The Tor Browser: js/src/jit/BaselineJIT.h@6474c204b198 (annotated)

js/src/jit/BaselineJIT.h@6474c204b198 (annotated)

js/src/jit/BaselineJIT.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef jit_BaselineJIT_h
 #define jit_BaselineJIT_h
 #ifdef JS_ION
 #include "mozilla/MemoryReporting.h"
 #include "jscntxt.h"
 #include "jscompartment.h"
 #include "ds/LifoAlloc.h"
 #include "jit/Bailouts.h"
 #include "jit/IonCode.h"
 #include "jit/IonMacroAssembler.h"
 namespace js {
 namespace jit {
 class StackValue;
 class ICEntry;
 class ICStub;
 class PCMappingSlotInfo
 {
     uint8_t slotInfo_;
   public:
     // SlotInfo encoding:
     //  Bits 0 & 1: number of slots at top of stack which are unsynced.
     //  Bits 2 & 3: SlotLocation of top slot value (only relevant if numUnsynced > 0).
     //  Bits 3 & 4: SlotLocation of next slot value (only relevant if numUnsynced > 1).
     enum SlotLocation { SlotInR0 = 0, SlotInR1 = 1, SlotIgnore = 3 };
     PCMappingSlotInfo()
       : slotInfo_(0)
     { }
     explicit PCMappingSlotInfo(uint8_t slotInfo)
       : slotInfo_(slotInfo)
     { }
     static inline bool ValidSlotLocation(SlotLocation loc) {
         return (loc == SlotInR0) || (loc == SlotInR1) || (loc == SlotIgnore);
     }
     static SlotLocation ToSlotLocation(const StackValue *stackVal);
     inline static PCMappingSlotInfo MakeSlotInfo() { return PCMappingSlotInfo(0); }
     inline static PCMappingSlotInfo MakeSlotInfo(SlotLocation topSlotLoc) {
         JS_ASSERT(ValidSlotLocation(topSlotLoc));
         return PCMappingSlotInfo(1 | (topSlotLoc << 2));
     }
     inline static PCMappingSlotInfo MakeSlotInfo(SlotLocation topSlotLoc, SlotLocation nextSlotLoc) {
         JS_ASSERT(ValidSlotLocation(topSlotLoc));
         JS_ASSERT(ValidSlotLocation(nextSlotLoc));
         return PCMappingSlotInfo(2 | (topSlotLoc << 2) | (nextSlotLoc) << 4);
     }
     inline unsigned numUnsynced() const {
         return slotInfo_ & 0x3;
     }
     inline SlotLocation topSlotLocation() const {
         return static_cast<SlotLocation>((slotInfo_ >> 2) & 0x3);
     }
     inline SlotLocation nextSlotLocation() const {
         return static_cast<SlotLocation>((slotInfo_ >> 4) & 0x3);
     }
     inline uint8_t toByte() const {
         return slotInfo_;
     }
 };
 // A CompactBuffer is used to store native code offsets (relative to the
 // previous pc) and PCMappingSlotInfo bytes. To allow binary search into this
 // table, we maintain a second table of "index" entries. Every X ops, the
 // compiler will add an index entry, so that from the index entry to the
 // actual native code offset, we have to iterate at most X times.
 struct PCMappingIndexEntry
 {
     // jsbytecode offset.
     uint32_t pcOffset;
     // Native code offset.
     uint32_t nativeOffset;
     // Offset in the CompactBuffer where data for pcOffset starts.
     uint32_t bufferOffset;
 };
 struct BaselineScript
 {
   public:
     static const uint32_t MAX_JSSCRIPT_LENGTH = 0x0fffffffu;
     // Limit the locals on a given script so that stack check on baseline frames
     // doesn't overflow a uint32_t value.
     // (MAX_JSSCRIPT_SLOTS * sizeof(Value)) must fit within a uint32_t.
     static const uint32_t MAX_JSSCRIPT_SLOTS = 0xffffu;
   private:
     // Code pointer containing the actual method.
