Inline ValueOption module

[kerams]

Continuing with #14927 and https://github.com/fsharp/fslang-design/blob/main/RFCs/FS-1115-InlineIfLambda-in-FSharp-Core.md.

Benchmark 1

Code

openBenchmarkDotNet.AttributesopenBenchmarkDotNet.ConfigsmoduleInline =let inlinedefaultWith defThunk option =match option with| ValueNone -> defThunk ()| ValueSome v -> v
let inlinemap mapping option =match option with| ValueNone -> ValueNone
| ValueSome x -> ValueSome (mapping x)moduleInlineAndLambda =let inlinedefaultWith([<InlineIfLambda>]defThunk)option =match option with| ValueNone -> defThunk ()| ValueSome v -> v
let inlinemap([<InlineIfLambda>]mapping)option =match option with| ValueNone -> ValueNone
| ValueSome x -> ValueSome (mapping x)// Some function with a bunch of instructions that isn't going to cause lambda inlining without InlineIfLambdalet inliney()=if1/1=1then100/100else2/3[<MemoryDiagnoser>]typeCurrent()=lets= ValueSome System.DateTime.Now.Day
letn= ValueOption<int>.None
[<NoCompilerInlining>]letf=10[<Benchmark>]member_.DefaultWithSingletonNone()=
ValueOption.defaultWith (fun()->41+ y ()) n
[<Benchmark>]member_.DefaultWithNone()=
ValueOption.defaultWith (fun()->42+ f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
ValueOption.map (fun x -> x +43+ y ()) s
[<Benchmark>]member_.MapSingletonNone()=
ValueOption.map (fun x -> x +44+ y ()) n
[<Benchmark>]member_.MapSome()=
ValueOption.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
ValueOption.map (fun x -> x + f + y ()) n
[<MemoryDiagnoser>]typeInline()=lets= ValueSome System.DateTime.Now.Day
letn= ValueOption<int>.None
[<NoCompilerInlining>]letf=10[<Benchmark>]member_.DefaultWithSingletonNone()=
Inline.defaultWith (fun()->41+ y ()) n
[<Benchmark>]member_.DefaultWithNone()=
Inline.defaultWith (fun()->42+ f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
Inline.map (fun x -> x +43+ y ()) s
[<Benchmark>]member_.MapSingletonNone()=
Inline.map (fun x -> x +44+ y ()) n
[<Benchmark>]member_.MapSome()=
Inline.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
Inline.map (fun x -> x + f + y ()) n
[<MemoryDiagnoser>]typeInlineAndLambda()=lets= ValueSome System.DateTime.Now.Day
letn= ValueOption<int>.None
[<NoCompilerInlining>]letf=10[<Benchmark>]member_.DefaultWithSingletonNone()=
InlineAndLambda.defaultWith (fun()->41+ y ()) n
[<Benchmark>]member_.DefaultWithNone()=
InlineAndLambda.defaultWith (fun()->42+ f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
InlineAndLambda.map (fun x -> x +43+ y ()) s
[<Benchmark>]member_.MapSingletonNone()=
InlineAndLambda.map (fun x -> x +44+ y ()) n
[<Benchmark>]member_.MapSome()=
InlineAndLambda.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
InlineAndLambda.map (fun x -> x + f + y ()) n
BenchmarkDotNet.Running.BenchmarkRunner.Run (
typeof<Current>.Assembly,
DefaultConfig.Instance.WithOption (ConfigOptions.JoinSummary,true))|> ignore

