Home | History | Annotate | Download | only in armv8
      1 //******************************************************************************
      2 //*
      3 //* Copyright (C) 2015 The Android Open Source Project
      4 //*
      5 //* Licensed under the Apache License, Version 2.0 (the "License");
      6 //* you may not use this file except in compliance with the License.
      7 //* You may obtain a copy of the License at:
      8 //*
      9 //* http://www.apache.org/licenses/LICENSE-2.0
     10 //*
     11 //* Unless required by applicable law or agreed to in writing, software
     12 //* distributed under the License is distributed on an "AS IS" BASIS,
     13 //* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 //* See the License for the specific language governing permissions and
     15 //* limitations under the License.
     16 //*
     17 //*****************************************************************************
     18 //* Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
     19 //*/
     20 ///**
     21 //******************************************************************************
     22 //* @file
     23 //*  ih264_weighted_bi_pred_av8.s
     24 //*
     25 //* @brief
     26 //*  Contains function definitions for weighted biprediction.
     27 //*
     28 //* @author
     29 //*  Kaushik Senthoor R
     30 //*
     31 //* @par List of Functions:
     32 //*
     33 //*  - ih264_weighted_bi_pred_luma_av8()
     34 //*  - ih264_weighted_bi_pred_chroma_av8()
     35 //*
     36 //* @remarks
     37 //*  None
     38 //*
     39 //*******************************************************************************
     40 //*/
     41 //*******************************************************************************
     42 //* @function
     43 //*  ih264_weighted_bi_pred_luma_av8()
     44 //*
     45 //* @brief
     46 //*  This routine performs the default weighted prediction as described in sec
     47 //* 8.4.2.3.2 titled "Weighted sample prediction process" for luma.
     48 //*
     49 //* @par Description:
     50 //*  This function gets two ht x wd blocks, calculates the weighted samples,
     51 //* rounds off, adds offset and stores it in the destination block.
     52 //*
     53 //* @param[in] puc_src1
     54 //*  UWORD8 Pointer to the buffer containing the input block 1.
     55 //*
     56 //* @param[in] puc_src2
     57 //*  UWORD8 Pointer to the buffer containing the input block 2.
     58 //*
     59 //* @param[out] puc_dst
     60 //*  UWORD8 pointer to the destination where the output block is stored.
     61 //*
     62 //* @param[in] src_strd1
     63 //*  Stride of the input buffer 1
     64 //*
     65 //* @param[in] src_strd2
     66 //*  Stride of the input buffer 2
     67 //*
     68 //* @param[in] dst_strd
     69 //*  Stride of the destination buffer
     70 //*
     71 //* @param[in] log_WD
     72 //*  number of bits to be rounded off
     73 //*
     74 //* @param[in] wt1
     75 //*  weight for the weighted prediction
     76 //*
     77 //* @param[in] wt2
     78 //*  weight for the weighted prediction
     79 //*
     80 //* @param[in] ofst1
     81 //*  offset 1 used after rounding off
     82 //*
     83 //* @param[in] ofst2
     84 //*  offset 2 used after rounding off
     85 //*
     86 //* @param[in] ht
     87 //*  integer height of the array
     88 //*
     89 //* @param[in] wd
     90 //*  integer width of the array
     91 //*
     92 //* @returns
     93 //*  None
     94 //*
     95 //* @remarks
     96 //*  (ht,wd) can be (4,4), (4,8), (8,4), (8,8), (8,16), (16,8) or (16,16).
     97 //*
     98 //*******************************************************************************
     99 //*/
    100 //void ih264_weighted_bi_pred_luma_av8(UWORD8 *puc_src1,
    101 //                                     UWORD8 *puc_src2,
    102 //                                     UWORD8 *puc_dst,
    103 //                                     WORD32 src_strd1,
    104 //                                     WORD32 src_strd2,
    105 //                                     WORD32 dst_strd,
    106 //                                     WORD32 log_WD,
    107 //                                     WORD32 wt1,
    108 //                                     WORD32 wt2,
    109 //                                     WORD16 ofst1,
    110 //                                     WORD16 ofst2,
    111 //                                     WORD32 ht,
    112 //                                     WORD32 wd)
    113 //
    114 //**************Variables Vs Registers*****************************************
    115 //    x0      => puc_src1
    116 //    x1      => puc_src2
    117 //    x2      => puc_dst
    118 //    w3      => src_strd1
    119 //    w4      => src_strd2
    120 //    w5      => dst_strd
    121 //    w6      => log_WD
    122 //    w7      => wt1
    123 //    [sp]    => wt2       (w8)
    124 //    [sp+8]  => ofst1     (w9)
    125 //    [sp+16] => ofst2     (w10)
    126 //    [sp+24] => ht        (w11)
    127 //    [sp+32] => wd        (w12)
    128 //
    129 .text
    130 .p2align 2
    131 .include "ih264_neon_macros.s"
    132 
    133 
    134 
    135     .global ih264_weighted_bi_pred_luma_av8
    136 
    137 ih264_weighted_bi_pred_luma_av8:
    138 
    139     // STMFD sp!, {x4-x12,x14}                //stack stores the values of the arguments
    140     push_v_regs
    141     sxtw      x3, w3
    142     sxtw      x4, w4
    143     sxtw      x5, w5
    144     stp       x19, x20, [sp, #-16]!
