MdePkg/Library/BaseLib/Ia32/MultU64x64.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation
   4 ; All rights reserved. This program and the accompanying materials
   5 ; are licensed and made available under the terms and conditions of the BSD License
   6 ; which accompanies this distribution.  The full text of the license may be found at
   7 ; http://opensource.org/licenses/bsd-license.php
   8 ;
   9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 ;
  12 ; Module Name:
  13 ;
  14 ;   MultU64x64.asm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   Calculate the product of a 64-bit integer and another 64-bit integer
  19 ;
  20 ;------------------------------------------------------------------------------
  21
  22     .386
  23     .model  flat,C
  24     .code
  25
  26 ;------------------------------------------------------------------------------
  27 ; UINT64
  28 ; EFIAPI
  29 ; InternalMathMultU64x64 (
  30 ;   IN      UINT64                    Multiplicand,
  31 ;   IN      UINT64                    Multiplier
  32 ;   );
  33 ;------------------------------------------------------------------------------
  34 InternalMathMultU64x64  PROC    USES    ebx
  35     mov     ebx, [esp + 8]              ; ebx <- M1[0..31]
  36     mov     edx, [esp + 16]             ; edx <- M2[0..31]
  37     mov     ecx, ebx
  38     mov     eax, edx
  39     imul    ebx, [esp + 20]             ; ebx <- M1[0..31] * M2[32..63]
  40     imul    edx, [esp + 12]             ; edx <- M1[32..63] * M2[0..31]
  41     add     ebx, edx                    ; carries are abandoned
  42     mul     ecx                         ; edx:eax <- M1[0..31] * M2[0..31]
  43     add     edx, ebx                    ; carries are abandoned
  44     ret
  45 InternalMathMultU64x64  ENDP
  46
  47     END