Decompiled

usingSystem;usingSystem.Diagnostics;usingSystem.Runtime.CompilerServices;using<StartupCode$Bench>;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Reports;usingMicrosoft.FSharp.Core;[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassProgram{publicstaticinty(){if(1/1==1){return100/100;}return2/3;}[CompilerGenerated]internalstaticintdefThunk@5(UnitunitVar0){return41+((1/1!=1)?(2/3):(100/100));}[CompilerGenerated]internalstaticintdefThunk@5-1(Program.Inline_,UnitunitVar0){return42+_.f+((1/1!=1)?(2/3):(100/100));}[CompilerGenerated]internalstaticintmapping@10(intx){returnx+43+((1/1!=1)?(2/3):(100/100));}[CompilerGenerated]internalstaticintmapping@10-1(intx){returnx+44+((1/1!=1)?(2/3):(100/100));}[CompilerGenerated]internalstaticintmapping@10-2(Program.Inline_,intx){returnx+_.f+((1/1!=1)?(2/3):(100/100));}[CompilerGenerated]internalstaticintmapping@10-3(Program.Inline_,intx){returnx+_.f+((1/1!=1)?(2/3):(100/100));}[CompilationMapping(SourceConstructFlags.Value)]internalstaticSummary[]arg@1{get{return $Program.arg@1;}}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassCurrent{publicCurrent():this(){this.s=FSharpValueOption<int>.NewValueSome(DateTime.Now.Day);this.n=FSharpValueOption<int>.ValueNone;this.f=10;}[Benchmark(43,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithSingletonNone(){returnValueOption.DefaultWith<int>(Program.DefaultWithSingletonNone@45.@_instance,this.n);}[Benchmark(47,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithNone(){returnValueOption.DefaultWith<int>(newProgram.DefaultWithNone@49(this),this.n);}[Benchmark(51,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonSome(){returnValueOption.Map<int,int>(Program.MapSingletonSome@53.@_instance,this.s);}[Benchmark(55,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonNone(){returnValueOption.Map<int,int>(Program.MapSingletonNone@57.@_instance,this.n);}[Benchmark(59,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSome(){returnValueOption.Map<int,int>(newProgram.MapSome@61(this),this.s);}[Benchmark(63,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapNone(){returnValueOption.Map<int,int>(newProgram.MapNone@65(this),this.n);}internalFSharpValueOption<int>s;internalFSharpValueOption<int>n;[NoCompilerInlining]internalintf;}[Serializable]internalsealedclassDefaultWithSingletonNone@45:FSharpFunc<Unit,int>{[CompilerGenerated][DebuggerNonUserCode]internalDefaultWithSingletonNone@45(){}publicoverrideintInvoke(UnitunitVar0){return41+((1/1!=1)?(2/3):(100/100));}// Note: this type is marked as 'beforefieldinit'.staticDefaultWithSingletonNone@45(){}internalstaticreadonlyProgram.DefaultWithSingletonNone@45@_instance=newProgram.DefaultWithSingletonNone@45();}[Serializable]internalsealedclassDefaultWithNone@49:FSharpFunc<Unit,int>{[CompilerGenerated][DebuggerNonUserCode]internalDefaultWithNone@49(Program.Current_){this._=_;}publicoverrideintInvoke(UnitunitVar0){return42+this._.f+((1/1!=1)?(2/3):(100/100));}publicProgram.Current_;}[Serializable]internalsealedclassMapSingletonSome@53:FSharpFunc<int,int>{[CompilerGenerated][DebuggerNonUserCode]internalMapSingletonSome@53(){}publicoverrideintInvoke(intx){returnx+43+((1/1!=1)?(2/3):(100/100));}// Note: this type is marked as 'beforefieldinit'.staticMapSingletonSome@53(){}internalstaticreadonlyProgram.MapSingletonSome@53@_instance=newProgram.MapSingletonSome@53();}[Serializable]internalsealedclassMapSingletonNone@57:FSharpFunc<int,int>{[CompilerGenerated][DebuggerNonUserCode]internalMapSingletonNone@57(){}publicoverrideintInvoke(intx){returnx+44+((1/1!=1)?(2/3):(100/100));}// Note: this type is marked as 'beforefieldinit'.staticMapSingletonNone@57(){}internalstaticreadonlyProgram.MapSingletonNone@57@_instance=newProgram.MapSingletonNone@57();}[Serializable]internalsealedclassMapSome@61:FSharpFunc<int,int>{[CompilerGenerated][DebuggerNonUserCode]internalMapSome@61(Program.Current_){this._=_;}publicoverrideintInvoke(intx){returnx+this._.f+((1/1!=1)?(2/3):(100/100));}publicProgram.Current_;}[Serializable]internalsealedclassMapNone@65:FSharpFunc<int,int>{[CompilerGenerated][DebuggerNonUserCode]internalMapNone@65(Program.Current_){this._=_;}publicoverrideintInvoke(intx){returnx+this._.f+((1/1!=1)?