1 files changed, 20 insertions, 3 deletions
diff --git a/MdePkg/Library/BaseLib/X64/InterlockedCompareExchange32.c b/MdePkg/Library/BaseLib/X64/InterlockedCompareExchange32.c
index 4a9fe6aca6..de1aac7e6a 100644
--- a/MdePkg/Library/BaseLib/X64/InterlockedCompareExchange32.c
+++ b/MdePkg/Library/BaseLib/X64/InterlockedCompareExchange32.c
@@ -12,9 +12,9 @@
 
 **/
 
-//
-// Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics
-//
+/**
+  Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
+**/
 long _InterlockedCompareExchange(
    long volatile * Destination,
    long Exchange,
@@ -23,6 +23,23 @@ long _InterlockedCompareExchange(
 
 #pragma intrinsic(_InterlockedCompareExchange)
 
+/**
+  Performs an atomic compare exchange operation on a 32-bit unsigned integer.
+
+  Performs an atomic compare exchange operation on the 32-bit unsigned integer
+  specified by Value.  If Value is equal to CompareValue, then Value is set to
+  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
+  then Value is returned.  The compare exchange operation must be performed using
+  MP safe mechanisms.
+
+  @param  Value         A pointer to the 32-bit value for the compare exchange
+                        operation.
+  @param  CompareValue  32-bit value used in compare operation.
+  @param  ExchangeValue 32-bit value used in exchange operation.
+
+  @return The original *Value before exchange.
+
+**/
 UINT32
 EFIAPI
 InternalSyncCompareExchange32 (