Faster equality in generic contexts

azure-pipelines.yml

@@ -794,7 +794,7 @@ stages:
             condition: always()
 
         # Test trimming on Windows
-        - job: Build_And_Test_Trimming_Windows
+        - job: Build_And_Test_AOT_Windows
           pool:
             name: $(DncEngPublicBuildPool)
             demands: ImageOverride -equals $(WindowsMachineQueueName)
@@ -825,9 +825,9 @@ stages:
             env:
               NativeToolsOnMachine: true
             displayName: Initial build and prepare packages.
-          - script: $(Build.SourcesDirectory)/tests/AheadOfTime/Trimming/check.cmd
+          - script: $(Build.SourcesDirectory)/tests/AheadOfTime/check.cmd
             displayName: Build, trim, publish and check the state of the trimmed app.
-            workingDirectory: $(Build.SourcesDirectory)/tests/AheadOfTime/Trimming
+            workingDirectory: $(Build.SourcesDirectory)/tests/AheadOfTime
           - task: PublishPipelineArtifact@1
             displayName: Publish Trim Tests Logs
             inputs:

docs/release-notes/.FSharp.Core/8.0.300.md

@@ -1,6 +1,8 @@
 ### Added
 
 * Minor tweaks to inline specifications to support Visibility PR ([PR #15484](https://github.com/dotnet/fsharp/pull/15484), [#PR 16427](https://github.com/dotnet/fsharp/pull/15484)
+* Optimize equality in generic contexts. ([PR #16615](https://github.com/dotnet/fsharp/pull/16615))
 
 ### Fixed
+
 * Preserve original stack traces in resumable state machines generated code if available. ([PR #16568](https://github.com/dotnet/fsharp/pull/16568))

eng/Build.ps1

@@ -680,7 +680,7 @@ try {
     }
 
     if ($testAOT) {
-        Push-Location "$RepoRoot\tests\AheadOfTime\Trimming"
+        Push-Location "$RepoRoot\tests\AheadOfTime"
         ./check.cmd
         Pop-Location
     }

tests/AheadOfTime/Equality/Equality.fsproj

@@ -0,0 +1,35 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
+    <DisableImplicitNuGetFallbackFolder>true</DisableImplicitNuGetFallbackFolder>
+    <DisableImplicitLibraryPacksFolder>true</DisableImplicitLibraryPacksFolder>
+    <PublishTrimmed>true</PublishTrimmed>
+    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <DotnetFscCompilerPath>$(MSBuildThisFileDirectory)../../../artifacts/bin/fsc/Release/net8.0/fsc.dll</DotnetFscCompilerPath>
+    <Fsc_DotNET_DotnetFscCompilerPath>$(MSBuildThisFileDirectory)../../../artifacts/bin/fsc/Release/net8.0/fsc.dll</Fsc_DotNET_DotnetFscCompilerPath>
+    <FSharpPreferNetFrameworkTools>False</FSharpPreferNetFrameworkTools>
+    <FSharpPrefer64BitTools>True</FSharpPrefer64BitTools>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+
+  <Import Project="$(MSBuildThisFileDirectory)../../../eng/Versions.props" />
+
+  <ItemGroup>
+    <PackageReference Include="FSharp.Core" Version="$(FSharpCorePreviewPackageVersionValue)"/>
+  </ItemGroup>
+
+</Project>

