Attachment #260960 for bug #149047

View Details Raw Unified Return to Bug 149047



2015-09-10  Filip Pizlo  <fpizlo@apple.com>

        Structure should be able to tell you if it had ever been a dictionary
        https://bugs.webkit.org/show_bug.cgi?id=149047

        Reviewed by NOBODY (OOPS!).

        Introduces the hasBeenDictionary flag to Structure, which tells you if this structure or
        any of its ancestors is a dictionary. We already implicitly tracked this for DFG
        watchpoint optimizations, so this is mainly just decoupling that existing logic from
        watchpoints. Having Structure::hasBeenDictionary() enables some of the heuristics in the
        property type inference work (https://bugs.webkit.org/show_bug.cgi?id=148610).

        * runtime/Structure.cpp:
        (JSC::Structure::Structure):
        (JSC::Structure::toDictionaryTransition):
        (JSC::Structure::dump):
        * runtime/Structure.h:

2015-09-10  Yusuke Suzuki  <utatane.tea@gmail.com>

        Unreviewed, fix Windows file loading in JSC shell after r189583



    setStaticFunctionsReified(false);
    setHasRareData(false);
    setTransitionWatchpointIsLikelyToBeFired(false);
    setHasBeenDictionary(false);
 
    ASSERT(inlineCapacity <= JSFinalObject::maxInlineCapacity());
    ASSERT(static_cast<PropertyOffset>(inlineCapacity) < firstOutOfLineOffset);

    setStaticFunctionsReified(false);
    setHasRareData(false);
    setTransitionWatchpointIsLikelyToBeFired(false);
    setHasBeenDictionary(false);
 
    TypeInfo typeInfo = TypeInfo(CellType, StructureFlags);
    m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), 0, typeInfo);

    setDidTransition(true);
    setStaticFunctionsReified(previous->staticFunctionsReified());
    setHasRareData(false);
    setHasBeenDictionary(previous->hasBeenDictionary());
 
    TypeInfo typeInfo = previous->typeInfo();
    m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), previous->indexingTypeIncludingHistory(), typeInfo);

    transition->m_offset = structure->m_offset;
    transition->setDictionaryKind(kind);
    transition->pin();
    transition->setHasBeenDictionary(true);

    transition->checkOffsetConsistency();
    return transition;


    switch (dictionaryKind()) {
    case NoneDictionaryKind:
        if (hasBeenDictionary())
            out.print(", Has been dictionary");
        break;
    case CachedDictionaryKind:
        out.print(", Dictionary");

        out.print(", UncacheableDictionary");
        break;
    }

    if (transitionWatchpointSetIsStillValid())
        out.print(", Leaf");
    else if (transitionWatchpointIsLikelyToBeFired())
        out.print(", Shady leaf");
    
    out.print("]");
}

Lines 429-437 public: Source/JavaScriptCore/runtime/Structure.h_sec1
- Source/JavaScriptCore/runtime/Structure.h -1 / +6 lines
429		429
430	// - We don't watch Structures that either decided not to be watched, or whose predecessors	430	// - We don't watch Structures that either decided not to be watched, or whose predecessors
431	// decided not to be watched. This happens either when a transition is fired while being	431	// decided not to be watched. This happens either when a transition is fired while being
432	// watched, or if a dictionary transition occurs.	432	// watched.
433	if (transitionWatchpointIsLikelyToBeFired())	433	if (transitionWatchpointIsLikelyToBeFired())
434	return false;	434	return false;
		435
		436	// - Don't watch Structures that had been dictionaries.
		437	if (hasBeenDictionary())
		438	return false;
435		439
436	return true;	440	return true;
437	}	441	}
Lines 523-528 public: Source/JavaScriptCore/runtime/Structure.h_sec2
523	DEFINE_BITFIELD(bool, hasCustomGetterSetterProperties, HasCustomGetterSetterProperties, 1, 25);	527	DEFINE_BITFIELD(bool, hasCustomGetterSetterProperties, HasCustomGetterSetterProperties, 1, 25);
524	DEFINE_BITFIELD(bool, didWatchInternalProperties, DidWatchInternalProperties, 1, 26);	528	DEFINE_BITFIELD(bool, didWatchInternalProperties, DidWatchInternalProperties, 1, 26);
525	DEFINE_BITFIELD(bool, transitionWatchpointIsLikelyToBeFired, TransitionWatchpointIsLikelyToBeFired, 1, 27);	529	DEFINE_BITFIELD(bool, transitionWatchpointIsLikelyToBeFired, TransitionWatchpointIsLikelyToBeFired, 1, 27);
		530	DEFINE_BITFIELD(bool, hasBeenDictionary, HasBeenDictionary, 1, 28);
526		531
527	private:	532	private:
528	friend class LLIntOffsetsExtractor;	533	friend class LLIntOffsetsExtractor;

