ARM64: Avoid LD3/ST3 at run time, not compile time

... and only if ThunderX is detected.  This can be easily expanded later
on to include other CPUs that are known to suffer from slow LD3/ST3, but
it doesn't make sense to disable LD3/ST3 for all non-Android Linux
platforms just because ThunderX is slow.

diff --git a/simd/jsimd.h b/simd/jsimd.h
index 1c598f0528792448a9257ce944f478788c5e3834..a312930f57e3eb770a5dd324b6f4089b89b7d11a 100644 (file)
--- a/simd/jsimd.h
+++ b/simd/jsimd.h
@@ -95,6 +95,13 @@ EXTERN(void) jsimd_extxrgb_ycc_convert_neon
         (JDIMENSION img_width, JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
          JDIMENSION output_row, int num_rows);
 
+EXTERN(void) jsimd_extrgb_ycc_convert_neon_slowld3
+        (JDIMENSION img_width, JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+         JDIMENSION output_row, int num_rows);
+EXTERN(void) jsimd_extbgr_ycc_convert_neon_slowld3
+        (JDIMENSION img_width, JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+         JDIMENSION output_row, int num_rows);
+
 EXTERN(void) jsimd_rgb_ycc_convert_mips_dspr2
         (JDIMENSION img_width, JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
          JDIMENSION output_row, int num_rows);
@@ -300,6 +307,13 @@ EXTERN(void) jsimd_ycc_rgb565_convert_neon
         (JDIMENSION out_width, JSAMPIMAGE input_buf, JDIMENSION input_row,
          JSAMPARRAY output_buf, int num_rows);
 
+EXTERN(void) jsimd_ycc_extrgb_convert_neon_slowst3
+        (JDIMENSION out_width, JSAMPIMAGE input_buf, JDIMENSION input_row,
+         JSAMPARRAY output_buf, int num_rows);
+EXTERN(void) jsimd_ycc_extbgr_convert_neon_slowst3
+        (JDIMENSION out_width, JSAMPIMAGE input_buf, JDIMENSION input_row,
+         JSAMPARRAY output_buf, int num_rows);
+
 EXTERN(void) jsimd_ycc_rgb_convert_mips_dspr2
         (JDIMENSION out_width, JSAMPIMAGE input_buf, JDIMENSION input_row,
          JSAMPARRAY output_buf, int num_rows);

diff --git a/simd/jsimd_arm64.c b/simd/jsimd_arm64.c
index 583a62b30ae748adb295335f981dea45e015540a..8633162211207855f8083adb97765bc77241f504 100644 (file)
--- a/simd/jsimd_arm64.c
+++ b/simd/jsimd_arm64.c
@@ -26,8 +26,12 @@
 #include <string.h>
 #include <ctype.h>
 
+#define JSIMD_FASTLD3 1
+#define JSIMD_FASTST3 2
+
 static unsigned int simd_support = ~0;
 static unsigned int simd_huffman = 1;
+static unsigned int simd_features = JSIMD_FASTLD3 | JSIMD_FASTST3;
 
 #if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
 
@@ -81,8 +85,9 @@ parse_proc_cpuinfo (int bufsize)
       }
       if (check_cpuinfo(buffer, "CPU part", "0x0a1"))
         /* The SIMD version of Huffman encoding is slower than the C version on
-           Cavium ThunderX. */
-        simd_huffman = 0;
+           Cavium ThunderX.  Also, ld3 and st3 are abyssmally slow on that
+           CPU. */
+        simd_huffman = simd_features = 0;
     }
     fclose(fd);
   }
@@ -136,6 +141,16 @@ init_simd (void)
   env = getenv("JSIMD_NOHUFFENC");
   if ((env != NULL) && (strcmp(env, "1") == 0))
     simd_huffman = 0;
+  env = getenv("JSIMD_FASTLD3");
+  if ((env != NULL) && (strcmp(env, "1") == 0))
+    simd_features |= JSIMD_FASTLD3;
+  if ((env != NULL) && (strcmp(env, "0") == 0))
+    simd_features &= ~JSIMD_FASTLD3;
+  env = getenv("JSIMD_FASTST3");
+  if ((env != NULL) && (strcmp(env, "1") == 0))
+    simd_features |= JSIMD_FASTST3;
+  if ((env != NULL) && (strcmp(env, "0") == 0))
+    simd_features &= ~JSIMD_FASTST3;
 }
 
