Convert small atomic fallbacks to managed

src/coreclr/System.Private.CoreLib/src/System/Threading/Interlocked.CoreCLR.cs

@@ -42,48 +42,6 @@ public static long Decrement(ref long location) =>
         #endregion
 
         #region Exchange
-        /// <summary>Sets a 8-bit unsigned integer to a specified value and returns the original value, as an atomic operation.</summary>
-        /// <param name="location1">The variable to set to the specified value.</param>
-        /// <param name="value">The value to which the <paramref name="location1"/> parameter is set.</param>
-        /// <returns>The original value of <paramref name="location1"/>.</returns>
-        /// <exception cref="NullReferenceException">The address of location1 is a null pointer.</exception>
-        [Intrinsic]
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static byte Exchange(ref byte location1, byte value)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return Exchange(ref location1, value); // Must expand intrinsic
-#else
-            if (Unsafe.IsNullRef(ref location1))
-                ThrowHelper.ThrowNullReferenceException();
-            return Exchange8(ref location1, value);
-#endif
-        }
-
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern byte Exchange8(ref byte location1, byte value);
-
-        /// <summary>Sets a 16-bit signed integer to a specified value and returns the original value, as an atomic operation.</summary>
-        /// <param name="location1">The variable to set to the specified value.</param>
-        /// <param name="value">The value to which the <paramref name="location1"/> parameter is set.</param>
-        /// <returns>The original value of <paramref name="location1"/>.</returns>
-        /// <exception cref="NullReferenceException">The address of location1 is a null pointer.</exception>
-        [Intrinsic]
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static short Exchange(ref short location1, short value)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return Exchange(ref location1, value); // Must expand intrinsic
-#else
-            if (Unsafe.IsNullRef(ref location1))
-                ThrowHelper.ThrowNullReferenceException();
-            return Exchange16(ref location1, value);
-#endif
-        }
-
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern short Exchange16(ref short location1, short value);
-
         /// <summary>Sets a 32-bit signed integer to a specified value and returns the original value, as an atomic operation.</summary>
         /// <param name="location1">The variable to set to the specified value.</param>
         /// <param name="value">The value to which the <paramref name="location1"/> parameter is set.</param>
@@ -162,50 +120,6 @@ public static T Exchange<T>([NotNullIfNotNull(nameof(value))] ref T location1, T
 #endregion
 
         #region CompareExchange
-        /// <summary>Compares two 8-bit unsigned integers for equality and, if they are equal, replaces the first value.</summary>
-        /// <param name="location1">The destination, whose value is compared with <paramref name="comparand"/> and possibly replaced.</param>
-        /// <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
-        /// <param name="comparand">The value that is compared to the value at <paramref name="location1"/>.</param>
-        /// <returns>The original value in <paramref name="location1"/>.</returns>
-        /// <exception cref="NullReferenceException">The address of <paramref name="location1"/> is a null pointer.</exception>
-        [Intrinsic]
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static byte CompareExchange(ref byte location1, byte value, byte comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand); // Must expand intrinsic
-#else
-            if (Unsafe.IsNullRef(ref location1))
-                ThrowHelper.ThrowNullReferenceException();
-            return CompareExchange8(ref location1, value, comparand);
-#endif
-        }
-
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern byte CompareExchange8(ref byte location1, byte value, byte comparand);
-
-        /// <summary>Compares two 16-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
-        /// <param name="location1">The destination, whose value is compared with <paramref name="comparand"/> and possibly replaced.</param>
-        /// <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
-        /// <param name="comparand">The value that is compared to the value at <paramref name="location1"/>.</param>
-        /// <returns>The original value in <paramref name="location1"/>.</returns>
-        /// <exception cref="NullReferenceException">The address of <paramref name="location1"/> is a null pointer.</exception>
-        [Intrinsic]
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static short CompareExchange(ref short location1, short value, short comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand); // Must expand intrinsic
-#else
-            if (Unsafe.IsNullRef(ref location1))
-                ThrowHelper.ThrowNullReferenceException();
-            return CompareExchange16(ref location1, value, comparand);
-#endif
-        }
-
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern short CompareExchange16(ref short location1, short value, short comparand);
-
         /// <summary>Compares two 32-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
         /// <param name="location1">The destination, whose value is compared with <paramref name="comparand"/> and possibly replaced.</param>
         /// <param name="value">The value that replaces the destination value if the comparison results in equality.</param>

src/coreclr/inc/winwrap.h

@@ -254,13 +254,4 @@ WszCreateProcess(
     LPPROCESS_INFORMATION lpProcessInformation
     );
 