    145     ldr       w8, [sp, #80]             //Load wt2 in w8
    146     ldr       w9, [sp, #88]             //Load ofst1 in w9
    147     add       w6, w6, #1                //w6  = log_WD + 1
    148     neg       w10, w6                   //w10 = -(log_WD + 1)
    149     dup       v0.8h, w10                //Q0  = -(log_WD + 1) (32-bit)
    150     ldr       w10, [sp, #96]            //Load ofst2 in w10
    151     ldr       w11, [sp, #104]           //Load ht in w11
    152     ldr       w12, [sp, #112]           //Load wd in w12
    153     add       w9, w9, #1                //w9 = ofst1 + 1
    154     add       w9, w9, w10               //w9 = ofst1 + ofst2 + 1
    155     mov       v2.s[0], w7
    156     mov       v2.s[1], w8               //D2 = {wt1(32-bit), wt2(32-bit)}
    157     asr       w9, w9, #1                //w9 = ofst = (ofst1 + ofst2 + 1) >> 1
    158     dup       v3.8b, w9                 //D3 = ofst (8-bit)
    159     cmp       w12, #16
    160     beq       loop_16                   //branch if wd is 16
    161     cmp       w12, #8                   //check if wd is 8
    162     beq       loop_8                    //branch if wd is 8
    163 
    164 loop_4:                                 //each iteration processes four rows
    165 
    166     ld1       {v4.s}[0], [x0], x3       //load row 1 in source 1
    167     ld1       {v4.s}[1], [x0], x3       //load row 2 in source 1
    168     ld1       {v6.s}[0], [x1], x4       //load row 1 in source 2
    169     ld1       {v6.s}[1], [x1], x4       //load row 2 in source 2
    170     uxtl      v4.8h, v4.8b              //converting rows 1,2 in source 1 to 16-bit
    171     ld1       {v8.s}[0], [x0], x3       //load row 3 in source 1
    172     ld1       {v8.s}[1], [x0], x3       //load row 4 in source 1
    173     uxtl      v6.8h, v6.8b              //converting rows 1,2 in source 2 to 16-bit
    174     ld1       {v10.s}[0], [x1], x4      //load row 3 in source 2
    175     ld1       {v10.s}[1], [x1], x4      //load row 4 in source 2
    176     uxtl      v8.8h, v8.8b              //converting rows 3,4 in source 1 to 16-bit
    177     uxtl      v10.8h, v10.8b            //converting rows 3,4 in source 2 to 16-bit
    178     mul       v4.8h, v4.8h , v2.h[0]    //weight 1 mult. for rows 1,2
    179     mla       v4.8h, v6.8h , v2.h[2]    //weight 2 mult. for rows 1,2
    180     mul       v8.8h, v8.8h , v2.h[0]    //weight 1 mult. for rows 3,4
    181     mla       v8.8h, v10.8h , v2.h[2]   //weight 2 mult. for rows 3,4
    182     subs      w11, w11, #4              //decrement ht by 4
    183     srshl     v4.8h, v4.8h , v0.8h      //rounds off the weighted samples from rows 1,2
    184     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from rows 3,4
    185     saddw     v4.8h, v4.8h , v3.8b      //adding offset for rows 1,2
    186     saddw     v8.8h, v8.8h , v3.8b      //adding offset for rows 3,4
    187     sqxtun    v4.8b, v4.8h              //saturating rows 1,2 to unsigned 8-bit
    188     sqxtun    v8.8b, v8.8h              //saturating rows 3,4 to unsigned 8-bit
    189     st1       {v4.s}[0], [x2], x5       //store row 1 in destination
    190     st1       {v4.s}[1], [x2], x5       //store row 2 in destination
    191     st1       {v8.s}[0], [x2], x5       //store row 3 in destination
    192     st1       {v8.s}[1], [x2], x5       //store row 4 in destination
    193     bgt       loop_4                    //if greater than 0 repeat the loop again
    194     b         end_loops
    195 
    196 loop_8:                                 //each iteration processes four rows
    197 
    198     ld1       {v4.8b}, [x0], x3         //load row 1 in source 1
    199     ld1       {v6.8b}, [x1], x4         //load row 1 in source 2
