A lot more classes have padding that can be reduced by reordering the…

…ir fields

https://bugs.webkit.org/show_bug.cgi?id=195579

Reviewed by Mark Lam.

Source/bmalloc:

* bmalloc/Heap.h:
* bmalloc/Scavenger.h:

Source/JavaScriptCore:

* assembler/LinkBuffer.h:
* dfg/DFGArrayifySlowPathGenerator.h:
(JSC::DFG::ArrayifySlowPathGenerator::ArrayifySlowPathGenerator):
* dfg/DFGCallArrayAllocatorSlowPathGenerator.h:
(JSC::DFG::CallArrayAllocatorSlowPathGenerator::CallArrayAllocatorSlowPathGenerator):
(JSC::DFG::CallArrayAllocatorWithVariableSizeSlowPathGenerator::CallArrayAllocatorWithVariableSizeSlowPathGenerator):
* dfg/DFGGraph.h:
* dfg/DFGNode.h:
(JSC::DFG::SwitchData::SwitchData):
* dfg/DFGPlan.cpp:
(JSC::DFG::Plan::Plan):
* dfg/DFGPlan.h:
* dfg/DFGSlowPathGenerator.h:
(JSC::DFG::CallSlowPathGenerator::CallSlowPathGenerator):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::SpeculativeJIT):
* dfg/DFGSpeculativeJIT.h:
* domjit/DOMJITSignature.h:
(JSC::DOMJIT::Signature::Signature):
(JSC::DOMJIT::Signature::effect):
(JSC::DOMJIT::Signature::argumentCount): Deleted.
* heap/MarkingConstraintSolver.h:
* heap/SlotVisitor.h:
* jit/CallFrameShuffleData.h:
* jit/JITDivGenerator.h:
* jit/SpillRegistersMode.h:
* parser/Nodes.h:
* profiler/ProfilerOSRExit.cpp:
(JSC::Profiler::OSRExit::OSRExit):
* profiler/ProfilerOSRExit.h:
* runtime/ArrayBufferView.h:
* runtime/SamplingProfiler.cpp:
(JSC::SamplingProfiler::SamplingProfiler):
* runtime/SamplingProfiler.h:
* runtime/TypeSet.cpp:
(JSC::StructureShape::StructureShape):
* runtime/TypeSet.h:
* runtime/Watchdog.h:

Source/WTF:

* wtf/CrossThreadQueue.h:
* wtf/Logger.h:
* wtf/MemoryPressureHandler.h:
* wtf/MetaAllocator.h:
* wtf/Threading.cpp:


Canonical link: https://commits.webkit.org/209940@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@242812 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/JavaScriptCore/ChangeLog

@@ -1,3 +1,49 @@
+2019-03-12  Robin Morisset  <rmorisset@apple.com>
+
+        A lot more classes have padding that can be reduced by reordering their fields
+        https://bugs.webkit.org/show_bug.cgi?id=195579
+
+        Reviewed by Mark Lam.
+
+        * assembler/LinkBuffer.h:
+        * dfg/DFGArrayifySlowPathGenerator.h:
+        (JSC::DFG::ArrayifySlowPathGenerator::ArrayifySlowPathGenerator):
+        * dfg/DFGCallArrayAllocatorSlowPathGenerator.h:
+        (JSC::DFG::CallArrayAllocatorSlowPathGenerator::CallArrayAllocatorSlowPathGenerator):
+        (JSC::DFG::CallArrayAllocatorWithVariableSizeSlowPathGenerator::CallArrayAllocatorWithVariableSizeSlowPathGenerator):
+        * dfg/DFGGraph.h:
+        * dfg/DFGNode.h:
+        (JSC::DFG::SwitchData::SwitchData):
+        * dfg/DFGPlan.cpp:
+        (JSC::DFG::Plan::Plan):
+        * dfg/DFGPlan.h:
+        * dfg/DFGSlowPathGenerator.h:
+        (JSC::DFG::CallSlowPathGenerator::CallSlowPathGenerator):
+        * dfg/DFGSpeculativeJIT.cpp:
+        (JSC::DFG::SpeculativeJIT::SpeculativeJIT):
+        * dfg/DFGSpeculativeJIT.h:
+        * domjit/DOMJITSignature.h:
+        (JSC::DOMJIT::Signature::Signature):
+        (JSC::DOMJIT::Signature::effect):
+        (JSC::DOMJIT::Signature::argumentCount): Deleted.
+        * heap/MarkingConstraintSolver.h:
+        * heap/SlotVisitor.h:
+        * jit/CallFrameShuffleData.h:
+        * jit/JITDivGenerator.h:
+        * jit/SpillRegistersMode.h:
+        * parser/Nodes.h:
+        * profiler/ProfilerOSRExit.cpp:
+        (JSC::Profiler::OSRExit::OSRExit):
+        * profiler/ProfilerOSRExit.h:
+        * runtime/ArrayBufferView.h:
+        * runtime/SamplingProfiler.cpp:
+        (JSC::SamplingProfiler::SamplingProfiler):
+        * runtime/SamplingProfiler.h:
+        * runtime/TypeSet.cpp:
+        (JSC::StructureShape::StructureShape):
+        * runtime/TypeSet.h:
+        * runtime/Watchdog.h:
+
 2019-03-12  Mark Lam  <mark.lam@apple.com>
 