-#ifdef HOST_WINDOWS
-
-//
-// Workaround for https://github.com/microsoft/WindowsAppSDK/issues/4074
-// Windows SDK is missing InterlockedCompareExchange8 definition.
-//
-#define InterlockedCompareExchange8 _InterlockedCompareExchange8
-
-#endif // HOST_WINDOWS
 #endif  // __WIN_WRAP_H__

src/coreclr/nativeaot/Runtime/EHHelpers.cpp

@@ -286,8 +286,6 @@ EXTERN_C CODE_LOCATION RhpCheckedAssignRefAVLocation;
 EXTERN_C CODE_LOCATION RhpCheckedLockCmpXchgAVLocation;
 EXTERN_C CODE_LOCATION RhpCheckedXchgAVLocation;
 #if !defined(HOST_AMD64) && !defined(HOST_ARM64)
-EXTERN_C CODE_LOCATION RhpLockCmpXchg8AVLocation;
-EXTERN_C CODE_LOCATION RhpLockCmpXchg16AVLocation;
 EXTERN_C CODE_LOCATION RhpLockCmpXchg32AVLocation;
 EXTERN_C CODE_LOCATION RhpLockCmpXchg64AVLocation;
 #endif
@@ -312,8 +310,6 @@ static bool InWriteBarrierHelper(uintptr_t faultingIP)
         (uintptr_t)&RhpCheckedLockCmpXchgAVLocation,
         (uintptr_t)&RhpCheckedXchgAVLocation,
 #if !defined(HOST_AMD64) && !defined(HOST_ARM64)
-        (uintptr_t)&RhpLockCmpXchg8AVLocation,
-        (uintptr_t)&RhpLockCmpXchg16AVLocation,
         (uintptr_t)&RhpLockCmpXchg32AVLocation,
         (uintptr_t)&RhpLockCmpXchg64AVLocation,
 #endif

src/coreclr/nativeaot/Runtime/arm/Interlocked.S

@@ -7,51 +7,6 @@
 #include <AsmOffsets.inc>         // generated by the build from AsmOffsets.cpp
 #include <unixasmmacros.inc>
 
-// WARNING: Code in EHHelpers.cpp makes assumptions about this helper, in particular:
-// - Function "InWriteBarrierHelper" assumes an AV due to passed in null pointer will happen at RhpLockCmpXchg8AVLocation
-// - Function "UnwindSimpleHelperToCaller" assumes no registers were pushed and LR contains the return address
-// r0 = destination address
-// r1 = value
-// r2 = comparand
-LEAF_ENTRY RhpLockCmpXchg8, _TEXT
-          dmb
-GLOBAL_LABEL RhpLockCmpXchg8AVLocation
-LOCAL_LABEL(CmpXchg8Retry):
-          ldrexb       r3, [r0]
-          cmp          r2, r3
-          bne          LOCAL_LABEL(CmpXchg8Exit)
-          strexb       r12, r1, [r0]
-          cmp          r12, #0
-          bne          LOCAL_LABEL(CmpXchg8Retry)
-LOCAL_LABEL(CmpXchg8Exit):
-          mov          r0, r3
-          dmb
-          bx           lr
-LEAF_END RhpLockCmpXchg8, _TEXT
-
-// WARNING: Code in EHHelpers.cpp makes assumptions about this helper, in particular:
-// - Function "InWriteBarrierHelper" assumes an AV due to passed in null pointer will happen at RhpLockCmpXchg16AVLocation
-// - Function "UnwindSimpleHelperToCaller" assumes no registers were pushed and LR contains the return address
-// r0 = destination address
-// r1 = value
-// r2 = comparand
-LEAF_ENTRY RhpLockCmpXchg16, _TEXT
-          uxth         r2, r2
-          dmb
-GLOBAL_LABEL RhpLockCmpXchg16AVLocation
-LOCAL_LABEL(CmpXchg16Retry):
-          ldrexh       r3, [r0]
-          cmp          r2, r3
-          bne          LOCAL_LABEL(CmpXchg16Exit)
-          strexh       r12, r1, [r0]
-          cmp          r12, #0
-          bne          LOCAL_LABEL(CmpXchg16Retry)
-LOCAL_LABEL(CmpXchg16Exit):
-          sxth         r0, r3
-          dmb
-          bx           lr
-LEAF_END RhpLockCmpXchg16, _TEXT
-
 // WARNING: Code in EHHelpers.cpp makes assumptions about this helper, in particular:
 // - Function "InWriteBarrierHelper" assumes an AV due to passed in null pointer will happen at RhpLockCmpXchg32AVLocation
 // - Function "UnwindSimpleHelperToCaller" assumes no registers were pushed and LR contains the return address

