CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
   4 ; 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 ;   MathRShiftU64.nasm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   64-bit Math Worker Function.
  19 ;   Shifts a 64-bit unsigned value right by a certain number of bits.
  20 ;
  21 ;------------------------------------------------------------------------------
  22
  23     SECTION .text
  24
  25 ;------------------------------------------------------------------------------
  26 ;
  27 ; void __cdecl __ashrdi3 (void)
  28 ;
  29 ;------------------------------------------------------------------------------
  30 global ASM_PFX(__ashrdi3)
  31 ASM_PFX(__ashrdi3):
  32     cmp cl,0x40
  33     jnc _Exit
  34     cmp cl,0x20
  35     jnc More32
  36     shrd eax,edx,cl
  37     shr edx,cl
  38     ret
  39 More32:
  40     mov eax,edx
  41     xor edx,edx
  42     and cl,0x1f
  43     shr eax,cl
  44     ret
  45 _Exit:
  46     xor eax,eax
  47     xor edx,edx
  48     ret
  49