MdePkg/Library/BaseLib/Ia32/MultU64x64.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2006 - 2008, 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.S
  15 #
  16 # Abstract:
  17 #
  18 #   Calculate the product of a 64-bit integer and another 64-bit integer
  19 #
  20 #------------------------------------------------------------------------------
  21
  22 ASM_GLOBAL ASM_PFX(InternalMathMultU64x64)
  23
  24 #------------------------------------------------------------------------------
  25 # UINT64
  26 # EFIAPI
  27 # InternalMathMultU64x64 (
  28 #   IN      UINT64                    Multiplicand,
  29 #   IN      UINT64                    Multiplier
  30 #   );
  31 #------------------------------------------------------------------------------
  32 ASM_PFX(InternalMathMultU64x64):
  33     push    %ebx
  34     movl    8(%esp), %ebx             # ebx <- M1[0..31]
  35     movl    16(%esp), %edx            # edx <- M2[0..31]
  36     movl    %ebx, %ecx
  37     movl    %edx, %eax
  38     imull   20(%esp), %ebx            # ebx <- M1[0..31] * M2[32..63]
  39     imull   12(%esp), %edx            # edx <- M1[32..63] * M2[0..31]
  40     addl    %edx, %ebx                # carries are abandoned
  41     mull    %ecx                      # edx:eax <- M1[0..31] * M2[0..31]
  42     addl    %ebx, %edx                # carries are abandoned
  43     pop     %ebx
  44     ret