    200     ld1       {v8.8b}, [x0], x3         //load row 2 in source 1
    201     ld1       {v10.8b}, [x1], x4        //load row 2 in source 2
    202     uxtl      v4.8h, v4.8b              //converting row 1 in source 1 to 16-bit
    203     ld1       {v12.8b}, [x0], x3        //load row 3 in source 1
    204     ld1       {v14.8b}, [x1], x4        //load row 3 in source 2
    205     uxtl      v6.8h, v6.8b              //converting row 1 in source 2 to 16-bit
    206     ld1       {v16.8b}, [x0], x3        //load row 4 in source 1
    207     ld1       {v18.8b}, [x1], x4        //load row 4 in source 2
    208     uxtl      v8.8h, v8.8b              //converting row 2 in source 1 to 16-bit
    209     uxtl      v10.8h, v10.8b            //converting row 2 in source 2 to 16-bit
    210     mul       v4.8h, v4.8h , v2.h[0]    //weight 1 mult. for row 1
    211     mla       v4.8h, v6.8h , v2.h[2]    //weight 2 mult. for row 1
    212     uxtl      v12.8h, v12.8b            //converting row 3 in source 1 to 16-bit
    213     uxtl      v14.8h, v14.8b            //converting row 3 in source 2 to 16-bit
    214     mul       v8.8h, v8.8h , v2.h[0]    //weight 1 mult. for row 2
    215     mla       v8.8h, v10.8h , v2.h[2]   //weight 2 mult. for row 2
    216     uxtl      v16.8h, v16.8b            //converting row 4 in source 1 to 16-bit
    217     uxtl      v18.8h, v18.8b            //converting row 4 in source 2 to 16-bit
    218     mul       v12.8h, v12.8h , v2.h[0]  //weight 1 mult. for row 3
    219     mla       v12.8h, v14.8h , v2.h[2]  //weight 2 mult. for row 3
    220     mul       v16.8h, v16.8h , v2.h[0]  //weight 1 mult. for row 4
    221     mla       v16.8h, v18.8h , v2.h[2]  //weight 2 mult. for row 4
    222     srshl     v4.8h, v4.8h , v0.8h      //rounds off the weighted samples from row 1
    223     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from row 2
    224     srshl     v12.8h, v12.8h , v0.8h    //rounds off the weighted samples from row 3
    225     saddw     v4.8h, v4.8h , v3.8b      //adding offset for row 1
    226     srshl     v16.8h, v16.8h , v0.8h    //rounds off the weighted samples from row 4
    227     saddw     v8.8h, v8.8h , v3.8b      //adding offset for row 2
    228     saddw     v12.8h, v12.8h , v3.8b    //adding offset for row 3
    229     sqxtun    v4.8b, v4.8h              //saturating row 1 to unsigned 8-bit
    230     saddw     v16.8h, v16.8h , v3.8b    //adding offset for row 4
    231     sqxtun    v8.8b, v8.8h              //saturating row 2 to unsigned 8-bit
    232     sqxtun    v12.8b, v12.8h            //saturating row 3 to unsigned 8-bit
    233     sqxtun    v16.8b, v16.8h            //saturating row 4 to unsigned 8-bit
    234     st1       {v4.8b}, [x2], x5         //store row 1 in destination
    235     st1       {v8.8b}, [x2], x5         //store row 2 in destination
    236     subs      w11, w11, #4              //decrement ht by 4
    237     st1       {v12.8b}, [x2], x5        //store row 3 in destination
    238     st1       {v16.8b}, [x2], x5        //store row 4 in destination
    239     bgt       loop_8                    //if greater than 0 repeat the loop again
    240     b         end_loops
    241 
    242 loop_16:                                //each iteration processes two rows
    243 
    244     ld1       {v4.8b, v5.8b}, [x0], x3  //load row 1 in source 1
    245     ld1       {v6.8b, v7.8b}, [x1], x4  //load row 1 in source 2
    246     ld1       {v8.8b, v9.8b}, [x0], x3  //load row 2 in source 1
    247     ld1       {v10.8b, v11.8b}, [x1], x4 //load row 2 in source 2
    248     uxtl      v20.8h, v4.8b             //converting row 1L in source 1 to 16-bit
