Add in .S file for GCC tool-chain.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5537 6f19259b-4bc3-4df7-8a09-765794883524

EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/MultU64x32.S

@@ -0,0 +1,71 @@
+#/*++
+#
+#Copyright (c) 2006, Intel Corporation                                                         
+#All rights reserved. This program and the accompanying materials                          
+#are licensed and made available under the terms and conditions of the BSD License         
+#which accompanies this distribution.  The full text of the license may be found at        
+#http://opensource.org/licenses/bsd-license.php                                            
+#                                                                                          
+#THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
+#WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             
+#
+#Module Name:
+#
+#   MultU64x32.c
+#
+#Abstract:
+#
+#  64-bit Multiplication function for IA-32
+#
+#--*/
+#include "EfiBind.h"
+#---------------------------------------------------------------------------
+    .686: 
+    #.MODEL flat,C
+    .code: 
+
+#---------------------------------------------------------------------------
+.globl ASM_PFX(MultU64x32)
+#UINT64
+#MultU64x32 (
+#  IN UINT64   Multiplicand,
+#  IN UINTN    Multiplier
+#  )
+#/*++
+#
+#Routine Description:
+#
+#  This routine allows a 64 bit value to be multiplied with a 32 bit 
+#  value returns 64bit result.
+#  No checking if the result is greater than 64bits
+#
+#Arguments:
+#
+#  Multiplicand  - multiplicand
+#  Multiplier    - multiplier
+#
+#Returns:
+#
+#  Multiplicand * Multiplier
+#
+#--*/
+ASM_PFX(MultU64x32):
+
+    movl   4(%esp), %eax # dword ptr Multiplicand[0]
+    mull   0xC(%esp)             # Multiplier
+    pushl  %eax
+    pushl  %edx
+    movl   0x10(%esp), %eax # dword ptr Multiplicand[4]
+    mull   0x14(%esp)           # Multiplier
+    #
+    # The value in edx stored by second multiplication overflows
+    # the output and should be discarded. So here we overwrite it
+    # with the edx value of first multiplication.
+    #
+    popl   %edx
+    addl   %eax, %edx
+    popl   %eax
+
+    ret
+#MultU64x32 ENDP
+