TAlpha::Negative 部分汇编

最新推荐文章于 2023-04-11 23:53:37 发布

原创最新推荐文章于 2023-04-11 23:53:37 发布 · 433 阅读

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#汇编 #c #byte #struct

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本文探讨了在图像处理与内存操作中优化算法的实现，通过使用汇编语言进行底层操作，实现了对图像数据的高效处理与内存优化。具体包括宽度调整、内存地址计算、循环遍历及逐像素的异或操作，显著提高了处理速度和内存使用效率。

      Width *= 3;
      register const int ld = iLineAdd + Width;
      Width >>= 1;
      Width--;
      for (register int i = Height - 1; i >= 0; i--)
       {
        register unsigned short int *ptr = (unsigned short int *)ptrBuffer;
        for (register int j = Width; j >= 0; j--)
         {
          *ptr = ~*ptr;
          ptr++;
         }
        ptrBuffer += ld;
       }

汇编代码

:00425E95 8D1C52         lea ebx, dword ptr [edx+2*edx] ; edx = Width
:00425E98 89DA           mov edx, ebx
;:00425E9A 81EA23010000  sub edx, 00000123
:00425EA0 8B5D0C         mov ebx, dword ptr [ebp+0C]
:00425EA3 03DA           add ebx, edx
:00425EA5 D1FA           sar edx, 1
:00425EA7 895DFC         mov dword ptr [ebp-04], ebx ; [ebp-04] = ld
:00425EAA 4A             dec edx
:00425EAB 49             dec ecx
:00425EAC 894DF8         mov dword ptr [ebp-08], ecx ; [ebp-08] = i
:00425EAF 837DF800       cmp dword ptr [ebp-08], 00000000
:00425EB3 7C50           jl 00425F05
:00425EB5 8BC8           mov ecx, eax ; eax = ptrBuffer
:00425EB7 8BDA           mov ebx, edx ; ebx = j
:00425EB9 85DB           test ebx, ebx
:00425EBB 7C0B           jl 00425EC8
:00425EBD 66F711         not word ptr [ecx] ; *ptr = ~*ptr
:00425EC0 83C102         add ecx, 00000002  ; ptr++ 
:00425EC3 4B             dec ebx            ; j-- 
:00425EC4 85DB           test ebx, ebx
:00425EC6 7DF5           jge 00425EBD
:00425EC8 0345FC         add eax, dword ptr [ebp-04]
:00425ECB FF4DF8         dec [ebp-08]
:00425ECE 837DF800       cmp dword ptr [ebp-08], 00000000
:00425ED2 7DE1           jge 00425EB5

 Width--;
 #ifdef _using_color_rgb_struct_
    register color_rgb *pDest;
    register const int ld = iPixelAdd + 3;
    for (register int i = Height - 1; i >= 0; i--)
     {
      for (register int j = Width; j >= 0; j--)
       {
        pDest = (color_rgb *)ptrDest;
        *((unsigned short int *)ptrDest) = ~*((unsigned short int *)ptrDest);
        pDest->r = ~pDest->r;

        ptrDest += ld;
       }

      ptrDest += iLineAdd;
     }
 #else

汇编代码

:00425ED6 4A        dec edx ; Width--
:00425ED7 8D7B03    lea edi, dword ptr [ebx+03] ; edi = ld
:00425EDA 49        dec ecx
:00425EDB 894DF4    mov dword ptr [ebp-0C], ecx ; [ebp-0C] = i
:00425EDE 837DF400  cmp dword ptr [ebp-0C], 00000000
:00425EE2 7C21      jl 00425F05
:00425EE4 8BF2      mov esi, edx ; j = Width
:00425EE6 85F6      test esi, esi ; esi = j
:00425EE8 7C0F      jl 00425EF9
:00425EEA 8BC8      mov ecx, eax ; ecx = pDest 多浪费一步
:00425EEC 66F710    not word ptr [eax]
:00425EEF F65102    not [ecx+02]
:00425EF2 03C7      add eax, edi ; ptrDest += ld
:00425EF4 4E        dec esi
:00425EF5 85F6      test esi, esi
:00425EF7 7DF1      jge 00425EEA
:00425EF9 03450C    add eax, dword ptr [ebp+0C] ; ptrDest += iLineAdd
:00425EFC FF4DF4    dec [ebp-0C] ; i--
:00425EFF 837DF400  cmp dword ptr [ebp-0C], 00000000
:00425F03 7DDF      jge 00425EE4

