text: /*
   *  Copyright 2014 The LibYuv Project Authors. All rights reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS. All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #include "libyuv/row.h"
  
  #ifdef __cplusplus
  namespace libyuv {
  extern "C" {
  #endif
  
  // This module is for GCC Neon armv8 64 bit.
  #if !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
  
  // Read 8 Y, 4 U and 4 V from 422
  #define READYUV422                                                             \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      MEMACCESS(1)                                                               \
      "ld1        {v1.s}[0], [%1], #4            \n"                             \
      MEMACCESS(2)                                                               \
      "ld1        {v1.s}[1], [%2], #4            \n"
  
  // Read 8 Y, 2 U and 2 V from 422
  #define READYUV411                                                             \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      MEMACCESS(1)                                                               \
      "ld1        {v2.h}[0], [%1], #2            \n"                             \
      MEMACCESS(2)                                                               \
      "ld1        {v2.h}[1], [%2], #2            \n"                             \
      "zip1       v1.8b, v2.8b, v2.8b            \n"
  
  // Read 8 Y, 8 U and 8 V from 444
  #define READYUV444                                                             \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      MEMACCESS(1)                                                               \
      "ld1        {v1.d}[0], [%1], #8            \n"                             \
      MEMACCESS(2)                                                               \
      "ld1        {v1.d}[1], [%2], #8            \n"                             \
      "uaddlp     v1.8h, v1.16b                  \n"                             \
      "rshrn      v1.8b, v1.8h, #1               \n"
  
  // Read 8 Y, and set 4 U and 4 V to 128
  #define READYUV400                                                             \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      "movi       v1.8b , #128                   \n"
  
  // Read 8 Y and 4 UV from NV12
  #define READNV12                                                               \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      MEMACCESS(1)                                                               \
      "ld1        {v2.8b}, [%1], #8              \n"                             \
      "uzp1       v1.8b, v2.8b, v2.8b            \n"                             \
      "uzp2       v3.8b, v2.8b, v2.8b            \n"                             \
      "ins        v1.s[1], v3.s[0]               \n"
  
  // Read 8 Y and 4 VU from NV21
  #define READNV21                                                               \
      MEMACCESS(0)                                                               \
      "ld1        {v0.8b}, [%0], #8              \n"                             \
      MEMACCESS(1)                                                               \
      "ld1        {v2.8b}, [%1], #8              \n"                             \
      "uzp1       v3.8b, v2.8b, v2.8b            \n"                             \
      "uzp2       v1.8b, v2.8b, v2.8b            \n"                             \
      "ins        v1.s[1], v3.s[0]               \n"
  
  // Read 8 YUY2
  #define READYUY2                                                               \
      MEMACCESS(0)                                                               \
      "ld2        {v0.8b, v1.8b}, [%0], #16      \n"                             \
      "uzp2       v3.8b, v1.8b, v1.8b            \n"                             \
      "uzp1       v1.8b, v1.8b, v1.8b            \n"                             \
      "ins        v1.s[1], v3.s[0]               \n"
  
  // Read 8 UYVY
  #define READUYVY                                                               \
      MEMACCESS(0)                                                               \
      "ld2        {v2.8b, v3.8b}, [%0], #16      \n"                             \
      "orr        v0.8b, v3.8b, v3.8b            \n"                             \
      "uzp1       v1.8b, v2.8b, v2.8b            \n"                             \
      "uzp2       v3.8b, v2.8b, v2.8b            \n"                             \
      "ins        v1.s[1], v3.s[0]               \n"
  
  #define YUV422TORGB_SETUP_REG                                                  \
      "movi       v24.8b, #128                   \n"                             \
      "movi       v25.8h, #74, lsl #0            \n" /* YG                     */\
      "movi       v26.8h, #16, lsl #0            \n"                             \
      "movi       v27.8h, #127, lsl #0           \n" /* UB                     */\
      "movi       v28.8h, #102, lsl #0           \n" /* VR                     */\
      "mvni       v29.8h, #0x18, lsl #0          \n" /* UG  -25                */\
      "mvni       v30.8h, #0x33, lsl #0          \n" /* VG  -52                */
  
  #define YUV422TORGB(vR, vG, vB)                                                \
      "eor        v1.8b, v1.8b, v24.8b           \n" /* Subtract 128 from U&V */ \
      "uxtl       v0.8h, v0.8b                   \n" /* Extract Y             */ \
      "shll       v2.8h, v1.8b, #8               \n" /* Replicate UV */          \
      "sub        v0.8h, v0.8h, v26.8h           \n" /* offset y */              \
      "uaddw      v1.8h, v2.8h, v1.8b            \n"                             \
      "mul        v0.8h, v0.8h, v25.8h           \n" /* Y x 74 */                \
      "mov        v2.d[0], v1.d[1]               \n" /* Extract V */             \
      "sxtl       v2.8h, v2.8b                   \n"                             \
      "sxtl       v1.8h, v1.8b                   \n" /* Extract U */             \
      "mul        " #vR ".8h, v2.8h, v28.8h      \n" /* R  = (V - 128) x VR */   \
      "mul        " #vB ".8h, v1.8h, v27.8h      \n" /* B  = (U - 128) x UB */   \
      "mul        " #vG ".8h, v1.8h, v29.8h      \n" /* G1 = (U - 128) x UG */   \
      "mul        v2.8h, v2.8h, v30.8h           \n" /* G2 = (V - 128) x VG */   \
      "sqadd      " #vR ".8h, " #vR ".8h, v0.8h  \n" /* R += (Y - 16) YG    */   \
      "sqadd      " #vB ".8h, " #vB ".8h, v0.8h  \n" /* B += (Y - 16) YG    */   \
      "sqadd      " #vG ".8h, " #vG ".8h, v2.8h  \n" /* G  = G1 + G2        */   \
      "sqadd      " #vG ".8h, " #vG ".8h, v0.8h  \n" /* G += (Y - 16) YG    */   \
      "sqshrun    " #vR ".8b, " #vR ".8h, #6     \n" /* R */                     \
      "sqshrun    " #vB ".8b, " #vB ".8h, #6     \n" /* B */                     \
      "sqshrun    " #vG ".8b, " #vG ".8h, #6     \n" /* G */
  
  #define RGBTOUV_SETUP_REG                                                      \
      "movi       v20.8h, #56, lsl #0  \n"  /* UB/VR coefficient (0.875) / 2 */  \
      "movi       v21.8h, #37, lsl #0  \n"  /* UG coefficient (-0.5781) / 2  */  \
      "movi       v22.8h, #19, lsl #0  \n"  /* UR coefficient (-0.2969) / 2  */  \
      "movi       v23.8h, #9,  lsl #0  \n"  /* VB coefficient (-0.1406) / 2  */  \
      "movi       v24.8h, #47, lsl #0  \n"  /* VG coefficient (-0.7344) / 2  */  \
      "movi       v25.16b, #0x80       \n"  /* 128.5 (0x8080 in 16-bit)      */
  
  
  #ifdef HAS_I444TOARGBROW_NEON
  void I444ToARGBRow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV444
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32 \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_argb),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I444TOARGBROW_NEON
  
  #ifdef HAS_I422TOARGBROW_NEON
  void I422ToARGBRow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_argb),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TOARGBROW_NEON
  
  #ifdef HAS_I411TOARGBROW_NEON
  void I411ToARGBRow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV411
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_argb),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I411TOARGBROW_NEON
  
  #ifdef HAS_I422TOBGRAROW_NEON
  void I422ToBGRARow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_bgra,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v21, v22, v23)
      "subs       %4, %4, #8                     \n"
      "movi       v20.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_bgra),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TOBGRAROW_NEON
  
  #ifdef HAS_I422TOABGRROW_NEON
  void I422ToABGRRow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_abgr,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v20, v21, v22)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_abgr),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TOABGRROW_NEON
  
  #ifdef HAS_I422TORGBAROW_NEON
  void I422ToRGBARow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_rgba,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v23, v22, v21)
      "subs       %4, %4, #8                     \n"
      "movi       v20.8b, #255                   \n" /* A */
      MEMACCESS(3)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%3], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_rgba),  // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TORGBAROW_NEON
  
  #ifdef HAS_I422TORGB24ROW_NEON
  void I422ToRGB24Row_NEON(const uint8* src_y,
                           const uint8* src_u,
                           const uint8* src_v,
                           uint8* dst_rgb24,
                           int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      MEMACCESS(3)
      "st3        {v20.8b,v21.8b,v22.8b}, [%3], #24     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_rgb24), // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TORGB24ROW_NEON
  
  #ifdef HAS_I422TORAWROW_NEON
  void I422ToRAWRow_NEON(const uint8* src_y,
                         const uint8* src_u,
                         const uint8* src_v,
                         uint8* dst_raw,
                         int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v20, v21, v22)
      "subs       %4, %4, #8                     \n"
      MEMACCESS(3)
      "st3        {v20.8b,v21.8b,v22.8b}, [%3], #24     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_u),     // %1
        "+r"(src_v),     // %2
        "+r"(dst_raw),   // %3
        "+r"(width)      // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TORAWROW_NEON
  
  #define ARGBTORGB565                                                           \
      "shll       v0.8h,  v22.8b, #8             \n"  /* R                    */ \
      "shll       v20.8h, v20.8b, #8             \n"  /* B                    */ \
      "shll       v21.8h, v21.8b, #8             \n"  /* G                    */ \
      "sri        v0.8h,  v21.8h, #5             \n"  /* RG                   */ \
      "sri        v0.8h,  v20.8h, #11            \n"  /* RGB                  */
  
  #ifdef HAS_I422TORGB565ROW_NEON
  void I422ToRGB565Row_NEON(const uint8* src_y,
                            const uint8* src_u,
                            const uint8* src_v,
                            uint8* dst_rgb565,
                            int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      ARGBTORGB565
      MEMACCESS(3)
      "st1        {v0.8h}, [%3], #16             \n"  // store 8 pixels RGB565.
      "b.gt       1b                             \n"
      : "+r"(src_y),    // %0
        "+r"(src_u),    // %1
        "+r"(src_v),    // %2
        "+r"(dst_rgb565),  // %3
        "+r"(width)     // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TORGB565ROW_NEON
  
  #define ARGBTOARGB1555                                                         \
      "shll       v0.8h,  v23.8b, #8             \n"  /* A                    */ \
      "shll       v22.8h, v22.8b, #8             \n"  /* R                    */ \
      "shll       v20.8h, v20.8b, #8             \n"  /* B                    */ \
      "shll       v21.8h, v21.8b, #8             \n"  /* G                    */ \
      "sri        v0.8h,  v22.8h, #1             \n"  /* AR                   */ \
      "sri        v0.8h,  v21.8h, #6             \n"  /* ARG                  */ \
      "sri        v0.8h,  v20.8h, #11            \n"  /* ARGB                 */
  
  #ifdef HAS_I422TOARGB1555ROW_NEON
  void I422ToARGB1555Row_NEON(const uint8* src_y,
                              const uint8* src_u,
                              const uint8* src_v,
                              uint8* dst_argb1555,
                              int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n"
      ARGBTOARGB1555
      MEMACCESS(3)
      "st1        {v0.8h}, [%3], #16             \n"  // store 8 pixels RGB565.
      "b.gt       1b                             \n"
      : "+r"(src_y),    // %0
        "+r"(src_u),    // %1
        "+r"(src_v),    // %2
        "+r"(dst_argb1555),  // %3
        "+r"(width)     // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TOARGB1555ROW_NEON
  
  #define ARGBTOARGB4444                                                         \
      /* Input v20.8b<=B, v21.8b<=G, v22.8b<=R, v23.8b<=A, v4.8b<=0x0f        */ \
      "ushr       v20.8b, v20.8b, #4             \n"  /* B                    */ \
      "bic        v21.8b, v21.8b, v4.8b          \n"  /* G                    */ \
      "ushr       v22.8b, v22.8b, #4             \n"  /* R                    */ \
      "bic        v23.8b, v23.8b, v4.8b          \n"  /* A                    */ \
      "orr        v0.8b,  v20.8b, v21.8b         \n"  /* BG                   */ \
      "orr        v1.8b,  v22.8b, v23.8b         \n"  /* RA                   */ \
      "zip1       v0.16b, v0.16b, v1.16b         \n"  /* BGRA                 */
  
  #ifdef HAS_I422TOARGB4444ROW_NEON
  void I422ToARGB4444Row_NEON(const uint8* src_y,
                              const uint8* src_u,
                              const uint8* src_v,
                              uint8* dst_argb4444,
                              int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
      "movi       v4.16b, #0x0f                  \n"  // bits to clear with vbic.
    "1:                                          \n"
      READYUV422
      YUV422TORGB(v22, v21, v20)
      "subs       %4, %4, #8                     \n"
      "movi       v23.8b, #255                   \n"
      ARGBTOARGB4444
      MEMACCESS(3)
      "st1        {v0.8h}, [%3], #16             \n"  // store 8 pixels ARGB4444.
      "b.gt       1b                             \n"
      : "+r"(src_y),    // %0
        "+r"(src_u),    // %1
        "+r"(src_v),    // %2
        "+r"(dst_argb4444),  // %3
        "+r"(width)     // %4
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_I422TOARGB4444ROW_NEON
  
