JIT: Non-void ThrowHelpers

[EgorBo]

If a method is "never returns" and has a non-void type - its basic-block won't be cold and converted to BBJ_THROW.

publicvoidTest(boolcondition){Console.WriteLine(condition?SomeProperty:100);}publicintSomeProperty=>thrownewNotImplementedException("not implemented on this platform");

Codegen:

; Method P:Test(bool):thisG_M12917_IG01:  4883EC28 subrsp,40G_M12917_IG02:  84D2 testdl,dl7507jne SHORT G_M12917_IG04G_M12917_IG03:  B964000000 movecx,100 EB07 jmp SHORT G_M12917_IG05G_M12917_IG04:  E89CE1FFFF call P:get_SomeProperty():int:this 8BC8 movecx,eaxG_M12917_IG05:  4883C428 addrsp,40 E951F5FFFF jmp System.Console:WriteLine(int); Total bytes of code: 31

New codegen:

; Method P:Test(System.Object):int:thisG_M12917_IG01:  4883EC28 subrsp,40G_M12917_IG02:  84D2 testdl,dl 750E jne SHORT G_M12917_IG04 B964000000 movecx,100G_M12917_IG03:  4883C428 addrsp,40 E9B2F6FFFF jmp System.Console:WriteLine(int)G_M12917_IG04:  E835DBFFFF call P:get_SomeProperty():int:this CC int3; Total bytes of code: 28

Jit-diff (--pmi -f):

