexicalEnvironmentRegister, addConstant(ident), virtualRegisterForArgument(1 + i), GetPutInfo(ThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization), symbolTableConstantIndex, offset.offset());
+            OpPutToScope::emit(this, m_lexicalEnvironmentRegister, addConstant(ident), virtualRegisterForArgument(1 + i), GetPutInfo(ThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization), SymbolTableOrScopeDepth::symbolTable(VirtualRegister { symbolTableConstantIndex }), offset.offset());
         }
     }
     
@@ -1803,7 +1803,7 @@
     if (!registerToProfile)
         return;
 
-    OpProfileType::emit(this, registerToProfile, 0, flag, { }, resolveType());
+    OpProfileType::emit(this, registerToProfile, { }, flag, { }, resolveType());
 
     // Don't emit expression info for this version of profile type. This generally means
     // we're profiling information for something that isn't in the actual text of a JavaScript
@@ -1823,7 +1823,7 @@
     if (!registerToProfile)
         return;
 
-    OpProfileType::emit(this, registerToProfile, 0,  flag, { }, resolveType());
+    OpProfileType::emit(this, registerToProfile, { },  flag, { }, resolveType());
     emitTypeProfilerExpressionInfo(startDivot, endDivot);
 }
 
@@ -1836,14 +1836,14 @@
         return;
 
     ProfileTypeBytecodeFlag flag;
-    int symbolTableOrScopeDepth;
+    SymbolTableOrScopeDepth symbolTableOrScopeDepth;
     if (var.local() || var.offset().isScope()) {
         flag = ProfileTypeBytecodeLocallyResolved;
         ASSERT(var.symbolTableConstantIndex());
-        symbolTableOrScopeDepth = var.symbolTableConstantIndex();
+        symbolTableOrScopeDepth = SymbolTableOrScopeDepth::symbolTable(VirtualRegister { var.symbolTableConstantIndex() });
     } else {
         flag = ProfileTypeBytecodeClosureVar;
-        symbolTableOrScopeDepth = localScopeDepth();
+        symbolTableOrScopeDepth = SymbolTableOrScopeDepth::scopeDepth(localScopeDepth());
     }
 
     OpProfileType::emit(this, registerToProfile, symbolTableOrScopeDepth, flag, addConstant(var.ident()), resolveType());
@@ -2512,18 +2512,18 @@
     case VarKind::Scope:
     case VarKind::Invalid: {
         GetPutInfo getPutInfo(0);
-        int scopeDepth;
+        SymbolTableOrScopeDepth symbolTableOrScopeDepth;
         ScopeOffset offset;
         if (variable.offset().isScope()) {
             offset = variable.offset().scopeOffset();
             getPutInfo = GetPutInfo(resolveMode, LocalClosureVar, initializationMode);
-            scopeDepth = variable.symbolTableConstantIndex();
+            symbolTableOrScopeDepth = SymbolTableOrScopeDepth::symbolTable(VirtualRegister { variable.symbolTableConstantIndex() });
         } else {
             ASSERT(resolveType() != LocalClosureVar);
             getPutInfo = GetPutInfo(resolveMode, resolveType(), initializationMode);
-            scopeDepth = localScopeDepth();
+            symbolTableOrScopeDepth = SymbolTableOrScopeDepth::scopeDepth(localScopeDepth());
         }
-        OpPutToScope::emit(this, scope, addConstant(variable.ident()), value, getPutInfo, scopeDepth, !!offset ? offset.offset() : 0);
+        OpPutToScope::emit(this, scope, addConstant(variable.ident()), value, getPutInfo, symbolTableOrScopeDepth, !!offset ? offset.offset() : 0);
         m_codeBlock->addPropertyAccessInstruction(m_lastInstruction.offset());
         return value;
     } }
@@ -3743,7 +3743,7 @@
     return dst;
 }
 
-int BytecodeGenerator::localScopeDepth() const
+unsigned BytecodeGenerator::localScopeDepth() const
 {
     return m_localScopeDepth;
 }
diff --git a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
index 95341a9..1c90313 100644
--- a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
+++ b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -1235,10 +1235,10 @@
         SegmentedVector<Label, 32> m_labels;
         SegmentedVector<LabelScope, 32> m_labelScopes;
         unsigned m_finallyDepth { 0 };
-        int m_localScopeDepth { 0 };
+        unsigned m_localScopeDepth { 0 };
         const CodeType m_codeType;
 
-        int localScopeDepth() const;
+        unsigned localScopeDepth() const;
         void pushLocalControlFlowScope();
         void popLocalControlFlowScope();
 
diff --git a/Source/JavaScriptCore/runtime/SymbolTableOrScopeDepth.h b/Source/JavaScriptCore/runtime/SymbolTableOrScopeDepth.h
new file mode 100644
index 0000000..91f5e8f
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/SymbolTableOrScopeDepth.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2019 Apple Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "VirtualRegister.h"
+#include <wtf/PrintStream.h>
+
+namespace JSC {
+
+class SymbolTableOrScopeDepth {
+public:
+    SymbolTableOrScopeDepth() = default;
+
+    static SymbolTableOrScopeDepth symbolTable(VirtualRegister reg)
+    {
+        ASSERT(reg.isConstant());
+        return SymbolTableOrScopeDepth(reg.offset() - FirstConstantRegisterIndex);
+    }
+
+    static SymbolTableOrScopeDepth scopeDepth(unsigned scopeDepth)
+    {
+        return SymbolTableOrScopeDepth(scopeDepth);
+    }
+
+    static SymbolTableOrScopeDepth raw(unsigned value)
+    {
+        return SymbolTableOrScopeDepth(value);
+    }
+
+    VirtualRegister symbolTable() const
+    {
+        return VirtualRegister(m_raw + FirstConstantRegisterIndex);
+    }
+
+    unsigned scopeDepth() const
+    {
+        return m_raw;
+    }
+
+    unsigned raw() const { return m_raw; }
+
+    void dump(PrintStream& out) const
+    {
+        out.print(m_raw);
+    }
+
+private:
+    SymbolTableOrScopeDepth(unsigned value)
+        : m_raw(value)
+    { }
+
+    unsigned m_raw { 0 };
+};
+
+} // namespace JSC