(2/3):(100/100));}publicProgram.Current_;}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassInline{publicInline():this(){this.s=FSharpValueOption<int>.NewValueSome(DateTime.Now.Day);this.n=FSharpValueOption<int>.ValueNone;this.f=10;}[Benchmark(77,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithSingletonNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}returnProgram.defThunk@5(null);}[Benchmark(81,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}returnProgram.defThunk@5-1(this,null);}[Benchmark(85,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonSome(){FSharpValueOption<int>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){intitem=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(Program.mapping@10(item));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(89,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){intitem=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(Program.mapping@10-1(item));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(93,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSome(){FSharpValueOption<int>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){intitem=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(Program.mapping@10-2(this,item));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(97,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){intitem=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(Program.mapping@10-3(this,item));}returnFSharpValueOption<int>.ValueNone;}internalFSharpValueOption<int>s;internalFSharpValueOption<int>n;[NoCompilerInlining]internalintf;}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassInlineAndLambda{publicInlineAndLambda():this(){this.s=FSharpValueOption<int>.NewValueSome(DateTime.Now.Day);this.n=FSharpValueOption<int>.ValueNone;this.f=10;}[Benchmark(111,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithSingletonNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}return41+((1/1!=1)?(2/3):(100/100));}[Benchmark(115,"C:\\code\\Test\\Bench\\Program.fs")]publicintDefaultWithNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}return42+this.f+((1/1!=1)?(2/3):(100/100));}[Benchmark(119,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonSome(){FSharpValueOption<int>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){intx=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(x+43+((1/1!=1)?(2/3):(100/100)));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(123,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSingletonNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){intx=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(x+44+((1/1!=1)?(2/3):(100/100)));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(127,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapSome(){FSharpValueOption<int>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){intx=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(x+this.f+((1/1!=1)?(2/3):(100/100)));}returnFSharpValueOption<int>.ValueNone;}[Benchmark(131,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<int>MapNone(){FSharpValueOption<int>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){intx=fsharpValueOption.Item;returnFSharpValueOption<int>.NewValueSome(x+this.f+((1/1!=1)?(2/3):(100/100)));}returnFSharpValueOption<int>.ValueNone;}internalFSharpValueOption<int>s;internalFSharpValueOption<int>n;[NoCompilerInlining]internalintf;}[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassInlineAndLambdaModule{[CompilationArgumentCounts(newint[]{1,1})]publicstaticadefaultWith<a>([InlineIfLambda]FSharpFunc<Unit,a>defThunk,FSharpValueOption<a>option){if(option.Tag==1){returnoption.Item;}returndefThunk.Invoke(null);}[CompilationArgumentCounts(newint[]{1,1})]publicstaticFSharpValueOption<b>map<a,b>([InlineIfLambda]FSharpFunc<a,b>mapping,FSharpValueOption<a>option){if(option.Tag==1){ax=option.Item;returnFSharpValueOption<b>.NewValueSome(mapping.Invoke(x));}returnFSharpValueOption<b>.ValueNone;}}[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassInlineModule{[CompilationArgumentCounts(newint[]{1,1})]publicstaticadefaultWith<a>(FSharpFunc<Unit,a>defThunk,FSharpValueOption<a>option){if(option.Tag==1){returnoption.Item;}returndefThunk.Invoke(null);}[CompilationArgumentCounts(newint[]{1,1})]publicstaticFSharpValueOption<b>map<a,b>(FSharpFunc<a,b>mapping,FSharpValueOption<a>option){if(option.Tag==1){ax=option.Item;returnFSharpValueOption<b>.NewValueSome(mapping.Invoke(x));}returnFSharpValueOption<b>.ValueNone;}}}