PMI CodeSize Diffs for System.Private.CoreLib.dll, framework assemblies for default jit
Summary of Code Size diffs:
(Lower is better)
Total bytes of base: 53821921
Total bytes of diff: 53816840
Total bytes of delta: -5081 (-0.01% of base)
diff is an improvement.
Top file regressions (bytes):
23 : Microsoft.Diagnostics.Tracing.TraceEvent.dasm (0.00% of base)
Top file improvements (bytes):
-1887 : FSharp.Core.dasm (-0.05% of base)
-1076 : System.Transactions.Local.dasm (-0.95% of base)
-1062 : System.Private.DataContractSerialization.dasm (-0.14% of base)
-786 : System.Private.Xml.dasm (-0.02% of base)
-75 : System.CodeDom.dasm (-0.04% of base)
-47 : System.Private.CoreLib.dasm (-0.00% of base)
-46 : System.Net.Primitives.dasm (-0.07% of base)
-27 : System.Net.Ping.dasm (-0.16% of base)
-20 : System.Net.Quic.dasm (-0.03% of base)
-15 : System.Data.Odbc.dasm (-0.01% of base)
-15 : System.Data.OleDb.dasm (-0.01% of base)
-15 : Microsoft.CodeAnalysis.dasm (-0.00% of base)
-14 : System.Net.Http.dasm (-0.00% of base)
-10 : System.Net.Sockets.dasm (-0.01% of base)
-5 : Microsoft.CodeAnalysis.VisualBasic.dasm (-0.00% of base)
-4 : System.Text.Json.dasm (-0.00% of base)
17 total files with Code Size differences (16 improved, 1 regressed), 254 unchanged.
Top method regressions (bytes):
123 ( 3.11% of base) : FSharp.Core.dasm - ArrayModule:transposeArrays(ref):ref (8 methods)
41 ( 1.24% of base) : Microsoft.Diagnostics.Tracing.TraceEvent.dasm - TraceEvent:PayloadString(int,IFormatProvider):String:this
25 ( 0.96% of base) : FSharp.Core.dasm - ArrayModule:Skip(int,ref):ref (8 methods)
21 ( 0.37% of base) : FSharp.Core.dasm - ArrayModule:GetSubArray(ref,int,int):ref (8 methods)
11 ( 0.29% of base) : FSharp.Core.dasm - ArrayModule:Zip(ref,ref):ref (8 methods)
11 ( 4.49% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):__Canon
11 ( 5.16% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):Vector`1
11 ( 6.04% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):Nullable`1
8 ( 0.32% of base) : FSharp.Core.dasm - ArrayModule:Iterate2(FSharpFunc`2,ref,ref) (8 methods)
8 ( 0.32% of base) : FSharp.Core.dasm - ArrayModule:IterateIndexed2(FSharpFunc`2,ref,ref) (8 methods)
8 ( 0.32% of base) : FSharp.Core.dasm - ArrayModule:Exists2(FSharpFunc`2,ref,ref):bool (8 methods)
8 ( 0.32% of base) : FSharp.Core.dasm - ArrayModule:ForAll2(FSharpFunc`2,ref,ref):bool (8 methods)
7 ( 0.43% of base) : System.Private.CoreLib.dasm - ModuleBuilder:GetMethodTokenNoLock(MethodInfo,bool):int:this
7 ( 4.14% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):double
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToInt64(DateTime):long
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToUInt64(DateTime):long
5 (16.67% of base) : System.Private.CoreLib.dasm - Convert:ToSingle(DateTime):float
5 (16.67% of base) : System.Private.CoreLib.dasm - Convert:ToDouble(DateTime):double
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToByte(DateTime):ubyte
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToInt16(DateTime):short
Top method improvements (bytes):
-661 (-5.01% of base) : FSharp.Core.dasm - Array2DModule:CopyTo(ref,int,int,ref,int,int,int,int) (8 methods)
-449 (-44.37% of base) : System.Transactions.Local.dasm - TransactionStatePromoted:EnterState(InternalTransaction):this
-308 (-19.82% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:Export(ICollection`1):this (2 methods)
-306 (-18.04% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:CanExport(ICollection`1):bool:this (2 methods)
-198 (-39.84% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:AddKnownTypes():this
-154 (-12.01% of base) : System.Private.Xml.dasm - <ReadElementContentAsBase64Async>d__38:MoveNext():this
-154 (-12.01% of base) : System.Private.Xml.dasm - <ReadElementContentAsBinHexAsync>d__39:MoveNext():this
-148 (-14.99% of base) : System.Private.Xml.dasm - <ReadContentAsBase64Async>d__36:MoveNext():this
-148 (-14.99% of base) : System.Private.Xml.dasm - <ReadContentAsBinHexAsync>d__37:MoveNext():this
-107 (-7.29% of base) : FSharp.Core.dasm - List:takeFreshConsTail(FSharpList`1,int,FSharpList`1) (8 methods)
-106 (-38.69% of base) : System.Private.Xml.dasm - XmlEventCache:Dispose(bool):this
-91 (-15.24% of base) : FSharp.Core.dasm - RuntimeHelpers:getCurr@311-1(FSharpRef`1,FSharpRef`1,Unit):IEnumerable`1 (8 methods)
-77 (-4.42% of base) : System.Transactions.Local.dasm - TransactionManager:Reenlist(Guid,ref,IEnlistmentNotification):Enlistment
-74 (-13.05% of base) : System.Transactions.Local.dasm - TransactionInterop:GetTransactionFromExportCookie(ref):Transaction
-72 (-75.79% of base) : System.Private.DataContractSerialization.dasm - XmlObjectSerializerReadContextComplex:ResolveDataContractInSharedTypeMode(String,String,byref,byref):DataContract:this
-64 (-65.98% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:Export():this