 GLOBAL(int)
@@ -210,14 +225,20 @@ jsimd_rgb_ycc_convert (j_compress_ptr cinfo,
 
   switch(cinfo->in_color_space) {
     case JCS_EXT_RGB:
-      neonfct=jsimd_extrgb_ycc_convert_neon;
+      if (simd_features & JSIMD_FASTLD3)
+        neonfct=jsimd_extrgb_ycc_convert_neon;
+      else
+        neonfct=jsimd_extrgb_ycc_convert_neon_slowld3;
       break;
     case JCS_EXT_RGBX:
     case JCS_EXT_RGBA:
       neonfct=jsimd_extrgbx_ycc_convert_neon;
       break;
     case JCS_EXT_BGR:
-      neonfct=jsimd_extbgr_ycc_convert_neon;
+      if (simd_features & JSIMD_FASTLD3)
+        neonfct=jsimd_extbgr_ycc_convert_neon;
+      else
+        neonfct=jsimd_extbgr_ycc_convert_neon_slowld3;
       break;
     case JCS_EXT_BGRX:
     case JCS_EXT_BGRA:
@@ -232,7 +253,10 @@ jsimd_rgb_ycc_convert (j_compress_ptr cinfo,
       neonfct=jsimd_extxrgb_ycc_convert_neon;
       break;
     default:
-      neonfct=jsimd_extrgb_ycc_convert_neon;
+      if (simd_features & JSIMD_FASTLD3)
+        neonfct=jsimd_extrgb_ycc_convert_neon;
+      else
+        neonfct=jsimd_extrgb_ycc_convert_neon_slowld3;
       break;
   }
 
@@ -255,14 +279,20 @@ jsimd_ycc_rgb_convert (j_decompress_ptr cinfo,
 
   switch(cinfo->out_color_space) {
     case JCS_EXT_RGB:
-      neonfct=jsimd_ycc_extrgb_convert_neon;
+      if (simd_features & JSIMD_FASTST3)
+        neonfct=jsimd_ycc_extrgb_convert_neon;
+      else
+        neonfct=jsimd_ycc_extrgb_convert_neon_slowst3;
       break;
     case JCS_EXT_RGBX:
     case JCS_EXT_RGBA:
       neonfct=jsimd_ycc_extrgbx_convert_neon;
       break;
     case JCS_EXT_BGR:
-      neonfct=jsimd_ycc_extbgr_convert_neon;
+      if (simd_features & JSIMD_FASTST3)
+        neonfct=jsimd_ycc_extbgr_convert_neon;
+      else
+        neonfct=jsimd_ycc_extbgr_convert_neon_slowst3;
       break;
     case JCS_EXT_BGRX:
     case JCS_EXT_BGRA:
@@ -277,7 +307,10 @@ jsimd_ycc_rgb_convert (j_decompress_ptr cinfo,
       neonfct=jsimd_ycc_extxrgb_convert_neon;
       break;
     default:
-      neonfct=jsimd_ycc_extrgb_convert_neon;
+      if (simd_features & JSIMD_FASTST3)
+        neonfct=jsimd_ycc_extrgb_convert_neon;
+      else
+        neonfct=jsimd_ycc_extrgb_convert_neon_slowst3;
       break;
   }
 

diff --git a/simd/jsimd_arm64_neon.S b/simd/jsimd_arm64_neon.S
index c1998ba7d4d8569678ba5f5fc5c13b966e6aaeae..3f003ce4fbe87091e89071f0991d5d3344e97830 100644 (file)
--- a/simd/jsimd_arm64_neon.S
+++ b/simd/jsimd_arm64_neon.S
@@ -1445,12 +1445,6 @@ asm_function jsimd_idct_2x2_neon
  * Colorspace conversion YCbCr -> RGB
  */
 
-#if defined(__APPLE__) || defined(__ANDROID__)
-/* TODO: expand this to include other devices that are known not to have a slow
- *       st3 implementation. */
-#define ST3_IS_FAST
-#endif
-
 .macro do_load size
   .if \size == 8
     ld1             {v4.8b}, [U], 8
@@ -1488,44 +1482,44 @@ asm_function jsimd_idct_2x2_neon
   .endif
 .endm
 
