Bug 215639 – REGRESSION (r265775): DFG ASSERTION FAILED: AI-clobberize disagreement; AI says FoldedClobber while clobberize says (Direct:[], Super:[])

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Ryan Haddad]

Seeing the following assertion failure on the debug JSC bot:

DFG ASSERTION FAILED: AI-clobberize disagreement; AI says FoldedClobber while clobberize says (Direct:[], Super:[])
./dfg/DFGCFAPhase.cpp(240) : void JSC::DFG::CFAPhase::performBlockCFA(JSC::DFG::BasicBlock *)

While handling node D@30

Graph at time of failure:

       12: DFG for test3#<no-hash>:[0x10d7bcab0->0x10d7bc5f0->0x10d7e5300, DFGFunctionCall, 29 (NeverInline)]:
       12:   Fixpoint state: FixpointNotConverged; Form: ThreadedCPS; Unification state: GloballyUnified; Ref count state: EverythingIsLive
       12:   Arguments for block#0: D@0

     0 12: Block #0 (bc#0): (OSR target)
     0 12:   Execution count: 1.000000
     0 12:   Predecessors:
     0 12:   Successors:
     0 12:   Dominated by: #root #0
     0 12:   Dominates: #0
     0 12:   Dominance Frontier: 
     0 12:   Iterated Dominance Frontier: 
     0 12:   States: StructuresAreWatched
     0 12:   Vars Before: arg0:(BytecodeTop, TOP, TOP, none:StructuresAreClobbered)
     0 12:   Intersected Vars Before: arg0:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc0:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc1:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc2:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc3:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc4:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc5:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc6:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc7:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc8:(FullTop, TOP, TOP, none:StructuresAreClobbered) loc9:(FullTop, TOP, TOP, none:StructuresAreClobbered)
     0 12:   Var Links: arg0:D@0
  0  0 12:    D@0:< 1:->	SetArgumentDefinitely(IsFlushed, this(a), W:SideState, bc#0, ExitValid)  predicting OtherObj
  1  0 12:    D@1:< 1:->	JSConstant(JS|PureInt, Other, Undefined, bc#0, ExitValid)
  2  0 12:    D@2:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc0, W:SideState, ClobbersExit, bc#0, ExitValid)
  3  0 12:    D@3:< 1:->	SetLocal(Check:Untyped:D@1, loc0(B~<Other>/FlushedJSValue), W:Stack(loc0), bc#0, ExitInvalid)  predicting Other
  4  0 12:    D@4:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc1, W:SideState, ClobbersExit, bc#0, ExitInvalid)
  5  0 12:    D@5:< 1:->	SetLocal(Check:Untyped:D@1, loc1(C~<Other>/FlushedJSValue), W:Stack(loc1), bc#0, ExitInvalid)  predicting Other
  6  0 12:    D@6:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc2, W:SideState, ClobbersExit, bc#0, ExitInvalid)
  7  0 12:    D@7:< 1:->	SetLocal(Check:Untyped:D@1, loc2(D~<Other>/FlushedJSValue), W:Stack(loc2), bc#0, ExitInvalid)  predicting Other
  8  0 12:    D@8:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc3, W:SideState, ClobbersExit, bc#0, ExitInvalid)
  9  0 12:    D@9:< 1:->	SetLocal(Check:Untyped:D@1, loc3(E~<Other>/FlushedJSValue), W:Stack(loc3), bc#0, ExitInvalid)  predicting Other
 10  0 12:   D@10:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc4, W:SideState, ClobbersExit, bc#0, ExitInvalid)
 11  0 12:   D@11:< 1:->	SetLocal(Check:Untyped:D@1, loc4(F~<Other>/FlushedJSValue), W:Stack(loc4), bc#0, ExitInvalid)  predicting Other
 12  0 12:   D@12:<!0:->	MovHint(Check:Untyped:D@1, MustGen, loc5, W:SideState, ClobbersExit, bc#0, ExitInvalid)
