[x265] [PATCH Review only] asm: pixel_sub_ps routine for 4x2 block size

[murugan at multicorewareinc.com]

# HG changeset patch
# User Murugan Vairavel <murugan at multicorewareinc.com>
# Date 1383839350 -19800
#      Thu Nov 07 21:19:10 2013 +0530
# Node ID d3517392c9845395895f6dbd62fb1a009df4df2f
# Parent  93cccbe49a93dd4c054ef06aca76974948793613
asm: pixel_sub_ps routine for 4x2 block size

diff -r 93cccbe49a93 -r d3517392c984 source/common/x86/pixel-sub8.asm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/common/x86/pixel-sub8.asm	Thu Nov 07 21:19:10 2013 +0530
@@ -0,0 +1,57 @@
+;*****************************************************************************
+;* Copyright (C) 2013 x265 project
+;*
+;* Authors: Murugan Vairavel <murugan at multicorewareinc.com>
+;*
+;* 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., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
+;*
+;* This program is also available under a commercial proprietary license.
+;* For more information, contact us at licensing at multicorewareinc.com.
+;*****************************************************************************/
+
+%include "x86inc.asm"
+%include "x86util.asm"
+
+SECTION_RODATA 32
+
+SECTION .text
+
+;-----------------------------------------------------------------------------
+; void pixel_sub_ps_c_4x2(int16_t *dest, intptr_t destride, pixel *src0, pixel *src1, intptr_t srcstride0, intptr_t srcstride1);
+;-----------------------------------------------------------------------------
+INIT_XMM sse2
+cglobal pixel_sub_ps_4x2, 4, 6, 6, dest, deststride, src0, src1
+
+add         r1,     r1
+mov         r4d,    r4m
+mov         r5d,    r5m
+
+movd        m0,     [r2]
+movd        m1,     [r3]
+pmovzxbw    m2,     m0
+pmovzxbw    m3,     m1
+
+movd        m0,     [r2 + r4]
+movd        m1,     [r3 + r5]
+pmovzxbw    m4,     m0
+pmovzxbw    m5,     m1
+
+psubw       m4,     m5
+psubw       m2,     m3
+
+movh    [r0],         m2
+movh    [r0 + r1],    m4
+
+RET