tests/AheadOfTime/Equality/Program.fs

@@ -0,0 +1,77 @@
+open System.Collections.Generic
+open NonStructuralComparison
+
+let failures = HashSet<string>()
+
+let reportFailure (s: string) = 
+    stderr.Write " NO: "
+    stderr.WriteLine s
+    failures.Add s |> ignore
+
+let test testName x y =
+    let result = HashIdentity.Structural.Equals(x, y)
+    if result = false
+    then
+        stderr.WriteLine($"\n***** {testName}: Expected: 'true' Result: '{result}' = FAIL\n");
+        reportFailure testName
+
+module BasicTypes =
+    test "test000" true true
+    test "test001" 1y 1y
+    test "test002" 1uy 1uy
+    test "test003" 1s 1s
+    test "test004" 1us 1us
+    test "test005" 1 1
+    test "test006" 1u 1u
+    test "test007" 1L 1L
+    test "test008" 1UL 1UL
+    test "test009" (nativeint 1) (nativeint 1)
+    test "test010" (unativeint 1) (unativeint 1)
+    test "test011" 'a' 'a'
+    test "test012" "a" "a"
+    test "test013" 1m 1m
+    test "test014" 1.0 1.0
+    test "test015" 1.0f 1.0f
+
+module Arrays =
+    test "test100" [|1|] [|1|]
+    test "test101" [|1L|] [|1L|]
+    test "test102" [|1uy|] [|1uy|]
+    test "test103" [|box 1|] [|box 1|]
+
+module Structs = 
+    test "test200" struct (1, 1) struct (1, 1)
+    test "test201" struct (1, 1, 1) struct (1, 1, 1)
+    test "test202" struct (1, 1, 1, 1) struct (1, 1, 1, 1)
+    test "test203" struct (1, 1, 1, 1, 1) struct (1, 1, 1, 1, 1)
+    test "test204" struct (1, 1, 1, 1, 1, 1) struct (1, 1, 1, 1, 1, 1)
+    test "test205" struct (1, 1, 1, 1, 1, 1, 1) struct (1, 1, 1, 1, 1, 1, 1)
+    test "test206" struct (1, 1, 1, 1, 1, 1, 1, 1) struct (1, 1, 1, 1, 1, 1, 1, 1)
+
+module OptionsAndCo = 
+    open System
+
+    test "test301" (Some 1) (Some 1)
+    test "test302" (ValueSome 1) (ValueSome 1)
+    test "test303" (Ok 1) (Ok 1)
+    test "test304" (Nullable 1) (Nullable 1)
+
+module Enums =
+    open System
+
+    type SomeEnum = 
+        | Case0 = 0
+        | Case1 = 1
+
+    test "test401" (enum<SomeEnum>(1)) (enum<SomeEnum>(1)) 
+    test "test402" (enum<DayOfWeek>(1)) (enum<DayOfWeek>(1)) 
+
+[<EntryPoint>]
+let main _ =
+    match failures with 
+    | set when set.Count = 0 -> 
+        stdout.WriteLine "All tests passed"
+        exit 0
+    | _ -> 
+        stdout.WriteLine "Some tests failed"
+        exit 1

tests/AheadOfTime/Equality/check.ps1

@@ -0,0 +1,32 @@
+Write-Host "Publish and Execute: net8.0 - Equality"
+
+$build_output = dotnet publish -restore -c release -f:net8.0 $(Join-Path $PSScriptRoot Equality.fsproj)
+
+# Checking that the build succeeded
+if ($LASTEXITCODE -ne 0)
+{
+    Write-Error "Build failed with exit code ${LASTEXITCODE}"
+    Write-Error "${build_output}" -ErrorAction Stop
+}
+
+$process = Start-Process `
+    -FilePath $(Join-Path $PSScriptRoot bin\release\net8.0\win-x64\publish\Equality.exe) `
+    -Wait `
+    -NoNewWindow `
+    -PassThru `
+    -RedirectStandardOutput $(Join-Path $PSScriptRoot output.txt)
+
+$output = Get-Content $(Join-Path $PSScriptRoot output.txt)
+
+# Checking that it is actually running.
+if ($LASTEXITCODE -ne 0)
+{
+    Write-Error "Test failed with exit code ${LASTEXITCODE}" -ErrorAction Stop
+}
+
+# Checking that the output is as expected.
+$expected = "All tests passed"
+if ($output -ne $expected)
+{
+    Write-Error "Test failed with unexpected output:`nExpected:`n`t${expected}`nActual`n`t${output}" -ErrorAction Stop
+}

tests/AheadOfTime/Trimming/check.ps1

@@ -39,7 +39,7 @@ function CheckTrim($root, $tfm, $outputfile, $expected_len) {
 # error NETSDK1124: Trimming assemblies requires .NET Core 3.0 or higher.
 