 13  0 12:   D@13:< 1:->	SetLocal(Check:Untyped:D@1, loc5(G~<Other>/FlushedJSValue), W:Stack(loc5), bc#0, ExitInvalid)  predicting Other
 14  0 12:   D@14:< 1:->	JSConstant(JS|PureInt, Function, Weak:Object: 0x10d7f65e0 with butterfly 0x0 (Structure %BO:Function), StructureID: 37855, bc#1, ExitValid)
 15  0 12:   D@15:< 1:->	JSConstant(JS|UseAsOther, OtherObj, Weak:Object: 0x10d2b4068 with butterfly 0x0 (Structure %BG:JSGlobalLexicalEnvironment), StructureID: 39390, bc#1, ExitValid)
 16  0 12:   D@16:<!0:->	MovHint(Check:Untyped:D@15, MustGen, loc4, W:SideState, ClobbersExit, bc#1, ExitValid)
 17  0 12:   D@17:< 1:->	SetLocal(Check:Untyped:D@15, loc4(H~<Object>/FlushedJSValue), W:Stack(loc4), bc#1, exit: bc#3, ExitValid)  predicting OtherObj
 18  0 12:   D@18:<!0:->	MovHint(Check:Untyped:D@15, MustGen, loc5, W:SideState, ClobbersExit, bc#3, ExitValid)
 19  0 12:   D@19:< 1:->	SetLocal(Check:Untyped:D@15, loc5(I~<Object>/FlushedJSValue), W:Stack(loc5), bc#3, exit: bc#6, ExitValid)  predicting OtherObj
 20  0 12:   D@20:<!0:->	InvalidationPoint(MustGen, W:SideState, Exits, bc#6, ExitValid)
 21  0 12:   D@21:< 1:->	JSConstant(JS|UseAsOther, OtherObj, Weak:Object: 0x10d5fa068 with butterfly 0x18078e88d8 (Structure %B2:global), StructureID: 32425, bc#7, ExitValid)
 22  0 12:   D@22:<!0:->	MovHint(Check:Untyped:D@21, MustGen, loc7, W:SideState, ClobbersExit, bc#7, ExitValid)
 23  0 12:   D@23:<!0:->	Check(MustGen, bc#7, ExitInvalid)
 24  0 12:   D@24:< 1:->	SetLocal(Check:Untyped:D@21, loc7(J~<Object>/FlushedJSValue), W:Stack(loc7), bc#7, exit: bc#14, ExitValid)  predicting OtherObj
 25  0 12:   D@25:<!0:->	Check(MustGen, bc#14, ExitValid)
 26  0 12:   D@26:< 1:->	JSConstant(JS|UseAsOther, Array, Weak:Object: 0x10d2979e8 with butterfly 0x18078e40d0 (Structure %EO:Array,ArrayWithContiguous), StructureID: 3285, bc#14, ExitValid)
 27  0 12:   D@27:<!0:->	MovHint(Check:Untyped:D@26, MustGen, loc8, W:SideState, ClobbersExit, bc#14, ExitValid)
 28  0 12:   D@28:< 1:->	SetLocal(Check:Untyped:D@26, loc8(K~<Array>/FlushedJSValue), W:Stack(loc8), bc#14, exit: bc#22, ExitValid)  predicting Array
 29  0 12:   D@29:< 1:->	JSConstant(JS|PureNum|UseAsOther|UseAsInt|ReallyWantsInt, NonBoolInt32, Int32: 5, bc#22, ExitValid)
 30  0 12:   D@35:<!0:->	CheckStructure(Cell:D@26, MustGen, [%EO:Array,ArrayWithContiguous], R:JSCell_structureID, Exits, bc#22, ExitValid)
 31  0 12:   D@36:< 1:->	GetButterfly(Cell:D@26, Storage|PureInt, R:JSObject_butterfly, Exits, bc#22, ExitValid)
 32  0 12:   D@30:< 1:->	GetByVal(KnownCell:D@26, Int32:D@29, Check:Untyped:D@36, JS|VarArgs|UseAsOther, Other, Contiguous+OriginalCopyOnWriteArray+OutOfBoundsSaneChain+AsIs+Read, R:Butterfly_publicLength,IndexedContiguousProperties, Exits, bc#22, ExitValid)  predicting Other
 33  0 12:   D@31:<!0:->	MovHint(Check:Untyped:D@30, MustGen, loc6, W:SideState, ClobbersExit, bc#22, ExitInvalid)
 34  0 12:   D@32:< 1:->	SetLocal(Check:Untyped:D@30, loc6(L~<Other>/FlushedJSValue), W:Stack(loc6), bc#22, exit: bc#27, ExitValid)  predicting Other
 35  0 12:   D@33:<!0:->	Return(Check:Untyped:D@30, MustGen, W:SideState, Exits, bc#27, ExitValid)
 36  0 12:   D@34:<!0:->	Flush(Check:Untyped:D@0, MustGen|IsFlushed, this(a), R:Stack(this), W:SideState, bc#27, ExitValid)  predicting OtherObj
     0 12:   States: InvalidBranchDirection, StructuresAreWatched
     0 12:   Vars After: 
     0 12:   Var Links: arg0:D@0 loc0:D@3 loc1:D@5 loc2:D@7 loc3:D@9 loc4:D@17 loc5:D@19 loc6:D@32 loc7:D@24 loc8:D@28

