/*

 * Loongson MMI optimizations for libjpeg-turbo

 *

 * Copyright (C) 2015, 2018, D. R. Commander.  All Rights Reserved.

 * Copyright (C) 2016-2017, Loongson Technology Corporation Limited, BeiJing.

 *                          All Rights Reserved.

 * Authors:  ZhuChen     <zhuchen@loongson.cn></zhuchen@loongson.cn>

 *           CaiWanwei   <caiwanwei@loongson.cn></caiwanwei@loongson.cn>

 *           SunZhangzhi <sunzhangzhi-cq@loongson.cn></sunzhangzhi-cq@loongson.cn>

 *

 * Based on the x86 SIMD extension for IJG JPEG library

 * Copyright (C) 1999-2006, MIYASAKA Masaru.

 *

 * This software is provided 'as-is', without any express or implied

 * warranty.  In no event will the authors be held liable for any damages

 * arising from the use of this software.

 *

 * Permission is granted to anyone to use this software for any purpose,

 * including commercial applications, and to alter it and redistribute it

 * freely, subject to the following restrictions:

 *

 * 1. The origin of this software must not be misrepresented; you must not

 *    claim that you wrote the original software. If you use this software

 *    in a product, an acknowledgment in the product documentation would be

 *    appreciated but is not required.

 * 2. Altered source versions must be plainly marked as such, and must not be

 *    misrepresented as being the original software.

 * 3. This notice may not be removed or altered from any source distribution.

 */

/* CHROMA DOWNSAMPLING */

#include "jsimd_mmi.h"

#include "jcsample.h"

void jsimd_h2v2_downsample_mmi(JDIMENSION image_width, int max_v_samp_factor,

                               JDIMENSION v_samp_factor,

                               JDIMENSION width_in_blocks,

                               JSAMPARRAY input_data, JSAMPARRAY output_data)

{

  int inrow, outrow, outcol, bias;

  JDIMENSION output_cols = width_in_blocks * DCTSIZE;

  JSAMPROW inptr0, inptr1, outptr;

  __m64 mm0, mm1, mm2, mm3, mm4, mm5, mm6 = 0.0, mm7;

  expand_right_edge(input_data, max_v_samp_factor, image_width,

                    output_cols * 2);

  bias = (1 << 17) + 1;                      /* 0x00020001 (bias pattern) */

  mm7 = _mm_set1_pi32(bias);                 /* mm7={1, 2, 1, 2} */

  mm6 = _mm_cmpeq_pi16(mm6, mm6);

  mm6 = _mm_srli_pi16(mm6, BYTE_BIT);        /* mm6={0xFF 0x00 0xFF 0x00 ..} */

  for (inrow = 0, outrow = 0; outrow < v_samp_factor;

       inrow += 2, outrow++) {

    inptr0 = input_data[inrow];

    inptr1 = input_data[inrow + 1];

    outptr = output_data[outrow];

    for (outcol = output_cols; outcol > 0;

         outcol -= 8, inptr0 += 16, inptr1 += 16, outptr += 8) {

      mm0 = _mm_load_si64((__m64 *)&inptr0[0]);

      mm1 = _mm_load_si64((__m64 *)&inptr1[0]);

      mm2 = _mm_load_si64((__m64 *)&inptr0[8]);

      mm3 = _mm_load_si64((__m64 *)&inptr1[8]);

      mm4 = mm0;

      mm5 = mm1;

      mm0 = _mm_and_si64(mm0, mm6);

      mm4 = _mm_srli_pi16(mm4, BYTE_BIT);

      mm1 = _mm_and_si64(mm1, mm6);

      mm5 = _mm_srli_pi16(mm5, BYTE_BIT);

      mm0 = _mm_add_pi16(mm0, mm4);

      mm1 = _mm_add_pi16(mm1, mm5);

      mm4 = mm2;

      mm5 = mm3;

      mm2 = _mm_and_si64(mm2, mm6);

      mm4 = _mm_srli_pi16(mm4, BYTE_BIT);

      mm3 = _mm_and_si64(mm3, mm6);

      mm5 = _mm_srli_pi16(mm5, BYTE_BIT);

      mm2 = _mm_add_pi16(mm2, mm4);

      mm3 = _mm_add_pi16(mm3, mm5);

      mm0 = _mm_add_pi16(mm0, mm1);

      mm2 = _mm_add_pi16(mm2, mm3);

      mm0 = _mm_add_pi16(mm0, mm7);

      mm2 = _mm_add_pi16(mm2, mm7);

      mm0 = _mm_srli_pi16(mm0, 2);

      mm2 = _mm_srli_pi16(mm2, 2);

      mm0 = _mm_packs_pu16(mm0, mm2);

      _mm_store_si64((__m64 *)&outptr[0], mm0);

    }

  }

}