 Width--;
 #ifdef _using_short_int_
    register const int ld = iPixelAdd + 2;
    for (register int i = Height - 1; i >= 0; i--)
     {
      for (register int j = Width; j >= 0; j--)
       {
        *ptrDest = ~*ptrDest;
        ptrDest++;
        *((unsigned short int *)ptrDest) = ~*((unsigned short int *)ptrDest);

        ptrDest += ld;
       }

      ptrDest += iLineAdd;
     }

汇编代码

:00425EC8 4A            dec edx ; Width--
:00425EC9 8D7302        lea esi, dword ptr [ebx+02] ; ld = iPixelAdd + 2
:00425ECC 81C223010000  add edx, 00000123
:00425ED2 8D79FF        lea edi, dword ptr [ecx-01] ; i = Height - 1
:00425ED5 85FF          test edi, edi
:00425ED7 7C1B          jl 00425EF4
:00425ED9 8BCA          mov ecx, edx
:00425EDB 85C9          test ecx, ecx
:00425EDD 7C0D          jl 00425EEC
:00425EDF F610          not byte ptr [eax] ; *ptrDest = ~*ptrDest
:00425EE1 40            inc eax ; ptrDest++
:00425EE2 66F710        not word ptr [eax] ; *((unsigned short int *)ptrDest) = ~*((unsigned short int *)ptrDest)
:00425EE5 03C6          add eax, esi ; ptrDest += ld
:00425EE7 49            dec ecx      ; j--
:00425EE8 85C9          test ecx, ecx
:00425EEA 7DF3          jge 00425EDF
:00425EEC 03450C        add eax, dword ptr [ebp+0C] ; ptrDest += iLineAdd
:00425EEF 4F            dec edi ; i--
:00425EF0 85FF          test edi, edi
:00425EF2 7DE5          jge 00425ED9

内循环do...while

 Width--;
 #ifdef _using_short_int_
    register const int ld = iPixelAdd + 2;
    for (register int i = Height - 1; i >= 0; i--)
     {
      register int j = Width;
      do
       {
        *ptrDest = ~*ptrDest;
        ptrDest++;
        *((unsigned short int *)ptrDest) = ~*((unsigned short int *)ptrDest);

        ptrDest += ld;
        j--;
       }while(j >= 0);

      ptrDest += iLineAdd;
     }

汇编代码

:00425E98 4A            dec edx  ; Width--
:00425E99 8D7B02        lea edi, dword ptr [ebx+02]
:00425E9C 81C223010000  add edx, 00000123
:00425EA2 8D71FF        lea esi, dword ptr [ecx-01]
:00425EA5 85F6          test esi, esi  ; esi = i
:00425EA7 7C17          jl 00425EC0
:00425EA9 8BCA          mov ecx, edx   ; j = Width
:00425EAB F610          not byte ptr [eax]  ; *ptrDest = ~*ptrDest
:00425EAD 40            inc eax             ; ptrDest++
:00425EAE 66F710        not word ptr [eax]  
:00425EB1 03C7          add eax, edi        ; ptrDest += ld
:00425EB3 49            dec ecx             ; j--
:00425EB4 85C9          test ecx, ecx
:00425EB6 7DF3          jge 00425EAB
:00425EB8 03450C        add eax, dword ptr [ebp+0C]  ; ptrDest += iLineAdd
:00425EBB 4E            dec esi        ;  i--  
:00425EBC 85F6          test esi, esi
:00425EBE 7DE9          jge 00425EA9