MdePkg/BaseLib: Support IA32 processors without CLFLUSH

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / MultU64x64.S

diff --git a/MdePkg/Library/BaseLib/Ia32/MultU64x64.S b/MdePkg/Library/BaseLib/Ia32/MultU64x64.S
index 0aae90c6ccdc91289ee0ff0d5026cc6be26a4b30..48f4ae037eafbd298e9736aaa6328a32acd988fa 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/MultU64x64.S
+++ b/MdePkg/Library/BaseLib/Ia32/MultU64x64.S
@@ -1,10 +1,10 @@
 #------------------------------------------------------------------------------\r
 #\r
-# Copyright (c) 2006 - 2008, Intel Corporation\r
-# All rights reserved. This program and the accompanying materials\r
+# Copyright (c) 2006 - 2008, 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
@@ -19,7 +19,7 @@
 #\r
 #------------------------------------------------------------------------------\r
 \r
-.globl ASM_PFX(InternalMathMultU64x64)\r
+ASM_GLOBAL ASM_PFX(InternalMathMultU64x64)\r
 \r
 #------------------------------------------------------------------------------\r
 # UINT64\r
@@ -30,15 +30,15 @@
 #   );\r
 #------------------------------------------------------------------------------\r
 ASM_PFX(InternalMathMultU64x64):\r
-    push    %ebx\r
-    movl    8(%esp), %ebx\r
-    movl    16(%esp), %edx\r
-    movl    %ebx, %ecx\r
-    movl    %edx, %eax\r
-    imull   20(%esp), %ebx\r
-    imull   12(%esp), %edx\r
-    addl    %edx, %ebx\r
-    mull    %ecx\r
-    addl    %ebx, %edx\r
+    push    %ebx                                     \r
+    movl    8(%esp), %ebx             # ebx <- M1[0..31]                \r
+    movl    16(%esp), %edx            # edx <- M2[0..31]                                   \r
+    movl    %ebx, %ecx                                                  \r
+    movl    %edx, %eax                \r
+    imull   20(%esp), %ebx            # ebx <- M1[0..31] * M2[32..63]   \r
+    imull   12(%esp), %edx            # edx <- M1[32..63] * M2[0..31]   \r
+    addl    %edx, %ebx                # carries are abandoned           \r
+    mull    %ecx                      # edx:eax <- M1[0..31] * M2[0..31]\r
+    addl    %ebx, %edx                # carries are abandoned           \r
     pop     %ebx\r
     ret\r