Refine the comments in PciSegmentLib

[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibRepStr / CompareMemWrapper.c

diff --git a/MdePkg/Library/BaseMemoryLibRepStr/CompareMemWrapper.c b/MdePkg/Library/BaseMemoryLibRepStr/CompareMemWrapper.c
index c8199d8dc31cb2badd25ee641ade2fb443fddf91..45fd3975f1bf1a8e5ffe2b54a89d10bfbf516197 100644 (file)
--- a/MdePkg/Library/BaseMemoryLibRepStr/CompareMemWrapper.c
+++ b/MdePkg/Library/BaseMemoryLibRepStr/CompareMemWrapper.c
@@ -1,6 +1,16 @@
 /** @file\r
   CompareMem() implementation.\r
 \r
+  The following BaseMemoryLib instances contain the same copy of this file:\r
+    BaseMemoryLib\r
+    BaseMemoryLibMmx\r
+    BaseMemoryLibSse2\r
+    BaseMemoryLibRepStr\r
+    BaseMemoryLibOptDxe\r
+    BaseMemoryLibOptPei\r
+    PeiMemoryLib\r
+    DxeMemoryLib\r
+\r
   Copyright (c) 2006, Intel Corporation<BR>\r
   All rights reserved. This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -10,58 +20,47 @@
   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
 \r
-  Module Name:  CompareMemWrapper.c\r
-\r
-  The following BaseMemoryLib instances share the same version of this file:\r
-\r
-    BaseMemoryLib\r
-    BaseMemoryLibMmx\r
-    BaseMemoryLibSse2\r
-    BaseMemoryLibRepStr\r
-    PeiMemoryLib\r
-    UefiMemoryLib\r
-\r
 **/\r
 \r
 #include "MemLibInternals.h"\r
 \r
 /**\r
-  Compares two memory buffers of a given length.\r
+  Compares the contents of two buffers.\r
 \r
-  This function compares Length bytes of SourceBuffer to Length bytes of\r
-  DestinationBuffer. If all Length bytes of the two buffers are identical, then\r
-  0 is returned. Otherwise, the value returned is the first mismatched byte in\r
-  SourceBuffer subtracted from the first mismatched byte in DestinationBuffer.\r
+  This function compares Length bytes of SourceBuffer to Length bytes of DestinationBuffer.\r
+  If all Length bytes of the two buffers are identical, then 0 is returned.  Otherwise, the\r
+  value returned is the first mismatched byte in SourceBuffer subtracted from the first\r
+  mismatched byte in DestinationBuffer.\r
 \r
-  If DestinationBuffer is NULL and Length > 0, then ASSERT().\r
-  If SourceBuffer is NULL and Length > 0, then ASSERT().\r
-  If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then\r
-  ASSERT().\r
+  If Length > 0 and DestinationBuffer is NULL, then ASSERT().\r
+  If Length > 0 and SourceBuffer is NULL, then ASSERT().\r
+  If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT().\r
   If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().\r
 \r
-  @param  DestinationBuffer First memory buffer\r
-  @param  SourceBuffer      Second memory buffer\r
-  @param  Length            Length of DestinationBuffer and SourceBuffer memory\r
-                            regions to compare\r
+  @param  DestinationBuffer Pointer to the destination buffer to compare.\r
+  @param  SourceBuffer      Pointer to the source buffer to compare.\r
+  @param  Length            Number of bytes to compare.\r
 \r
-  @retval 0         if DestinationBuffer == SourceBuffer\r
-  @retval Non-zero  if DestinationBuffer != SourceBuffer\r
+  @return 0                 All Length bytes of the two buffers are identical.\r
+  @retval Non-zero          The first mismatched byte in SourceBuffer subtracted from the first\r
+                            mismatched byte in DestinationBuffer.\r
 \r
 **/\r
 INTN\r
 EFIAPI\r
 CompareMem (\r
-  IN      CONST VOID                *DestinationBuffer,\r
-  IN      CONST VOID                *SourceBuffer,\r
-  IN      UINTN                     Length\r
+  IN CONST VOID  *DestinationBuffer,\r
+  IN CONST VOID  *SourceBuffer,\r
+  IN UINTN       Length\r
   )\r
 {\r
-  ASSERT (DestinationBuffer != NULL);\r
-  ASSERT (SourceBuffer != NULL);\r
-  ASSERT (Length <= MAX_ADDRESS - (UINTN)DestinationBuffer + 1);\r
-  ASSERT (Length <= MAX_ADDRESS - (UINTN)SourceBuffer + 1);\r
-  if (Length == 0) {\r
+  if (Length == 0 || DestinationBuffer == SourceBuffer) {\r
     return 0;\r
   }\r
+  ASSERT (DestinationBuffer != NULL);\r
+  ASSERT (SourceBuffer != NULL);\r
+  ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)DestinationBuffer));\r
+  ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)SourceBuffer));\r
+\r
   return InternalMemCompareMem (DestinationBuffer, SourceBuffer, Length);\r
 }\r