MdePkg/Library/BaseLib/Ia32/MultU64x64.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   MultU64x64.nasm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   Calculate the product of a 64-bit integer and another 64-bit integer
  13 ;
  14 ;------------------------------------------------------------------------------
  15
  16     SECTION .text
  17
  18 ;------------------------------------------------------------------------------
  19 ; UINT64
  20 ; EFIAPI
  21 ; InternalMathMultU64x64 (
  22 ;   IN      UINT64                    Multiplicand,
  23 ;   IN      UINT64                    Multiplier
  24 ;   );
  25 ;------------------------------------------------------------------------------
  26 global ASM_PFX(InternalMathMultU64x64)
  27 ASM_PFX(InternalMathMultU64x64):
  28     push    ebx
  29     mov     ebx, [esp + 8]              ; ebx <- M1[0..31]
  30     mov     edx, [esp + 16]             ; edx <- M2[0..31]
  31     mov     ecx, ebx
  32     mov     eax, edx
  33     imul    ebx, [esp + 20]             ; ebx <- M1[0..31] * M2[32..63]
  34     imul    edx, [esp + 12]             ; edx <- M1[32..63] * M2[0..31]
  35     add     ebx, edx                    ; carries are abandoned
  36     mul     ecx                         ; edx:eax <- M1[0..31] * M2[0..31]
  37     add     edx, ebx                    ; carries are abandoned
  38     pop     ebx
  39     ret
  40