Prevent tailcalls when pinning locals; add regression coverage (#19148)

Copilot · web-flow · commit efe3c9db371f · 2025-12-16T10:23:05.000+01:00
diff --git a/tests/FSharp.Compiler.ComponentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOff.il.release.bsl b/tests/FSharp.Compiler.ComponentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOff.il.release.bsl
@@ -16,16 +16,6 @@
 
   .hash algorithm 0x00008004
   .ver 0:0:0:0
-}
-.mresource public FSharpSignatureCompressedData.assembly
-{
-  
-  
-}
-.mresource public FSharpOptimizationCompressedData.assembly
-{
-  
-  
 }
 .module assembly.exe
 
@@ -130,9 +120,7 @@
       IL_000c:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance int32  CompareTo(object obj,
-                                      class [runtime]System.Collections.IComparer comp) cil managed
+    .method public hidebysig virtual final instance int32  CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -228,9 +216,7 @@
       IL_000b:  ret
     } 
 
-    .method public hidebysig instance bool 
-            Equals(valuetype floatsanddoubles/Float obj,
-                   class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Float obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -249,9 +235,7 @@
       IL_0013:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance bool  Equals(object obj,
-                                  class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig virtual final instance bool  Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -451,9 +435,7 @@
       IL_000c:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance int32  CompareTo(object obj,
-                                      class [runtime]System.Collections.IComparer comp) cil managed
+    .method public hidebysig virtual final instance int32  CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -549,9 +531,7 @@
       IL_000b:  ret
     } 
 
-    .method public hidebysig instance bool 
-            Equals(valuetype floatsanddoubles/Double obj,
-                   class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Double obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -570,9 +550,7 @@
       IL_0013:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance bool  Equals(object obj,
-                                  class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig virtual final instance bool  Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -1400,4 +1378,3 @@
 
 
 
-
diff --git a/tests/FSharp.Compiler.ComponentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOn.il.release.bsl b/tests/FSharp.Compiler.ComponentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOn.il.release.bsl
@@ -16,16 +16,6 @@
 
   .hash algorithm 0x00008004
   .ver 0:0:0:0
-}
-.mresource public FSharpSignatureCompressedData.assembly
-{
-  
-  
-}
-.mresource public FSharpOptimizationCompressedData.assembly
-{
-  
-  
 }
 .module assembly.exe
 
@@ -130,9 +120,7 @@
       IL_000c:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance int32  CompareTo(object obj,
-                                      class [runtime]System.Collections.IComparer comp) cil managed
+    .method public hidebysig virtual final instance int32  CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -228,9 +216,7 @@
       IL_000b:  ret
     } 
 
-    .method public hidebysig instance bool 
-            Equals(valuetype floatsanddoubles/Float obj,
-                   class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Float obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -249,9 +235,7 @@
       IL_0013:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance bool  Equals(object obj,
-                                  class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig virtual final instance bool  Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -451,9 +435,7 @@
       IL_000c:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance int32  CompareTo(object obj,
-                                      class [runtime]System.Collections.IComparer comp) cil managed
+    .method public hidebysig virtual final instance int32  CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -549,9 +531,7 @@
       IL_000b:  ret
     } 
 
-    .method public hidebysig instance bool 
-            Equals(valuetype floatsanddoubles/Double obj,
-                   class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Double obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -570,9 +550,7 @@
       IL_0013:  ret
     } 
 
-    .method public hidebysig virtual final 
-            instance bool  Equals(object obj,
-                                  class [runtime]System.Collections.IEqualityComparer comp) cil managed
+    .method public hidebysig virtual final instance bool  Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
     {
       .custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
       
@@ -1410,4 +1388,3 @@
 
 
 
-
diff --git a/tests/FSharp.Compiler.ComponentTests/EmittedIL/TailCalls.fs b/tests/FSharp.Compiler.ComponentTests/EmittedIL/TailCalls.fs
@@ -251,7 +251,7 @@ let run() =
     IL_0040:  ldc.i4.s   42
     IL_0042:  ldc.i4.5
     IL_0043:  call       void TailCall06::foo<int32>(int32,
-                                                     !!0)
+                                                      !!0)
             """
             ]
 
@@ -276,3 +276,34 @@ let rec countdown n =
             """
             ]
 