  #ifdef HAS_YTOARGBROW_NEON
  void YToARGBRow_NEON(const uint8* src_y,
                       uint8* dst_argb,
                       int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUV400
      YUV422TORGB(v22, v21, v20)
      "subs       %2, %2, #8                     \n"
      "movi       v23.8b, #255                   \n"
      MEMACCESS(1)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%1], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(dst_argb),  // %1
        "+r"(width)      // %2
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_YTOARGBROW_NEON
  
  #ifdef HAS_I400TOARGBROW_NEON
  void I400ToARGBRow_NEON(const uint8* src_y,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      "movi       v23.8b, #255                   \n"
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v20.8b}, [%0], #8             \n"
      "orr        v21.8b, v20.8b, v20.8b         \n"
      "orr        v22.8b, v20.8b, v20.8b         \n"
      "subs       %2, %2, #8                     \n"
      MEMACCESS(1)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%1], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(dst_argb),  // %1
        "+r"(width)      // %2
      :
      : "cc", "memory", "v20", "v21", "v22", "v23"
    );
  }
  #endif  // HAS_I400TOARGBROW_NEON
  
  #ifdef HAS_NV12TOARGBROW_NEON
  void NV12ToARGBRow_NEON(const uint8* src_y,
                          const uint8* src_uv,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READNV12
      YUV422TORGB(v22, v21, v20)
      "subs       %3, %3, #8                     \n"
      "movi       v23.8b, #255                   \n"
      MEMACCESS(2)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%2], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_uv),    // %1
        "+r"(dst_argb),  // %2
        "+r"(width)      // %3
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_NV12TOARGBROW_NEON
  
  #ifdef HAS_NV21TOARGBROW_NEON
  void NV21ToARGBRow_NEON(const uint8* src_y,
                          const uint8* src_uv,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READNV21
      YUV422TORGB(v22, v21, v20)
      "subs       %3, %3, #8                     \n"
      "movi       v23.8b, #255                   \n"
      MEMACCESS(2)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%2], #32     \n"
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_uv),    // %1
        "+r"(dst_argb),  // %2
        "+r"(width)      // %3
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_NV21TOARGBROW_NEON
  
  #ifdef HAS_NV12TORGB565ROW_NEON
  void NV12ToRGB565Row_NEON(const uint8* src_y,
                            const uint8* src_uv,
                            uint8* dst_rgb565,
                            int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READNV12
      YUV422TORGB(v22, v21, v20)
      "subs       %3, %3, #8                     \n"
      ARGBTORGB565
      MEMACCESS(2)
      "st1        {v0.8h}, [%2], 16              \n"  // store 8 pixels RGB565.
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_uv),    // %1
        "+r"(dst_rgb565),  // %2
        "+r"(width)      // %3
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_NV12TORGB565ROW_NEON
  
  #ifdef HAS_NV21TORGB565ROW_NEON
  void NV21ToRGB565Row_NEON(const uint8* src_y,
                            const uint8* src_uv,
                            uint8* dst_rgb565,
                            int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READNV21
      YUV422TORGB(v22, v21, v20)
      "subs       %3, %3, #8                     \n"
      ARGBTORGB565
      MEMACCESS(2)
      "st1        {v0.8h}, [%2], 16              \n"  // store 8 pixels RGB565.
      "b.gt       1b                             \n"
      : "+r"(src_y),     // %0
        "+r"(src_uv),    // %1
        "+r"(dst_rgb565),  // %2
        "+r"(width)      // %3
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_NV21TORGB565ROW_NEON
  
  #ifdef HAS_YUY2TOARGBROW_NEON
  void YUY2ToARGBRow_NEON(const uint8* src_yuy2,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READYUY2
      YUV422TORGB(v22, v21, v20)
      "subs       %2, %2, #8                     \n"
      "movi       v23.8b, #255                   \n"
      MEMACCESS(1)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%1], #32      \n"
      "b.gt       1b                             \n"
      : "+r"(src_yuy2),  // %0
        "+r"(dst_argb),  // %1
        "+r"(width)      // %2
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_YUY2TOARGBROW_NEON
  
  #ifdef HAS_UYVYTOARGBROW_NEON
  void UYVYToARGBRow_NEON(const uint8* src_uyvy,
                          uint8* dst_argb,
                          int width) {
    asm volatile (
      YUV422TORGB_SETUP_REG
    "1:                                          \n"
      READUYVY
      YUV422TORGB(v22, v21, v20)
      "subs       %2, %2, #8                     \n"
      "movi       v23.8b, #255                   \n"
      MEMACCESS(1)
      "st4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%1], 32      \n"
      "b.gt       1b                             \n"
      : "+r"(src_uyvy),  // %0
        "+r"(dst_argb),  // %1
        "+r"(width)      // %2
      :
      : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20",
        "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_UYVYTOARGBROW_NEON
  
  // Reads 16 pairs of UV and write even values to dst_u and odd to dst_v.
  #ifdef HAS_SPLITUVROW_NEON
  void SplitUVRow_NEON(const uint8* src_uv, uint8* dst_u, uint8* dst_v,
                       int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v0.16b,v1.16b}, [%0], #32     \n"  // load 16 pairs of UV
      "subs       %3, %3, #16                    \n"  // 16 processed per loop
      MEMACCESS(1)
      "st1        {v0.16b}, [%1], #16            \n"  // store U
      MEMACCESS(2)
      "st1        {v1.16b}, [%2], #16            \n"  // store V
      "b.gt       1b                             \n"
      : "+r"(src_uv),  // %0
        "+r"(dst_u),   // %1
        "+r"(dst_v),   // %2
        "+r"(width)    // %3  // Output registers
      :                       // Input registers
      : "cc", "memory", "v0", "v1"  // Clobber List
    );
  }
  #endif  // HAS_SPLITUVROW_NEON
  
  // Reads 16 U's and V's and writes out 16 pairs of UV.
  #ifdef HAS_MERGEUVROW_NEON
  void MergeUVRow_NEON(const uint8* src_u, const uint8* src_v, uint8* dst_uv,
                       int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load U
      MEMACCESS(1)
      "ld1        {v1.16b}, [%1], #16            \n"  // load V
      "subs       %3, %3, #16                    \n"  // 16 processed per loop
      MEMACCESS(2)
      "st2        {v0.16b,v1.16b}, [%2], #32     \n"  // store 16 pairs of UV
      "b.gt       1b                             \n"
      :
        "+r"(src_u),   // %0
        "+r"(src_v),   // %1
        "+r"(dst_uv),  // %2
        "+r"(width)    // %3  // Output registers
      :                       // Input registers
      : "cc", "memory", "v0", "v1"  // Clobber List
    );
  }
  #endif  // HAS_MERGEUVROW_NEON
  
  // Copy multiple of 32.  vld4.8  allow unaligned and is fastest on a15.
  #ifdef HAS_COPYROW_NEON
  void CopyRow_NEON(const uint8* src, uint8* dst, int count) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32       \n"  // load 32
      "subs       %2, %2, #32                    \n"  // 32 processed per loop
      MEMACCESS(1)
      "st1        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32       \n"  // store 32
      "b.gt       1b                             \n"
    : "+r"(src),   // %0
      "+r"(dst),   // %1
      "+r"(count)  // %2  // Output registers
    :                     // Input registers
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_COPYROW_NEON
  
  // SetRow writes 'count' bytes using an 8 bit value repeated.
  void SetRow_NEON(uint8* dst, uint8 v8, int count) {
    asm volatile (
      "dup        v0.16b, %w2                    \n"  // duplicate 16 bytes
    "1:                                          \n"
      "subs      %1, %1, #16                     \n"  // 16 bytes per loop
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"  // store
      "b.gt      1b                              \n"
    : "+r"(dst),   // %0
      "+r"(count)  // %1
    : "r"(v8)      // %2
    : "cc", "memory", "v0"
    );
  }
  
  void ARGBSetRow_NEON(uint8* dst, uint32 v32, int count) {
    asm volatile (
      "dup        v0.4s, %w2                     \n"  // duplicate 4 ints
    "1:                                          \n"
      "subs      %1, %1, #4                      \n"  // 4 ints per loop
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"  // store
      "b.gt      1b                              \n"
    : "+r"(dst),   // %0
      "+r"(count)  // %1
    : "r"(v32)     // %2
    : "cc", "memory", "v0"
    );
  }
  
  #ifdef HAS_MIRRORROW_NEON
  void MirrorRow_NEON(const uint8* src, uint8* dst, int width) {
    asm volatile (
      // Start at end of source row.
      "add        %0, %0, %2                     \n"
      "sub        %0, %0, #16                    \n"
  
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], %3             \n"  // src -= 16
      "subs       %2, %2, #16                    \n"  // 16 pixels per loop.
      "rev64      v0.16b, v0.16b                 \n"
      MEMACCESS(1)
      "st1        {v0.D}[1], [%1], #8            \n"  // dst += 16
      MEMACCESS(1)
      "st1        {v0.D}[0], [%1], #8            \n"
      "b.gt       1b                             \n"
    : "+r"(src),   // %0
      "+r"(dst),   // %1
      "+r"(width)  // %2
    : "r"((ptrdiff_t)-16)    // %3
    : "cc", "memory", "v0"
    );
  }
  #endif  // HAS_MIRRORROW_NEON
  
  #ifdef HAS_MIRRORUVROW_NEON
  void MirrorUVRow_NEON(const uint8* src_uv, uint8* dst_u, uint8* dst_v,
                        int width) {
    asm volatile (
      // Start at end of source row.
      "add        %0, %0, %3, lsl #1             \n"
      "sub        %0, %0, #16                    \n"
  
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v0.8b, v1.8b}, [%0], %4       \n"  // src -= 16
      "subs       %3, %3, #8                     \n"  // 8 pixels per loop.
      "rev64      v0.8b, v0.8b                   \n"
      "rev64      v1.8b, v1.8b                   \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // dst += 8
      MEMACCESS(2)
      "st1        {v1.8b}, [%2], #8              \n"
      "b.gt       1b                             \n"
    : "+r"(src_uv),  // %0
      "+r"(dst_u),   // %1
      "+r"(dst_v),   // %2
      "+r"(width)    // %3
    : "r"((ptrdiff_t)-16)      // %4
    : "cc", "memory", "v0", "v1"
    );
  }
  #endif  // HAS_MIRRORUVROW_NEON
  
  #ifdef HAS_ARGBMIRRORROW_NEON
  void ARGBMirrorRow_NEON(const uint8* src, uint8* dst, int width) {
    asm volatile (
      // Start at end of source row.
      "add        %0, %0, %2, lsl #2             \n"
      "sub        %0, %0, #16                    \n"
  
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], %3             \n"  // src -= 16
      "subs       %2, %2, #4                     \n"  // 4 pixels per loop.
      "rev64      v0.4s, v0.4s                   \n"
      MEMACCESS(1)
      "st1        {v0.D}[1], [%1], #8            \n"  // dst += 16
      MEMACCESS(1)
      "st1        {v0.D}[0], [%1], #8            \n"
      "b.gt       1b                             \n"
    : "+r"(src),   // %0
      "+r"(dst),   // %1
      "+r"(width)  // %2
    : "r"((ptrdiff_t)-16)    // %3
    : "cc", "memory", "v0"
    );
  }
  #endif  // HAS_ARGBMIRRORROW_NEON
  
  #ifdef HAS_RGB24TOARGBROW_NEON
  void RGB24ToARGBRow_NEON(const uint8* src_rgb24, uint8* dst_argb, int pix) {
    asm volatile (
      "movi       v4.8b, #255                    \n"  // Alpha
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v1.8b,v2.8b,v3.8b}, [%0], #24 \n"  // load 8 pixels of RGB24.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      MEMACCESS(1)
      "st4        {v1.8b,v2.8b,v3.8b,v4.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_rgb24),  // %0
      "+r"(dst_argb),   // %1
      "+r"(pix)         // %2
    :
    : "cc", "memory", "v1", "v2", "v3", "v4"  // Clobber List
    );
  }
  #endif  // HAS_RGB24TOARGBROW_NEON
  
  #ifdef HAS_RAWTOARGBROW_NEON
  void RAWToARGBRow_NEON(const uint8* src_raw, uint8* dst_argb, int pix) {
    asm volatile (
      "movi       v5.8b, #255                    \n"  // Alpha
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v0.8b,v1.8b,v2.8b}, [%0], #24 \n"  // read r g b
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "orr        v3.8b, v1.8b, v1.8b            \n"  // move g
      "orr        v4.8b, v0.8b, v0.8b            \n"  // move r
      MEMACCESS(1)
      "st4        {v2.8b,v3.8b,v4.8b,v5.8b}, [%1], #32 \n"  // store b g r a
      "b.gt       1b                             \n"
    : "+r"(src_raw),   // %0
      "+r"(dst_argb),  // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5"  // Clobber List
    );
  }
  #endif  // HAS_RAWTOARGBROW_NEON
  
