cbp_sse2.asm

这是一个压缩解压包,用C语言进行编程的,里面有详细的源代码.

;/****************************************************************************
; *
; *  XVID MPEG-4 VIDEO CODEC
; *  - SSE2 CBP computation -
; *
; *  Copyright (C) 2002 Daniel Smith <[e-mail]>
; *                2002 Pascal Massimino <[e-mail]>
; *
; *  This program is free software ; you can redistribute it and/or modify
; *  it under the terms of the GNU General Public License as published by
; *  the Free Software Foundation ; either version 2 of the License, or
; *  (at your option) any later version.
; *
; *  This program is distributed in the hope that it will be useful,
; *  but WITHOUT ANY WARRANTY ; without even the implied warranty of
; *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; *  GNU General Public License for more details.
; *
; *  You should have received a copy of the GNU General Public License
; *  along with this program ; if not, write to the Free Software
; *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
; *
; * $Id: cbp_sse2.asm,v 1.7 2004/08/29 10:02:38 edgomez Exp $
; *
; ***************************************************************************/

BITS 32

;=============================================================================
; Macros
;=============================================================================

%macro cglobal 1
	%ifdef PREFIX
		%ifdef MARK_FUNCS
			global _%1:function %1.endfunc-%1
			%define %1 _%1:function %1.endfunc-%1
		%else
			global _%1
			%define %1 _%1
		%endif
	%else
		%ifdef MARK_FUNCS
			global %1:function %1.endfunc-%1
		%else
			global %1
		%endif
	%endif
%endmacro

%macro LOOP_SSE2 1
  movdqa xmm0, [edx+(%1)*128]
  pand xmm0, xmm7
  movdqa xmm1, [edx+(%1)*128+16]

  por xmm0, [edx+(%1)*128+32]
  por xmm1, [edx+(%1)*128+48]
  por xmm0, [edx+(%1)*128+64]
  por xmm1, [edx+(%1)*128+80]
  por xmm0, [edx+(%1)*128+96]
  por xmm1, [edx+(%1)*128+112]

  por xmm0, xmm1        ; xmm0 = xmm1 = 128 bits worth of info
  psadbw xmm0, xmm6     ; contains 2 dwords with sums
  movhlps xmm1, xmm0    ; move high dword from xmm0 to low xmm1
  por xmm0, xmm1        ; combine
  movd ecx, xmm0        ; if ecx set, values were found
  test ecx, ecx
%endmacro

;=============================================================================
; Data (Read Only)
;=============================================================================

%ifdef FORMAT_COFF
SECTION .rodata
%else
SECTION .rodata align=16
%endif

ALIGN 16
ignore_dc:
  dw 0, -1, -1, -1, -1, -1, -1, -1

;=============================================================================
; Code
;=============================================================================

SECTION .text

;-----------------------------------------------------------------------------
; uint32_t calc_cbp_sse2(const int16_t coeff[6*64]);
;-----------------------------------------------------------------------------

ALIGN 16
cglobal calc_cbp_sse2
calc_cbp_sse2:
  mov edx, [esp+4]         ; coeff[]
  xor eax, eax             ; cbp = 0

  movdqu xmm7, [ignore_dc] ; mask to ignore dc value
  pxor xmm6, xmm6          ; zero

  LOOP_SSE2 0
  test ecx, ecx
  jz .blk2
  or eax, (1<<5)

.blk2
  LOOP_SSE2 1
  test ecx, ecx
  jz .blk3
  or eax, (1<<4)

.blk3
  LOOP_SSE2 2
  test ecx, ecx
  jz .blk4
  or eax, (1<<3)

.blk4
  LOOP_SSE2 3
  test ecx, ecx
  jz .blk5
  or eax, (1<<2)

.blk5
  LOOP_SSE2 4
  test ecx, ecx
  jz .blk6
  or eax, (1<<1)

.blk6
  LOOP_SSE2 5
  test ecx, ecx
  jz .finished
  or eax, (1<<0)

.finished
	ret
.endfunc