     HeapPtr<JitCode> method_;
     // For heavyweight scripts, template objects to use for the call object and
     // decl env object (linked via the call object's enclosing scope).
     HeapPtrObject templateScope_;
     // Allocated space for fallback stubs.
     FallbackICStubSpace fallbackStubSpace_;
     // Native code offset right before the scope chain is initialized.
     uint32_t prologueOffset_;
     // Native code offset right before the frame is popped and the method
     // returned from.
     uint32_t epilogueOffset_;
     // The offsets for the toggledJump instructions for SPS update ICs.
 #ifdef DEBUG
     mozilla::DebugOnly<bool> spsOn_;
 #endif
     uint32_t spsPushToggleOffset_;
     // Native code offsets right after the debug prologue VM call returns, or
     // would have returned. This offset is recorded even when debug mode is
     // off to aid on-stack debug mode recompilation.
     //
     // We don't need one for the debug epilogue because that always happens
     // right before the epilogue, so we just use the epilogue offset.
     uint32_t postDebugPrologueOffset_;
   public:
     enum Flag {
         // Flag set by JSScript::argumentsOptimizationFailed. Similar to
         // JSScript::needsArgsObj_, but can be read from JIT code.
         NEEDS_ARGS_OBJ = 1 << 0,
         // Flag set when discarding JIT code, to indicate this script is
         // on the stack and should not be discarded.
         ACTIVE = 1 << 1,
         // Flag set when the script contains any writes to its on-stack
         // (rather than call object stored) arguments.
         MODIFIES_ARGUMENTS = 1 << 2,
         // Flag set when compiled for use for debug mode. Handles various
         // Debugger hooks and compiles toggled calls for traps.
         DEBUG_MODE = 1 << 3
     };
   private:
     uint32_t flags_;
   private:
     void trace(JSTracer *trc);
     uint32_t icEntriesOffset_;
     uint32_t icEntries_;
     uint32_t pcMappingIndexOffset_;
     uint32_t pcMappingIndexEntries_;
     uint32_t pcMappingOffset_;
     uint32_t pcMappingSize_;
     // List mapping indexes of bytecode type sets to the offset of the opcode
     // they correspond to, for use by TypeScript::BytecodeTypes.
     uint32_t bytecodeTypeMapOffset_;
   public:
     // Do not call directly, use BaselineScript::New. This is public for cx->new_.
     BaselineScript(uint32_t prologueOffset, uint32_t epilogueOffset,
                    uint32_t spsPushToggleOffset, uint32_t postDebugPrologueOffset);
     static BaselineScript *New(JSContext *cx, uint32_t prologueOffset,
                                uint32_t epilogueOffset, uint32_t postDebugPrologueOffset,
                                uint32_t spsPushToggleOffset, size_t icEntries,
                                size_t pcMappingIndexEntries, size_t pcMappingSize,
                                size_t bytecodeTypeMapEntries);
     static void Trace(JSTracer *trc, BaselineScript *script);
     static void Destroy(FreeOp *fop, BaselineScript *script);
     void purgeOptimizedStubs(Zone *zone);
     static inline size_t offsetOfMethod() {
         return offsetof(BaselineScript, method_);
     }
     void addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf, size_t *data,
                                 size_t *fallbackStubs) const {
         *data += mallocSizeOf(this);
         // |data| already includes the ICStubSpace itself, so use
         // sizeOfExcludingThis.
