MdePkg/BaseLib: Support IA32 processors without CMOVx

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / SwapBytes64.asm

diff --git a/MdePkg/Library/BaseLib/Ia32/SwapBytes64.asm b/MdePkg/Library/BaseLib/Ia32/SwapBytes64.asm
index 72e366bd4d05c3a06ecca93abb44e385b218cdad..7020753721abdedef14e7f2576d12289848709a1 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/SwapBytes64.asm
+++ b/MdePkg/Library/BaseLib/Ia32/SwapBytes64.asm
@@ -1,10 +1,10 @@
 ;------------------------------------------------------------------------------\r
 ;\r
-; Copyright (c) 2006, Intel Corporation\r
-; All rights reserved. This program and the accompanying materials\r
+; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
+; This program and the accompanying materials\r
 ; are licensed and made available under the terms and conditions of the BSD License\r
 ; which accompanies this distribution.  The full text of the license may be found at\r
-; http://opensource.org/licenses/bsd-license.php\r
+; http://opensource.org/licenses/bsd-license.php.\r
 ;\r
 ; 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
@@ -21,13 +21,20 @@
 ;\r
 ;------------------------------------------------------------------------------\r
 \r
-    .586P\r
+    .586\r
     .model  flat,C\r
     .code\r
 \r
+;------------------------------------------------------------------------------\r
+; UINT64\r
+; EFIAPI\r
+; InternalMathSwapBytes64 (\r
+;   IN      UINT64                    Operand\r
+;   );\r
+;------------------------------------------------------------------------------\r
 InternalMathSwapBytes64 PROC\r
-    mov     eax, [esp + 8]\r
-    mov     edx, [esp + 4]\r
+    mov     eax, [esp + 8]              ; eax <- upper 32 bits\r
+    mov     edx, [esp + 4]              ; edx <- lower 32 bits\r
     bswap   eax\r
     bswap   edx\r
     ret\r