src/coreclr/nativeaot/Runtime/portable.cpp

@@ -367,18 +367,6 @@ COOP_PINVOKE_HELPER(Object *, RhpCheckedXchg, (Object ** location, Object * valu
     return ret;
 }
 
-COOP_PINVOKE_HELPER(uint8_t, RhpLockCmpXchg8, (uint8_t * location, uint8_t value, uint8_t comparand))
-{
-    ASSERT_UNCONDITIONALLY("NYI");
-    return 0;
-}
-
-COOP_PINVOKE_HELPER(int16_t, RhpLockCmpXchg16, (int16_t * location, int16_t value, int16_t comparand))
-{
-    ASSERT_UNCONDITIONALLY("NYI");
-    return 0;
-}
-
 COOP_PINVOKE_HELPER(int32_t, RhpLockCmpXchg32, (int32_t * location, int32_t value, int32_t comparand))
 {
     // @TODO: USE_PORTABLE_HELPERS - Null check

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs

@@ -821,14 +821,6 @@ internal static partial void NativeRuntimeEventSource_LogWaitHandleWaitStart(
         //
         // Interlocked helpers
         //
-        [MethodImplAttribute(MethodImplOptions.InternalCall)]
-        [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg8")]
-        internal static extern byte InterlockedCompareExchange(ref byte location1, byte value, byte comparand);
-
-        [MethodImplAttribute(MethodImplOptions.InternalCall)]
-        [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg16")]
-        internal static extern short InterlockedCompareExchange(ref short location1, short value, short comparand);
-
         [MethodImplAttribute(MethodImplOptions.InternalCall)]
         [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg32")]
         internal static extern int InterlockedCompareExchange(ref int location1, int value, int comparand);

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Interlocked.cs

@@ -11,26 +11,6 @@ public static partial class Interlocked
     {
         #region CompareExchange
 
-        [Intrinsic]
-        public static byte CompareExchange(ref byte location1, byte value, byte comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand);
-#else
-            return RuntimeImports.InterlockedCompareExchange(ref location1, value, comparand);
-#endif
-        }
-
-        [Intrinsic]
-        public static short CompareExchange(ref short location1, short value, short comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand);
-#else
-            return RuntimeImports.InterlockedCompareExchange(ref location1, value, comparand);
-#endif
-        }
-
         [Intrinsic]
         public static int CompareExchange(ref int location1, int value, int comparand)
         {
@@ -70,40 +50,6 @@ public static T CompareExchange<T>(ref T location1, T value, T comparand) where
 
         #region Exchange
 
-        [Intrinsic]
-        public static byte Exchange(ref byte location1, byte value)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return Exchange(ref location1, value);
-#else
-            byte oldValue;
-
-            do
-            {
-                oldValue = location1;
-            } while (CompareExchange(ref location1, value, oldValue) != oldValue);
-
-            return oldValue;
-#endif
-        }
-
-        [Intrinsic]
-        public static short Exchange(ref short location1, short value)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return Exchange(ref location1, value);
-#else
-            short oldValue;
-
-            do
-            {
-                oldValue = location1;
-            } while (CompareExchange(ref location1, value, oldValue) != oldValue);
-
-            return oldValue;
-#endif
-        }
-
         [Intrinsic]
         public static int Exchange(ref int location1, int value)
         {