    249     ld1       {v12.8b, v13.8b}, [x0], x3 //load row 3 in source 1
    250     ld1       {v14.8b, v15.8b}, [x1], x4 //load row 3 in source 2
    251     uxtl      v22.8h, v6.8b             //converting row 1L in source 2 to 16-bit
    252     ld1       {v16.8b, v17.8b}, [x0], x3 //load row 4 in source 1
    253     ld1       {v18.8b, v19.8b}, [x1], x4 //load row 4 in source 2
    254     uxtl      v4.8h, v5.8b              //converting row 1H in source 1 to 16-bit
    255     uxtl      v6.8h, v7.8b              //converting row 1H in source 2 to 16-bit
    256     mul       v20.8h, v20.8h , v2.h[0]  //weight 1 mult. for row 1L
    257     mla       v20.8h, v22.8h , v2.h[2]  //weight 2 mult. for row 1L
    258     uxtl      v24.8h, v8.8b             //converting row 2L in source 1 to 16-bit
    259     uxtl      v26.8h, v10.8b            //converting row 2L in source 2 to 16-bit
    260     mul       v4.8h, v4.8h , v2.h[0]    //weight 1 mult. for row 1H
    261     mla       v4.8h, v6.8h , v2.h[2]    //weight 2 mult. for row 1H
    262     uxtl      v8.8h, v9.8b              //converting row 2H in source 1 to 16-bit
    263     uxtl      v10.8h, v11.8b            //converting row 2H in source 2 to 16-bit
    264     mul       v24.8h, v24.8h , v2.h[0]  //weight 1 mult. for row 2L
    265     mla       v24.8h, v26.8h , v2.h[2]  //weight 2 mult. for row 2L
    266     uxtl      v28.8h, v12.8b            //converting row 3L in source 1 to 16-bit
    267     uxtl      v30.8h, v14.8b            //converting row 3L in source 2 to 16-bit
    268     mul       v8.8h, v8.8h , v2.h[0]    //weight 1 mult. for row 2H
    269     mla       v8.8h, v10.8h , v2.h[2]   //weight 2 mult. for row 2H
    270     uxtl      v12.8h, v13.8b            //converting row 3H in source 1 to 16-bit
    271     uxtl      v14.8h, v15.8b            //converting row 3H in source 2 to 16-bit
    272     mul       v28.8h, v28.8h , v2.h[0]  //weight 1 mult. for row 3L
    273     mla       v28.8h, v30.8h , v2.h[2]  //weight 2 mult. for row 3L
    274     uxtl      v22.8h, v16.8b            //converting row 4L in source 1 to 16-bit
    275     uxtl      v6.8h, v18.8b             //converting row 4L in source 2 to 16-bit
    276     mul       v12.8h, v12.8h , v2.h[0]  //weight 1 mult. for row 3H
    277     mla       v12.8h, v14.8h , v2.h[2]  //weight 2 mult. for row 3H
    278     uxtl      v16.8h, v17.8b            //converting row 4H in source 1 to 16-bit
    279     uxtl      v18.8h, v19.8b            //converting row 4H in source 2 to 16-bit
    280     mul       v22.8h, v22.8h , v2.h[0]  //weight 1 mult. for row 4L
    281     mla       v22.8h, v6.8h , v2.h[2]   //weight 2 mult. for row 4L
    282     srshl     v20.8h, v20.8h , v0.8h    //rounds off the weighted samples from row 1L
    283     mul       v16.8h, v16.8h , v2.h[0]  //weight 1 mult. for row 4H
    284     mla       v16.8h, v18.8h , v2.h[2]  //weight 2 mult. for row 4H
    285     srshl     v4.8h, v4.8h , v0.8h      //rounds off the weighted samples from row 1H
    286     srshl     v24.8h, v24.8h , v0.8h    //rounds off the weighted samples from row 2L
    287     saddw     v20.8h, v20.8h , v3.8b    //adding offset for row 1L
    288     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from row 2H
    289     saddw     v4.8h, v4.8h , v3.8b      //adding offset for row 1H
    290     srshl     v28.8h, v28.8h , v0.8h    //rounds off the weighted samples from row 3L
    291     saddw     v24.8h, v24.8h , v3.8b    //adding offset for row 2L
    292     srshl     v12.8h, v12.8h , v0.8h    //rounds off the weighted samples from row 3H
    293     saddw     v8.8h, v8.8h , v3.8b      //adding offset for row 2H
    294     srshl     v22.8h, v22.8h , v0.8h    //rounds off the weighted samples from row 4L