  #define RGB565TOARGB                                                           \
      "shrn       v6.8b, v0.8h, #5               \n"  /* G xxGGGGGG           */ \
      "shl        v6.8b, v6.8b, #2               \n"  /* G GGGGGG00 upper 6   */ \
      "ushr       v4.8b, v6.8b, #6               \n"  /* G 000000GG lower 2   */ \
      "orr        v1.8b, v4.8b, v6.8b            \n"  /* G                    */ \
      "xtn        v2.8b, v0.8h                   \n"  /* B xxxBBBBB           */ \
      "ushr       v0.8h, v0.8h, #11              \n"  /* R 000RRRRR           */ \
      "xtn2       v2.16b,v0.8h                   \n"  /* R in upper part      */ \
      "shl        v2.16b, v2.16b, #3             \n"  /* R,B BBBBB000 upper 5 */ \
      "ushr       v0.16b, v2.16b, #5             \n"  /* R,B 00000BBB lower 3 */ \
      "orr        v0.16b, v0.16b, v2.16b         \n"  /* R,B                  */ \
      "dup        v2.2D, v0.D[1]                 \n"  /* R                    */
  
  #ifdef HAS_RGB565TOARGBROW_NEON
  void RGB565ToARGBRow_NEON(const uint8* src_rgb565, uint8* dst_argb, int pix) {
    asm volatile (
      "movi       v3.8b, #255                    \n"  // Alpha
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 RGB565 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      RGB565TOARGB
      MEMACCESS(1)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_rgb565),  // %0
      "+r"(dst_argb),    // %1
      "+r"(pix)          // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v6"  // Clobber List
    );
  }
  #endif  // HAS_RGB565TOARGBROW_NEON
  
  #define ARGB1555TOARGB                                                         \
      "ushr       v2.8h, v0.8h, #10              \n"  /* R xxxRRRRR           */ \
      "shl        v2.8h, v2.8h, #3               \n"  /* R RRRRR000 upper 5   */ \
      "xtn        v3.8b, v2.8h                   \n"  /* RRRRR000 AAAAAAAA    */ \
                                                                                 \
      "sshr       v2.8h, v0.8h, #15              \n"  /* A AAAAAAAA           */ \
      "xtn2       v3.16b, v2.8h                  \n"                             \
                                                                                 \
      "xtn        v2.8b, v0.8h                   \n"  /* B xxxBBBBB           */ \
      "shrn2      v2.16b,v0.8h, #5               \n"  /* G xxxGGGGG           */ \
                                                                                 \
      "ushr       v1.16b, v3.16b, #5             \n"  /* R,A 00000RRR lower 3 */ \
      "shl        v0.16b, v2.16b, #3             \n"  /* B,G BBBBB000 upper 5 */ \
      "ushr       v2.16b, v0.16b, #5             \n"  /* B,G 00000BBB lower 3 */ \
                                                                                 \
      "orr        v0.16b, v0.16b, v2.16b         \n"  /* B,G                  */ \
      "orr        v2.16b, v1.16b, v3.16b         \n"  /* R,A                  */ \
      "dup        v1.2D, v0.D[1]                 \n"                             \
      "dup        v3.2D, v2.D[1]                 \n"
  
  // RGB555TOARGB is same as ARGB1555TOARGB but ignores alpha.
  #define RGB555TOARGB                                                           \
      "ushr       v2.8h, v0.8h, #10              \n"  /* R xxxRRRRR           */ \
      "shl        v2.8h, v2.8h, #3               \n"  /* R RRRRR000 upper 5   */ \
      "xtn        v3.8b, v2.8h                   \n"  /* RRRRR000             */ \
                                                                                 \
      "xtn        v2.8b, v0.8h                   \n"  /* B xxxBBBBB           */ \
      "shrn2      v2.16b,v0.8h, #5               \n"  /* G xxxGGGGG           */ \
                                                                                 \
      "ushr       v1.16b, v3.16b, #5             \n"  /* R   00000RRR lower 3 */ \
      "shl        v0.16b, v2.16b, #3             \n"  /* B,G BBBBB000 upper 5 */ \
      "ushr       v2.16b, v0.16b, #5             \n"  /* B,G 00000BBB lower 3 */ \
                                                                                 \
      "orr        v0.16b, v0.16b, v2.16b         \n"  /* B,G                  */ \
      "orr        v2.16b, v1.16b, v3.16b         \n"  /* R                    */ \
      "dup        v1.2D, v0.D[1]                 \n"  /* G */                    \
  
  #ifdef HAS_ARGB1555TOARGBROW_NEON
  void ARGB1555ToARGBRow_NEON(const uint8* src_argb1555, uint8* dst_argb,
                              int pix) {
    asm volatile (
      "movi       v3.8b, #255                    \n"  // Alpha
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB1555 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGB1555TOARGB
      MEMACCESS(1)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_argb1555),  // %0
      "+r"(dst_argb),    // %1
      "+r"(pix)          // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_ARGB1555TOARGBROW_NEON
  
  #define ARGB4444TOARGB                                                         \
      "shrn       v1.8b,  v0.8h, #8              \n"  /* v1(l) AR             */ \
      "xtn2       v1.16b, v0.8h                  \n"  /* v1(h) GB             */ \
      "shl        v2.16b, v1.16b, #4             \n"  /* B,R BBBB0000         */ \
      "ushr       v3.16b, v1.16b, #4             \n"  /* G,A 0000GGGG         */ \
      "ushr       v0.16b, v2.16b, #4             \n"  /* B,R 0000BBBB         */ \
      "shl        v1.16b, v3.16b, #4             \n"  /* G,A GGGG0000         */ \
      "orr        v2.16b, v0.16b, v2.16b         \n"  /* B,R BBBBBBBB         */ \
      "orr        v3.16b, v1.16b, v3.16b         \n"  /* G,A GGGGGGGG         */ \
      "dup        v0.2D, v2.D[1]                 \n"                             \
      "dup        v1.2D, v3.D[1]                 \n"
  
  #ifdef HAS_ARGB4444TOARGBROW_NEON
  void ARGB4444ToARGBRow_NEON(const uint8* src_argb4444, uint8* dst_argb,
                              int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB4444 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGB4444TOARGB
      MEMACCESS(1)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_argb4444),  // %0
      "+r"(dst_argb),    // %1
      "+r"(pix)          // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4"  // Clobber List
    );
  }
  #endif  // HAS_ARGB4444TOARGBROW_NEON
  
  #ifdef HAS_ARGBTORGB24ROW_NEON
  void ARGBToRGB24Row_NEON(const uint8* src_argb, uint8* dst_rgb24, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v1.8b,v2.8b,v3.8b,v4.8b}, [%0], #32 \n"  // load 8 ARGB pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      MEMACCESS(1)
      "st3        {v1.8b,v2.8b,v3.8b}, [%1], #24 \n"  // store 8 pixels of RGB24.
      "b.gt       1b                             \n"
    : "+r"(src_argb),   // %0
      "+r"(dst_rgb24),  // %1
      "+r"(pix)         // %2
    :
    : "cc", "memory", "v1", "v2", "v3", "v4"  // Clobber List
    );
  }
  #endif  // HAS_ARGBTORGB24ROW_NEON
  
  #ifdef HAS_ARGBTORAWROW_NEON
  void ARGBToRAWRow_NEON(const uint8* src_argb, uint8* dst_raw, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v1.8b,v2.8b,v3.8b,v4.8b}, [%0], #32 \n"  // load b g r a
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "orr        v4.8b, v2.8b, v2.8b            \n"  // mov g
      "orr        v5.8b, v1.8b, v1.8b            \n"  // mov b
      MEMACCESS(1)
      "st3        {v3.8b,v4.8b,v5.8b}, [%1], #24 \n"  // store r g b
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_raw),   // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v1", "v2", "v3", "v4", "v5"  // Clobber List
    );
  }
  #endif  // HAS_ARGBTORAWROW_NEON
  
  #ifdef HAS_YUY2TOYROW_NEON
  void YUY2ToYRow_NEON(const uint8* src_yuy2, uint8* dst_y, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v0.16b,v1.16b}, [%0], #32     \n"  // load 16 pixels of YUY2.
      "subs       %2, %2, #16                    \n"  // 16 processed per loop.
      MEMACCESS(1)
      "st1        {v0.16b}, [%1], #16            \n"  // store 16 pixels of Y.
      "b.gt       1b                             \n"
    : "+r"(src_yuy2),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1"  // Clobber List
    );
  }
  #endif  // HAS_YUY2TOYROW_NEON
  
  #ifdef HAS_UYVYTOYROW_NEON
  void UYVYToYRow_NEON(const uint8* src_uyvy, uint8* dst_y, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v0.16b,v1.16b}, [%0], #32     \n"  // load 16 pixels of UYVY.
      "subs       %2, %2, #16                    \n"  // 16 processed per loop.
      MEMACCESS(1)
      "st1        {v1.16b}, [%1], #16            \n"  // store 16 pixels of Y.
      "b.gt       1b                             \n"
    : "+r"(src_uyvy),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1"  // Clobber List
    );
  }
  #endif  // HAS_UYVYTOYROW_NEON
  
  #ifdef HAS_YUY2TOUV422ROW_NEON
  void YUY2ToUV422Row_NEON(const uint8* src_yuy2, uint8* dst_u, uint8* dst_v,
                           int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 16 YUY2 pixels
      "subs       %3, %3, #16                    \n"  // 16 pixels = 8 UVs.
      MEMACCESS(1)
      "st1        {v1.8b}, [%1], #8              \n"  // store 8 U.
      MEMACCESS(2)
      "st1        {v3.8b}, [%2], #8              \n"  // store 8 V.
      "b.gt       1b                             \n"
    : "+r"(src_yuy2),  // %0
      "+r"(dst_u),     // %1
      "+r"(dst_v),     // %2
      "+r"(pix)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_YUY2TOUV422ROW_NEON
  
  #ifdef HAS_UYVYTOUV422ROW_NEON
  void UYVYToUV422Row_NEON(const uint8* src_uyvy, uint8* dst_u, uint8* dst_v,
                           int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 16 UYVY pixels
      "subs       %3, %3, #16                    \n"  // 16 pixels = 8 UVs.
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 U.
      MEMACCESS(2)
      "st1        {v2.8b}, [%2], #8              \n"  // store 8 V.
      "b.gt       1b                             \n"
    : "+r"(src_uyvy),  // %0
      "+r"(dst_u),     // %1
      "+r"(dst_v),     // %2
      "+r"(pix)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_UYVYTOUV422ROW_NEON
  
  #ifdef HAS_YUY2TOUVROW_NEON
  void YUY2ToUVRow_NEON(const uint8* src_yuy2, int stride_yuy2,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_yuy2b = src_yuy2 + stride_yuy2;
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 16 pixels
      "subs       %4, %4, #16                    \n"  // 16 pixels = 8 UVs.
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load next row
      "urhadd     v1.8b, v1.8b, v5.8b            \n"  // average rows of U
      "urhadd     v3.8b, v3.8b, v7.8b            \n"  // average rows of V
      MEMACCESS(2)
      "st1        {v1.8b}, [%2], #8              \n"  // store 8 U.
      MEMACCESS(3)
      "st1        {v3.8b}, [%3], #8              \n"  // store 8 V.
      "b.gt       1b                             \n"
    : "+r"(src_yuy2),     // %0
      "+r"(src_yuy2b),    // %1
      "+r"(dst_u),        // %2
      "+r"(dst_v),        // %3
      "+r"(pix)           // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4",
      "v5", "v6", "v7"  // Clobber List
    );
  }
  #endif  // HAS_YUY2TOUVROW_NEON
  
  #ifdef HAS_UYVYTOUVROW_NEON
  void UYVYToUVRow_NEON(const uint8* src_uyvy, int stride_uyvy,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_uyvyb = src_uyvy + stride_uyvy;
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 16 pixels
      "subs       %4, %4, #16                    \n"  // 16 pixels = 8 UVs.
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load next row
      "urhadd     v0.8b, v0.8b, v4.8b            \n"  // average rows of U
      "urhadd     v2.8b, v2.8b, v6.8b            \n"  // average rows of V
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 U.
      MEMACCESS(3)
      "st1        {v2.8b}, [%3], #8              \n"  // store 8 V.
      "b.gt       1b                             \n"
    : "+r"(src_uyvy),     // %0
      "+r"(src_uyvyb),    // %1
      "+r"(dst_u),        // %2
      "+r"(dst_v),        // %3
      "+r"(pix)           // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4",
      "v5", "v6", "v7"  // Clobber List
    );
  }
  #endif  // HAS_UYVYTOUVROW_NEON
  