         *fallbackStubs += fallbackStubSpace_.sizeOfExcludingThis(mallocSizeOf);
     }
     bool active() const {
         return flags_ & ACTIVE;
     }
     void setActive() {
         flags_ |= ACTIVE;
     }
     void resetActive() {
         flags_ &= ~ACTIVE;
     }
     void setNeedsArgsObj() {
         flags_ |= NEEDS_ARGS_OBJ;
     }
     void setModifiesArguments() {
         flags_ |= MODIFIES_ARGUMENTS;
     }
     bool modifiesArguments() {
         return flags_ & MODIFIES_ARGUMENTS;
     }
     void setDebugMode() {
         flags_ |= DEBUG_MODE;
     }
     bool debugMode() const {
         return flags_ & DEBUG_MODE;
     }
     uint32_t prologueOffset() const {
         return prologueOffset_;
     }
     uint8_t *prologueEntryAddr() const {
         return method_->raw() + prologueOffset_;
     }
     uint32_t epilogueOffset() const {
         return epilogueOffset_;
     }
     uint8_t *epilogueEntryAddr() const {
         return method_->raw() + epilogueOffset_;
     }
     uint32_t postDebugPrologueOffset() const {
         return postDebugPrologueOffset_;
     }
     uint8_t *postDebugPrologueAddr() const {
         return method_->raw() + postDebugPrologueOffset_;
     }
     ICEntry *icEntryList() {
         return (ICEntry *)(reinterpret_cast<uint8_t *>(this) + icEntriesOffset_);
     }
     PCMappingIndexEntry *pcMappingIndexEntryList() {
         return (PCMappingIndexEntry *)(reinterpret_cast<uint8_t *>(this) + pcMappingIndexOffset_);
     }
     uint8_t *pcMappingData() {
         return reinterpret_cast<uint8_t *>(this) + pcMappingOffset_;
     }
     FallbackICStubSpace *fallbackStubSpace() {
         return &fallbackStubSpace_;
     }
     JitCode *method() const {
         return method_;
     }
     void setMethod(JitCode *code) {
         JS_ASSERT(!method_);
         method_ = code;
     }
     JSObject *templateScope() const {
         return templateScope_;
     }
     void setTemplateScope(JSObject *templateScope) {
         JS_ASSERT(!templateScope_);
         templateScope_ = templateScope;
     }
     void toggleBarriers(bool enabled) {
         method()->togglePreBarriers(enabled);
     }
     bool containsCodeAddress(uint8_t *addr) const {
         return method()->raw() <= addr && addr <= method()->raw() + method()->instructionsSize();
     }
     ICEntry &icEntry(size_t index);
     ICEntry *maybeICEntryFromReturnOffset(CodeOffsetLabel returnOffset);
     ICEntry &icEntryFromReturnOffset(CodeOffsetLabel returnOffset);
     ICEntry &icEntryFromPCOffset(uint32_t pcOffset);
     ICEntry &icEntryForDebugModeRecompileFromPCOffset(uint32_t pcOffset);
     ICEntry &icEntryFromPCOffset(uint32_t pcOffset, ICEntry *prevLookedUpEntry);
     ICEntry *maybeICEntryFromReturnAddress(uint8_t *returnAddr);
     ICEntry &icEntryFromReturnAddress(uint8_t *returnAddr);
     uint8_t *returnAddressForIC(const ICEntry &ent);
     size_t numICEntries() const {
         return icEntries_;
     }
     void copyICEntries(JSScript *script, const ICEntry *entries, MacroAssembler &masm);
     void adoptFallbackStubs(FallbackICStubSpace *stubSpace);
     PCMappingIndexEntry &pcMappingIndexEntry(size_t index);
     CompactBufferReader pcMappingReader(size_t indexEntry);
     size_t numPCMappingIndexEntries() const {
         return pcMappingIndexEntries_;
     }
     void copyPCMappingIndexEntries(const PCMappingIndexEntry *entries);
     void copyPCMappingEntries(const CompactBufferWriter &entries);
     uint8_t *nativeCodeForPC(JSScript *script, jsbytecode *pc, PCMappingSlotInfo *slotInfo = nullptr);
     jsbytecode *pcForReturnOffset(JSScript *script, uint32_t nativeOffset);
     jsbytecode *pcForReturnAddress(JSScript *script, uint8_t *nativeAddress);
     // Toggle debug traps (used for breakpoints and step mode) in the script.
