;/*****************************************************************************
; *
; *  XVID MPEG-4 VIDEO CODEC
; *	 xmm 8x8 block-based halfpel interpolation
; *
; *  Copyright(C) 2002 Michael Militzer <michael@xvid.org>
; *  Copyright(C) 2002 -Skal-
; *
; *  This file is part of XviD, a free MPEG-4 video encoder/decoder
; *
; *  XviD 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
; *
; *  Under section 8 of the GNU General Public License, the copyright
; *  holders of XVID explicitly forbid distribution in the following
; *  countries:
; *
; *    - Japan
; *    - United States of America
; *
; *  Linking XviD statically or dynamically with other modules is making a
; *  combined work based on XviD.  Thus, the terms and conditions of the
; *  GNU General Public License cover the whole combination.
; *
; *  As a special exception, the copyright holders of XviD give you
; *  permission to link XviD with independent modules that communicate with
; *  XviD solely through the VFW1.1 and DShow interfaces, regardless of the
; *  license terms of these independent modules, and to copy and distribute
; *  the resulting combined work under terms of your choice, provided that
; *  every copy of the combined work is accompanied by a complete copy of
; *  the source code of XviD (the version of XviD used to produce the
; *  combined work), being distributed under the terms of the GNU General
; *  Public License plus this exception.  An independent module is a module
; *  which is not derived from or based on XviD.
; *
; *  Note that people who make modified versions of XviD are not obligated
; *  to grant this special exception for their modified versions; it is
; *  their choice whether to do so.  The GNU General Public License gives
; *  permission to release a modified version without this exception; this
; *  exception also makes it possible to release a modified version which
; *  carries forward this exception.
; *
; * $Id: interpolate8x8_xmm.asm,v 1.3 2002/11/17 00:20:30 edgomez Exp $
; *
; ****************************************************************************/

bits 32

%macro cglobal 1 
	%ifdef PREFIX
		global _%1 
		%define %1 _%1
	%else
		global %1
	%endif
%endmacro

section .data


align 16

mmx_one
times 8 db 1

section .text

cglobal interpolate8x8_halfpel_h_xmm
cglobal interpolate8x8_halfpel_v_xmm
cglobal interpolate8x8_halfpel_hv_xmm

;===========================================================================
;
; void interpolate8x8_halfpel_h_xmm(uint8_t * const dst,
;						const uint8_t * const src,
;						const uint32_t stride,
;						const uint32_t rounding);
;
;===========================================================================

%macro COPY_H_SSE_RND0 0
  movq mm0,  [eax]
  pavgb mm0, [eax+1]
  movq mm1,  [eax+edx]
  pavgb mm1, [eax+edx+1]
  lea eax,[eax+2*edx]
  movq [ecx],mm0
  movq [ecx+edx],mm1
%endmacro

%macro COPY_H_SSE_RND1 0
  movq mm0, [eax]
  movq mm1, [eax+edx]
  movq mm4, mm0
  movq mm5, mm1
  movq mm2, [eax+1]  
  movq mm3, [eax+edx+1]
  pavgb mm0, mm2
  pxor mm2, mm4
  pavgb mm1, mm3
  lea eax,[eax+2*edx]
  pxor mm3, mm5
  pand mm2, mm7
  pand mm3, mm7
  psubb mm0, mm2
  movq [ecx], mm0
  psubb mm1, mm3
	movq [ecx+edx], mm1
%endmacro

align 16
interpolate8x8_halfpel_h_xmm:

  mov eax, [esp+16]; rounding
  mov ecx, [esp+ 4] ; Dst
  test eax,eax
  mov eax, [esp+ 8] ; Src
  mov edx, [esp+12] ; stride

  jnz near .rounding1

  COPY_H_SSE_RND0
  lea ecx,[ecx+2*edx]
  COPY_H_SSE_RND0
  lea ecx,[ecx+2*edx]
  COPY_H_SSE_RND0
  lea ecx,[ecx+2*edx]
  COPY_H_SSE_RND0
  ret

.rounding1
   ; we use: (i+j)/2 = ( i+j+1 )/2 - (i^j)&1
  movq mm7, [mmx_one]
  COPY_H_SSE_RND1
  lea ecx, [ecx+2*edx]
  COPY_H_SSE_RND1
  lea ecx,[ecx+2*edx]
  COPY_H_SSE_RND1
  lea ecx,[ecx+2*edx]
  COPY_H_SSE_RND1
  ret

;===========================================================================
;
; void interpolate8x8_halfpel_v_xmm(uint8_t * const dst,
;						const uint8_t * const src,
;						const uint32_t stride,
;						const uint32_t rounding);
;
;===========================================================================

%macro COPY_V_SSE_RND0 0
  movq mm0,  [eax]  
  movq mm1,  [eax+edx]
  pavgb mm0, mm1
  pavgb mm1, [eax+2*edx]
  lea eax,[eax+2*edx]
  movq [ecx],mm0
  movq [ecx+edx],mm1
%endmacro

%macro COPY_V_SSE_RND1 0
  movq mm0, mm2
  movq mm1, [eax]
  movq mm2, [eax+edx]
  lea eax,[eax+2*edx]
  movq mm4, mm0
  movq mm5, mm1
  pavgb mm0, mm1
  pxor mm4, mm1  
  pavgb mm1, mm2
  pxor mm5, mm2
  pand mm4, mm7    ; lsb's of (i^j)...
  pand mm5, mm7    ; lsb's of (i^j)...
  psubb mm0, mm4 ; ...are substracted from result of pavgb
  movq [ecx], mm0
  psubb mm1, mm5 ; ...are substracted from result of pavgb
  movq [ecx+edx], mm1
%endmacro

align 16
interpolate8x8_halfpel_v_xmm:

  mov eax, [esp+16]; rounding
  mov ecx, [esp+ 4] ; Dst
  test eax,eax
  mov eax, [esp+ 8] ; Src
  mov edx, [esp+12] ; stride