  // Select 2 channels from ARGB on alternating pixels.  e.g.  BGBGBGBG
  #ifdef HAS_ARGBTOBAYERROW_NEON
  void ARGBToBayerRow_NEON(const uint8* src_argb, uint8* dst_bayer,
                           uint32 selector, int pix) {
    asm volatile (
      "mov        v2.s[0], %w3                   \n"  // selector
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b,v1.16b}, [%0], 32      \n"  // load row 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop
      "tbl        v4.8b, {v0.16b}, v2.8b         \n"  // look up 4 pixels
      "tbl        v5.8b, {v1.16b}, v2.8b         \n"  // look up 4 pixels
      "trn1       v4.4s, v4.4s, v5.4s            \n"  // combine 8 pixels
      MEMACCESS(1)
      "st1        {v4.8b}, [%1], #8              \n"  // store 8.
      "b.gt       1b                             \n"
    : "+r"(src_argb),   // %0
      "+r"(dst_bayer),  // %1
      "+r"(pix)         // %2
    : "r"(selector)     // %3
    : "cc", "memory", "v0", "v1", "v2", "v4", "v5"   // Clobber List
    );
  }
  #endif  // HAS_ARGBTOBAYERROW_NEON
  
  // Select G channels from ARGB.  e.g.  GGGGGGGG
  #ifdef HAS_ARGBTOBAYERGGROW_NEON
  void ARGBToBayerGGRow_NEON(const uint8* src_argb, uint8* dst_bayer,
                             uint32 /*selector*/, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load row 8 pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop
      MEMACCESS(1)
      "st1        {v1.8b}, [%1], #8              \n"  // store 8 G's.
      "b.gt       1b                             \n"
    : "+r"(src_argb),   // %0
      "+r"(dst_bayer),  // %1
      "+r"(pix)         // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_ARGBTOBAYERGGROW_NEON
  
  // For BGRAToARGB, ABGRToARGB, RGBAToARGB, and ARGBToRGBA.
  #ifdef HAS_ARGBSHUFFLEROW_NEON
  void ARGBShuffleRow_NEON(const uint8* src_argb, uint8* dst_argb,
                           const uint8* shuffler, int pix) {
    asm volatile (
      MEMACCESS(3)
      "ld1        {v2.16b}, [%3]                 \n"  // shuffler
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 4 pixels.
      "subs       %2, %2, #4                     \n"  // 4 processed per loop
      "tbl        v1.16b, {v0.16b}, v2.16b       \n"  // look up 4 pixels
      MEMACCESS(1)
      "st1        {v1.16b}, [%1], #16            \n"  // store 4.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_argb),  // %1
      "+r"(pix)        // %2
    : "r"(shuffler)    // %3
    : "cc", "memory", "v0", "v1", "v2"  // Clobber List
    );
  }
  #endif  // HAS_ARGBSHUFFLEROW_NEON
  
  #ifdef HAS_I422TOYUY2ROW_NEON
  void I422ToYUY2Row_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_yuy2, int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v0.8b, v1.8b}, [%0], #16      \n"  // load 16 Ys
      "orr        v2.8b, v1.8b, v1.8b            \n"
      MEMACCESS(1)
      "ld1        {v1.8b}, [%1], #8              \n"  // load 8 Us
      MEMACCESS(2)
      "ld1        {v3.8b}, [%2], #8              \n"  // load 8 Vs
      "subs       %4, %4, #16                    \n"  // 16 pixels
      MEMACCESS(3)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%3], #32 \n"  // Store 16 pixels.
      "b.gt       1b                             \n"
    : "+r"(src_y),     // %0
      "+r"(src_u),     // %1
      "+r"(src_v),     // %2
      "+r"(dst_yuy2),  // %3
      "+r"(width)      // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"
    );
  }
  #endif  // HAS_I422TOYUY2ROW_NEON
  
  #ifdef HAS_I422TOUYVYROW_NEON
  void I422ToUYVYRow_NEON(const uint8* src_y,
                          const uint8* src_u,
                          const uint8* src_v,
                          uint8* dst_uyvy, int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld2        {v1.8b,v2.8b}, [%0], #16       \n"  // load 16 Ys
      "orr        v3.8b, v2.8b, v2.8b            \n"
      MEMACCESS(1)
      "ld1        {v0.8b}, [%1], #8              \n"  // load 8 Us
      MEMACCESS(2)
      "ld1        {v2.8b}, [%2], #8              \n"  // load 8 Vs
      "subs       %4, %4, #16                    \n"  // 16 pixels
      MEMACCESS(3)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%3], #32 \n"  // Store 16 pixels.
      "b.gt       1b                             \n"
    : "+r"(src_y),     // %0
      "+r"(src_u),     // %1
      "+r"(src_v),     // %2
      "+r"(dst_uyvy),  // %3
      "+r"(width)      // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"
    );
  }
  #endif  // HAS_I422TOUYVYROW_NEON
  
  #ifdef HAS_ARGBTORGB565ROW_NEON
  void ARGBToRGB565Row_NEON(const uint8* src_argb, uint8* dst_rgb565, int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%0], #32 \n"  // load 8 pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGBTORGB565
      MEMACCESS(1)
      "st1        {v0.16b}, [%1], #16            \n"  // store 8 pixels RGB565.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_rgb565),  // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v20", "v21", "v22", "v23"
    );
  }
  #endif  // HAS_ARGBTORGB565ROW_NEON
  
  #ifdef HAS_ARGBTOARGB1555ROW_NEON
  void ARGBToARGB1555Row_NEON(const uint8* src_argb, uint8* dst_argb1555,
                              int pix) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%0], #32 \n"  // load 8 pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGBTOARGB1555
      MEMACCESS(1)
      "st1        {v0.16b}, [%1], #16            \n"  // store 8 pixels ARGB1555.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_argb1555),  // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v20", "v21", "v22", "v23"
    );
  }
  #endif  // HAS_ARGBTOARGB1555ROW_NEON
  
  #ifdef HAS_ARGBTOARGB4444ROW_NEON
  void ARGBToARGB4444Row_NEON(const uint8* src_argb, uint8* dst_argb4444,
                              int pix) {
    asm volatile (
      "movi       v4.16b, #0x0f                  \n"  // bits to clear with vbic.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v20.8b,v21.8b,v22.8b,v23.8b}, [%0], #32 \n"  // load 8 pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGBTOARGB4444
      MEMACCESS(1)
      "st1        {v0.16b}, [%1], #16            \n"  // store 8 pixels ARGB4444.
      "b.gt       1b                             \n"
    : "+r"(src_argb),      // %0
      "+r"(dst_argb4444),  // %1
      "+r"(pix)            // %2
    :
    : "cc", "memory", "v0", "v1", "v4", "v20", "v21", "v22", "v23"
    );
  }
  #endif  // HAS_ARGBTOARGB4444ROW_NEON
  
  #ifdef HAS_ARGBTOYROW_NEON
  void ARGBToYRow_NEON(const uint8* src_argb, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v3.8h, v0.8b, v4.8b            \n"  // B
      "umlal      v3.8h, v1.8b, v5.8b            \n"  // G
      "umlal      v3.8h, v2.8b, v6.8b            \n"  // R
      "sqrshrun   v0.8b, v3.8h, #7               \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGBTOYROW_NEON
  
  #ifdef HAS_ARGBTOYJROW_NEON
  void ARGBToYJRow_NEON(const uint8* src_argb, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #15                     \n"  // B * 0.11400 coefficient
      "movi       v5.8b, #75                     \n"  // G * 0.58700 coefficient
      "movi       v6.8b, #38                     \n"  // R * 0.29900 coefficient
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v3.8h, v0.8b, v4.8b            \n"  // B
      "umlal      v3.8h, v1.8b, v5.8b            \n"  // G
      "umlal      v3.8h, v2.8b, v6.8b            \n"  // R
      "sqrshrun   v0.8b, v3.8h, #7               \n"  // 15 bit to 8 bit Y
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6"
    );
  }
  #endif  // HAS_ARGBTOYJROW_NEON
  
  // 8x1 pixels.
  #ifdef HAS_ARGBTOUV444ROW_NEON
  void ARGBToUV444Row_NEON(const uint8* src_argb, uint8* dst_u, uint8* dst_v,
                           int pix) {
    asm volatile (
      "movi       v24.8b, #112                   \n"  // UB / VR 0.875 coefficient
      "movi       v25.8b, #74                    \n"  // UG -0.5781 coefficient
      "movi       v26.8b, #38                    \n"  // UR -0.2969 coefficient
      "movi       v27.8b, #18                    \n"  // VB -0.1406 coefficient
      "movi       v28.8b, #94                    \n"  // VG -0.7344 coefficient
      "movi       v29.16b,#0x80                  \n"  // 128.5
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "umull      v4.8h, v0.8b, v24.8b           \n"  // B
      "umlsl      v4.8h, v1.8b, v25.8b           \n"  // G
      "umlsl      v4.8h, v2.8b, v26.8b           \n"  // R
      "add        v4.8h, v4.8h, v29.8h           \n"  // +128 -> unsigned
  
      "umull      v3.8h, v2.8b, v24.8b           \n"  // R
      "umlsl      v3.8h, v1.8b, v28.8b           \n"  // G
      "umlsl      v3.8h, v0.8b, v27.8b           \n"  // B
      "add        v3.8h, v3.8h, v29.8h           \n"  // +128 -> unsigned
  
      "uqshrn     v0.8b, v4.8h, #8               \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v3.8h, #8               \n"  // 16 bit to 8 bit V
  
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels U.
      MEMACCESS(2)
      "st1        {v1.8b}, [%2], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_u),     // %1
      "+r"(dst_v),     // %2
      "+r"(pix)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4",
      "v24", "v25", "v26", "v27", "v28", "v29"
    );
  }
  #endif  // HAS_ARGBTOUV444ROW_NEON
  
  // 16x1 pixels -> 8x1.  pix is number of argb pixels. e.g. 16.
  #ifdef HAS_ARGBTOUV422ROW_NEON
  void ARGBToUV422Row_NEON(const uint8* src_argb, uint8* dst_u, uint8* dst_v,
                           int pix) {
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
  
      "uaddlp     v0.8h, v0.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v2.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "subs       %3, %3, #16                    \n"  // 16 processed per loop.
      "mul        v3.8h, v0.8h, v20.8h           \n"  // B
      "mls        v3.8h, v1.8h, v21.8h           \n"  // G
      "mls        v3.8h, v2.8h, v22.8h           \n"  // R
      "add        v3.8h, v3.8h, v25.8h           \n"  // +128 -> unsigned
  
      "mul        v4.8h, v2.8h, v20.8h           \n"  // R
      "mls        v4.8h, v1.8h, v24.8h           \n"  // G
      "mls        v4.8h, v0.8h, v23.8h           \n"  // B
      "add        v4.8h, v4.8h, v25.8h           \n"  // +128 -> unsigned
  
      "uqshrn     v0.8b, v3.8h, #8               \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v4.8h, #8               \n"  // 16 bit to 8 bit V
  
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels U.
      MEMACCESS(2)
      "st1        {v1.8b}, [%2], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_u),     // %1
      "+r"(dst_v),     // %2
      "+r"(pix)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ARGBTOUV422ROW_NEON
  
  // 32x1 pixels -> 8x1.  pix is number of argb pixels. e.g. 32.
  #ifdef HAS_ARGBTOUV411ROW_NEON
  void ARGBToUV411Row_NEON(const uint8* src_argb, uint8* dst_u, uint8* dst_v,
                           int pix) {
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v0.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v2.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(0)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%0], #64 \n"  // load next 16.
      "uaddlp     v4.8h, v4.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v5.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v6.8h, v6.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "addp       v0.8h, v0.8h, v4.8h            \n"  // B 16 shorts -> 8 shorts.
      "addp       v1.8h, v1.8h, v5.8h            \n"  // G 16 shorts -> 8 shorts.
      "addp       v2.8h, v2.8h, v6.8h            \n"  // R 16 shorts -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %3, %3, #32                    \n"  // 32 processed per loop.
      "mul        v3.8h, v0.8h, v20.8h           \n"  // B
      "mls        v3.8h, v1.8h, v21.8h           \n"  // G
      "mls        v3.8h, v2.8h, v22.8h           \n"  // R
      "add        v3.8h, v3.8h, v25.8h           \n"  // +128 -> unsigned
      "mul        v4.8h, v2.8h, v20.8h           \n"  // R
      "mls        v4.8h, v1.8h, v24.8h           \n"  // G
      "mls        v4.8h, v0.8h, v23.8h           \n"  // B
      "add        v4.8h, v4.8h, v25.8h           \n"  // +128 -> unsigned
      "uqshrn     v0.8b, v3.8h, #8               \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v4.8h, #8               \n"  // 16 bit to 8 bit V
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels U.
      MEMACCESS(2)
      "st1        {v1.8b}, [%2], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_u),     // %1
      "+r"(dst_v),     // %2
      "+r"(pix)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ARGBTOUV411ROW_NEON
  
  // 16x2 pixels -> 8x1.  pix is number of argb pixels. e.g. 16.
  #define RGBTOUV(QB, QG, QR) \
      "mul        v3.8h, " #QB ",v20.8h          \n"  /* B                    */ \
      "mul        v4.8h, " #QR ",v20.8h          \n"  /* R                    */ \
      "mls        v3.8h, " #QG ",v21.8h          \n"  /* G                    */ \
      "mls        v4.8h, " #QG ",v24.8h          \n"  /* G                    */ \
      "mls        v3.8h, " #QR ",v22.8h          \n"  /* R                    */ \
      "mls        v4.8h, " #QB ",v23.8h          \n"  /* B                    */ \
      "add        v3.8h, v3.8h, v25.8h           \n"  /* +128 -> unsigned     */ \
      "add        v4.8h, v4.8h, v25.8h           \n"  /* +128 -> unsigned     */ \
      "uqshrn     v0.8b, v3.8h, #8               \n"  /* 16 bit to 8 bit U    */ \
      "uqshrn     v1.8b, v4.8h, #8               \n"  /* 16 bit to 8 bit V    */
  
  // TODO(fbarchard): Consider vhadd vertical, then vpaddl horizontal, avoid shr.
  // TODO(fbarchard): consider ptrdiff_t for all strides.
  