BenchmarkDotNet=v0.13.5, OS=Windows 11 (10.0.22621.1992/22H2/2022Update/SunValley2)
AMD Ryzen 9 7900, 1 CPU, 24 logical and 12 physical cores
.NET SDK=8.0.100-preview.6.23330.14
[Host] : .NET 8.0.0 (8.0.23.32907), X64 RyuJIT AVX2 DEBUG
DefaultJob : .NET 8.0.0 (8.0.23.32907), X64 RyuJIT AVX2

Type	Method	Mean	Error	StdDev	Gen0	Allocated
Current	DefaultWithSingletonNone	0.6079 ns	0.0107 ns	0.0100 ns	-	-
Inline	DefaultWithSingletonNone	0.0060 ns	0.0014 ns	0.0013 ns	-	-
InlineAndLambda	DefaultWithSingletonNone	0.1994 ns	0.0096 ns	0.0090 ns	-	-
Current	DefaultWithNone	3.3048 ns	0.0588 ns	0.0550 ns	0.0014	24 B
Inline	DefaultWithNone	0.1957 ns	0.0078 ns	0.0069 ns	-	-
InlineAndLambda	DefaultWithNone	0.1968 ns	0.0097 ns	0.0090 ns	-	-
Current	MapSingletonSome	3.2679 ns	0.0240 ns	0.0212 ns	-	-
Inline	MapSingletonSome	2.8726 ns	0.0082 ns	0.0076 ns	-	-
InlineAndLambda	MapSingletonSome	2.8581 ns	0.0035 ns	0.0028 ns	-	-
Current	MapSingletonNone	0.5504 ns	0.0037 ns	0.0033 ns	-	-
Inline	MapSingletonNone	0.2003 ns	0.0063 ns	0.0059 ns	-	-
InlineAndLambda	MapSingletonNone	0.2014 ns	0.0031 ns	0.0028 ns	-	-
Current	MapSome	4.6083 ns	0.0375 ns	0.0350 ns	0.0014	24 B
Inline	MapSome	3.0991 ns	0.0823 ns	0.0979 ns	-	-
InlineAndLambda	MapSome	3.0532 ns	0.0084 ns	0.0075 ns	-	-
Current	MapNone	3.0646 ns	0.0280 ns	0.0262 ns	0.0014	24 B
Inline	MapNone	0.2004 ns	0.0015 ns	0.0012 ns	-	-
InlineAndLambda	MapNone	0.2042 ns	0.0032 ns	0.0026 ns	-	-

