StdLib/LibC/CRT/Ia32/shldi3.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>
   4 # This program and the accompanying materials are licensed and made available
   5 # under the terms and conditions of the BSD License which accompanies this
   6 # 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 #   MathLShiftS64.S
  15 #
  16 # Abstract:
  17 #
  18 #   64-bit Math Worker Function.
  19 #   Shifts a 64-bit signed value left by a certain number of bits.
  20 #
  21 #------------------------------------------------------------------------------
  22
  23     .686:
  24     .code:
  25
  26 ASM_GLOBAL ASM_PFX(__ashldi3)
  27
  28 #------------------------------------------------------------------------------
  29 #
  30 # void __cdecl __ashldi3 (void)
  31 #
  32 #------------------------------------------------------------------------------
  33 ASM_PFX(__ashldi3):
  34     #
  35     # Handle shifting of 64 or more bits (return 0)
  36     #
  37     cmpb    $64, %cl
  38     jae     ReturnZero
  39
  40     #
  41     # Handle shifting of between 0 and 31 bits
  42     #
  43     cmpb    $32, %cl
  44     jae     More32
  45     shld    %cl, %eax, %edx
  46     shl     %cl, %eax
  47     ret
  48
  49     #
  50     # Handle shifting of between 32 and 63 bits
  51     #
  52 More32:
  53     movl    %eax, %edx
  54     xor     %eax, %eax
  55     and     $31, %cl
  56     shl     %cl, %edx
  57     ret
  58
  59 ReturnZero:
  60     xor     %eax, %eax
  61     xor     %edx, %edx
  62     ret