  #ifdef HAS_ARGBTOUVROW_NEON
  void ARGBToUVRow_NEON(const uint8* src_argb, int src_stride_argb,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_argb_1 = src_argb + src_stride_argb;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v0.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v2.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      MEMACCESS(1)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%1], #64 \n"  // load next 16
      "uadalp     v0.8h, v4.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v6.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v1.8h, v2.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(src_argb_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ARGBTOUVROW_NEON
  
  // TODO(fbarchard): Subsample match C code.
  #ifdef HAS_ARGBTOUVJROW_NEON
  void ARGBToUVJRow_NEON(const uint8* src_argb, int src_stride_argb,
                         uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_argb_1 = src_argb + src_stride_argb;
    asm volatile (
      "movi       v20.8h, #63, lsl #0            \n"  // UB/VR coeff (0.500) / 2
      "movi       v21.8h, #42, lsl #0            \n"  // UG coeff (-0.33126) / 2
      "movi       v22.8h, #21, lsl #0            \n"  // UR coeff (-0.16874) / 2
      "movi       v23.8h, #10, lsl #0            \n"  // VB coeff (-0.08131) / 2
      "movi       v24.8h, #53, lsl #0            \n"  // VG coeff (-0.41869) / 2
      "movi       v25.16b, #0x80                 \n"  // 128.5 (0x8080 in 16-bit)
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v0.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v2.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%1], #64  \n"  // load next 16
      "uadalp     v0.8h, v4.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v6.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v1.8h, v2.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(src_argb_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ARGBTOUVJROW_NEON
  
  #ifdef HAS_BGRATOUVROW_NEON
  void BGRAToUVRow_NEON(const uint8* src_bgra, int src_stride_bgra,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_bgra_1 = src_bgra + src_stride_bgra;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v3.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v3.8h, v2.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v1.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%1], #64 \n"  // load 16 more
      "uadalp     v0.8h, v7.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v3.8h, v6.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v5.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v3.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v1.8h, v2.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_bgra),  // %0
      "+r"(src_bgra_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_BGRATOUVROW_NEON
  
  #ifdef HAS_ABGRTOUVROW_NEON
  void ABGRToUVRow_NEON(const uint8* src_abgr, int src_stride_abgr,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_abgr_1 = src_abgr + src_stride_abgr;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v3.8h, v2.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v0.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%1], #64 \n"  // load 16 more.
      "uadalp     v3.8h, v6.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v4.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v3.8h, #1               \n"  // 2x average
      "urshr      v2.8h, v2.8h, #1               \n"
      "urshr      v1.8h, v1.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v2.8h, v1.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_abgr),  // %0
      "+r"(src_abgr_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ABGRTOUVROW_NEON
  
  #ifdef HAS_RGBATOUVROW_NEON
  void RGBAToUVRow_NEON(const uint8* src_rgba, int src_stride_rgba,
                        uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_rgba_1 = src_rgba + src_stride_rgba;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v1.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v2.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v3.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld4        {v4.16b,v5.16b,v6.16b,v7.16b}, [%1], #64 \n"  // load 16 more.
      "uadalp     v0.8h, v5.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v6.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v7.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v1.8h, v2.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_rgba),  // %0
      "+r"(src_rgba_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_RGBATOUVROW_NEON
  
  #ifdef HAS_RGB24TOUVROW_NEON
  void RGB24ToUVRow_NEON(const uint8* src_rgb24, int src_stride_rgb24,
                         uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_rgb24_1 = src_rgb24 + src_stride_rgb24;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v0.16b,v1.16b,v2.16b}, [%0], #48 \n"  // load 16 pixels.
      "uaddlp     v0.8h, v0.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v2.8h, v2.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld3        {v4.16b,v5.16b,v6.16b}, [%1], #48 \n"  // load 16 more.
      "uadalp     v0.8h, v4.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v2.8h, v6.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v0.8h, v0.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v2.8h, v2.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v0.8h, v1.8h, v2.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_rgb24),  // %0
      "+r"(src_rgb24_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_RGB24TOUVROW_NEON
  
  #ifdef HAS_RAWTOUVROW_NEON
  void RAWToUVRow_NEON(const uint8* src_raw, int src_stride_raw,
                       uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_raw_1 = src_raw + src_stride_raw;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v0.16b,v1.16b,v2.16b}, [%0], #48 \n"  // load 8 RAW pixels.
      "uaddlp     v2.8h, v2.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uaddlp     v1.8h, v1.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uaddlp     v0.8h, v0.16b                  \n"  // R 16 bytes -> 8 shorts.
      MEMACCESS(1)
      "ld3        {v4.16b,v5.16b,v6.16b}, [%1], #48 \n"  // load 8 more RAW pixels
      "uadalp     v2.8h, v6.16b                  \n"  // B 16 bytes -> 8 shorts.
      "uadalp     v1.8h, v5.16b                  \n"  // G 16 bytes -> 8 shorts.
      "uadalp     v0.8h, v4.16b                  \n"  // R 16 bytes -> 8 shorts.
  
      "urshr      v2.8h, v2.8h, #1               \n"  // 2x average
      "urshr      v1.8h, v1.8h, #1               \n"
      "urshr      v0.8h, v0.8h, #1               \n"
  
      "subs       %4, %4, #16                    \n"  // 32 processed per loop.
      RGBTOUV(v2.8h, v1.8h, v0.8h)
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_raw),  // %0
      "+r"(src_raw_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_RAWTOUVROW_NEON
  
  // 16x2 pixels -> 8x1.  pix is number of argb pixels. e.g. 16.
  #ifdef HAS_RGB565TOUVROW_NEON
  void RGB565ToUVRow_NEON(const uint8* src_rgb565, int src_stride_rgb565,
                          uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_rgb565_1 = src_rgb565 + src_stride_rgb565;
    asm volatile (
      "movi       v22.8h, #56, lsl #0            \n"  // UB / VR coeff (0.875) / 2
      "movi       v23.8h, #37, lsl #0            \n"  // UG coeff (-0.5781) / 2
      "movi       v24.8h, #19, lsl #0            \n"  // UR coeff (-0.2969) / 2
      "movi       v25.8h, #9 , lsl #0            \n"  // VB coeff (-0.1406) / 2
      "movi       v26.8h, #47, lsl #0            \n"  // VG coeff (-0.7344) / 2
      "movi       v27.16b, #0x80                 \n"  // 128.5 (0x8080 in 16-bit)
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 RGB565 pixels.
      RGB565TOARGB
      "uaddlp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v18.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v20.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // next 8 RGB565 pixels.
      RGB565TOARGB
      "uaddlp     v17.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v19.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v21.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // load 8 RGB565 pixels.
      RGB565TOARGB
      "uadalp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v18.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v20.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // next 8 RGB565 pixels.
      RGB565TOARGB
      "uadalp     v17.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v19.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v21.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      "ins        v16.D[1], v17.D[0]             \n"
      "ins        v18.D[1], v19.D[0]             \n"
      "ins        v20.D[1], v21.D[0]             \n"
  
      "urshr      v4.8h, v16.8h, #1              \n"  // 2x average
      "urshr      v5.8h, v18.8h, #1              \n"
      "urshr      v6.8h, v20.8h, #1              \n"
  
      "subs       %4, %4, #16                    \n"  // 16 processed per loop.
      "mul        v16.8h, v4.8h, v22.8h          \n"  // B
      "mls        v16.8h, v5.8h, v23.8h          \n"  // G
      "mls        v16.8h, v6.8h, v24.8h          \n"  // R
      "add        v16.8h, v16.8h, v27.8h         \n"  // +128 -> unsigned
      "mul        v17.8h, v6.8h, v22.8h          \n"  // R
      "mls        v17.8h, v5.8h, v26.8h          \n"  // G
      "mls        v17.8h, v4.8h, v25.8h          \n"  // B
      "add        v17.8h, v17.8h, v27.8h         \n"  // +128 -> unsigned
      "uqshrn     v0.8b, v16.8h, #8              \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v17.8h, #8              \n"  // 16 bit to 8 bit V
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_rgb565),  // %0
      "+r"(src_rgb565_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23", "v24",
      "v25", "v26", "v27"
    );
  }
  #endif  // HAS_RGB565TOUVROW_NEON
  
  // 16x2 pixels -> 8x1.  pix is number of argb pixels. e.g. 16.
  #ifdef HAS_ARGB1555TOUVROW_NEON
  void ARGB1555ToUVRow_NEON(const uint8* src_argb1555, int src_stride_argb1555,
                          uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_argb1555_1 = src_argb1555 + src_stride_argb1555;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB1555 pixels.
      RGB555TOARGB
      "uaddlp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v17.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v18.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // next 8 ARGB1555 pixels.
      RGB555TOARGB
      "uaddlp     v26.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v27.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v28.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // load 8 ARGB1555 pixels.
      RGB555TOARGB
      "uadalp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v17.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v18.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // next 8 ARGB1555 pixels.
      RGB555TOARGB
      "uadalp     v26.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v27.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v28.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      "ins        v16.D[1], v26.D[0]             \n"
      "ins        v17.D[1], v27.D[0]             \n"
      "ins        v18.D[1], v28.D[0]             \n"
  
      "urshr      v4.8h, v16.8h, #1              \n"  // 2x average
      "urshr      v5.8h, v17.8h, #1              \n"
      "urshr      v6.8h, v18.8h, #1              \n"
  
      "subs       %4, %4, #16                    \n"  // 16 processed per loop.
      "mul        v2.8h, v4.8h, v20.8h           \n"  // B
      "mls        v2.8h, v5.8h, v21.8h           \n"  // G
      "mls        v2.8h, v6.8h, v22.8h           \n"  // R
      "add        v2.8h, v2.8h, v25.8h           \n"  // +128 -> unsigned
      "mul        v3.8h, v6.8h, v20.8h           \n"  // R
      "mls        v3.8h, v5.8h, v24.8h           \n"  // G
      "mls        v3.8h, v4.8h, v23.8h           \n"  // B
      "add        v3.8h, v3.8h, v25.8h           \n"  // +128 -> unsigned
      "uqshrn     v0.8b, v2.8h, #8               \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v3.8h, #8               \n"  // 16 bit to 8 bit V
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb1555),  // %0
      "+r"(src_argb1555_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6",
      "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23", "v24", "v25",
      "v26", "v27", "v28"
    );
  }
  #endif  // HAS_ARGB1555TOUVROW_NEON
  
  // 16x2 pixels -> 8x1.  pix is number of argb pixels. e.g. 16.
  #ifdef HAS_ARGB4444TOUVROW_NEON
  void ARGB4444ToUVRow_NEON(const uint8* src_argb4444, int src_stride_argb4444,
                            uint8* dst_u, uint8* dst_v, int pix) {
    const uint8* src_argb4444_1 = src_argb4444 + src_stride_argb4444;
    asm volatile (
      RGBTOUV_SETUP_REG
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB4444 pixels.
      ARGB4444TOARGB
      "uaddlp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v17.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v18.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // next 8 ARGB4444 pixels.
      ARGB4444TOARGB
      "uaddlp     v26.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uaddlp     v27.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uaddlp     v28.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // load 8 ARGB4444 pixels.
      ARGB4444TOARGB
      "uadalp     v16.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v17.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v18.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"  // next 8 ARGB4444 pixels.
      ARGB4444TOARGB
      "uadalp     v26.4h, v0.8b                  \n"  // B 8 bytes -> 4 shorts.
      "uadalp     v27.4h, v1.8b                  \n"  // G 8 bytes -> 4 shorts.
      "uadalp     v28.4h, v2.8b                  \n"  // R 8 bytes -> 4 shorts.
  
