reactos/win32ss/gdi/dib/i386/dib32bpp_hline.s

   1 /*
   2  * PROJECT:         Win32 subsystem
   3  * LICENSE:         See COPYING in the top level directory
   4  * FILE:            subsystems/win32/win32k/dib/i386/dib32bpp_hline.c
   5  * PURPOSE:         ASM optimised 32bpp HLine
   6  * PROGRAMMERS:     Magnus Olsen
   7  */
   8
   9 #include <asm.inc>
  10
  11 .code
  12
  13 PUBLIC _DIB_32BPP_HLine
  14
  15 _DIB_32BPP_HLine:
  16                   sub     esp, 12             // rember the base is not hex it is dec
  17                   mov     ecx, [esp+16]
  18                   mov     [esp+4], ebx
  19                   mov     edx, [esp+20]      // edx =  LONG x1
  20                   mov     [esp+8], edi
  21                   mov     edi, [esp+28]
  22                   mov     eax, [ecx+36]
  23                   mov     ebx, [esp+24]      // ebx =  LONG x2
  24                   imul    eax, edi
  25                   mov     edi, [ecx+32]
  26                   sub     ebx, edx            // cx  = (x2 - x1) ;
  27                   add     eax, edi
  28                   lea     edx, [eax+edx*4]
  29                   mov     [esp], edx
  30                   cld
  31                   mov     eax, [esp+32]
  32                   mov     edi, [esp]
  33                   test    edi, 3             // Align to fullword boundary
  34                   jnz     short _save_rest
  35                   mov     ecx, ebx           // Setup count of fullwords to fill
  36                   rep stosd
  37
  38                   mov     ebx, [esp+4]
  39                   mov     edi, [esp+8]
  40                   add     esp, 12
  41                   ret
  42 _save_rest:
  43                   stosw
  44                   ror     eax, 16
  45                   mov     ecx, ebx           // Setup count of fullwords to fill
  46                   dec     ecx
  47                   rep stosd                  // The actual fill
  48                   shr     eax, 16
  49                   stosw
  50
  51                   mov     ebx, [esp+4]
  52                   mov     edi, [esp+8]
  53                   add     esp, 12
  54                   ret
  55
  56 END