-.macro do_store bpp, size
+.macro do_store bpp, size, fast_st3
   .if \bpp == 24
     .if \size == 8
-#ifdef ST3_IS_FAST
-      st3           {v10.8b, v11.8b, v12.8b}, [RGB], 24
-#else
-      st1           {v10.b}[0], [RGB], #1
-      st1           {v11.b}[0], [RGB], #1
-      st1           {v12.b}[0], [RGB], #1
-
-      st1           {v10.b}[1], [RGB], #1
-      st1           {v11.b}[1], [RGB], #1
-      st1           {v12.b}[1], [RGB], #1
-
-      st1           {v10.b}[2], [RGB], #1
-      st1           {v11.b}[2], [RGB], #1
-      st1           {v12.b}[2], [RGB], #1
-
-      st1           {v10.b}[3], [RGB], #1
-      st1           {v11.b}[3], [RGB], #1
-      st1           {v12.b}[3], [RGB], #1
-
-      st1           {v10.b}[4], [RGB], #1
-      st1           {v11.b}[4], [RGB], #1
-      st1           {v12.b}[4], [RGB], #1
-
-      st1           {v10.b}[5], [RGB], #1
-      st1           {v11.b}[5], [RGB], #1
-      st1           {v12.b}[5], [RGB], #1
-
-      st1           {v10.b}[6], [RGB], #1
-      st1           {v11.b}[6], [RGB], #1
-      st1           {v12.b}[6], [RGB], #1
-
-      st1           {v10.b}[7], [RGB], #1
-      st1           {v11.b}[7], [RGB], #1
-      st1           {v12.b}[7], [RGB], #1
-#endif
+      .if \fast_st3 == 1
+        st3         {v10.8b, v11.8b, v12.8b}, [RGB], 24
+      .else
+        st1         {v10.b}[0], [RGB], #1
+        st1         {v11.b}[0], [RGB], #1
+        st1         {v12.b}[0], [RGB], #1
+
+        st1         {v10.b}[1], [RGB], #1
+        st1         {v11.b}[1], [RGB], #1
+        st1         {v12.b}[1], [RGB], #1
+
+        st1         {v10.b}[2], [RGB], #1
+        st1         {v11.b}[2], [RGB], #1
+        st1         {v12.b}[2], [RGB], #1
+
+        st1         {v10.b}[3], [RGB], #1
+        st1         {v11.b}[3], [RGB], #1
+        st1         {v12.b}[3], [RGB], #1
+
+        st1         {v10.b}[4], [RGB], #1
+        st1         {v11.b}[4], [RGB], #1
+        st1         {v12.b}[4], [RGB], #1
+
+        st1         {v10.b}[5], [RGB], #1
+        st1         {v11.b}[5], [RGB], #1
+        st1         {v12.b}[5], [RGB], #1
+
+        st1         {v10.b}[6], [RGB], #1
+        st1         {v11.b}[6], [RGB], #1
+        st1         {v12.b}[6], [RGB], #1
+
+        st1         {v10.b}[7], [RGB], #1
+        st1         {v11.b}[7], [RGB], #1
+        st1         {v12.b}[7], [RGB], #1
+      .endif
     .elseif \size == 4
       st3           {v10.b, v11.b, v12.b}[0], [RGB], 3
       st3           {v10.b, v11.b, v12.b}[1], [RGB], 3
@@ -1573,7 +1567,9 @@ asm_function jsimd_idct_2x2_neon
   .endif
 .endm
 
-.macro generate_jsimd_ycc_rgb_convert_neon colorid, bpp, r_offs, rsize, g_offs, gsize, b_offs, bsize, defsize
+.macro generate_jsimd_ycc_rgb_convert_neon colorid, bpp, r_offs, rsize, \
+                                           g_offs, gsize, b_offs, bsize, \
+                                           defsize, fast_st3 = 1
 
 /*
  * 2-stage pipelined YCbCr->RGB conversion
@@ -1615,7 +1611,7 @@ asm_function jsimd_idct_2x2_neon
   .endif
 .endm
 