Return to Bug 149047

Lines 208-213 Structure::Structure(VM& vm, JSGlobalObj Source/JavaScriptCore/runtime/Structure.cpp_sec1
- Source/JavaScriptCore/runtime/Structure.cpp -1 / +11 lines
208	setStaticFunctionsReified(false);	208	setStaticFunctionsReified(false);
209	setHasRareData(false);	209	setHasRareData(false);
210	setTransitionWatchpointIsLikelyToBeFired(false);	210	setTransitionWatchpointIsLikelyToBeFired(false);
		211	setHasBeenDictionary(false);
211		212
212	ASSERT(inlineCapacity <= JSFinalObject::maxInlineCapacity());	213	ASSERT(inlineCapacity <= JSFinalObject::maxInlineCapacity());
213	ASSERT(static_cast<PropertyOffset>(inlineCapacity) < firstOutOfLineOffset);	214	ASSERT(static_cast<PropertyOffset>(inlineCapacity) < firstOutOfLineOffset);
Lines 239-244 Structure::Structure(VM& vm) Source/JavaScriptCore/runtime/Structure.cpp_sec2
239	setStaticFunctionsReified(false);	240	setStaticFunctionsReified(false);
240	setHasRareData(false);	241	setHasRareData(false);
241	setTransitionWatchpointIsLikelyToBeFired(false);	242	setTransitionWatchpointIsLikelyToBeFired(false);
		243	setHasBeenDictionary(false);
242		244
243	TypeInfo typeInfo = TypeInfo(CellType, StructureFlags);	245	TypeInfo typeInfo = TypeInfo(CellType, StructureFlags);
244	m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), 0, typeInfo);	246	m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), 0, typeInfo);
Lines 268-273 Structure::Structure(VM& vm, Structure* Source/JavaScriptCore/runtime/Structure.cpp_sec3
268	setDidTransition(true);	270	setDidTransition(true);
269	setStaticFunctionsReified(previous->staticFunctionsReified());	271	setStaticFunctionsReified(previous->staticFunctionsReified());
270	setHasRareData(false);	272	setHasRareData(false);
		273	setHasBeenDictionary(previous->hasBeenDictionary());
271		274
272	TypeInfo typeInfo = previous->typeInfo();	275	TypeInfo typeInfo = previous->typeInfo();
273	m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), previous->indexingTypeIncludingHistory(), typeInfo);	276	m_blob = StructureIDBlob(vm.heap.structureIDTable().allocateID(this), previous->indexingTypeIncludingHistory(), typeInfo);
Lines 537-543 Structure* Structure::toDictionaryTransi Source/JavaScriptCore/runtime/Structure.cpp_sec4
537	transition->m_offset = structure->m_offset;	540	transition->m_offset = structure->m_offset;
538	transition->setDictionaryKind(kind);	541	transition->setDictionaryKind(kind);
539	transition->pin();	542	transition->pin();
540	transition->setTransitionWatchpointIsLikelyToBeFired(true);	543	transition->setHasBeenDictionary(true);
541		544
542	transition->checkOffsetConsistency();	545	transition->checkOffsetConsistency();
543	return transition;	546	return transition;
Lines 1156-1161 void Structure::dump(PrintStream& out) c Source/JavaScriptCore/runtime/Structure.cpp_sec5
1156		1159
1157	switch (dictionaryKind()) {	1160	switch (dictionaryKind()) {
1158	case NoneDictionaryKind:	1161	case NoneDictionaryKind:
		1162	if (hasBeenDictionary())
		1163	out.print(", Has been dictionary");
1159	break;	1164	break;
1160	case CachedDictionaryKind:	1165	case CachedDictionaryKind:
1161	out.print(", Dictionary");	1166	out.print(", Dictionary");
Lines 1164-1169 void Structure::dump(PrintStream& out) c Source/JavaScriptCore/runtime/Structure.cpp_sec6
1164	out.print(", UncacheableDictionary");	1169	out.print(", UncacheableDictionary");
1165	break;	1170	break;
1166	}	1171	}
		1172
		1173	if (transitionWatchpointSetIsStillValid())
		1174	out.print(", Leaf");
		1175	else if (transitionWatchpointIsLikelyToBeFired())
		1176	out.print(", Shady leaf");
1167		1177
1168	out.print("]");	1178	out.print("]");
1169	}	1179	}

Lines 1-3 Source/JavaScriptCore/ChangeLog_sec1
- Source/JavaScriptCore/ChangeLog +19 lines
		1	2015-09-10 Filip Pizlo <fpizlo@apple.com>
		2
		3	Structure should be able to tell you if it had ever been a dictionary
		4	https://bugs.webkit.org/show_bug.cgi?id=149047
		5
		6	Reviewed by NOBODY (OOPS!).
		7
		8	Introduces the hasBeenDictionary flag to Structure, which tells you if this structure or
		9	any of its ancestors is a dictionary. We already implicitly tracked this for DFG
		10	watchpoint optimizations, so this is mainly just decoupling that existing logic from
		11	watchpoints. Having Structure::hasBeenDictionary() enables some of the heuristics in the
		12	property type inference work (https://bugs.webkit.org/show_bug.cgi?id=148610).
		13
		14	* runtime/Structure.cpp:
		15	(JSC::Structure::Structure):
		16	(JSC::Structure::toDictionaryTransition):
		17	(JSC::Structure::dump):
		18	* runtime/Structure.h:
		19
1	2015-09-10 Yusuke Suzuki <utatane.tea@gmail.com>	20	2015-09-10 Yusuke Suzuki <utatane.tea@gmail.com>
2		21
3	Unreviewed, fix Windows file loading in JSC shell after r189583	22	Unreviewed, fix Windows file loading in JSC shell after r189583