Add 4 to 1 scaling NEON optimization

BUG=webm:1419

Change-Id: If82a93935d2453e61b7647aae70983db1740bec7

3 files changed, 275 insertions, 37 deletions

diff --git a/vp9/encoder/arm/neon/vp9_frame_scale_neon.c b/vp9/encoder/arm/neon/vp9_frame_scale_neon.c
index 448957cc5..bbed00f58 100644
--- a/vp9/encoder/arm/neon/vp9_frame_scale_neon.c
+++ b/vp9/encoder/arm/neon/vp9_frame_scale_neon.c
@@ -45,11 +45,61 @@ static INLINE void scale_plane_2_to_1_phase_0_neon(const uint8_t *src,
   } while (--y);
 }
 
+static INLINE void scale_plane_4_to_1_phase_0_neon(const uint8_t *src,
+                                                   const int src_stride,
+                                                   uint8_t *dst,
+                                                   const int dst_stride,
+                                                   const int w, const int h) {
+  const int max_width = (w + 15) & ~15;
+  int y = h;
+
+  assert(w && h);
+
+  do {
+    int x = max_width;
+    do {
+      const uint8x16x4_t s = vld4q_u8(src);
+      vst1q_u8(dst, s.val[0]);
+      src += 64;
+      dst += 16;
+      x -= 16;
+    } while (x);
+    src += 4 * (src_stride - max_width);
+    dst += dst_stride - max_width;
+  } while (--y);
+}
+
+static INLINE void scale_plane_bilinear_phase_non_0_kernel(
+    const uint8x16_t in0, const uint8x16_t in1, const uint8x16_t in2,
+    const uint8x16_t in3, const uint8x8_t coef0, const uint8x8_t coef1,
+    uint8_t *const dst) {
+  const uint16x8_t h0 = vmull_u8(vget_low_u8(in0), coef0);
+  const uint16x8_t h1 = vmull_u8(vget_high_u8(in0), coef0);
+  const uint16x8_t h2 = vmull_u8(vget_low_u8(in2), coef0);
+  const uint16x8_t h3 = vmull_u8(vget_high_u8(in2), coef0);
+  const uint16x8_t h4 = vmlal_u8(h0, vget_low_u8(in1), coef1);
+  const uint16x8_t h5 = vmlal_u8(h1, vget_high_u8(in1), coef1);
+  const uint16x8_t h6 = vmlal_u8(h2, vget_low_u8(in3), coef1);
+  const uint16x8_t h7 = vmlal_u8(h3, vget_high_u8(in3), coef1);
+
+  const uint8x8_t hor0 = vrshrn_n_u16(h4, 7);  // temp: 00 01 02 03 04 05 06 07
+  const uint8x8_t hor1 = vrshrn_n_u16(h5, 7);  // temp: 08 09 0A 0B 0C 0D 0E 0F
+  const uint8x8_t hor2 = vrshrn_n_u16(h6, 7);  // temp: 10 11 12 13 14 15 16 17
+  const uint8x8_t hor3 = vrshrn_n_u16(h7, 7);  // temp: 18 19 1A 1B 1C 1D 1E 1F
+  const uint16x8_t v0 = vmull_u8(hor0, coef0);
+  const uint16x8_t v1 = vmull_u8(hor1, coef0);
+  const uint16x8_t v2 = vmlal_u8(v0, hor2, coef1);
+  const uint16x8_t v3 = vmlal_u8(v1, hor3, coef1);
+  // dst: 0 1 2 3 4 5 6 7  8 9 A B C D E F
+  const uint8x16_t d = vcombine_u8(vrshrn_n_u16(v2, 7), vrshrn_n_u16(v3, 7));
+  vst1q_u8(dst, d);
+}
+
 static INLINE void scale_plane_2_to_1_bilinear_phase_non_0_neon(
     const uint8_t *const src, const int src_stride, uint8_t *dst,
     const int dst_stride, const int w, const int h, const int16_t c0,
     const int16_t c1) {
-  const int max_width = (w + 7) & ~7;
+  const int max_width = (w + 15) & ~15;
   const uint8_t *src0 = src;
   const uint8_t *src1 = src + src_stride;
   const uint8x8_t coef0 = vdup_n_u8(c0);
@@ -61,25 +111,18 @@ static INLINE void scale_plane_2_to_1_bilinear_phase_non_0_neon(
   do {
     int x = max_width;
     do {
-      // 00 02 04 06 08 0A 0C 0E  01 03 05 07 09 0B 0D 0F
-      const uint8x8x2_t s0 = vld2_u8(src0);
-      // 10 12 14 16 18 1A 1C 1E  11 13 15 17 19 1B 1D 1F
-      const uint8x8x2_t s1 = vld2_u8(src1);
-      const uint16x8_t h0 = vmull_u8(s0.val[0], coef0);
-      const uint16x8_t h1 = vmull_u8(s1.val[0], coef0);
-      const uint16x8_t h2 = vmlal_u8(h0, s0.val[1], coef1);
-      const uint16x8_t h3 = vmlal_u8(h1, s1.val[1], coef1);
-
-      const uint8x8_t hor0 = vrshrn_n_u16(h2, 7);  // 00 01 02 03 04 05 06 07
-      const uint8x8_t hor1 = vrshrn_n_u16(h3, 7);  // 10 11 12 13 14 15 16 17
-      const uint16x8_t v0 = vmull_u8(hor0, coef0);
-      const uint16x8_t v1 = vmlal_u8(v0, hor1, coef1);
-      const uint8x8_t d = vrshrn_n_u16(v1, 7);  // 00 01 02 03 04 05 06 07
-      vst1_u8(dst, d);
-      src0 += 16;
-      src1 += 16;
-      dst += 8;
-      x -= 8;
+      // 000 002 004 006 008 00A 00C 00E  010 012 014 016 018 01A 01C 01E
+      // 001 003 005 007 009 00B 00D 00F  011 013 015 017 019 01B 01D 01F
+      const uint8x16x2_t s0 = vld2q_u8(src0);
+      // 100 102 104 106 108 10A 10C 10E  110 112 114 116 118 11A 11C 11E
+      // 101 103 105 107 109 10B 10D 10F  111 113 115 117 119 11B 11D 11F
+      const uint8x16x2_t s1 = vld2q_u8(src1);
+      scale_plane_bilinear_phase_non_0_kernel(s0.val[0], s0.val[1], s1.val[0],
+                                              s1.val[1], coef0, coef1, dst);
+      src0 += 32;
+      src1 += 32;
+      dst += 16;
+      x -= 16;
     } while (x);
     src0 += 2 * (src_stride - max_width);
     src1 += 2 * (src_stride - max_width);
@@ -87,6 +130,46 @@ static INLINE void scale_plane_2_to_1_bilinear_phase_non_0_neon(
   } while (--y);
 }
 