     // If |pc| is nullptr, toggle traps for all ops in the script. Else, only
     // toggle traps at |pc|.
     void toggleDebugTraps(JSScript *script, jsbytecode *pc);
     void toggleSPS(bool enable);
     void noteAccessedGetter(uint32_t pcOffset);
     void noteArrayWriteHole(uint32_t pcOffset);
     static size_t offsetOfFlags() {
         return offsetof(BaselineScript, flags_);
     }
     static void writeBarrierPre(Zone *zone, BaselineScript *script);
     uint32_t *bytecodeTypeMap() {
         JS_ASSERT(bytecodeTypeMapOffset_);
         return reinterpret_cast<uint32_t *>(reinterpret_cast<uint8_t *>(this) + bytecodeTypeMapOffset_);
     }
 };
 inline bool
 IsBaselineEnabled(JSContext *cx)
 {
     return cx->runtime()->options().baseline();
 }
 MethodStatus
 CanEnterBaselineMethod(JSContext *cx, RunState &state);
 MethodStatus
 CanEnterBaselineAtBranch(JSContext *cx, InterpreterFrame *fp, bool newType);
 IonExecStatus
 EnterBaselineMethod(JSContext *cx, RunState &state);
 IonExecStatus
 EnterBaselineAtBranch(JSContext *cx, InterpreterFrame *fp, jsbytecode *pc);
 void
 FinishDiscardBaselineScript(FreeOp *fop, JSScript *script);
 void
 AddSizeOfBaselineData(JSScript *script, mozilla::MallocSizeOf mallocSizeOf, size_t *data,
                       size_t *fallbackStubs);
 void
 ToggleBaselineSPS(JSRuntime *runtime, bool enable);
 struct BaselineBailoutInfo
 {
     // Pointer into the current C stack, where overwriting will start.
     uint8_t *incomingStack;
     // The top and bottom heapspace addresses of the reconstructed stack
     // which will be copied to the bottom.
     uint8_t *copyStackTop;
     uint8_t *copyStackBottom;
     // Fields to store the top-of-stack baseline values that are held
     // in registers.  The setR0 and setR1 fields are flags indicating
     // whether each one is initialized.
     uint32_t setR0;
     Value valueR0;
     uint32_t setR1;
     Value valueR1;
     // The value of the frame pointer register on resume.
     void *resumeFramePtr;
     // The native code address to resume into.
     void *resumeAddr;
     // If resuming into a TypeMonitor IC chain, this field holds the
     // address of the first stub in that chain.  If this field is
     // set, then the actual jitcode resumed into is the jitcode for
     // the first stub, not the resumeAddr above.  The resumeAddr
     // above, in this case, is pushed onto the stack so that the
     // TypeMonitor chain can tail-return into the main jitcode when done.
     ICStub *monitorStub;
     // Number of baseline frames to push on the stack.
     uint32_t numFrames;
     // The bailout kind.
     BailoutKind bailoutKind;
 };
 uint32_t
 BailoutIonToBaseline(JSContext *cx, JitActivation *activation, IonBailoutIterator &iter,
                      bool invalidate, BaselineBailoutInfo **bailoutInfo,
                      const ExceptionBailoutInfo *exceptionInfo = nullptr);
 // Mark baseline scripts on the stack as active, so that they are not discarded
 // during GC.
 void
 MarkActiveBaselineScripts(Zone *zone);
 MethodStatus
 BaselineCompile(JSContext *cx, JSScript *script);
 } // namespace jit
 } // namespace js
 #endif // JS_ION
 #endif /* jit_BaselineJIT_h */

The Tor Browser / annotate

js/src/jit/BaselineJIT.h@6474c204b198 (annotated)

js/src/jit/BaselineJIT.h