         The HasIndexedProperty node does GC.

Source/JavaScriptCore/assembler/LinkBuffer.h

@@ -93,10 +93,10 @@ class LinkBuffer {
     LinkBuffer(MacroAssembler& macroAssembler, MacroAssemblerCodePtr<tag> code, size_t size, JITCompilationEffort effort = JITCompilationMustSucceed, bool shouldPerformBranchCompaction = true)
         : m_size(size)
         , m_didAllocate(false)
-        , m_code(code.template retagged<LinkBufferPtrTag>())
 #ifndef NDEBUG
         , m_completed(false)
 #endif
+        , m_code(code.template retagged<LinkBufferPtrTag>())
     {
 #if ENABLE(BRANCH_COMPACTION)
         m_shouldPerformBranchCompaction = shouldPerformBranchCompaction;
@@ -342,11 +342,11 @@ class LinkBuffer {
     bool m_shouldPerformBranchCompaction { true };
 #endif
     bool m_didAllocate;
-    MacroAssemblerCodePtr<LinkBufferPtrTag> m_code;
 #ifndef NDEBUG
     bool m_completed;
 #endif
     bool m_alreadyDisassembled { false };
+    MacroAssemblerCodePtr<LinkBufferPtrTag> m_code;
     Vector<RefPtr<SharedTask<void(LinkBuffer&)>>> m_linkTasks;
 };
 

Source/JavaScriptCore/dfg/DFGArrayifySlowPathGenerator.h

@@ -43,8 +43,8 @@ class ArrayifySlowPathGenerator : public JumpingSlowPathGenerator<MacroAssembler
         GPRReg propertyGPR, GPRReg tempGPR, GPRReg structureGPR)
         : JumpingSlowPathGenerator<MacroAssembler::JumpList>(from, jit)
         , m_op(node->op())
-        , m_arrayMode(node->arrayMode())
         , m_structure(node->op() == ArrayifyToStructure ? node->structure() : RegisteredStructure())
+        , m_arrayMode(node->arrayMode())
         , m_baseGPR(baseGPR)
         , m_propertyGPR(propertyGPR)
         , m_tempGPR(tempGPR)
@@ -134,8 +134,8 @@ class ArrayifySlowPathGenerator : public JumpingSlowPathGenerator<MacroAssembler
 
 private:
     NodeType m_op;
-    ArrayMode m_arrayMode;
     RegisteredStructure m_structure;
+    ArrayMode m_arrayMode;
     GPRReg m_baseGPR;
     GPRReg m_propertyGPR;
     GPRReg m_tempGPR;

Source/JavaScriptCore/dfg/DFGCallArrayAllocatorSlowPathGenerator.h

@@ -42,8 +42,8 @@ class CallArrayAllocatorSlowPathGenerator : public JumpingSlowPathGenerator<Macr
         , m_function(function)
         , m_resultGPR(resultGPR)
         , m_storageGPR(storageGPR)
-        , m_structure(structure)
         , m_size(size)
+        , m_structure(structure)
     {
         ASSERT(size < static_cast<size_t>(std::numeric_limits<int32_t>::max()));
         jit->silentSpillAllRegistersImpl(false, m_plans, resultGPR);
@@ -67,8 +67,8 @@ class CallArrayAllocatorSlowPathGenerator : public JumpingSlowPathGenerator<Macr
     P_JITOperation_EStZB m_function;
     GPRReg m_resultGPR;
     GPRReg m_storageGPR;
-    RegisteredStructure m_structure;
     int m_size;
+    RegisteredStructure m_structure;
     Vector<SilentRegisterSavePlan, 2> m_plans;
 };
 