-.macro do_yuv_to_rgb_stage2_store_load_stage1
+.macro do_yuv_to_rgb_stage2_store_load_stage1 fast_st3
     rshrn           v20.4h, v20.4s, #15
     rshrn           v24.4h, v24.4s, #14
     rshrn           v28.4h, v28.4s, #14
@@ -1662,7 +1658,7 @@ asm_function jsimd_idct_2x2_neon
     prfm            pldl1keep, [Y, #64]
     sri             v25.8h, v29.8h, #11
   .endif
-    do_store        \bpp, 8
+    do_store        \bpp, 8, \fast_st3
     smull           v28.4s, v6.4h, v1.h[3]  /* multiply by 29033 */
     smull2          v30.4s, v6.8h, v1.h[3]  /* multiply by 29033 */
 .endm
@@ -1677,13 +1673,21 @@ asm_function jsimd_idct_2x2_neon
  */
 
 .balign 16
+.if \fast_st3 == 1
 Ljsimd_ycc_\colorid\()_neon_consts:
+.else
+Ljsimd_ycc_\colorid\()_neon_slowst3_consts:
+.endif
   .short 0,      0,     0,      0
   .short 22971, -11277, -23401, 29033
   .short -128,  -128,   -128,   -128
   .short -128,  -128,   -128,   -128
 
+.if \fast_st3 == 1
 asm_function jsimd_ycc_\colorid\()_convert_neon
+.else
+asm_function jsimd_ycc_\colorid\()_convert_neon_slowst3
+.endif
     OUTPUT_WIDTH    .req x0
     INPUT_BUF       .req x1
     INPUT_ROW       .req x2
@@ -1753,12 +1757,12 @@ asm_function jsimd_ycc_\colorid\()_convert_neon
     subs            N, N, #8
     b.lt            2f
 1:
-    do_yuv_to_rgb_stage2_store_load_stage1
+    do_yuv_to_rgb_stage2_store_load_stage1 \fast_st3
     subs            N, N, #8
     b.ge            1b
 2:
     do_yuv_to_rgb_stage2
-    do_store        \bpp, 8
+    do_store        \bpp, 8, \fast_st3
     tst             N, #7
     b.eq            8f
 3:
@@ -1777,15 +1781,15 @@ asm_function jsimd_ycc_\colorid\()_convert_neon
     do_yuv_to_rgb
     tst             N, #4
     b.eq            6f
-    do_store        \bpp, 4
+    do_store        \bpp, 4, \fast_st3
 6:
     tst             N, #2
     b.eq            7f
-    do_store        \bpp, 2
+    do_store        \bpp, 2, \fast_st3
 7:
     tst             N, #1
     b.eq            8f
-    do_store        \bpp, 1
+    do_store        \bpp, 1, \fast_st3
 8:
     subs            NUM_ROWS, NUM_ROWS, #1
     b.gt            0b
@@ -1827,7 +1831,7 @@ asm_function jsimd_ycc_\colorid\()_convert_neon
 
 .endm
 
-/*--------------------------------- id ----- bpp R  rsize G  gsize B  bsize defsize */
+/*--------------------------------- id ----- bpp R  rsize G  gsize B  bsize defsize fast_st3*/
 generate_jsimd_ycc_rgb_convert_neon extrgb,  24, 0, .4h,  1, .4h,  2, .4h,  .8b
 generate_jsimd_ycc_rgb_convert_neon extbgr,  24, 2, .4h,  1, .4h,  0, .4h,  .8b
 generate_jsimd_ycc_rgb_convert_neon extrgbx, 32, 0, .4h,  1, .4h,  2, .4h,  .8b
@@ -1836,6 +1840,9 @@ generate_jsimd_ycc_rgb_convert_neon extxbgr, 32, 3, .4h,  2, .4h,  1, .4h,  .8b
 generate_jsimd_ycc_rgb_convert_neon extxrgb, 32, 1, .4h,  2, .4h,  3, .4h,  .8b
 generate_jsimd_ycc_rgb_convert_neon rgb565,  16, 0, .4h,  0, .4h,  0, .4h,  .8b
 
+generate_jsimd_ycc_rgb_convert_neon extrgb,  24, 0, .4h,  1, .4h,  2, .4h,  .8b,    0
+generate_jsimd_ycc_rgb_convert_neon extbgr,  24, 2, .4h,  1, .4h,  0, .4h,  .8b,    0
+
 .purgem do_load
 .purgem do_store
 
