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Move GetHashCode nullcheck to managed #130657

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Move GetHashCode nullcheck to managed #130657

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fd7c690
Move GetHashCode nullcheck to managed
MichalPetryka Jul 14, 2026
c5a4ba0
Refactor TryGetHashCode to accept only non-null objects
MichalPetryka Jul 14, 2026
0d3c019
Add AggressiveInlining to GetHashCode method
MichalPetryka Jul 14, 2026
0ec6ca6
Remove AggressiveInlining from GetHashCode
MichalPetryka Jul 14, 2026
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11 changes: 6 additions & 5 deletions ...eclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -237,13 +237,18 @@ public static void PrepareDelegate(Delegate d)
/// returned.
/// </summary>
[MethodImpl(MethodImplOptions.InternalCall)]
internal static extern int TryGetHashCode(object? o);
internal static extern int TryGetHashCode(object o);

[LibraryImport(QCall, EntryPoint = "ObjectNative_GetHashCodeSlow")]
private static partial int GetHashCodeSlow(ObjectHandleOnStack o);

public static int GetHashCode(object? o)
{
if (o is null)

@jkotas jkotas Jul 14, 2026

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This will make the method less likely to be inclined by the JIT, and when it gets inlined, the inlined code is going to be bigger. Both of these can manifest as regressions.

@MichalPetryka MichalPetryka Jul 14, 2026

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This will make the method less likely to be inclined by the JIT, and when it gets inlined, the inlined code is going to be bigger. Both of these can manifest as regressions.

Yeah but when inlining the check can be eliminated, wheras otherwise it would always execute before.

@jkotas jkotas Jul 14, 2026

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These claims need numbers.

{
return 0;
}

int hashCode = TryGetHashCode(o);
if (hashCode == 0)
{
Expand All @@ -254,10 +259,6 @@ public static int GetHashCode(object? o)
[MethodImpl(MethodImplOptions.NoInlining)]
static int GetHashCodeWorker(object? o)
{
if (o is null)
{
return 0;
}
return GetHashCodeSlow(ObjectHandleOnStack.Create(ref o));
}
}
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3 changes: 1 addition & 2 deletions src/coreclr/vm/comutilnative.cpp
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Expand Up @@ -1585,8 +1585,7 @@ FCIMPL1(INT32, ObjectNative::TryGetHashCode, Object* obj)
{
FCALL_CONTRACT;

if (obj == NULL)
return 0;
_ASSERTE(obj != NULL);

OBJECTREF objRef = ObjectToOBJECTREF(obj);
return objRef->TryGetHashCode();
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