@@ -79,9 +79,9 @@ class CallArrayAllocatorWithVariableSizeSlowPathGenerator : public JumpingSlowPa
         GPRReg resultGPR, RegisteredStructure contiguousStructure, RegisteredStructure arrayStorageStructure, GPRReg sizeGPR, GPRReg storageGPR)
         : JumpingSlowPathGenerator<MacroAssembler::JumpList>(from, jit)
         , m_function(function)
-        , m_resultGPR(resultGPR)
         , m_contiguousStructure(contiguousStructure)
         , m_arrayStorageOrContiguousStructure(arrayStorageStructure)
+        , m_resultGPR(resultGPR)
         , m_sizeGPR(sizeGPR)
         , m_storageGPR(storageGPR)
     {
@@ -113,9 +113,9 @@ class CallArrayAllocatorWithVariableSizeSlowPathGenerator : public JumpingSlowPa
 
 private:
     P_JITOperation_EStZB m_function;
-    GPRReg m_resultGPR;
     RegisteredStructure m_contiguousStructure;
     RegisteredStructure m_arrayStorageOrContiguousStructure;
+    GPRReg m_resultGPR;
     GPRReg m_sizeGPR;
     GPRReg m_storageGPR;
     Vector<SilentRegisterSavePlan, 2> m_plans;

Source/JavaScriptCore/dfg/DFGGraph.h

@@ -1022,16 +1022,6 @@ class Graph : public virtual Scannable {
     // So argumentFormats[0] are the argument formats for the normal call entrypoint.
     Vector<Vector<FlushFormat>> m_argumentFormats;
 
-    // This maps an entrypoint index to a particular op_catch bytecode offset. By convention,
-    // it'll never have zero as a key because we use zero to mean the op_enter entrypoint.
-    HashMap<unsigned, unsigned> m_entrypointIndexToCatchBytecodeOffset;
-
-    // This is the number of logical entrypoints that we're compiling. This is only used
-    // in SSA. Each EntrySwitch node must have m_numberOfEntrypoints cases. Note, this is
-    // not the same as m_roots.size(). m_roots.size() represents the number of roots in
-    // the CFG. In SSA, m_roots.size() == 1 even if we're compiling more than one entrypoint.
-    unsigned m_numberOfEntrypoints { UINT_MAX };
-
     SegmentedVector<VariableAccessData, 16> m_variableAccessData;
     SegmentedVector<ArgumentPosition, 8> m_argumentPositions;
     Bag<Transition> m_transitions;
@@ -1064,7 +1054,17 @@ class Graph : public virtual Scannable {
     unsigned m_localVars;
     unsigned m_nextMachineLocal;
     unsigned m_parameterSlots;
-
+
+    // This is the number of logical entrypoints that we're compiling. This is only used
+    // in SSA. Each EntrySwitch node must have m_numberOfEntrypoints cases. Note, this is
+    // not the same as m_roots.size(). m_roots.size() represents the number of roots in
+    // the CFG. In SSA, m_roots.size() == 1 even if we're compiling more than one entrypoint.
+    unsigned m_numberOfEntrypoints { UINT_MAX };
+
+    // This maps an entrypoint index to a particular op_catch bytecode offset. By convention,
+    // it'll never have zero as a key because we use zero to mean the op_enter entrypoint.
+    HashMap<unsigned, unsigned> m_entrypointIndexToCatchBytecodeOffset;
+
     HashSet<String> m_localStrings;
     HashMap<const StringImpl*, String> m_copiedStrings;
 

Source/JavaScriptCore/dfg/DFGNode.h

@@ -213,16 +213,16 @@ struct SwitchData {
     // constructing this should make sure to initialize everything they
     // care about manually.
     SwitchData()
-        : kind(static_cast<SwitchKind>(-1))
-        , switchTableIndex(UINT_MAX)
+        : switchTableIndex(UINT_MAX)
+        , kind(static_cast<SwitchKind>(-1))
         , didUseJumpTable(false)
     {
     }
 
     Vector<SwitchCase> cases;
     BranchTarget fallThrough;
-    SwitchKind kind;
     size_t switchTableIndex;
+    SwitchKind kind;
     bool didUseJumpTable;
 };
 

Source/JavaScriptCore/dfg/DFGPlan.cpp

@@ -136,12 +136,12 @@ Profiler::CompilationKind profilerCompilationKindForMode(CompilationMode mode)
 Plan::Plan(CodeBlock* passedCodeBlock, CodeBlock* profiledDFGCodeBlock,
     CompilationMode mode, unsigned osrEntryBytecodeIndex,
     const Operands<Optional<JSValue>>& mustHandleValues)
-    : m_vm(passedCodeBlock->vm())
+    : m_mode(mode)
+    , m_vm(passedCodeBlock->vm())
     , m_codeBlock(passedCodeBlock)
     , m_profiledDFGCodeBlock(profiledDFGCodeBlock)
-    , m_mode(mode)
-    , m_osrEntryBytecodeIndex(osrEntryBytecodeIndex)
     , m_mustHandleValues(mustHandleValues)
+    , m_osrEntryBytecodeIndex(osrEntryBytecodeIndex)
     , m_compilation(UNLIKELY(m_vm->m_perBytecodeProfiler) ? adoptRef(new Profiler::Compilation(m_vm->m_perBytecodeProfiler->ensureBytecodesFor(m_codeBlock), profilerCompilationKindForMode(mode))) : nullptr)
     , m_inlineCallFrames(adoptRef(new InlineCallFrameSet()))
     , m_identifiers(m_codeBlock)