    ; we process 2 line at a time

  jnz near .rounding1

  COPY_V_SSE_RND0
  lea ecx, [ecx+2*edx]
  COPY_V_SSE_RND0
  lea ecx, [ecx+2*edx]
  COPY_V_SSE_RND0
  lea ecx, [ecx+2*edx]
  COPY_V_SSE_RND0
  ret

.rounding1
   ; we use: (i+j)/2 = ( i+j+1 )/2 - (i^j)&1
  movq mm7, [mmx_one]
  movq mm2, [eax]   ; loop invariant
  add eax, edx

  COPY_V_SSE_RND1
  lea ecx,[ecx+2*edx]
  COPY_V_SSE_RND1
  lea ecx,[ecx+2*edx]
  COPY_V_SSE_RND1
  lea ecx,[ecx+2*edx]
  COPY_V_SSE_RND1
  ret

;===========================================================================
;
; void interpolate8x8_halfpel_hv_xmm(uint8_t * const dst,
;						const uint8_t * const src,
;						const uint32_t stride, 
;						const uint32_t rounding);
;
;
;===========================================================================

; The trick is to correct the result of 'pavgb' with some combination of the
; lsb's of the 4 input values i,j,k,l, and their intermediate 'pavgb' (s and t).
; The boolean relations are:
;   (i+j+k+l+3)/4 = (s+t+1)/2 - (ij&kl)&st 
;   (i+j+k+l+2)/4 = (s+t+1)/2 - (ij|kl)&st
;   (i+j+k+l+1)/4 = (s+t+1)/2 - (ij&kl)|st
;   (i+j+k+l+0)/4 = (s+t+1)/2 - (ij|kl)|st
; with  s=(i+j+1)/2, t=(k+l+1)/2, ij = i^j, kl = k^l, st = s^t.

; Moreover, we process 2 lines at a times, for better overlapping (~15% faster).

%macro COPY_HV_SSE_RND0 0
    lea eax,[eax+edx]

    movq mm0, [eax]
    movq mm1, [eax+1]

    movq mm6, mm0
    pavgb mm0, mm1  ; mm0=(j+k+1)/2. preserved for next step
    lea eax,[eax+edx]
    pxor mm1, mm6   ; mm1=(j^k).     preserved for next step

    por mm3, mm1    ; ij |= jk
    movq mm6, mm2
    pxor mm6, mm0   ; mm6 = s^t
    pand mm3, mm6   ; (ij|jk) &= st
    pavgb mm2, mm0  ; mm2 = (s+t+1)/2
    pand mm3, mm7   ; mask lsb
    psubb mm2, mm3  ; apply.

    movq [ecx], mm2

    movq mm2, [eax]
    movq mm3, [eax+1]
    movq mm6, mm2
    pavgb mm2, mm3  ; preserved for next iteration
    lea ecx,[ecx+edx]
    pxor mm3, mm6   ; preserved for next iteration

    por mm1, mm3
    movq mm6, mm0
    pxor mm6, mm2
    pand mm1, mm6
    pavgb mm0, mm2

    pand mm1, mm7
    psubb mm0, mm1

    movq [ecx], mm0
%endmacro

%macro COPY_HV_SSE_RND1 0
    lea eax,[eax+edx]

    movq mm0, [eax]
    movq mm1, [eax+1]

    movq mm6, mm0
    pavgb mm0, mm1  ; mm0=(j+k+1)/2. preserved for next step
    lea eax,[eax+edx]
    pxor mm1, mm6   ; mm1=(j^k).     preserved for next step

    pand mm3, mm1
    movq mm6, mm2
    pxor mm6, mm0
    por mm3, mm6
    pavgb mm2, mm0
    pand mm3, mm7
    psubb mm2, mm3

    movq [ecx], mm2

    movq mm2, [eax]
    movq mm3, [eax+1]
    movq mm6, mm2
    pavgb mm2, mm3  ; preserved for next iteration
    lea ecx,[ecx+edx]
    pxor mm3, mm6   ; preserved for next iteration

    pand mm1, mm3
    movq mm6, mm0
    pxor mm6, mm2
    por mm1, mm6
    pavgb mm0, mm2
    pand mm1, mm7
    psubb mm0, mm1

    movq [ecx], mm0
%endmacro

align 16
interpolate8x8_halfpel_hv_xmm:
  mov eax, [esp+16] ; rounding
  mov ecx, [esp+ 4] ; Dst
  test eax,eax
  mov eax, [esp+ 8] ; Src
  mov edx, [esp+12] ; stride

  movq mm7, [mmx_one]

    ; loop invariants: mm2=(i+j+1)/2  and  mm3= i^j
  movq mm2, [eax]
  movq mm3, [eax+1]
  movq mm6, mm2
  pavgb mm2, mm3
  pxor mm3, mm6   ; mm2/mm3 ready

  jnz near .rounding1

  COPY_HV_SSE_RND0
  add ecx, edx
  COPY_HV_SSE_RND0
  add ecx, edx
  COPY_HV_SSE_RND0
  add ecx, edx
  COPY_HV_SSE_RND0
  ret

.rounding1
  COPY_HV_SSE_RND1
  add ecx, edx
  COPY_HV_SSE_RND1
  add ecx, edx
  COPY_HV_SSE_RND1
  add ecx, edx
  COPY_HV_SSE_RND1
  ret                    