-63 (-18.42% of base) : System.Transactions.Local.dasm - TransactionInterop:GetExportCookie(Transaction,ref):ref
-56 (-25.69% of base) : System.Transactions.Local.dasm - TransactionInterop:GetTransmitterPropagationToken(Transaction):ref
-56 (-25.69% of base) : System.Transactions.Local.dasm - TransactionInterop:GetDtcTransaction(Transaction):IDtcTransaction
-56 (-28.00% of base) : System.Transactions.Local.dasm - TransactionInterop:GetTransactionFromDtcTransaction(IDtcTransaction):Transaction
Top method regressions (percentages):
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToInt64(DateTime):long
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToUInt64(DateTime):long
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToByte(DateTime):ubyte
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToInt16(DateTime):short
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToUInt16(DateTime):ushort
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToInt32(DateTime):int
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToUInt32(DateTime):int
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToBoolean(DateTime):bool
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToChar(DateTime):ushort
5 (18.52% of base) : System.Private.CoreLib.dasm - Convert:ToSByte(DateTime):byte
5 (16.67% of base) : System.Private.CoreLib.dasm - Convert:ToSingle(DateTime):float
5 (16.67% of base) : System.Private.CoreLib.dasm - Convert:ToDouble(DateTime):double
11 ( 6.04% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):Nullable`1
11 ( 5.16% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):Vector`1
11 ( 4.49% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):__Canon
7 ( 4.14% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):double
123 ( 3.11% of base) : FSharp.Core.dasm - ArrayModule:transposeArrays(ref):ref (8 methods)
5 ( 2.84% of base) : System.Net.Primitives.dasm - IPAddress:IsLoopback(IPAddress):bool
3 ( 1.83% of base) : FSharp.Core.dasm - IEnumerator:getCurrent@238(FSharpFunc`2,FSharpRef`1,FSharpRef`1,Unit):int
1 ( 1.82% of base) : System.Transactions.Local.dasm - TransactionStatePromotedBase:CreateBlockingClone(InternalTransaction):this
Top method improvements (percentages):
-72 (-75.79% of base) : System.Private.DataContractSerialization.dasm - XmlObjectSerializerReadContextComplex:ResolveDataContractInSharedTypeMode(String,String,byref,byref):DataContract:this
-64 (-65.98% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:Export():this
-449 (-44.37% of base) : System.Transactions.Local.dasm - TransactionStatePromoted:EnterState(InternalTransaction):this
-198 (-39.84% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:AddKnownTypes():this
-106 (-38.69% of base) : System.Private.Xml.dasm - XmlEventCache:Dispose(bool):this
-52 (-37.96% of base) : System.Transactions.Local.dasm - TransactionInterop:GetWhereabouts():ref
-32 (-37.21% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):ubyte:this
-32 (-37.21% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):short:this
-32 (-37.21% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):int:this
-32 (-37.21% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):long:this
-32 (-37.21% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):Nullable`1:this
-32 (-35.96% of base) : FSharp.Core.dasm - BaseRangeEnumerator`1:getCurrent(BaseRangeEnumerator`1):double:this
-31 (-35.23% of base) : System.Net.Primitives.dasm - IPAddress:.ctor(ref,long):this
-9 (-29.03% of base) : System.Private.DataContractSerialization.dasm - XsdDataContractExporter:AddType(Type):this
-56 (-28.00% of base) : System.Transactions.Local.dasm - TransactionInterop:GetTransactionFromDtcTransaction(IDtcTransaction):Transaction
-20 (-25.97% of base) : System.Net.Primitives.dasm - IPAddress:.ctor(ref):this
-56 (-25.69% of base) : System.Transactions.Local.dasm - TransactionInterop:GetTransmitterPropagationToken(Transaction):ref
-56 (-25.69% of base) : System.Transactions.Local.dasm - TransactionInterop:GetDtcTransaction(Transaction):IDtcTransaction
-11 (-23.91% of base) : FSharp.Core.dasm - OperatorIntrinsics:current@5245(VariableStepIntegralRangeState`1,Unit):int
-11 (-23.91% of base) : FSharp.Core.dasm - OperatorIntrinsics:current@5245-3(VariableStepIntegralRangeState`1,Unit):int
240 total methods with Code Size differences (203 improved, 37 regressed), 267870 unchanged.
--------------------------------------------------------------------------------
Completed analysis in 31.16s

Regressions -- more blocks are now cold (additional jumps)
Example: https://www.diffchecker.com/xiYGrCam (ToSingle will throw an exception for T=DateTime)

[EgorBo]

@dotnet/jit-contrib PTAL, will address LazyStringHelper problem separately, the new jit-diff is -5081

[AndyAyersMS]

Do you need AllowUnsafeBlocks for your test case?