@@ -1887,50 +1894,44 @@ generate_jsimd_ycc_rgb_convert_neon rgb565,  16, 0, .4h,  0, .4h,  0, .4h,  .8b
   .endif
 .endm
 
-#if defined(__APPLE__) || defined(__ANDROID__)
-/* TODO: expand this to include other devices that are known not to have a slow
- *       ld3 implementation. */
-#define LD3_IS_FAST
-#endif
-
-.macro do_load bpp, size
+.macro do_load bpp, size, fast_ld3
   .if \bpp == 24
     .if \size == 8
-#ifdef LD3_IS_FAST
-      ld3           {v10.8b, v11.8b, v12.8b}, [RGB], #24
-#else
-      ld1           {v10.b}[0], [RGB], #1
-      ld1           {v11.b}[0], [RGB], #1
-      ld1           {v12.b}[0], [RGB], #1
-
-      ld1           {v10.b}[1], [RGB], #1
-      ld1           {v11.b}[1], [RGB], #1
-      ld1           {v12.b}[1], [RGB], #1
-
-      ld1           {v10.b}[2], [RGB], #1
-      ld1           {v11.b}[2], [RGB], #1
-      ld1           {v12.b}[2], [RGB], #1
-
-      ld1           {v10.b}[3], [RGB], #1
-      ld1           {v11.b}[3], [RGB], #1
-      ld1           {v12.b}[3], [RGB], #1
-
-      ld1           {v10.b}[4], [RGB], #1
-      ld1           {v11.b}[4], [RGB], #1
-      ld1           {v12.b}[4], [RGB], #1
-
-      ld1           {v10.b}[5], [RGB], #1
-      ld1           {v11.b}[5], [RGB], #1
-      ld1           {v12.b}[5], [RGB], #1
-
-      ld1           {v10.b}[6], [RGB], #1
-      ld1           {v11.b}[6], [RGB], #1
-      ld1           {v12.b}[6], [RGB], #1
-
-      ld1           {v10.b}[7], [RGB], #1
-      ld1           {v11.b}[7], [RGB], #1
-      ld1           {v12.b}[7], [RGB], #1
-#endif
+      .if \fast_ld3 == 1
+        ld3         {v10.8b, v11.8b, v12.8b}, [RGB], #24
+      .else
+        ld1         {v10.b}[0], [RGB], #1
+        ld1         {v11.b}[0], [RGB], #1
+        ld1         {v12.b}[0], [RGB], #1
+
+        ld1         {v10.b}[1], [RGB], #1
+        ld1         {v11.b}[1], [RGB], #1
+        ld1         {v12.b}[1], [RGB], #1
+
+        ld1         {v10.b}[2], [RGB], #1
+        ld1         {v11.b}[2], [RGB], #1
+        ld1         {v12.b}[2], [RGB], #1
+
+        ld1         {v10.b}[3], [RGB], #1
+        ld1         {v11.b}[3], [RGB], #1
+        ld1         {v12.b}[3], [RGB], #1
+
+        ld1         {v10.b}[4], [RGB], #1
+        ld1         {v11.b}[4], [RGB], #1
+        ld1         {v12.b}[4], [RGB], #1
+
+        ld1         {v10.b}[5], [RGB], #1
+        ld1         {v11.b}[5], [RGB], #1
+        ld1         {v12.b}[5], [RGB], #1
+
+        ld1         {v10.b}[6], [RGB], #1
+        ld1         {v11.b}[6], [RGB], #1
+        ld1         {v12.b}[6], [RGB], #1
+
+        ld1         {v10.b}[7], [RGB], #1
+        ld1         {v11.b}[7], [RGB], #1
+        ld1         {v12.b}[7], [RGB], #1
+      .endif
       prfm          pldl1keep, [RGB, #128]
     .elseif \size == 4
       ld3           {v10.b, v11.b, v12.b}[0], [RGB], #3
@@ -1967,7 +1968,8 @@ generate_jsimd_ycc_rgb_convert_neon rgb565,  16, 0, .4h,  0, .4h,  0, .4h,  .8b
   .endif
 .endm
 
-.macro generate_jsimd_rgb_ycc_convert_neon colorid, bpp, r_offs, g_offs, b_offs
+.macro generate_jsimd_rgb_ycc_convert_neon colorid, bpp, r_offs, g_offs, \
+                                           b_offs, fast_ld3 = 1
 
