MdePkg/Library/BaseLib/Ia32/DivU64x64Remainder.S

   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 #   DivU64x64Remainder.asm
  15 #
  16 # Abstract:
  17 #
  18 #   Calculate the quotient of a 64-bit integer by a 64-bit integer and returns
  19 #   both the quotient and the remainder
  20 #
  21 #------------------------------------------------------------------------------
  22
  23 .globl ASM_PFX(InternalMathDivRemU64x32), ASM_PFX(InternalMathDivRemU64x64)
  24
  25 #------------------------------------------------------------------------------
  26 # UINT64
  27 # EFIAPI
  28 # InternalMathDivRemU64x64 (
  29 #   IN      UINT64                    Dividend,
  30 #   IN      UINT64                    Divisor,
  31 #   OUT     UINT64                    *Remainder    OPTIONAL
  32 #   );
  33 #------------------------------------------------------------------------------
  34 ASM_PFX(InternalMathDivRemU64x64):
  35     movl    16(%esp), %ecx
  36     testl   %ecx, %ecx
  37     jnz     Hard
  38     movl    20(%esp), %ecx
  39     jecxz   L1
  40     and     $0, 4(%ecx)
  41     movl    %ecx, 16(%esp)
  42 L1:
  43     jmp     ASM_PFX(InternalMathDivRemU64x32)
  44 Hard:
  45     push    %ebx
  46     push    %esi
  47     push    %edi
  48     mov     20(%esp), %edx
  49     mov     16(%esp), %eax
  50     movl    %edx, %edi
  51     movl    %eax, %esi
  52     mov     24(%esp), %ebx
  53 L2:
  54     shrl    %edx
  55     rcrl    $1, %eax
  56     shrdl   $1, %ecx, %ebx
  57     shrl    %ecx
  58     jnz     L2
  59     divl    %ebx
  60     movl    %eax, %ebx
  61     movl    28(%esp), %ecx
  62     mull    24(%esp)
  63     imull   %ebx, %ecx
  64     addl    %ecx, %edx
  65     mov     32(%esp), %ecx
  66     jc      TooLarge
  67     cmpl    %edx, %edi
  68     ja      Correct
  69     jb      TooLarge
  70     cmpl    %eax, %esi
  71     jae     Correct
  72 TooLarge:
  73     decl    %ebx
  74     jecxz   Return
  75     sub     24(%esp), %eax
  76     sbb     28(%esp), %edx
  77 Correct:
  78     jecxz   Return
  79     subl    %eax, %esi
  80     sbbl    %edx, %edi
  81     movl    %esi, (%ecx)
  82     movl    %edi, 4(%ecx)
  83 Return:
  84     movl    %ebx, %eax
  85     xorl    %edx, %edx
  86     pop     %edi
  87     pop     %esi
  88     pop     %ebx
  89     ret