      "ins        v16.D[1], v26.D[0]             \n"
      "ins        v17.D[1], v27.D[0]             \n"
      "ins        v18.D[1], v28.D[0]             \n"
  
      "urshr      v4.8h, v16.8h, #1              \n"  // 2x average
      "urshr      v5.8h, v17.8h, #1              \n"
      "urshr      v6.8h, v18.8h, #1              \n"
  
      "subs       %4, %4, #16                    \n"  // 16 processed per loop.
      "mul        v2.8h, v4.8h, v20.8h           \n"  // B
      "mls        v2.8h, v5.8h, v21.8h           \n"  // G
      "mls        v2.8h, v6.8h, v22.8h           \n"  // R
      "add        v2.8h, v2.8h, v25.8h           \n"  // +128 -> unsigned
      "mul        v3.8h, v6.8h, v20.8h           \n"  // R
      "mls        v3.8h, v5.8h, v24.8h           \n"  // G
      "mls        v3.8h, v4.8h, v23.8h           \n"  // B
      "add        v3.8h, v3.8h, v25.8h           \n"  // +128 -> unsigned
      "uqshrn     v0.8b, v2.8h, #8               \n"  // 16 bit to 8 bit U
      "uqshrn     v1.8b, v3.8h, #8               \n"  // 16 bit to 8 bit V
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 pixels U.
      MEMACCESS(3)
      "st1        {v1.8b}, [%3], #8              \n"  // store 8 pixels V.
      "b.gt       1b                             \n"
    : "+r"(src_argb4444),  // %0
      "+r"(src_argb4444_1),  // %1
      "+r"(dst_u),     // %2
      "+r"(dst_v),     // %3
      "+r"(pix)        // %4
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6",
      "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23", "v24", "v25",
      "v26", "v27", "v28"
  
    );
  }
  #endif  // HAS_ARGB4444TOUVROW_NEON
  
  #ifdef HAS_RGB565TOYROW_NEON
  void RGB565ToYRow_NEON(const uint8* src_rgb565, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v24.8b, #13                    \n"  // B * 0.1016 coefficient
      "movi       v25.8b, #65                    \n"  // G * 0.5078 coefficient
      "movi       v26.8b, #33                    \n"  // R * 0.2578 coefficient
      "movi       v27.8b, #16                    \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 RGB565 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      RGB565TOARGB
      "umull      v3.8h, v0.8b, v24.8b           \n"  // B
      "umlal      v3.8h, v1.8b, v25.8b           \n"  // G
      "umlal      v3.8h, v2.8b, v26.8b           \n"  // R
      "sqrshrun   v0.8b, v3.8h, #7               \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v27.8b           \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_rgb565),  // %0
      "+r"(dst_y),       // %1
      "+r"(pix)          // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v6",
      "v24", "v25", "v26", "v27"
    );
  }
  #endif  // HAS_RGB565TOYROW_NEON
  
  #ifdef HAS_ARGB1555TOYROW_NEON
  void ARGB1555ToYRow_NEON(const uint8* src_argb1555, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB1555 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGB1555TOARGB
      "umull      v3.8h, v0.8b, v4.8b            \n"  // B
      "umlal      v3.8h, v1.8b, v5.8b            \n"  // G
      "umlal      v3.8h, v2.8b, v6.8b            \n"  // R
      "sqrshrun   v0.8b, v3.8h, #7               \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_argb1555),  // %0
      "+r"(dst_y),         // %1
      "+r"(pix)            // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGB1555TOYROW_NEON
  
  #ifdef HAS_ARGB4444TOYROW_NEON
  void ARGB4444ToYRow_NEON(const uint8* src_argb4444, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v24.8b, #13                    \n"  // B * 0.1016 coefficient
      "movi       v25.8b, #65                    \n"  // G * 0.5078 coefficient
      "movi       v26.8b, #33                    \n"  // R * 0.2578 coefficient
      "movi       v27.8b, #16                    \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 8 ARGB4444 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      ARGB4444TOARGB
      "umull      v3.8h, v0.8b, v24.8b           \n"  // B
      "umlal      v3.8h, v1.8b, v25.8b           \n"  // G
      "umlal      v3.8h, v2.8b, v26.8b           \n"  // R
      "sqrshrun   v0.8b, v3.8h, #7               \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v27.8b           \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_argb4444),  // %0
      "+r"(dst_y),         // %1
      "+r"(pix)            // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v24", "v25", "v26", "v27"
    );
  }
  #endif  // HAS_ARGB4444TOYROW_NEON
  
  #ifdef HAS_BGRATOYROW_NEON
  void BGRAToYRow_NEON(const uint8* src_bgra, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v1.8b, v4.8b           \n"  // R
      "umlal      v16.8h, v2.8b, v5.8b           \n"  // G
      "umlal      v16.8h, v3.8b, v6.8b           \n"  // B
      "sqrshrun   v0.8b, v16.8h, #7              \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_bgra),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16"
    );
  }
  #endif  // HAS_BGRATOYROW_NEON
  
  #ifdef HAS_ABGRTOYROW_NEON
  void ABGRToYRow_NEON(const uint8* src_abgr, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v0.8b, v4.8b           \n"  // R
      "umlal      v16.8h, v1.8b, v5.8b           \n"  // G
      "umlal      v16.8h, v2.8b, v6.8b           \n"  // B
      "sqrshrun   v0.8b, v16.8h, #7              \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_abgr),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16"
    );
  }
  #endif  // HAS_ABGRTOYROW_NEON
  
  #ifdef HAS_RGBATOYROW_NEON
  void RGBAToYRow_NEON(const uint8* src_rgba, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v1.8b, v4.8b           \n"  // B
      "umlal      v16.8h, v2.8b, v5.8b           \n"  // G
      "umlal      v16.8h, v3.8b, v6.8b           \n"  // R
      "sqrshrun   v0.8b, v16.8h, #7              \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_rgba),  // %0
      "+r"(dst_y),     // %1
      "+r"(pix)        // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16"
    );
  }
  #endif  // HAS_RGBATOYROW_NEON
  
  #ifdef HAS_RGB24TOYROW_NEON
  void RGB24ToYRow_NEON(const uint8* src_rgb24, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v0.8b,v1.8b,v2.8b}, [%0], #24 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v0.8b, v4.8b           \n"  // B
      "umlal      v16.8h, v1.8b, v5.8b           \n"  // G
      "umlal      v16.8h, v2.8b, v6.8b           \n"  // R
      "sqrshrun   v0.8b, v16.8h, #7              \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_rgb24),  // %0
      "+r"(dst_y),      // %1
      "+r"(pix)         // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16"
    );
  }
  #endif  // HAS_RGB24TOYROW_NEON
  
  #ifdef HAS_RAWTOYROW_NEON
  void RAWToYRow_NEON(const uint8* src_raw, uint8* dst_y, int pix) {
    asm volatile (
      "movi       v4.8b, #33                     \n"  // R * 0.2578 coefficient
      "movi       v5.8b, #65                     \n"  // G * 0.5078 coefficient
      "movi       v6.8b, #13                     \n"  // B * 0.1016 coefficient
      "movi       v7.8b, #16                     \n"  // Add 16 constant
    "1:                                          \n"
      MEMACCESS(0)
      "ld3        {v0.8b,v1.8b,v2.8b}, [%0], #24 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v0.8b, v4.8b           \n"  // B
      "umlal      v16.8h, v1.8b, v5.8b           \n"  // G
      "umlal      v16.8h, v2.8b, v6.8b           \n"  // R
      "sqrshrun   v0.8b, v16.8h, #7              \n"  // 16 bit to 8 bit Y
      "uqadd      v0.8b, v0.8b, v7.8b            \n"
      MEMACCESS(1)
      "st1        {v0.8b}, [%1], #8              \n"  // store 8 pixels Y.
      "b.gt       1b                             \n"
    : "+r"(src_raw),  // %0
      "+r"(dst_y),    // %1
      "+r"(pix)       // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16"
    );
  }
  #endif  // HAS_RAWTOYROW_NEON
  
  // Bilinear filter 16x2 -> 16x1
  #ifdef HAS_INTERPOLATEROW_NEON
  void InterpolateRow_NEON(uint8* dst_ptr,
                           const uint8* src_ptr, ptrdiff_t src_stride,
                           int dst_width, int source_y_fraction) {
    int y1_fraction = source_y_fraction;
    int y0_fraction = 256 - y1_fraction;
    const uint8* src_ptr1 = src_ptr + src_stride;
    asm volatile (
      "cmp        %4, #0                         \n"
      "b.eq       100f                           \n"
      "cmp        %4, #64                        \n"
      "b.eq       75f                            \n"
      "cmp        %4, #128                       \n"
      "b.eq       50f                            \n"
      "cmp        %4, #192                       \n"
      "b.eq       25f                            \n"
  
      "dup        v5.16b, %w4                    \n"
      "dup        v4.16b, %w5                    \n"
      // General purpose row blend.
    "1:                                          \n"
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"
      MEMACCESS(2)
      "ld1        {v1.16b}, [%2], #16            \n"
      "subs       %3, %3, #16                    \n"
      "umull      v2.8h, v0.8b,  v4.8b           \n"
      "umull2     v3.8h, v0.16b, v4.16b          \n"
      "umlal      v2.8h, v1.8b,  v5.8b           \n"
      "umlal2     v3.8h, v1.16b, v5.16b          \n"
      "rshrn      v0.8b,  v2.8h, #8              \n"
      "rshrn2     v0.16b, v3.8h, #8              \n"
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"
      "b.gt       1b                             \n"
      "b          99f                            \n"
  
      // Blend 25 / 75.
    "25:                                         \n"
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"
      MEMACCESS(2)
      "ld1        {v1.16b}, [%2], #16            \n"
      "subs       %3, %3, #16                    \n"
      "urhadd     v0.16b, v0.16b, v1.16b         \n"
      "urhadd     v0.16b, v0.16b, v1.16b         \n"
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"
      "b.gt       25b                            \n"
      "b          99f                            \n"
  
      // Blend 50 / 50.
    "50:                                         \n"
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"
      MEMACCESS(2)
      "ld1        {v1.16b}, [%2], #16            \n"
      "subs       %3, %3, #16                    \n"
      "urhadd     v0.16b, v0.16b, v1.16b         \n"
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"
      "b.gt       50b                            \n"
      "b          99f                            \n"
  
      // Blend 75 / 25.
    "75:                                         \n"
      MEMACCESS(1)
      "ld1        {v1.16b}, [%1], #16            \n"
      MEMACCESS(2)
      "ld1        {v0.16b}, [%2], #16            \n"
      "subs       %3, %3, #16                    \n"
      "urhadd     v0.16b, v0.16b, v1.16b         \n"
      "urhadd     v0.16b, v0.16b, v1.16b         \n"
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"
      "b.gt       75b                            \n"
      "b          99f                            \n"
  
      // Blend 100 / 0 - Copy row unchanged.
    "100:                                        \n"
      MEMACCESS(1)
      "ld1        {v0.16b}, [%1], #16            \n"
      "subs       %3, %3, #16                    \n"
      MEMACCESS(0)
      "st1        {v0.16b}, [%0], #16            \n"
      "b.gt       100b                           \n"
  
    "99:                                         \n"
    : "+r"(dst_ptr),          // %0
      "+r"(src_ptr),          // %1
      "+r"(src_ptr1),         // %2
      "+r"(dst_width),        // %3
      "+r"(y1_fraction),      // %4
      "+r"(y0_fraction)       // %5
    :
    : "cc", "memory", "v0", "v1", "v3", "v4", "v5"
    );
  }
  #endif  // HAS_INTERPOLATEROW_NEON
  
  // dr * (256 - sa) / 256 + sr = dr - dr * sa / 256 + sr
  #ifdef HAS_ARGBBLENDROW_NEON
  void ARGBBlendRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
                         uint8* dst_argb, int width) {
    asm volatile (
      "subs       %3, %3, #8                     \n"
      "b.lt       89f                            \n"
      // Blend 8 pixels.
    "8:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB0 pixels
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load 8 ARGB1 pixels
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "umull      v16.8h, v4.8b, v3.8b           \n"  // db * a
      "umull      v17.8h, v5.8b, v3.8b           \n"  // dg * a
      "umull      v18.8h, v6.8b, v3.8b           \n"  // dr * a
      "uqrshrn    v16.8b, v16.8h, #8             \n"  // db >>= 8
      "uqrshrn    v17.8b, v17.8h, #8             \n"  // dg >>= 8
      "uqrshrn    v18.8b, v18.8h, #8             \n"  // dr >>= 8
      "uqsub      v4.8b, v4.8b, v16.8b           \n"  // db - (db * a / 256)
      "uqsub      v5.8b, v5.8b, v17.8b           \n"  // dg - (dg * a / 256)
      "uqsub      v6.8b, v6.8b, v18.8b           \n"  // dr - (dr * a / 256)
      "uqadd      v0.8b, v0.8b, v4.8b            \n"  // + sb
      "uqadd      v1.8b, v1.8b, v5.8b            \n"  // + sg
      "uqadd      v2.8b, v2.8b, v6.8b            \n"  // + sr
      "movi       v3.8b, #255                    \n"  // a = 255
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.ge       8b                             \n"
  