 /*
  * 2-stage pipelined RGB->YCbCr conversion
@@ -2020,9 +2022,9 @@ generate_jsimd_ycc_rgb_convert_neon rgb565,  16, 0, .4h,  0, .4h,  0, .4h,  .8b
 
 /* TODO: expand macros and interleave instructions if some in-order
  *       ARM64 processor actually can dual-issue LOAD/STORE with ALU */
-.macro do_rgb_to_yuv_stage2_store_load_stage1
+.macro do_rgb_to_yuv_stage2_store_load_stage1 fast_ld3
     do_rgb_to_yuv_stage2
-    do_load         \bpp, 8
+    do_load         \bpp, 8, \fast_ld3
     st1             {v20.8b}, [Y], #8
     st1             {v21.8b}, [U], #8
     st1             {v22.8b}, [V], #8
@@ -2030,13 +2032,21 @@ generate_jsimd_ycc_rgb_convert_neon rgb565,  16, 0, .4h,  0, .4h,  0, .4h,  .8b
 .endm
 
 .balign 16
+.if \fast_ld3 == 1
 Ljsimd_\colorid\()_ycc_neon_consts:
+.else
+Ljsimd_\colorid\()_ycc_neon_slowld3_consts:
+.endif
   .short 19595, 38470, 7471, 11059
   .short 21709, 32768, 27439, 5329
   .short 32767, 128, 32767, 128
   .short 32767, 128, 32767, 128
 
+.if \fast_ld3 == 1
 asm_function jsimd_\colorid\()_ycc_convert_neon
+.else
+asm_function jsimd_\colorid\()_ycc_convert_neon_slowld3
+.endif
     OUTPUT_WIDTH    .req w0
     INPUT_BUF       .req x1
     OUTPUT_BUF      .req x2
@@ -2081,12 +2091,12 @@ asm_function jsimd_\colorid\()_ycc_convert_neon
     /* Inner loop over pixels */
     subs            N, N, #8
     b.lt            3f
-    do_load         \bpp, 8
+    do_load         \bpp, 8, \fast_ld3
     do_rgb_to_yuv_stage1
     subs            N, N, #8
     b.lt            2f
 1:
-    do_rgb_to_yuv_stage2_store_load_stage1
+    do_rgb_to_yuv_stage2_store_load_stage1 \fast_ld3
     subs            N, N, #8
     b.ge            1b
 2:
@@ -2096,13 +2106,13 @@ asm_function jsimd_\colorid\()_ycc_convert_neon
     b.eq            8f
 3:
     tbz             N, #2, 3f
-    do_load         \bpp, 4
+    do_load         \bpp, 4, \fast_ld3
 3:
     tbz             N, #1, 4f
-    do_load         \bpp, 2
+    do_load         \bpp, 2, \fast_ld3
 4:
     tbz             N, #0, 5f
-    do_load         \bpp, 1
+    do_load         \bpp, 1, \fast_ld3
 5:
     do_rgb_to_yuv
     tbz             N, #2, 6f
@@ -2143,7 +2153,7 @@ asm_function jsimd_\colorid\()_ycc_convert_neon
 
 .endm
 
-/*--------------------------------- id ----- bpp R  G  B */
+/*--------------------------------- id ----- bpp R  G  B  Fast LD3 */
 generate_jsimd_rgb_ycc_convert_neon extrgb,  24, 0, 1, 2
 generate_jsimd_rgb_ycc_convert_neon extbgr,  24, 2, 1, 0
 generate_jsimd_rgb_ycc_convert_neon extrgbx, 32, 0, 1, 2
@@ -2151,6 +2161,9 @@ generate_jsimd_rgb_ycc_convert_neon extbgrx, 32, 2, 1, 0
 generate_jsimd_rgb_ycc_convert_neon extxbgr, 32, 3, 2, 1
 generate_jsimd_rgb_ycc_convert_neon extxrgb, 32, 1, 2, 3
 
+generate_jsimd_rgb_ycc_convert_neon extrgb,  24, 0, 1, 2, 0
+generate_jsimd_rgb_ycc_convert_neon extbgr,  24, 2, 1, 0, 0
+
 .purgem do_load
 .purgem do_store