Benchmark 2

Code

openBenchmarkDotNet.AttributesopenBenchmarkDotNet.ConfigsmoduleInline =let inlinedefaultWith defThunk option =match option with| ValueNone -> defThunk ()| ValueSome v -> v
let inlinemap mapping option =match option with| ValueNone -> ValueNone
| ValueSome x -> ValueSome (mapping x)moduleInlineAndLambda =let inlinedefaultWith([<InlineIfLambda>]defThunk)option =match option with| ValueNone -> defThunk ()| ValueSome v -> v
let inlinemap([<InlineIfLambda>]mapping)option =match option with| ValueNone -> ValueNone
| ValueSome x -> ValueSome (mapping x)// Some function with a bunch of instructions that isn't going to cause lambda inlining without InlineIfLambdalet inliney()=if1/1=1then100L /100L
else2L /3L
[<MemoryDiagnoser>]typeCurrent()=lets= ValueSome (int64 System.DateTime.Now.Day)letn= ValueOption<int64>.None
[<NoCompilerInlining>]letf=10L
[<Benchmark>]member_.DefaultWithSingletonNone()=
ValueOption.defaultWith (fun()->41L + y ()) n
[<Benchmark>]member_.DefaultWithNone()=
ValueOption.defaultWith (fun()->42L + f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
ValueOption.map (fun x -> x +43L + y ()) s
[<Benchmark>]member_.MapSingletonNone()=
ValueOption.map (fun x -> x +44L + y ()) n
[<Benchmark>]member_.MapSome()=
ValueOption.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
ValueOption.map (fun x -> x + f + y ()) n
[<MemoryDiagnoser>]typeInline()=lets= ValueSome (int64 System.DateTime.Now.Day)letn= ValueOption<int64>.None
[<NoCompilerInlining>]letf=10L
[<Benchmark>]member_.DefaultWithSingletonNone()=
Inline.defaultWith (fun()->41L + y ()) n
[<Benchmark>]member_.DefaultWithNone()=
Inline.defaultWith (fun()->42L + f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
Inline.map (fun x -> x +43L + y ()) s
[<Benchmark>]member_.MapSingletonNone()=
Inline.map (fun x -> x +44L + y ()) n
[<Benchmark>]member_.MapSome()=
Inline.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
Inline.map (fun x -> x + f + y ()) n
[<MemoryDiagnoser>]typeInlineAndLambda()=lets= ValueSome (int64 System.DateTime.Now.Day)letn= ValueOption<int64>.None
[<NoCompilerInlining>]letf=10L
[<Benchmark>]member_.DefaultWithSingletonNone()=
InlineAndLambda.defaultWith (fun()->41L + y ()) n
[<Benchmark>]member_.DefaultWithNone()=
InlineAndLambda.defaultWith (fun()->42L + f + y ()) n
[<Benchmark>]member_.MapSingletonSome()=
InlineAndLambda.map (fun x -> x +43L + y ()) s
[<Benchmark>]member_.MapSingletonNone()=
InlineAndLambda.map (fun x -> x +44L + y ()) n
[<Benchmark>]member_.MapSome()=
InlineAndLambda.map (fun x -> x + f + y ()) s
[<Benchmark>]member_.MapNone()=
InlineAndLambda.map (fun x -> x + f + y ()) n
BenchmarkDotNet.Running.BenchmarkRunner.Run (
typeof<Current>.Assembly,
DefaultConfig.Instance.WithOption (ConfigOptions.JoinSummary,true))|> ignore