    295     saddw     v28.8h, v28.8h , v3.8b    //adding offset for row 3L
    296     srshl     v16.8h, v16.8h , v0.8h    //rounds off the weighted samples from row 4H
    297     saddw     v12.8h, v12.8h , v3.8b    //adding offset for row 3H
    298     sqxtun    v26.8b, v20.8h            //saturating row 1L to unsigned 8-bit
    299     saddw     v22.8h, v22.8h , v3.8b    //adding offset for row 4L
    300     sqxtun    v27.8b, v4.8h             //saturating row 1H to unsigned 8-bit
    301     saddw     v16.8h, v16.8h , v3.8b    //adding offset for row 4H
    302     sqxtun    v10.8b, v24.8h            //saturating row 2L to unsigned 8-bit
    303     sqxtun    v11.8b, v8.8h             //saturating row 2H to unsigned 8-bit
    304     sqxtun    v30.8b, v28.8h            //saturating row 3L to unsigned 8-bit
    305     sqxtun    v31.8b, v12.8h            //saturating row 3H to unsigned 8-bit
    306     st1       {v26.8b, v27.8b}, [x2], x5 //store row 1 in destination
    307     sqxtun    v14.8b, v22.8h            //saturating row 4L to unsigned 8-bit
    308     sqxtun    v15.8b, v16.8h            //saturating row 4H to unsigned 8-bit
    309     st1       {v10.8b, v11.8b}, [x2], x5 //store row 2 in destination
    310     subs      w11, w11, #4              //decrement ht by 4
    311     st1       {v30.8b, v31.8b}, [x2], x5 //store row 3 in destination
    312     st1       {v14.8b, v15.8b}, [x2], x5 //store row 4 in destination
    313     bgt       loop_16                   //if greater than 0 repeat the loop again
    314 
    315 end_loops:
    316 
    317     // LDMFD sp!,{x4-x12,x15}                //Reload the registers from sp
    318     ldp       x19, x20, [sp], #16
    319     pop_v_regs
    320     ret
    321 
    322 
    323 //*******************************************************************************
    324 //* @function
    325 //*  ih264_weighted_bi_pred_chroma_av8()
    326 //*
    327 //* @brief
    328 //*  This routine performs the default weighted prediction as described in sec
    329 //* 8.4.2.3.2 titled "Weighted sample prediction process" for chroma.
    330 //*
    331 //* @par Description:
    332 //*  This function gets two ht x wd blocks, calculates the weighted samples,
    333 //* rounds off, adds offset and stores it in the destination block for U and V.
    334 //*
    335 //* @param[in] puc_src1
    336 //*  UWORD8 Pointer to the buffer containing the input block 1.
    337 //*
    338 //* @param[in] puc_src2
    339 //*  UWORD8 Pointer to the buffer containing the input block 2.
    340 //*
    341 //* @param[out] puc_dst
    342 //*  UWORD8 pointer to the destination where the output block is stored.
    343 //*
    344 //* @param[in] src_strd1
    345 //*  Stride of the input buffer 1
    346 //*
    347 //* @param[in] src_strd2
    348 //*  Stride of the input buffer 2
    349 //*
    350 //* @param[in] dst_strd
    351 //*  Stride of the destination buffer
    352 //*
    353 //* @param[in] log_WD
    354 //*  number of bits to be rounded off
    355 //*
    356 //* @param[in] wt1
    357 //*  weights for the weighted prediction in U and V
    358 //*
    359 //* @param[in] wt2
    360 //*  weights for the weighted prediction in U and V
    361 //*
    362 //* @param[in] ofst1
    363 //*  offset 1 used after rounding off for U an dV
    364 //*
    365 //* @param[in] ofst2
    366 //*  offset 2 used after rounding off for U and V
    367 //*
    368 //* @param[in] ht
    369 //*  integer height of the array
    370 //*
    371 //* @param[in] wd
    372 //*  integer width of the array
    373 //*
    374 //* @returns
    375 //*  None
    376 //*
    377 //* @remarks
    378 //*  (ht,wd) can be (2,2), (2,4), (4,2), (4,4), (4,8), (8,4) or (8,8).