Source/JavaScriptCore/dfg/DFGPlan.h

@@ -129,18 +129,22 @@ class Plan : public ThreadSafeRefCounted<Plan> {
     // Warning: pretty much all of the pointer fields in this object get nulled by cancel(). So, if
     // you're writing code that is callable on the cancel path, be sure to null check everything!
 
+    CompilationMode m_mode;
+
     VM* m_vm;
 
     // These can be raw pointers because we visit them during every GC in checkLivenessAndVisitChildren.
     CodeBlock* m_codeBlock;
     CodeBlock* m_profiledDFGCodeBlock;
 
-    CompilationMode m_mode;
-    const unsigned m_osrEntryBytecodeIndex;
     Operands<Optional<JSValue>> m_mustHandleValues;
     bool m_mustHandleValuesMayIncludeGarbage { true };
     Lock m_mustHandleValueCleaningLock;
 
+    bool m_willTryToTierUp { false };
+
+    const unsigned m_osrEntryBytecodeIndex;
+
     ThreadData* m_threadData;
 
     RefPtr<Profiler::Compilation> m_compilation;
@@ -155,8 +159,6 @@ class Plan : public ThreadSafeRefCounted<Plan> {
     DesiredGlobalProperties m_globalProperties;
     RecordedStatuses m_recordedStatuses;
 
-    bool m_willTryToTierUp { false };
-
     HashMap<unsigned, Vector<unsigned>> m_tierUpInLoopHierarchy;
     Vector<unsigned> m_tierUpAndOSREnterBytecodes;
 

Source/JavaScriptCore/dfg/DFGSlowPathGenerator.h

@@ -66,8 +66,8 @@ class SlowPathGenerator {
 
 protected:
     virtual void generateInternal(SpeculativeJIT*) = 0;
-    MacroAssembler::Label m_label;
     Node* m_currentNode;
+    MacroAssembler::Label m_label;
     unsigned m_streamIndex;
     NodeOrigin m_origin;
 };
@@ -97,7 +97,7 @@ class JumpingSlowPathGenerator : public SlowPathGenerator {
     MacroAssembler::Label m_to;
 };
 
-enum class ExceptionCheckRequirement {
+enum class ExceptionCheckRequirement : uint8_t {
     CheckNeeded,
     CheckNotNeeded
 };
@@ -109,10 +109,10 @@ class CallSlowPathGenerator : public JumpingSlowPathGenerator<JumpType> {
         JumpType from, SpeculativeJIT* jit, FunctionType function,
         SpillRegistersMode spillMode, ExceptionCheckRequirement requirement, ResultType result)
         : JumpingSlowPathGenerator<JumpType>(from, jit)
-        , m_function(function)
         , m_spillMode(spillMode)
         , m_exceptionCheckRequirement(requirement)
         , m_result(result)
+        , m_function(function)
     {
         if (m_spillMode == NeedToSpill)
             jit->silentSpillAllRegistersImpl(false, m_plans, extractResult(result));
@@ -149,11 +149,11 @@ class CallSlowPathGenerator : public JumpingSlowPathGenerator<JumpType> {
         this->jumpTo(jit);
     }
 
-    FunctionType m_function;
+    MacroAssembler::Call m_call;
     SpillRegistersMode m_spillMode;
     ExceptionCheckRequirement m_exceptionCheckRequirement;
     ResultType m_result;
-    MacroAssembler::Call m_call;
+    FunctionType m_function;
     Vector<SilentRegisterSavePlan, 2> m_plans;
 };
 

Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp

@@ -71,13 +71,13 @@
 namespace JSC { namespace DFG {
 
 SpeculativeJIT::SpeculativeJIT(JITCompiler& jit)
-    : m_compileOkay(true)
-    , m_jit(jit)
+    : m_jit(jit)
     , m_graph(m_jit.graph())
     , m_currentNode(0)
     , m_lastGeneratedNode(LastNodeType)
     , m_indexInBlock(0)
     , m_generationInfo(m_jit.graph().frameRegisterCount())
+    , m_compileOkay(true)
     , m_state(m_jit.graph())
     , m_interpreter(m_jit.graph(), m_state)
     , m_stream(&jit.jitCode()->variableEventStream)