Decompiled

usingSystem;usingSystem.Diagnostics;usingSystem.Runtime.CompilerServices;using<StartupCode$Bench>;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Reports;usingMicrosoft.FSharp.Core;[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassProgram{publicstaticlongy(){if(1/1==1){return100L/100L;}return2L/3L;}[CompilerGenerated]internalstaticlongdefThunk@5(UnitunitVar0){return41L+((1/1!=1)?(2L/3L):(100L/100L));}[CompilerGenerated]internalstaticlongdefThunk@5-1(Program.Inline_,UnitunitVar0){return42L+_.f+((1/1!=1)?(2L/3L):(100L/100L));}[CompilerGenerated]internalstaticlongmapping@10(longx){returnx+43L+((1/1!=1)?(2L/3L):(100L/100L));}[CompilerGenerated]internalstaticlongmapping@10-1(longx){returnx+44L+((1/1!=1)?(2L/3L):(100L/100L));}[CompilerGenerated]internalstaticlongmapping@10-2(Program.Inline_,longx){returnx+_.f+((1/1!=1)?(2L/3L):(100L/100L));}[CompilerGenerated]internalstaticlongmapping@10-3(Program.Inline_,longx){returnx+_.f+((1/1!=1)?(2L/3L):(100L/100L));}[CompilationMapping(SourceConstructFlags.Value)]internalstaticSummary[]arg@1{get{return $Program.arg@1;}}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassCurrent{publicCurrent():this(){this.s=FSharpValueOption<long>.NewValueSome((long)DateTime.Now.Day);this.n=FSharpValueOption<long>.ValueNone;this.f=10L;}[Benchmark(43,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithSingletonNone(){returnValueOption.DefaultWith<long>(Program.DefaultWithSingletonNone@45.@_instance,this.n);}[Benchmark(47,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithNone(){returnValueOption.DefaultWith<long>(newProgram.DefaultWithNone@49(this),this.n);}[Benchmark(51,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonSome(){returnValueOption.Map<long,long>(Program.MapSingletonSome@53.@_instance,this.s);}[Benchmark(55,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonNone(){returnValueOption.Map<long,long>(Program.MapSingletonNone@57.@_instance,this.n);}[Benchmark(59,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSome(){returnValueOption.Map<long,long>(newProgram.MapSome@61(this),this.s);}[Benchmark(63,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapNone(){returnValueOption.Map<long,long>(newProgram.MapNone@65(this),this.n);}internalFSharpValueOption<long>s;internalFSharpValueOption<long>n;[NoCompilerInlining]internallongf;}[Serializable]internalsealedclassDefaultWithSingletonNone@45:FSharpFunc<Unit,long>{[CompilerGenerated][DebuggerNonUserCode]internalDefaultWithSingletonNone@45(){}publicoverridelongInvoke(UnitunitVar0){return41L+((1/1!=1)?(2L/3L):(100L/100L));}// Note: this type is marked as 'beforefieldinit'.staticDefaultWithSingletonNone@45(){}internalstaticreadonlyProgram.DefaultWithSingletonNone@45@_instance=newProgram.DefaultWithSingletonNone@45();}[Serializable]internalsealedclassDefaultWithNone@49:FSharpFunc<Unit,long>{[CompilerGenerated][DebuggerNonUserCode]internalDefaultWithNone@49(Program.Current_){this._=_;}publicoverridelongInvoke(UnitunitVar0){return42L+this._.f+((1/1!=1)?(2L/3L):(100L/100L));}publicProgram.Current_;}[Serializable]internalsealedclassMapSingletonSome@53:FSharpFunc<long,long>{[CompilerGenerated][DebuggerNonUserCode]internalMapSingletonSome@53(){}publicoverridelongInvoke(longx){returnx+43L+((1/1!=1)?(2L/3L):(100L/100L));}// Note: this type is marked as 'beforefieldinit'.staticMapSingletonSome@53(){}internalstaticreadonlyProgram.MapSingletonSome@53@_instance=newProgram.MapSingletonSome@53();}[Serializable]internalsealedclassMapSingletonNone@57:FSharpFunc<long,long>{[CompilerGenerated][DebuggerNonUserCode]internalMapSingletonNone@57(){}publicoverridelongInvoke(longx){returnx+44L+((1/1!=1)?(2L/3L):(100L/100L));}// Note: this type is marked as 'beforefieldinit'.staticMapSingletonNone@57(){}internalstaticreadonlyProgram.MapSingletonNone@57@_instance=newProgram.MapSingletonNone@57();}[Serializable]internalsealedclassMapSome@61:FSharpFunc<long,long>{[CompilerGenerated][DebuggerNonUserCode]internalMapSome@61(Program.Current_){this._=_;}publicoverridelongInvoke(longx){returnx+this._.f+((1/1!=1)?(2L/3L):(100L/100L));}publicProgram.Current_;}[Serializable]internalsealedclassMapNone@65:FSharpFunc<long,long>{[CompilerGenerated][DebuggerNonUserCode]internalMapNone@65(Program.Current_){this._=_;}publicoverridelongInvoke(longx){returnx+this._.f+((1/1!=1)?