       12: GC Values:
       12:     Weak:Object: 0x10d2979e8 with butterfly 0x18078e40d0 (Structure %EO:Array,ArrayWithContiguous), StructureID: 3285
       12:     Weak:Object: 0x10d5fa068 with butterfly 0x18078e88d8 (Structure %B2:global), StructureID: 32425
       12:     Weak:Object: 0x10d2b4068 with butterfly 0x0 (Structure %BG:JSGlobalLexicalEnvironment), StructureID: 39390
       12:     Weak:Object: 0x10d7f65e0 with butterfly 0x0 (Structure %BO:Function), StructureID: 37855
       12: Desired watchpoints:
       12:     Watchpoint sets: 0x10d29a680
       12:     Inline watchpoint sets: 0x10d7f9b08, 0x10d2cd0c0, 0x10d7f9788, 0x10d2cd280, 0x10d7f8448, 0x10d7f9478, 0x10d7f91d8, 0x10d7f9f68
       12:     SymbolTables: 
       12:     FunctionExecutables: 0x10d7e5300
       12:     Buffer views: 
       12:     Object property conditions: 
       12: Structures:
       12:     %B2:global                     = 0x10d7cd810:[0x7ea9, global, {Object:100, Function:101, Array:102, RegExp:103, String:104, Promise:105, BigInt:106, Intl:107, $vm:108, WebAssembly:109, Symbol.toStringTag:110, debug:111, describe:112, describeArray:113, print:114, printErr:115, quit:116, gc:117, fullGC:118, edenGC:119, gcHeapSize:120, MemoryFootprint:121, resetMemoryPeak:122, addressOf:123, version:124, run:125, runString:126, load:127, loadString:128, readFile:129, read:130, checkSyntax:131, sleepSeconds:132, jscStack:133, readline:134, preciseTime:135, neverInlineFunction:136, noInline:137, noDFG:138, noFTL:139, noOSRExitFuzzing:140, numberOfDFGCompiles:141, callerIsOMGCompiled:142, jscOptions:143, optimizeNextInvocation:144, reoptimizationRetryCount:145, transferArrayBuffer:146, failNextNewCodeBlock:147, OSRExit:148, isFinalTier:149, predictInt32:150, isInt32:151, isPureNaN:152, fiatInt52:153, effectful42:154, makeMasquerader:155, hasCustomProperties:156, createGlobalObject:157, createHeapBigInt:158, useBigInt32:159, isBigInt32:160, isHeapBigInt:161, dumpTypesForAllVariables:162, drainMicrotasks:163, setTimeout:164, releaseWeakRefs:165, finalizationRegistryLiveCount:166, finalizationRegistryDeadCount:167, getRandomSeed:168, setRandomSeed:169, isRope:170, callerSourceOrigin:171, is32BitPlatform:172, checkModuleSyntax:173, platformSupportsSamplingProfiler:174, generateHeapSnapshot:175, generateHeapSnapshotForGCDebugging:176, resetSuperSamplerState:177, ensureArrayStorage:178, startSamplingProfiler:179, samplingProfilerStackTraces:180, stress/folding-get-by-val-with-immutable-butterfly-out-of-bounds-foldable.js.mini-mode: DFG ASSERTION FAILED: AI-clobberize disagreement; AI says FoldedClobber while clobberize says (Direct:[], Super:[])
stress/folding-get-by-val-with-immutable-butterfly-out-of-bounds-foldable.js.mini-mode: ./dfg/DFGCFAPhase.cpp(240) : void JSC::DFG::CFAPhase::performBlockCFA(JSC::DFG::BasicBlock *)
stress/folding-get-by-val-with-immutable-butterfly-out-of-bounds-foldable.js.mini-mode: 


https://build.webkit.org/builders/Apple-Catalina-Debug-JSC-Tests/builds/1366

[Radar WebKit Bug Importer]

<rdar://problem/67376432>

[Ryan Haddad]

https://trac.webkit.org/changeset/265775/webkit is the only JSC change in the regression range.

[Saam Barati]

Should be easy to fix.

[Saam Barati]

fix forthcoming

[Saam Barati]

Created attachment 406855 [details]
patch

[Robin Morisset]

Comment on attachment 406855 [details]
patch

r=me

[EWS]

Committed r265893: <https://trac.webkit.org/changeset/265893>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 406855 [details].