 # Check net7.0 trimmed assemblies
-CheckTrim -root "SelfContained_Trimming_Test" -tfm "net8.0" -outputfile "FSharp.Core.dll" -expected_len 287232
+CheckTrim -root "SelfContained_Trimming_Test" -tfm "net8.0" -outputfile "FSharp.Core.dll" -expected_len 284160
 
 # Check net8.0 trimmed assemblies
-CheckTrim -root "StaticLinkedFSharpCore_Trimming_Test" -tfm "net8.0" -outputfile "StaticLinkedFSharpCore_Trimming_Test.dll" -expected_len 8820736
+CheckTrim -root "StaticLinkedFSharpCore_Trimming_Test" -tfm "net8.0" -outputfile "StaticLinkedFSharpCore_Trimming_Test.dll" -expected_len 8817152

tests/AheadOfTime/check.cmd

@@ -0,0 +1,3 @@
+@echo off
+powershell -ExecutionPolicy ByPass -NoProfile -command "& """%~dp0Trimming\check.ps1""""
+powershell -ExecutionPolicy ByPass -NoProfile -command "& """%~dp0Equality\check.ps1""""

tests/benchmarks/CompiledCodeBenchmarks/MicroPerf/Benchmarks.fs

@@ -1,11 +1,11 @@
-namespace TaskPerf
+namespace MicroPerf
 
 open BenchmarkDotNet.Running
 
-module Main = 
+module Main =
 
     [<EntryPoint>]
-    let main _ = 
+    let main args = 
         printfn "Running benchmarks..."
-        let _ = BenchmarkRunner.Run<Collections.CollectionsBenchmark>()
-        0  
+        BenchmarkSwitcher.FromAssembly(typeof<Equality.FSharpCoreFunctions>.Assembly).Run(args) |> ignore
+        0

tests/benchmarks/CompiledCodeBenchmarks/MicroPerf/Equality/Arrays.fs

@@ -0,0 +1,23 @@
+namespace Equality
+
+open BenchmarkDotNet.Attributes
+
+type Arrays() =
+
+    let numbers = Array.init 1000 id
+
+    [<Benchmark>]
+    member _.Int32() =
+        numbers |> Array.countBy  (fun n -> [| n % 7 |])
+
+    [<Benchmark>]
+    member _.Int64() =
+        numbers |> Array.countBy  (fun n -> [| int64 (n % 7) |])
+
+    [<Benchmark>]
+    member _.Byte() =
+        numbers |> Array.countBy  (fun n -> [| byte (n % 7) |])
+
+    [<Benchmark>]
+    member _.Obj() =
+        numbers |> Array.countBy  (fun n -> [| box (n % 7) |])

tests/benchmarks/CompiledCodeBenchmarks/MicroPerf/Equality/BasicTypes.fs

@@ -0,0 +1,63 @@
+namespace Equality
+
+open BenchmarkDotNet.Attributes
+
+[<MemoryDiagnoser>]
+type BasicTypes() =
+
+    let bools = Array.init 1000 (fun n -> n % 2 = 0)
+    let sbytes = Array.init 1000 sbyte
+    let bytes = Array.init 1000 byte
+    let int16s = Array.init 1000 int16
+    let uint16s = Array.init 1000 uint16
+    let int32s = Array.init 1000 id
+    let uint32s = Array.init 1000 uint32
+    let int64s = Array.init 1000 int64
+    let uint64s = Array.init 1000 uint64
+    let intptrs = Array.init 1000 nativeint
+    let uintptrs = Array.init 1000 unativeint
+    let chars = Array.init 1000 char
+    let strings = Array.init 1000 string
+    let decimals = Array.init 1000 decimal
+
+    [<Benchmark>]
+    member _.Bool() = bools |> Array.distinct
+
+    [<Benchmark>]
+    member _.SByte() = sbytes |> Array.distinct
+
+    [<Benchmark>]
+    member _.Byte() = bytes |> Array.distinct
+
+    [<Benchmark>]
+    member _.Int16() = int16s |> Array.distinct
+
+    [<Benchmark>]
+    member _.UInt16() = uint16s |> Array.distinct
+
+    [<Benchmark>]
+    member _.Int32() = int32s |> Array.distinct
+
+    [<Benchmark>]
+    member _.UInt32() = uint32s |> Array.distinct
+
+    [<Benchmark>]
+    member _.Int64() = int64s |> Array.distinct
+
+    [<Benchmark>]
+    member _.UInt64() = uint64s |> Array.distinct
+
+    [<Benchmark>]
+    member _.IntPtr() = intptrs |> Array.distinct
+
+    [<Benchmark>]
+    member _.UIntPtr() = uintptrs |> Array.distinct
+
+    [<Benchmark>]
+    member _.Char() = chars |> Array.distinct
+
+    [<Benchmark>]
+    member _.String() = strings |> Array.distinct
+
+    [<Benchmark>]
+    member _.Decimal() = decimals |> Array.distinct