    379 //*
    380 //*******************************************************************************
    381 //*/
    382 //void ih264_weighted_bi_pred_chroma_av8(UWORD8 *puc_src1,
    383 //                                       UWORD8 *puc_src2,
    384 //                                       UWORD8 *puc_dst,
    385 //                                       WORD32 src_strd1,
    386 //                                       WORD32 src_strd2,
    387 //                                       WORD32 dst_strd,
    388 //                                       WORD32 log_WD,
    389 //                                       WORD32 wt1,
    390 //                                       WORD32 wt2,
    391 //                                       WORD32 ofst1,
    392 //                                       WORD32 ofst2,
    393 //                                       WORD32 ht,
    394 //                                       WORD32 wd)
    395 //
    396 //**************Variables Vs Registers*****************************************
    397 //    x0      => puc_src1
    398 //    x1      => puc_src2
    399 //    x2      => puc_dst
    400 //    w3      => src_strd1
    401 //    w4      => src_strd2
    402 //    w5      => dst_strd
    403 //    w6      => log_WD
    404 //    w7      => wt1
    405 //    [sp]    => wt2       (w8)
    406 //    [sp+8]  => ofst1     (w9)
    407 //    [sp+16] => ofst2     (w10)
    408 //    [sp+24] => ht        (w11)
    409 //    [sp+32] => wd        (w12)
    410 //
    411 
    412 
    413 
    414 
    415 
    416     .global ih264_weighted_bi_pred_chroma_av8
    417 
    418 ih264_weighted_bi_pred_chroma_av8:
    419 
    420     // STMFD sp!, {x4-x12,x14}                //stack stores the values of the arguments
    421     push_v_regs
    422     sxtw      x3, w3
    423     sxtw      x4, w4
    424     sxtw      x5, w5
    425     stp       x19, x20, [sp, #-16]!
    426 
    427 
    428     ldr       w8, [sp, #80]             //Load wt2 in w8
    429     dup       v4.4s, w8                 //Q2 = (wt2_u, wt2_v) (32-bit)
    430     dup       v2.4s, w7                 //Q1 = (wt1_u, wt1_v) (32-bit)
    431     add       w6, w6, #1                //w6  = log_WD + 1
    432     ldr       w9, [sp, #88]             //Load ofst1 in w9
    433     ldr       w10, [sp, #96]            //Load ofst2 in w10
    434     neg       w20, w6                   //w20 = -(log_WD + 1)
    435     dup       v0.8h, w20                //Q0  = -(log_WD + 1) (16-bit)
    436     ldr       w11, [sp, #104]           //Load ht in x11
    437     ldr       w12, [sp, #112]           //Load wd in x12
    438     dup       v20.8h, w9                //0ffset1
    439     dup       v21.8h, w10               //0ffset2
    440     srhadd    v6.8b, v20.8b, v21.8b
    441     sxtl      v6.8h, v6.8b
    442     cmp       w12, #8                   //check if wd is 8
    443     beq       loop_8_uv                 //branch if wd is 8
    444     cmp       w12, #4                   //check if wd is 4
    445     beq       loop_4_uv                 //branch if wd is 4
    446 
    447 loop_2_uv:                              //each iteration processes two rows
    448 
    449     ld1       {v8.s}[0], [x0], x3       //load row 1 in source 1
    450     ld1       {v8.s}[1], [x0], x3       //load row 2 in source 1
    451     ld1       {v10.s}[0], [x1], x4      //load row 1 in source 2
    452     ld1       {v10.s}[1], [x1], x4      //load row 2 in source 2
    453     uxtl      v8.8h, v8.8b              //converting rows 1,2 in source 1 to 16-bit
    454     uxtl      v10.8h, v10.8b            //converting rows 1,2 in source 2 to 16-bit
    455     mul       v8.8h, v8.8h , v2.8h      //weight 1 mult. for rows 1,2
    456     mla       v8.8h, v10.8h , v4.8h     //weight 2 mult. for rows 1,2
    457     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from rows 1,2
    458     add       v8.8h, v8.8h , v6.8h      //adding offset for rows 1,2
    459     sqxtun    v8.8b, v8.8h              //saturating rows 1,2 to unsigned 8-bit/
    460     st1       {v8.s}[0], [x2], x5       //store row 1 in destination