(2L/3L):(100L/100L));}publicProgram.Current_;}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassInline{publicInline():this(){this.s=FSharpValueOption<long>.NewValueSome((long)DateTime.Now.Day);this.n=FSharpValueOption<long>.ValueNone;this.f=10L;}[Benchmark(77,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithSingletonNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}returnProgram.defThunk@5(null);}[Benchmark(81,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}returnProgram.defThunk@5-1(this,null);}[Benchmark(85,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonSome(){FSharpValueOption<long>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){longitem=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(Program.mapping@10(item));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(89,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){longitem=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(Program.mapping@10-1(item));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(93,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSome(){FSharpValueOption<long>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){longitem=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(Program.mapping@10-2(this,item));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(97,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){longitem=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(Program.mapping@10-3(this,item));}returnFSharpValueOption<long>.ValueNone;}internalFSharpValueOption<long>s;internalFSharpValueOption<long>n;[NoCompilerInlining]internallongf;}[MemoryDiagnoser(true)][CompilationMapping(SourceConstructFlags.ObjectType)][Serializable]publicclassInlineAndLambda{publicInlineAndLambda():this(){this.s=FSharpValueOption<long>.NewValueSome((long)DateTime.Now.Day);this.n=FSharpValueOption<long>.ValueNone;this.f=10L;}[Benchmark(111,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithSingletonNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}return41L+((1/1!=1)?(2L/3L):(100L/100L));}[Benchmark(115,"C:\\code\\Test\\Bench\\Program.fs")]publiclongDefaultWithNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){returnfsharpValueOption.Item;}return42L+this.f+((1/1!=1)?(2L/3L):(100L/100L));}[Benchmark(119,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonSome(){FSharpValueOption<long>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){longx=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(x+43L+((1/1!=1)?(2L/3L):(100L/100L)));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(123,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSingletonNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){longx=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(x+44L+((1/1!=1)?(2L/3L):(100L/100L)));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(127,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapSome(){FSharpValueOption<long>fsharpValueOption=this.s;if(fsharpValueOption.Tag==1){longx=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(x+this.f+((1/1!=1)?(2L/3L):(100L/100L)));}returnFSharpValueOption<long>.ValueNone;}[Benchmark(131,"C:\\code\\Test\\Bench\\Program.fs")]publicFSharpValueOption<long>MapNone(){FSharpValueOption<long>fsharpValueOption=this.n;if(fsharpValueOption.Tag==1){longx=fsharpValueOption.Item;returnFSharpValueOption<long>.NewValueSome(x+this.f+((1/1!=1)?(2L/3L):(100L/100L)));}returnFSharpValueOption<long>.ValueNone;}internalFSharpValueOption<long>s;internalFSharpValueOption<long>n;[NoCompilerInlining]internallongf;}[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassInlineAndLambdaModule{[CompilationArgumentCounts(newint[]{1,1})]publicstaticadefaultWith<a>([InlineIfLambda]FSharpFunc<Unit,a>defThunk,FSharpValueOption<a>option){if(option.Tag==1){returnoption.Item;}returndefThunk.Invoke(null);}[CompilationArgumentCounts(newint[]{1,1})]publicstaticFSharpValueOption<b>map<a,b>([InlineIfLambda]FSharpFunc<a,b>mapping,FSharpValueOption<a>option){if(option.Tag==1){ax=option.Item;returnFSharpValueOption<b>.NewValueSome(mapping.Invoke(x));}returnFSharpValueOption<b>.ValueNone;}}[CompilationMapping(SourceConstructFlags.Module)]publicstaticclassInlineModule{[CompilationArgumentCounts(newint[]{1,1})]publicstaticadefaultWith<a>(FSharpFunc<Unit,a>defThunk,FSharpValueOption<a>option){if(option.Tag==1){returnoption.Item;}returndefThunk.Invoke(null);}[CompilationArgumentCounts(newint[]{1,1})]publicstaticFSharpValueOption<b>map<a,b>(FSharpFunc<a,b>mapping,FSharpValueOption<a>option){if(option.Tag==1){ax=option.Item;returnFSharpValueOption<b>.NewValueSome(mapping.Invoke(x));}returnFSharpValueOption<b>.ValueNone;}}}

