ARM Skia NEON patches - 40 - arm64: S32A_D565_Opaque

Here are some perf results:

+-------+------------+------------+
| count | Cortex-A53 | Cortex-A57 |
+-------+------------+------------+
|     1 |     -2.54% |     -5.39% |
+-------+------------+------------+
|     2 |     -0.66% |     -2.08% |
+-------+------------+------------+
|     4 |    -11.13% |      0.00% |
+-------+------------+------------+
|     8 |     -5.79% |     -1.30% |
+-------+------------+------------+
|    16 |     71.60% |     93.27% |
+-------+------------+------------+
|    64 |     30.99% |     57.35% |
+-------+------------+------------+
|   256 |     25.41% |     52.59% |
+-------+------------+------------+
|  1024 |     25.56% |     53.76% |
+-------+------------+------------+

Signed-off-by: Kévin PETIT <kevin.petit@arm.com>

BUG=skia:
R=mtklein@google.com, djsollen@google.com

Author: kevin.petit@arm.com

Review URL: https://codereview.chromium.org/346843003

1 files changed, 92 insertions, 5 deletions

diff --git a/src/opts/SkBlitRow_opts_arm_neon.cpp b/src/opts/SkBlitRow_opts_arm_neon.cpp
index 01a6a2aa74..a8a0535baa 100644
--- a/src/opts/SkBlitRow_opts_arm_neon.cpp
+++ b/src/opts/SkBlitRow_opts_arm_neon.cpp
@@ -365,7 +365,98 @@ void S32A_D565_Opaque_neon(uint16_t* SK_RESTRICT dst,
                       );
     }
 }
-#endif
+
+#else // #ifdef SK_CPU_ARM32
+
+void S32A_D565_Opaque_neon(uint16_t* SK_RESTRICT dst,
+                           const SkPMColor* SK_RESTRICT src, int count,
+                           U8CPU alpha, int /*x*/, int /*y*/) {
+    SkASSERT(255 == alpha);
+
+    if (count >= 16) {
+        asm (
+            "movi    v4.8h, #0x80                   \t\n"
+
+            "1:                                     \t\n"
+            "sub     %[count], %[count], #16        \t\n"
+            "ld1     {v16.8h-v17.8h}, [%[dst]]      \t\n"
+            "ld4     {v0.16b-v3.16b}, [%[src]], #64 \t\n"
+            "prfm    pldl1keep, [%[src],#512]       \t\n"
+            "prfm    pldl1keep, [%[dst],#256]       \t\n"
+            "ushr    v20.8h, v17.8h, #5             \t\n"
+            "ushr    v31.8h, v16.8h, #5             \t\n"
+            "xtn     v6.8b, v31.8h                  \t\n"
+            "xtn2    v6.16b, v20.8h                 \t\n"
+            "ushr    v20.8h, v17.8h, #11            \t\n"
+            "shl     v19.16b, v6.16b, #2            \t\n"
+            "ushr    v31.8h, v16.8h, #11            \t\n"
+            "xtn     v22.8b, v31.8h                 \t\n"
+            "xtn2    v22.16b, v20.8h                \t\n"
+            "shl     v18.16b, v22.16b, #3           \t\n"
+            "mvn     v3.16b, v3.16b                 \t\n"
+            "xtn     v16.8b, v16.8h                 \t\n"
+            "mov     v7.16b, v4.16b                 \t\n"
+            "xtn2    v16.16b, v17.8h                \t\n"
+            "umlal   v7.8h, v3.8b, v19.8b           \t\n"
+            "shl     v16.16b, v16.16b, #3           \t\n"
+            "mov     v22.16b, v4.16b                \t\n"
+            "ushr    v24.8h, v7.8h, #6              \t\n"
+            "umlal   v22.8h, v3.8b, v18.8b          \t\n"
+            "ushr    v20.8h, v22.8h, #5             \t\n"
+            "addhn   v20.8b, v22.8h, v20.8h         \t\n"
+            "cmp     %[count], #16                  \t\n"
+            "mov     v6.16b, v4.16b                 \t\n"
+            "mov     v5.16b, v4.16b                 \t\n"
+            "umlal   v6.8h, v3.8b, v16.8b           \t\n"
+            "umlal2  v5.8h, v3.16b, v19.16b         \t\n"
+            "mov     v17.16b, v4.16b                \t\n"
+            "ushr    v19.8h, v6.8h, #5              \t\n"
+            "umlal2  v17.8h, v3.16b, v18.16b        \t\n"
+            "addhn   v7.8b, v7.8h, v24.8h           \t\n"
+            "ushr    v18.8h, v5.8h, #6              \t\n"
+            "ushr    v21.8h, v17.8h, #5             \t\n"
+            "addhn2  v7.16b, v5.8h, v18.8h          \t\n"
+            "addhn2  v20.16b, v17.8h, v21.8h        \t\n"
+            "mov     v22.16b, v4.16b                \t\n"
+            "addhn   v6.8b, v6.8h, v19.8h           \t\n"
+            "umlal2  v22.8h, v3.16b, v16.16b        \t\n"
+            "ushr    v5.8h, v22.8h, #5              \t\n"
+            "addhn2  v6.16b, v22.8h, v5.8h          \t\n"
+            "uqadd   v7.16b, v1.16b, v7.16b         \t\n"
+            "uqadd   v20.16b, v2.16b, v20.16b       \t\n"
+            "uqadd   v6.16b, v0.16b, v6.16b         \t\n"
+            "shll    v22.8h, v20.8b, #8             \t\n"
+            "shll    v5.8h, v7.8b, #8               \t\n"
+            "sri     v22.8h, v5.8h, #5              \t\n"
+            "shll    v17.8h, v6.8b, #8              \t\n"
+            "shll2   v23.8h, v20.16b, #8            \t\n"
+            "shll2   v7.8h, v7.16b, #8              \t\n"
+            "sri     v22.8h, v17.8h, #11            \t\n"
+            "sri     v23.8h, v7.8h, #5              \t\n"
+            "shll2   v6.8h, v6.16b, #8              \t\n"
+            "st1     {v22.8h}, [%[dst]], #16        \t\n"
+            "sri     v23.8h, v6.8h, #11             \t\n"
+            "st1     {v23.8h}, [%[dst]], #16        \t\n"
+            "b.ge    1b                             \t\n"
+            : [dst] "+&r" (dst), [src] "+&r" (src), [count] "+&r" (count)
+            :: "cc", "memory", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
+               "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23", "v24",
+               "v31"
+        );
+    }
+        // Leftovers
+    if (count > 0) {
+        do {
+            SkPMColor c = *src++;
+            SkPMColorAssert(c);
+            if (c) {
+                *dst = SkSrcOver32To16(c, *dst);
+            }
+            dst += 1;
+        } while (--count != 0);
+    }
+}
+#endif // #ifdef SK_CPU_ARM32
 
 static inline uint16x8_t SkDiv255Round_neon8(uint16x8_t prod) {
     prod += vdupq_n_u16(128);
@@ -1552,11 +1643,7 @@ const SkBlitRow::Proc sk_blitrow_platform_565_procs_arm_neon[] = {
     // no dither
     S32_D565_Opaque_neon,
     S32_D565_Blend_neon,
-#ifdef SK_CPU_ARM32
     S32A_D565_Opaque_neon,
-#else
-    NULL,
-#endif
     S32A_D565_Blend_neon,
 
     // dither