    461     st1       {v8.s}[1], [x2], x5       //store row 2 in destination
    462     subs      w11, w11, #2              //decrement ht by 2
    463     bgt       loop_2_uv                 //if greater than 0 repeat the loop again
    464     b         end_loops_uv
    465 
    466 loop_4_uv:                              //each iteration processes two rows
    467 
    468     ld1       {v8.8b}, [x0], x3         //load row 1 in source 1
    469     ld1       {v10.8b}, [x1], x4        //load row 1 in source 2
    470     uxtl      v8.8h, v8.8b              //converting row 1 in source 1 to 16-bit
    471     ld1       {v12.8b}, [x0], x3        //load row 2 in source 1
    472     uxtl      v10.8h, v10.8b            //converting row 1 in source 2 to 16-bit
    473     ld1       {v14.8b}, [x1], x4        //load row 2 in source 2
    474     uxtl      v12.8h, v12.8b            //converting row 2 in source 1 to 16-bit
    475     mul       v8.8h, v8.8h , v2.8h      //weight 1 mult. for row 1
    476     mla       v8.8h, v10.8h , v4.8h     //weight 2 mult. for row 1
    477     uxtl      v14.8h, v14.8b            //converting row 2 in source 2 to 16-bit
    478     mul       v12.8h, v12.8h , v2.8h    //weight 1 mult. for row 2
    479     mla       v12.8h, v14.8h , v4.8h    //weight 2 mult. for row 2
    480     subs      w11, w11, #2              //decrement ht by 2
    481     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from row 1
    482     srshl     v12.8h, v12.8h , v0.8h    //rounds off the weighted samples from row 2
    483     add       v8.8h, v8.8h , v6.8h      //adding offset for row 1
    484     add       v12.8h, v12.8h , v6.8h    //adding offset for row 2
    485     sqxtun    v8.8b, v8.8h              //saturating row 1 to unsigned 8-bit
    486     sqxtun    v12.8b, v12.8h            //saturating row 2 to unsigned 8-bit
    487     st1       {v8.8b}, [x2], x5         //store row 1 in destination
    488     st1       {v12.8b}, [x2], x5        //store row 2 in destination
    489     bgt       loop_4_uv                 //if greater than 0 repeat the loop again
    490     b         end_loops_uv
    491 
    492 loop_8_uv:                              //each iteration processes two rows
    493 
    494     ld1       {v8.8b, v9.8b}, [x0], x3  //load row 1 in source 1
    495     ld1       {v10.8b, v11.8b}, [x1], x4 //load row 1 in source 2
    496     ld1       {v12.8b, v13.8b}, [x0], x3 //load row 2 in source 1
    497     ld1       {v14.8b, v15.8b}, [x1], x4 //load row 2 in source 2
    498     uxtl      v24.8h, v8.8b             //converting row 1L in source 1 to 16-bit
    499     ld1       {v16.8b, v17.8b}, [x0], x3 //load row 3 in source 1
    500     ld1       {v18.8b, v19.8b}, [x1], x4 //load row 3 in source 2
    501     uxtl      v26.8h, v10.8b            //converting row 1L in source 2 to 16-bit
    502     ld1       {v20.8b, v21.8b}, [x0], x3 //load row 4 in source 1
    503     ld1       {v22.8b, v23.8b}, [x1], x4 //load row 4 in source 2
    504     uxtl      v8.8h, v9.8b              //converting row 1H in source 1 to 16-bit
    505     uxtl      v10.8h, v11.8b            //converting row 1H in source 2 to 16-bit
    506     mul       v24.8h, v24.8h , v2.8h    //weight 1 mult. for row 1L
    507     mla       v24.8h, v26.8h , v4.8h    //weight 2 mult. for row 1L
    508     uxtl      v28.8h, v12.8b            //converting row 2L in source 1 to 16-bit
    509     uxtl      v30.8h, v14.8b            //converting row 2L in source 2 to 16-bit
    510     mul       v8.8h, v8.8h , v2.8h      //weight 1 mult. for row 1H
    511     mla       v8.8h, v10.8h , v4.8h     //weight 2 mult. for row 1H
    512     uxtl      v12.8h, v13.8b            //converting row 2H in source 1 to 16-bit
    513     uxtl      v14.8h, v15.8b            //converting row 2H in source 2 to 16-bit
    514     mul       v28.8h, v28.8h , v2.8h    //weight 1 mult. for row 2L
    515     mla       v28.8h, v30.8h , v4.8h    //weight 2 mult. for row 2L
    516     uxtl      v26.8h, v16.8b            //converting row 3L in source 1 to 16-bit