    "89:                                         \n"
      "adds       %3, %3, #8-1                   \n"
      "b.lt       99f                            \n"
  
      // Blend 1 pixels.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.b,v1.b,v2.b,v3.b}[0], [%0], #4 \n"  // load 1 pixel ARGB0.
      MEMACCESS(1)
      "ld4        {v4.b,v5.b,v6.b,v7.b}[0], [%1], #4 \n"  // load 1 pixel ARGB1.
      "subs       %3, %3, #1                     \n"  // 1 processed per loop.
      "umull      v16.8h, v4.8b, v3.8b           \n"  // db * a
      "umull      v17.8h, v5.8b, v3.8b           \n"  // dg * a
      "umull      v18.8h, v6.8b, v3.8b           \n"  // dr * a
      "uqrshrn    v16.8b, v16.8h, #8             \n"  // db >>= 8
      "uqrshrn    v17.8b, v17.8h, #8             \n"  // dg >>= 8
      "uqrshrn    v18.8b, v18.8h, #8             \n"  // dr >>= 8
      "uqsub      v4.8b, v4.8b, v16.8b           \n"  // db - (db * a / 256)
      "uqsub      v5.8b, v5.8b, v17.8b           \n"  // dg - (dg * a / 256)
      "uqsub      v6.8b, v6.8b, v18.8b           \n"  // dr - (dr * a / 256)
      "uqadd      v0.8b, v0.8b, v4.8b            \n"  // + sb
      "uqadd      v1.8b, v1.8b, v5.8b            \n"  // + sg
      "uqadd      v2.8b, v2.8b, v6.8b            \n"  // + sr
      "movi       v3.8b, #255                    \n"  // a = 255
      MEMACCESS(2)
      "st4        {v0.b,v1.b,v2.b,v3.b}[0], [%2], #4 \n"  // store 1 pixel.
      "b.ge       1b                             \n"
  
    "99:                                         \n"
  
    : "+r"(src_argb0),    // %0
      "+r"(src_argb1),    // %1
      "+r"(dst_argb),     // %2
      "+r"(width)         // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v16", "v17", "v18"
    );
  }
  #endif  // HAS_ARGBBLENDROW_NEON
  
  // Attenuate 8 pixels at a time.
  #ifdef HAS_ARGBATTENUATEROW_NEON
  void ARGBAttenuateRow_NEON(const uint8* src_argb, uint8* dst_argb, int width) {
    asm volatile (
      // Attenuate 8 pixels.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v4.8h, v0.8b, v3.8b            \n"  // b * a
      "umull      v5.8h, v1.8b, v3.8b            \n"  // g * a
      "umull      v6.8h, v2.8b, v3.8b            \n"  // r * a
      "uqrshrn    v0.8b, v4.8h, #8               \n"  // b >>= 8
      "uqrshrn    v1.8b, v5.8h, #8               \n"  // g >>= 8
      "uqrshrn    v2.8b, v6.8h, #8               \n"  // r >>= 8
      MEMACCESS(1)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_argb),   // %0
      "+r"(dst_argb),   // %1
      "+r"(width)       // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6"
    );
  }
  #endif  // HAS_ARGBATTENUATEROW_NEON
  
  // Quantize 8 ARGB pixels (32 bytes).
  // dst = (dst * scale >> 16) * interval_size + interval_offset;
  #ifdef HAS_ARGBQUANTIZEROW_NEON
  void ARGBQuantizeRow_NEON(uint8* dst_argb, int scale, int interval_size,
                            int interval_offset, int width) {
    asm volatile (
      "dup        v4.8h, %w2                     \n"
      "ushr       v4.8h, v4.8h, #1               \n"  // scale >>= 1
      "dup        v5.8h, %w3                     \n"  // interval multiply.
      "dup        v6.8h, %w4                     \n"  // interval add
  
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0]  \n"  // load 8 pixels of ARGB.
      "subs       %1, %1, #8                     \n"  // 8 processed per loop.
      "uxtl       v0.8h, v0.8b                   \n"  // b (0 .. 255)
      "uxtl       v1.8h, v1.8b                   \n"
      "uxtl       v2.8h, v2.8b                   \n"
      "sqdmulh    v0.8h, v0.8h, v4.8h            \n"  // b * scale
      "sqdmulh    v1.8h, v1.8h, v4.8h            \n"  // g
      "sqdmulh    v2.8h, v2.8h, v4.8h            \n"  // r
      "mul        v0.8h, v0.8h, v5.8h            \n"  // b * interval_size
      "mul        v1.8h, v1.8h, v5.8h            \n"  // g
      "mul        v2.8h, v2.8h, v5.8h            \n"  // r
      "add        v0.8h, v0.8h, v6.8h            \n"  // b + interval_offset
      "add        v1.8h, v1.8h, v6.8h            \n"  // g
      "add        v2.8h, v2.8h, v6.8h            \n"  // r
      "uqxtn      v0.8b, v0.8h                   \n"
      "uqxtn      v1.8b, v1.8h                   \n"
      "uqxtn      v2.8b, v2.8h                   \n"
      MEMACCESS(0)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(dst_argb),       // %0
      "+r"(width)           // %1
    : "r"(scale),           // %2
      "r"(interval_size),   // %3
      "r"(interval_offset)  // %4
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6"
    );
  }
  #endif  // HAS_ARGBQUANTIZEROW_NEON
  
  // Shade 8 pixels at a time by specified value.
  // NOTE vqrdmulh.s16 q10, q10, d0[0] must use a scaler register from 0 to 8.
  // Rounding in vqrdmulh does +1 to high if high bit of low s16 is set.
  #ifdef HAS_ARGBSHADEROW_NEON
  void ARGBShadeRow_NEON(const uint8* src_argb, uint8* dst_argb, int width,
                         uint32 value) {
    asm volatile (
      "dup        v0.4s, %w3                     \n"  // duplicate scale value.
      "zip1       v0.8b, v0.8b, v0.8b            \n"  // v0.8b aarrggbb.
      "ushr       v0.8h, v0.8h, #1               \n"  // scale / 2.
  
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "uxtl       v4.8h, v4.8b                   \n"  // b (0 .. 255)
      "uxtl       v5.8h, v5.8b                   \n"
      "uxtl       v6.8h, v6.8b                   \n"
      "uxtl       v7.8h, v7.8b                   \n"
      "sqrdmulh   v4.8h, v4.8h, v0.h[0]          \n"  // b * scale * 2
      "sqrdmulh   v5.8h, v5.8h, v0.h[1]          \n"  // g
      "sqrdmulh   v6.8h, v6.8h, v0.h[2]          \n"  // r
      "sqrdmulh   v7.8h, v7.8h, v0.h[3]          \n"  // a
      "uqxtn      v4.8b, v4.8h                   \n"
      "uqxtn      v5.8b, v5.8h                   \n"
      "uqxtn      v6.8b, v6.8h                   \n"
      "uqxtn      v7.8b, v7.8h                   \n"
      MEMACCESS(1)
      "st4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_argb),       // %0
      "+r"(dst_argb),       // %1
      "+r"(width)           // %2
    : "r"(value)            // %3
    : "cc", "memory", "v0", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGBSHADEROW_NEON
  
  // Convert 8 ARGB pixels (64 bytes) to 8 Gray ARGB pixels
  // Similar to ARGBToYJ but stores ARGB.
  // C code is (15 * b + 75 * g + 38 * r + 64) >> 7;
  #ifdef HAS_ARGBGRAYROW_NEON
  void ARGBGrayRow_NEON(const uint8* src_argb, uint8* dst_argb, int width) {
    asm volatile (
      "movi       v24.8b, #15                    \n"  // B * 0.11400 coefficient
      "movi       v25.8b, #75                    \n"  // G * 0.58700 coefficient
      "movi       v26.8b, #38                    \n"  // R * 0.29900 coefficient
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "umull      v4.8h, v0.8b, v24.8b           \n"  // B
      "umlal      v4.8h, v1.8b, v25.8b           \n"  // G
      "umlal      v4.8h, v2.8b, v26.8b           \n"  // R
      "sqrshrun   v0.8b, v4.8h, #7               \n"  // 15 bit to 8 bit B
      "orr        v1.8b, v0.8b, v0.8b            \n"  // G
      "orr        v2.8b, v0.8b, v0.8b            \n"  // R
      MEMACCESS(1)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"  // store 8 pixels.
      "b.gt       1b                             \n"
    : "+r"(src_argb),  // %0
      "+r"(dst_argb),  // %1
      "+r"(width)      // %2
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v24", "v25", "v26"
    );
  }
  #endif  // HAS_ARGBGRAYROW_NEON
  
  // Convert 8 ARGB pixels (32 bytes) to 8 Sepia ARGB pixels.
  //    b = (r * 35 + g * 68 + b * 17) >> 7
  //    g = (r * 45 + g * 88 + b * 22) >> 7
  //    r = (r * 50 + g * 98 + b * 24) >> 7
  
  #ifdef HAS_ARGBSEPIAROW_NEON
  void ARGBSepiaRow_NEON(uint8* dst_argb, int width) {
    asm volatile (
      "movi       v20.8b, #17                    \n"  // BB coefficient
      "movi       v21.8b, #68                    \n"  // BG coefficient
      "movi       v22.8b, #35                    \n"  // BR coefficient
      "movi       v24.8b, #22                    \n"  // GB coefficient
      "movi       v25.8b, #88                    \n"  // GG coefficient
      "movi       v26.8b, #45                    \n"  // GR coefficient
      "movi       v28.8b, #24                    \n"  // BB coefficient
      "movi       v29.8b, #98                    \n"  // BG coefficient
      "movi       v30.8b, #50                    \n"  // BR coefficient
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0] \n"  // load 8 ARGB pixels.
      "subs       %1, %1, #8                     \n"  // 8 processed per loop.
      "umull      v4.8h, v0.8b, v20.8b           \n"  // B to Sepia B
      "umlal      v4.8h, v1.8b, v21.8b           \n"  // G
      "umlal      v4.8h, v2.8b, v22.8b           \n"  // R
      "umull      v5.8h, v0.8b, v24.8b           \n"  // B to Sepia G
      "umlal      v5.8h, v1.8b, v25.8b           \n"  // G
      "umlal      v5.8h, v2.8b, v26.8b           \n"  // R
      "umull      v6.8h, v0.8b, v28.8b           \n"  // B to Sepia R
      "umlal      v6.8h, v1.8b, v29.8b           \n"  // G
      "umlal      v6.8h, v2.8b, v30.8b           \n"  // R
      "uqshrn     v0.8b, v4.8h, #7               \n"  // 16 bit to 8 bit B
      "uqshrn     v1.8b, v5.8h, #7               \n"  // 16 bit to 8 bit G
      "uqshrn     v2.8b, v6.8h, #7               \n"  // 16 bit to 8 bit R
      MEMACCESS(0)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // store 8 pixels.
      "b.gt       1b                             \n"
    : "+r"(dst_argb),  // %0
      "+r"(width)      // %1
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
      "v20", "v21", "v22", "v24", "v25", "v26", "v28", "v29", "v30"
    );
  }
  #endif  // HAS_ARGBSEPIAROW_NEON
  
  // Tranform 8 ARGB pixels (32 bytes) with color matrix.
  // TODO(fbarchard): Was same as Sepia except matrix is provided.  This function
  // needs to saturate.  Consider doing a non-saturating version.
  #ifdef HAS_ARGBCOLORMATRIXROW_NEON
  void ARGBColorMatrixRow_NEON(const uint8* src_argb, uint8* dst_argb,
                               const int8* matrix_argb, int width) {
    asm volatile (
      MEMACCESS(3)
      "ld1        {v2.16b}, [%3]                 \n"  // load 3 ARGB vectors.
      "sxtl       v0.8h, v2.8b                   \n"  // B,G coefficients s16.
      "sxtl2      v1.8h, v2.16b                  \n"  // R,A coefficients s16.
  