BenchmarkDotNet=v0.13.5, OS=Windows 11 (10.0.22621.1992/22H2/2022Update/SunValley2)
AMD Ryzen 9 7900, 1 CPU, 24 logical and 12 physical cores
.NET SDK=8.0.100-preview.6.23330.14
[Host] : .NET 8.0.0 (8.0.23.32907), X64 RyuJIT AVX2 DEBUG
DefaultJob : .NET 8.0.0 (8.0.23.32907), X64 RyuJIT AVX2

Type	Method	Mean	Error	StdDev	Median	Gen0	Allocated
Current	DefaultWithSingletonNone	30.7785 ns	0.0699 ns	0.0546 ns	30.7517 ns	-	-
Inline	DefaultWithSingletonNone	0.0061 ns	0.0023 ns	0.0020 ns	0.0065 ns	-	-
InlineAndLambda	DefaultWithSingletonNone	0.0112 ns	0.0068 ns	0.0064 ns	0.0081 ns	-	-
Current	DefaultWithNone	32.9885 ns	0.1077 ns	0.0954 ns	32.9771 ns	0.0014	24 B
Inline	DefaultWithNone	0.0079 ns	0.0017 ns	0.0014 ns	0.0079 ns	-	-
InlineAndLambda	DefaultWithNone	0.1987 ns	0.0069 ns	0.0065 ns	0.1995 ns	-	-
Current	MapSingletonSome	31.2620 ns	0.0629 ns	0.0491 ns	31.2560 ns	-	-
Inline	MapSingletonSome	0.2333 ns	0.0028 ns	0.0024 ns	0.2324 ns	-	-
InlineAndLambda	MapSingletonSome	0.2293 ns	0.0026 ns	0.0025 ns	0.2294 ns	-	-
Current	MapSingletonNone	31.4863 ns	0.1252 ns	0.1046 ns	31.4460 ns	-	-
Inline	MapSingletonNone	0.0468 ns	0.0018 ns	0.0016 ns	0.0467 ns	-	-
InlineAndLambda	MapSingletonNone	0.0318 ns	0.0024 ns	0.0022 ns	0.0306 ns	-	-
Current	MapSome	35.9461 ns	0.0499 ns	0.0417 ns	35.9411 ns	0.0014	24 B
Inline	MapSome	0.2216 ns	0.0044 ns	0.0041 ns	0.2203 ns	-	-
InlineAndLambda	MapSome	0.2208 ns	0.0053 ns	0.0049 ns	0.2192 ns	-	-
Current	MapNone	38.2091 ns	0.1792 ns	0.1589 ns	38.1327 ns	0.0014	24 B
Inline	MapNone	0.2368 ns	0.0016 ns	0.0015 ns	0.2365 ns	-	-
InlineAndLambda	MapNone	0.0373 ns	0.0028 ns	0.0026 ns	0.0380 ns	-	-

Analysis

My conclusion is identical to #14927 - do use both inline and InlineIfLambda. However, there is also one important anomaly to be aware of, as highlighted between the 2 sets of benchmarks.

ValueOption<int> functions are namely surprisingly slow, to the point that they might be slower than Option<int> despite the latter having to allocate. This is due to a deficiency in JIT, where it produces suboptimal machine code when structs are smaller than the register size. When we switch to ValueOption<int64>, ValueOption is clearly the winner compared to Option. The difference between status quo and inlined functions becomes even more stark (several orders of magnitude), because the non-inlined functions take a significant performance hit with int64.

This is something to keep in mind when benchmarking fsharp/fslang-suggestions#739.

[T-Gro]

For the default scenarios (DefaultWithSingletonNone, DefaultWithNone), doing InlineAndLambda is doing worse than Inline.
Wouldn't it then make sense to have the function inline, but not the argument?

[kerams]

I don't know. It's not massively slower in absolute terms, and who knows what the JIT would produce if the caller function and/or lambda bodies were larger. I'd use the attribute too, if only for consistency's sake.

[T-Gro]

If the bodies were larger, it should probably also stay un-inlined.
You are right the absolute diff is small, and compared to non-inlined scenario this is a massive improvement either way.

Just the relative diff stands out in this case, whereas elsewhere the lambda inlining was either superior or at least on par.

[vzarytovskii]

I think JIT should be fine in general. It should'be be a HUGE lambda for it to not inline. We probably can remove IILAttribute for the singleton version, with comment that it was slower, I guess?

[kerams]

No, because we're talking about one ValueOption.defaultWith used either with a singleton closure or one that captures values.

[vzarytovskii]

No, because we're talking about one ValueOption.defaultWith used either with a singleton closure or one that captures values.

Wait, that's what I meant, remove attribute for the defaultWith alltogether.

[kerams]

Ok, I was confused by the mention of singleton.

[vzarytovskii]

Ok, I was confused by the mention of singleton.

I'm a bit slow today, so it's possible that I thought of one thing, and wrote a different one.

[T-Gro]

I ran the same benchmark and added also cases with a lot larger lambda body, as well as a case which maps over ValueSome (therefore never invoking the lambda/code).

The Inline version (without InlineIfLambda attr) was always slightly faster.

=> Would prefer to have the attr removed (as is now with the latest commit)