Source/JavaScriptCore/dfg/DFGSpeculativeJIT.h

@@ -1652,12 +1652,6 @@ class SpeculativeJIT {
 
     void cageTypedArrayStorage(GPRReg);
 
-    // It is possible, during speculative generation, to reach a situation in which we
-    // can statically determine a speculation will fail (for example, when two nodes
-    // will make conflicting speculations about the same operand). In such cases this
-    // flag is cleared, indicating no further code generation should take place.
-    bool m_compileOkay;
-
     void recordSetLocal(
         VirtualRegister bytecodeReg, VirtualRegister machineReg, DataFormat format)
     {
@@ -1700,6 +1694,12 @@ class SpeculativeJIT {
     RegisterBank<GPRInfo> m_gprs;
     RegisterBank<FPRInfo> m_fprs;
 
+    // It is possible, during speculative generation, to reach a situation in which we
+    // can statically determine a speculation will fail (for example, when two nodes
+    // will make conflicting speculations about the same operand). In such cases this
+    // flag is cleared, indicating no further code generation should take place.
+    bool m_compileOkay;
+
     Vector<MacroAssembler::Label> m_osrEntryHeads;
 
     struct BranchRecord {

Source/JavaScriptCore/domjit/DOMJITSignature.h

@@ -43,19 +43,19 @@ class Signature {
     constexpr Signature(uintptr_t unsafeFunction, const ClassInfo* classInfo, Effect effect, SpeculatedType result, Arguments... arguments)
         : unsafeFunction(unsafeFunction)
         , classInfo(classInfo)
-        , effect(effect)
         , result(result)
         , arguments {static_cast<SpeculatedType>(arguments)...}
         , argumentCount(sizeof...(Arguments))
+        , effect(effect)
     {
     }
 
     uintptr_t unsafeFunction;
     const ClassInfo* const classInfo;
-    const Effect effect;
     const SpeculatedType result;
     const SpeculatedType arguments[JSC_DOMJIT_SIGNATURE_MAX_ARGUMENTS];
     const unsigned argumentCount;
+    const Effect effect;
 };
 
 } }

Source/JavaScriptCore/heap/MarkingConstraintSolver.h

@@ -97,8 +97,8 @@ class MarkingConstraintSolver {
     Vector<unsigned, 32> m_toExecuteSequentially;
     Lock m_lock;
     Condition m_condition;
-    unsigned m_numThreadsThatMayProduceWork { 0 };
     bool m_pickNextIsStillActive { true };
+    unsigned m_numThreadsThatMayProduceWork { 0 };
     Vector<VisitCounter, 16> m_visitCounters;
 };
 

Source/JavaScriptCore/heap/SlotVisitor.h

@@ -234,13 +234,13 @@ class SlotVisitor {
 
     MarkStackArray m_collectorStack;
     MarkStackArray m_mutatorStack;
-    bool m_ignoreNewOpaqueRoots { false }; // Useful as a debugging mode.
 
     size_t m_bytesVisited;
     size_t m_visitCount;
     size_t m_nonCellVisitCount { 0 }; // Used for incremental draining, ignored otherwise.
     Checked<size_t, RecordOverflow> m_extraMemorySize { 0 };
     bool m_isInParallelMode;
+    bool m_ignoreNewOpaqueRoots { false }; // Useful as a debugging mode.
 
     HeapVersion m_markingVersion;
 

Source/JavaScriptCore/jit/CallFrameShuffleData.h

@@ -35,9 +35,9 @@ namespace JSC {
 struct CallFrameShuffleData {
     WTF_MAKE_FAST_ALLOCATED;
 public:
-    unsigned numLocals { UINT_MAX };
     ValueRecovery callee;
     Vector<ValueRecovery> args;
+    unsigned numLocals { UINT_MAX };
     unsigned numPassedArgs { UINT_MAX };
 #if USE(JSVALUE64)
     RegisterMap<ValueRecovery> registers;

Source/JavaScriptCore/jit/JITDivGenerator.h

@@ -70,8 +70,8 @@ class JITDivGenerator {
     FPRReg m_rightFPR;
     GPRReg m_scratchGPR;
     FPRReg m_scratchFPR;
-    ArithProfile* m_arithProfile;
     bool m_didEmitFastPath { false };
+    ArithProfile* m_arithProfile;
 
     CCallHelpers::JumpList m_endJumpList;
     CCallHelpers::JumpList m_slowPathJumpList;