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v16.8b,v17.8b,v18.8b,v19.8b}, [%0], #32 \n"  // load 8 pixels.
      "subs       %2, %2, #8                     \n"  // 8 processed per loop.
      "uxtl       v16.8h, v16.8b                 \n"  // b (0 .. 255) 16 bit
      "uxtl       v17.8h, v17.8b                 \n"  // g
      "uxtl       v18.8h, v18.8b                 \n"  // r
      "uxtl       v19.8h, v19.8b                 \n"  // a
      "mul        v22.8h, v16.8h, v0.h[0]        \n"  // B = B * Matrix B
      "mul        v23.8h, v16.8h, v0.h[4]        \n"  // G = B * Matrix G
      "mul        v24.8h, v16.8h, v1.h[0]        \n"  // R = B * Matrix R
      "mul        v25.8h, v16.8h, v1.h[4]        \n"  // A = B * Matrix A
      "mul        v4.8h, v17.8h, v0.h[1]         \n"  // B += G * Matrix B
      "mul        v5.8h, v17.8h, v0.h[5]         \n"  // G += G * Matrix G
      "mul        v6.8h, v17.8h, v1.h[1]         \n"  // R += G * Matrix R
      "mul        v7.8h, v17.8h, v1.h[5]         \n"  // A += G * Matrix A
      "sqadd      v22.8h, v22.8h, v4.8h          \n"  // Accumulate B
      "sqadd      v23.8h, v23.8h, v5.8h          \n"  // Accumulate G
      "sqadd      v24.8h, v24.8h, v6.8h          \n"  // Accumulate R
      "sqadd      v25.8h, v25.8h, v7.8h          \n"  // Accumulate A
      "mul        v4.8h, v18.8h, v0.h[2]         \n"  // B += R * Matrix B
      "mul        v5.8h, v18.8h, v0.h[6]         \n"  // G += R * Matrix G
      "mul        v6.8h, v18.8h, v1.h[2]         \n"  // R += R * Matrix R
      "mul        v7.8h, v18.8h, v1.h[6]         \n"  // A += R * Matrix A
      "sqadd      v22.8h, v22.8h, v4.8h          \n"  // Accumulate B
      "sqadd      v23.8h, v23.8h, v5.8h          \n"  // Accumulate G
      "sqadd      v24.8h, v24.8h, v6.8h          \n"  // Accumulate R
      "sqadd      v25.8h, v25.8h, v7.8h          \n"  // Accumulate A
      "mul        v4.8h, v19.8h, v0.h[3]         \n"  // B += A * Matrix B
      "mul        v5.8h, v19.8h, v0.h[7]         \n"  // G += A * Matrix G
      "mul        v6.8h, v19.8h, v1.h[3]         \n"  // R += A * Matrix R
      "mul        v7.8h, v19.8h, v1.h[7]         \n"  // A += A * Matrix A
      "sqadd      v22.8h, v22.8h, v4.8h          \n"  // Accumulate B
      "sqadd      v23.8h, v23.8h, v5.8h          \n"  // Accumulate G
      "sqadd      v24.8h, v24.8h, v6.8h          \n"  // Accumulate R
      "sqadd      v25.8h, v25.8h, v7.8h          \n"  // Accumulate A
      "sqshrun    v16.8b, v22.8h, #6             \n"  // 16 bit to 8 bit B
      "sqshrun    v17.8b, v23.8h, #6             \n"  // 16 bit to 8 bit G
      "sqshrun    v18.8b, v24.8h, #6             \n"  // 16 bit to 8 bit R
      "sqshrun    v19.8b, v25.8h, #6             \n"  // 16 bit to 8 bit A
      MEMACCESS(1)
      "st4        {v16.8b,v17.8b,v18.8b,v19.8b}, [%1], #32 \n"  // store 8 pixels.
      "b.gt       1b                             \n"
    : "+r"(src_argb),   // %0
      "+r"(dst_argb),   // %1
      "+r"(width)       // %2
    : "r"(matrix_argb)  // %3
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16", "v17",
      "v18", "v19", "v22", "v23", "v24", "v25"
    );
  }
  #endif  // HAS_ARGBCOLORMATRIXROW_NEON
  
  // TODO(fbarchard): fix vqshrun in ARGBMultiplyRow_NEON and reenable.
  // Multiply 2 rows of ARGB pixels together, 8 pixels at a time.
  #ifdef HAS_ARGBMULTIPLYROW_NEON
  void ARGBMultiplyRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
                            uint8* dst_argb, int width) {
    asm volatile (
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load 8 more pixels.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "umull      v0.8h, v0.8b, v4.8b            \n"  // multiply B
      "umull      v1.8h, v1.8b, v5.8b            \n"  // multiply G
      "umull      v2.8h, v2.8b, v6.8b            \n"  // multiply R
      "umull      v3.8h, v3.8b, v7.8b            \n"  // multiply A
      "rshrn      v0.8b, v0.8h, #8               \n"  // 16 bit to 8 bit B
      "rshrn      v1.8b, v1.8h, #8               \n"  // 16 bit to 8 bit G
      "rshrn      v2.8b, v2.8h, #8               \n"  // 16 bit to 8 bit R
      "rshrn      v3.8b, v3.8h, #8               \n"  // 16 bit to 8 bit A
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
  
    : "+r"(src_argb0),  // %0
      "+r"(src_argb1),  // %1
      "+r"(dst_argb),   // %2
      "+r"(width)       // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGBMULTIPLYROW_NEON
  
  // Add 2 rows of ARGB pixels together, 8 pixels at a time.
  #ifdef HAS_ARGBADDROW_NEON
  void ARGBAddRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
                       uint8* dst_argb, int width) {
    asm volatile (
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load 8 more pixels.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "uqadd      v0.8b, v0.8b, v4.8b            \n"
      "uqadd      v1.8b, v1.8b, v5.8b            \n"
      "uqadd      v2.8b, v2.8b, v6.8b            \n"
      "uqadd      v3.8b, v3.8b, v7.8b            \n"
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
  
    : "+r"(src_argb0),  // %0
      "+r"(src_argb1),  // %1
      "+r"(dst_argb),   // %2
      "+r"(width)       // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGBADDROW_NEON
  
  // Subtract 2 rows of ARGB pixels, 8 pixels at a time.
  #ifdef HAS_ARGBSUBTRACTROW_NEON
  void ARGBSubtractRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
                            uint8* dst_argb, int width) {
    asm volatile (
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"  // load 8 ARGB pixels.
      MEMACCESS(1)
      "ld4        {v4.8b,v5.8b,v6.8b,v7.8b}, [%1], #32 \n"  // load 8 more pixels.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "uqsub      v0.8b, v0.8b, v4.8b            \n"
      "uqsub      v1.8b, v1.8b, v5.8b            \n"
      "uqsub      v2.8b, v2.8b, v6.8b            \n"
      "uqsub      v3.8b, v3.8b, v7.8b            \n"
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
  
    : "+r"(src_argb0),  // %0
      "+r"(src_argb1),  // %1
      "+r"(dst_argb),   // %2
      "+r"(width)       // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7"
    );
  }
  #endif  // HAS_ARGBSUBTRACTROW_NEON
  
  // Adds Sobel X and Sobel Y and stores Sobel into ARGB.
  // A = 255
  // R = Sobel
  // G = Sobel
  // B = Sobel
  #ifdef HAS_SOBELROW_NEON
  void SobelRow_NEON(const uint8* src_sobelx, const uint8* src_sobely,
                       uint8* dst_argb, int width) {
    asm volatile (
      "movi       v3.8b, #255                    \n"  // alpha
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.8b}, [%0], #8              \n"  // load 8 sobelx.
      MEMACCESS(1)
      "ld1        {v1.8b}, [%1], #8              \n"  // load 8 sobely.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "uqadd      v0.8b, v0.8b, v1.8b            \n"  // add
      "orr        v1.8b, v0.8b, v0.8b            \n"
      "orr        v2.8b, v0.8b, v0.8b            \n"
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_sobelx),  // %0
      "+r"(src_sobely),  // %1
      "+r"(dst_argb),    // %2
      "+r"(width)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"
    );
  }
  #endif  // HAS_SOBELROW_NEON
  
  // Adds Sobel X and Sobel Y and stores Sobel into plane.
  #ifdef HAS_SOBELTOPLANEROW_NEON
  void SobelToPlaneRow_NEON(const uint8* src_sobelx, const uint8* src_sobely,
                            uint8* dst_y, int width) {
    asm volatile (
      // 16 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.16b}, [%0], #16            \n"  // load 16 sobelx.
      MEMACCESS(1)
      "ld1        {v1.16b}, [%1], #16            \n"  // load 16 sobely.
      "subs       %3, %3, #16                    \n"  // 16 processed per loop.
      "uqadd      v0.16b, v0.16b, v1.16b         \n"  // add
      MEMACCESS(2)
      "st1        {v0.16b}, [%2], #16            \n"  // store 16 pixels.
      "b.gt       1b                             \n"
    : "+r"(src_sobelx),  // %0
      "+r"(src_sobely),  // %1
      "+r"(dst_y),       // %2
      "+r"(width)        // %3
    :
    : "cc", "memory", "v0", "v1"
    );
  }
  #endif  // HAS_SOBELTOPLANEROW_NEON
  
  // Mixes Sobel X, Sobel Y and Sobel into ARGB.
  // A = 255
  // R = Sobel X
  // G = Sobel
  // B = Sobel Y
  #ifdef HAS_SOBELXYROW_NEON
  void SobelXYRow_NEON(const uint8* src_sobelx, const uint8* src_sobely,
                       uint8* dst_argb, int width) {
    asm volatile (
      "movi       v3.8b, #255                    \n"  // alpha
      // 8 pixel loop.
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v2.8b}, [%0], #8              \n"  // load 8 sobelx.
      MEMACCESS(1)
      "ld1        {v0.8b}, [%1], #8              \n"  // load 8 sobely.
      "subs       %3, %3, #8                     \n"  // 8 processed per loop.
      "uqadd      v1.8b, v0.8b, v2.8b            \n"  // add
      MEMACCESS(2)
      "st4        {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"  // store 8 ARGB pixels
      "b.gt       1b                             \n"
    : "+r"(src_sobelx),  // %0
      "+r"(src_sobely),  // %1
      "+r"(dst_argb),    // %2
      "+r"(width)        // %3
    :
    : "cc", "memory", "v0", "v1", "v2", "v3"
    );
  }
  #endif  // HAS_SOBELXYROW_NEON
  
  // SobelX as a matrix is
  // -1  0  1
  // -2  0  2
  // -1  0  1
  #ifdef HAS_SOBELXROW_NEON
  void SobelXRow_NEON(const uint8* src_y0, const uint8* src_y1,
                      const uint8* src_y2, uint8* dst_sobelx, int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.8b}, [%0],%5               \n"  // top
      MEMACCESS(0)
      "ld1        {v1.8b}, [%0],%6               \n"
      "usubl      v0.8h, v0.8b, v1.8b            \n"
      MEMACCESS(1)
      "ld1        {v2.8b}, [%1],%5               \n"  // center * 2
      MEMACCESS(1)
      "ld1        {v3.8b}, [%1],%6               \n"
      "usubl      v1.8h, v2.8b, v3.8b            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      MEMACCESS(2)
      "ld1        {v2.8b}, [%2],%5               \n"  // bottom
      MEMACCESS(2)
      "ld1        {v3.8b}, [%2],%6               \n"
      "subs       %4, %4, #8                     \n"  // 8 pixels
      "usubl      v1.8h, v2.8b, v3.8b            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      "abs        v0.8h, v0.8h                   \n"
      "uqxtn      v0.8b, v0.8h                   \n"
      MEMACCESS(3)
      "st1        {v0.8b}, [%3], #8              \n"  // store 8 sobelx
      "b.gt       1b                             \n"
    : "+r"(src_y0),      // %0
      "+r"(src_y1),      // %1
      "+r"(src_y2),      // %2
      "+r"(dst_sobelx),  // %3
      "+r"(width)        // %4
    : "r"(2),            // %5
      "r"(6)             // %6
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_SOBELXROW_NEON
  
  // SobelY as a matrix is
  // -1 -2 -1
  //  0  0  0
  //  1  2  1
  #ifdef HAS_SOBELYROW_NEON
  void SobelYRow_NEON(const uint8* src_y0, const uint8* src_y1,
                      uint8* dst_sobely, int width) {
    asm volatile (
    "1:                                          \n"
      MEMACCESS(0)
      "ld1        {v0.8b}, [%0],%4               \n"  // left
      MEMACCESS(1)
      "ld1        {v1.8b}, [%1],%4               \n"
      "usubl      v0.8h, v0.8b, v1.8b            \n"
      MEMACCESS(0)
      "ld1        {v2.8b}, [%0],%4               \n"  // center * 2
      MEMACCESS(1)
      "ld1        {v3.8b}, [%1],%4               \n"
      "usubl      v1.8h, v2.8b, v3.8b            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      MEMACCESS(0)
      "ld1        {v2.8b}, [%0],%5               \n"  // right
      MEMACCESS(1)
      "ld1        {v3.8b}, [%1],%5               \n"
      "subs       %3, %3, #8                     \n"  // 8 pixels
      "usubl      v1.8h, v2.8b, v3.8b            \n"
      "add        v0.8h, v0.8h, v1.8h            \n"
      "abs        v0.8h, v0.8h                   \n"
      "uqxtn      v0.8b, v0.8h                   \n"
      MEMACCESS(2)
      "st1        {v0.8b}, [%2], #8              \n"  // store 8 sobely
      "b.gt       1b                             \n"
    : "+r"(src_y0),      // %0
      "+r"(src_y1),      // %1
      "+r"(dst_sobely),  // %2
      "+r"(width)        // %3
    : "r"(1),            // %4
      "r"(6)             // %5
    : "cc", "memory", "v0", "v1", "v2", "v3"  // Clobber List
    );
  }
  #endif  // HAS_SOBELYROW_NEON
  #endif  // !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
  
  #ifdef __cplusplus
  }  // extern "C"
  }  // namespace libyuv
  #endif
  