    517     uxtl      v10.8h, v18.8b            //converting row 3L in source 2 to 16-bit
    518     mul       v12.8h, v12.8h , v2.8h    //weight 1 mult. for row 2H
    519     mla       v12.8h, v14.8h , v4.8h    //weight 2 mult. for row 2H
    520     uxtl      v16.8h, v17.8b            //converting row 3H in source 1 to 16-bit
    521     uxtl      v18.8h, v19.8b            //converting row 3H in source 2 to 16-bit
    522     mul       v26.8h, v26.8h , v2.8h    //weight 1 mult. for row 3L
    523     mla       v26.8h, v10.8h , v4.8h    //weight 2 mult. for row 3L
    524     uxtl      v30.8h, v20.8b            //converting row 4L in source 1 to 16-bit
    525     uxtl      v14.8h, v22.8b            //converting row 4L in source 2 to 16-bit
    526     mul       v16.8h, v16.8h , v2.8h    //weight 1 mult. for row 3H
    527     mla       v16.8h, v18.8h , v4.8h    //weight 2 mult. for row 3H
    528     uxtl      v20.8h, v21.8b            //converting row 4H in source 1 to 16-bit
    529     uxtl      v22.8h, v23.8b            //converting row 4H in source 2 to 16-bit
    530     mul       v30.8h, v30.8h , v2.8h    //weight 1 mult. for row 4L
    531     mla       v30.8h, v14.8h , v4.8h    //weight 2 mult. for row 4L
    532     srshl     v24.8h, v24.8h , v0.8h    //rounds off the weighted samples from row 1L
    533     mul       v20.8h, v20.8h , v2.8h    //weight 1 mult. for row 4H
    534     mla       v20.8h, v22.8h , v4.8h    //weight 2 mult. for row 4H
    535     srshl     v8.8h, v8.8h , v0.8h      //rounds off the weighted samples from row 1H
    536     srshl     v28.8h, v28.8h , v0.8h    //rounds off the weighted samples from row 2L
    537     add       v24.8h, v24.8h , v6.8h    //adding offset for row 1L
    538     srshl     v12.8h, v12.8h , v0.8h    //rounds off the weighted samples from row 2H
    539     add       v8.8h, v8.8h , v6.8h      //adding offset for row 1H
    540     srshl     v26.8h, v26.8h , v0.8h    //rounds off the weighted samples from row 3L
    541     add       v28.8h, v28.8h , v6.8h    //adding offset for row 2L
    542     srshl     v16.8h, v16.8h , v0.8h    //rounds off the weighted samples from row 3H
    543     add       v12.8h, v12.8h , v6.8h    //adding offset for row 2H
    544     srshl     v30.8h, v30.8h , v0.8h    //rounds off the weighted samples from row 4L
    545     add       v26.8h, v26.8h , v6.8h    //adding offset for row 3L
    546     srshl     v20.8h, v20.8h , v0.8h    //rounds off the weighted samples from row 4H
    547     add       v16.8h, v16.8h , v6.8h    //adding offset for row 3H
    548     sqxtun    v10.8b, v24.8h            //saturating row 1L to unsigned 8-bit
    549     add       v30.8h, v30.8h , v6.8h    //adding offset for row 4L
    550     sqxtun    v11.8b, v8.8h             //saturating row 1H to unsigned 8-bit
    551     add       v20.8h, v20.8h , v6.8h    //adding offset for row 4H
    552     sqxtun    v18.8b, v28.8h            //saturating row 2L to unsigned 8-bit
    553     sqxtun    v19.8b, v12.8h            //saturating row 2H to unsigned 8-bit
    554     sqxtun    v14.8b, v26.8h            //saturating row 3L to unsigned 8-bit
    555     sqxtun    v15.8b, v16.8h            //saturating row 3H to unsigned 8-bit
    556     st1       {v10.8b, v11.8b}, [x2], x5 //store row 1 in destination
    557     sqxtun    v22.8b, v30.8h            //saturating row 4L to unsigned 8-bit
    558     sqxtun    v23.8b, v20.8h            //saturating row 4H to unsigned 8-bit
    559     st1       {v18.8b, v19.8b}, [x2], x5 //store row 2 in destination
    560     subs      w11, w11, #4              //decrement ht by 4
    561     st1       {v14.8b, v15.8b}, [x2], x5 //store row 3 in destination
    562     st1       {v22.8b, v23.8b}, [x2], x5 //store row 4 in destination
    563     bgt       loop_8_uv                 //if greater than 0 repeat the loop again
    564 
    565 end_loops_uv:
    566 
    567     // LDMFD sp!,{x4-x12,x15}                //Reload the registers from sp
    568     ldp       x19, x20, [sp], #16
    569     pop_v_regs
    570     ret
    571 
    572 
    573 
    574