+    [<Fact>]
+    let ``TailCall 08 - No tail call when pinning local byref``() =
+        FSharp """
+module TailCall08
+
+open Microsoft.FSharp.NativeInterop
+open System.Runtime.CompilerServices
+
+[<MethodImpl(MethodImplOptions.NoInlining)>]
+let bar (pValue: nativeptr<int>) : unit =
+    let value = NativePtr.read pValue
+    printfn "value = %A" value
+
+[<MethodImpl(MethodImplOptions.NoInlining)>]
+let foo() =
+    let mutable value = 42
+    use ptr = fixed &value
+    bar ptr
+
+[<EntryPoint>]
+let main _ =
+    foo()
+    0
+        """
+        |> asExe
+        |> compileWithTailCalls
+        |> shouldSucceed
+        |> run
+        |> shouldSucceed
+        |> verifyOutput "value = 42\n"
+

Original file line number	Diff line number	Diff line change
`@@ -16,16 +16,6 @@`
`16`	`16`
`17`	`17`	`.hash algorithm 0x00008004`
`18`	`18`	`.ver 0:0:0:0`
`19`		`-}`
`20`		`-.mresource public FSharpSignatureCompressedData.assembly`
`21`		`-{`
`22`		`-`
`23`		`-`
`24`		`-}`
`25`		`-.mresource public FSharpOptimizationCompressedData.assembly`
`26`		`-{`
`27`		`-`
`28`		`-`
`29`	`19`	`}`
`30`	`20`	`.module assembly.exe`
`31`	`21`
`@@ -130,9 +120,7 @@`
`130`	`120`	`IL_000c: ret`
`131`	`121`	`}`
`132`	`122`
`133`		`- .method public hidebysig virtual final`
`134`		`- instance int32 CompareTo(object obj,`
`135`		`- class [runtime]System.Collections.IComparer comp) cil managed`
	`123`	`+ .method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed`
`136`	`124`	`{`
`137`	`125`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`138`	`126`
`@@ -228,9 +216,7 @@`
`228`	`216`	`IL_000b: ret`
`229`	`217`	`}`
`230`	`218`
`231`		`- .method public hidebysig instance bool`
`232`		`- Equals(valuetype floatsanddoubles/Float obj,`
`233`		`- class [runtime]System.Collections.IEqualityComparer comp) cil managed`
	`219`	`+ .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Float obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed`
`234`	`220`	`{`
`235`	`221`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`236`	`222`
`@@ -249,9 +235,7 @@`
`249`	`235`	`IL_0013: ret`
`250`	`236`	`}`
`251`	`237`
`252`		`- .method public hidebysig virtual final`
`253`		`- instance bool Equals(object obj,`
`254`		`- class [runtime]System.Collections.IEqualityComparer comp) cil managed`
	`238`	`+ .method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed`
`255`	`239`	`{`
`256`	`240`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`257`	`241`
`@@ -451,9 +435,7 @@`
`451`	`435`	`IL_000c: ret`
`452`	`436`	`}`
`453`	`437`
`454`		`- .method public hidebysig virtual final`
`455`		`- instance int32 CompareTo(object obj,`
`456`		`- class [runtime]System.Collections.IComparer comp) cil managed`
	`438`	`+ .method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed`
`457`	`439`	`{`
`458`	`440`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`459`	`441`
`@@ -549,9 +531,7 @@`
`549`	`531`	`IL_000b: ret`
`550`	`532`	`}`
`551`	`533`
`552`		`- .method public hidebysig instance bool`
`553`		`- Equals(valuetype floatsanddoubles/Double obj,`
`554`		`- class [runtime]System.Collections.IEqualityComparer comp) cil managed`
	`534`	`+ .method public hidebysig instance bool Equals(valuetype floatsanddoubles/Double obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed`
`555`	`535`	`{`
`556`	`536`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`557`	`537`
`@@ -570,9 +550,7 @@`
`570`	`550`	`IL_0013: ret`
`571`	`551`	`}`
`572`	`552`
`573`		`- .method public hidebysig virtual final`
`574`		`- instance bool Equals(object obj,`
`575`		`- class [runtime]System.Collections.IEqualityComparer comp) cil managed`
	`553`	`+ .method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed`
`576`	`554`	`{`
`577`	`555`	`.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )`
`578`	`556`
`@@ -1400,4 +1378,3 @@`
`1400`	`1378`
`1401`	`1379`
`1402`	`1380`
`1403`		`-`