src/coreclr/nativeaot/Test.CoreLib/src/System/Runtime/RuntimeImports.cs

@@ -90,14 +90,6 @@ internal static IntPtr RhGetModuleSection(TypeManagerHandle module, ReadyToRunSe
         //
         // Interlocked helpers
         //
-        [MethodImplAttribute(MethodImplOptions.InternalCall)]
-        [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg8")]
-        internal static extern byte InterlockedCompareExchange(ref byte location1, byte value, byte comparand);
-
-        [MethodImplAttribute(MethodImplOptions.InternalCall)]
-        [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg16")]
-        internal static extern short InterlockedCompareExchange(ref short location1, short value, short comparand);
-
         [MethodImplAttribute(MethodImplOptions.InternalCall)]
         [RuntimeImport(RuntimeLibrary, "RhpLockCmpXchg32")]
         internal static extern int InterlockedCompareExchange(ref int location1, int value, int comparand);

src/coreclr/nativeaot/Test.CoreLib/src/System/Threading/Interlocked.cs

@@ -18,26 +18,6 @@ public static IntPtr CompareExchange(ref IntPtr location1, IntPtr value, IntPtr
 #endif
         }
 
-        [Intrinsic]
-        public static byte CompareExchange(ref byte location1, byte value, byte comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand);
-#else
-            return RuntimeImports.InterlockedCompareExchange(ref location1, value, comparand);
-#endif
-        }
-
-        [Intrinsic]
-        public static short CompareExchange(ref short location1, short value, short comparand)
-        {
-#if TARGET_X86 || TARGET_AMD64 || TARGET_ARM64
-            return CompareExchange(ref location1, value, comparand);
-#else
-            return RuntimeImports.InterlockedCompareExchange(ref location1, value, comparand);
-#endif
-        }
-
         [Intrinsic]
         public static int CompareExchange(ref int location1, int value, int comparand)
         {

src/coreclr/pal/inc/pal.h

@@ -3636,20 +3636,6 @@ Return Values
 The function returns the initial value pointed to by Target.
 
 --*/
-Define_InterlockMethod(
-    CHAR,
-    InterlockedExchange8(IN OUT CHAR volatile *Target, CHAR Value),
-    InterlockedExchange8(Target, Value),
-    __atomic_exchange_n(Target, Value, __ATOMIC_ACQ_REL)
-)
-
-Define_InterlockMethod(
-    SHORT,
-    InterlockedExchange16(IN OUT SHORT volatile *Target, SHORT Value),
-    InterlockedExchange16(Target, Value),
-    __atomic_exchange_n(Target, Value, __ATOMIC_ACQ_REL)
-)
-
 Define_InterlockMethod(
     LONG,
     InterlockedExchange(IN OUT LONG volatile *Target, LONG Value),
@@ -3708,26 +3694,6 @@ Return Values
 The return value is the initial value of the destination.
 
 --*/
-Define_InterlockMethod(
-    CHAR,
-    InterlockedCompareExchange8(IN OUT CHAR volatile *Destination, IN CHAR Exchange, IN CHAR Comperand),
-    InterlockedCompareExchange8(Destination, Exchange, Comperand),
-    __sync_val_compare_and_swap(
-        Destination, /* The pointer to a variable whose value is to be compared with. */
-        Comperand, /* The value to be compared */
-        Exchange /* The value to be stored */)
-)
-
-Define_InterlockMethod(
-    SHORT,
-    InterlockedCompareExchange16(IN OUT SHORT volatile *Destination, IN SHORT Exchange, IN SHORT Comperand),
-    InterlockedCompareExchange16(Destination, Exchange, Comperand),
-    __sync_val_compare_and_swap(
-        Destination, /* The pointer to a variable whose value is to be compared with. */
-        Comperand, /* The value to be compared */
-        Exchange /* The value to be stored */)
-)
-
 Define_InterlockMethod(
     LONG,
     InterlockedCompareExchange(IN OUT LONG volatile *Destination, IN LONG Exchange, IN LONG Comperand),