+static INLINE void scale_plane_4_to_1_bilinear_phase_non_0_neon(
+    const uint8_t *const src, const int src_stride, uint8_t *dst,
+    const int dst_stride, const int w, const int h, const int16_t c0,
+    const int16_t c1) {
+  const int max_width = (w + 15) & ~15;
+  const uint8_t *src0 = src;
+  const uint8_t *src1 = src + src_stride;
+  const uint8x8_t coef0 = vdup_n_u8(c0);
+  const uint8x8_t coef1 = vdup_n_u8(c1);
+  int y = h;
+
+  assert(w && h);
+
+  do {
+    int x = max_width;
+    do {
+      // (*) -- useless
+      // 000 004 008 00C 010 014 018 01C  020 024 028 02C 030 034 038 03C
+      // 001 005 009 00D 011 015 019 01D  021 025 029 02D 031 035 039 03D
+      // 002 006 00A 00E 012 016 01A 01E  022 026 02A 02E 032 036 03A 03E (*)
+      // 003 007 00B 00F 013 017 01B 01F  023 027 02B 02F 033 037 03B 03F (*)
+      const uint8x16x4_t s0 = vld4q_u8(src0);
+      // 100 104 108 10C 110 114 118 11C  120 124 128 12C 130 134 138 13C
+      // 101 105 109 10D 111 115 119 11D  121 125 129 12D 131 135 139 13D
+      // 102 106 10A 10E 112 116 11A 11E  122 126 12A 12E 132 136 13A 13E (*)
+      // 103 107 10B 10F 113 117 11B 11F  123 127 12B 12F 133 137 13B 13F (*)
+      const uint8x16x4_t s1 = vld4q_u8(src1);
+      scale_plane_bilinear_phase_non_0_kernel(s0.val[0], s0.val[1], s1.val[0],
+                                              s1.val[1], coef0, coef1, dst);
+      src0 += 64;
+      src1 += 64;
+      dst += 16;
+      x -= 16;
+    } while (x);
+    src0 += 4 * (src_stride - max_width);
+    src1 += 4 * (src_stride - max_width);
+    dst += dst_stride - max_width;
+  } while (--y);
+}
+
 static INLINE uint8x8_t scale_filter(const uint8x8_t *const s,
                                      const int16x8_t filters) {
   const int16x8_t filter3 = vdupq_lane_s16(vget_low_s16(filters), 3);
@@ -126,7 +209,7 @@ static void scale_plane_2_to_1_general_neon(const uint8_t *src,
   src -= (SUBPEL_TAPS / 2 - 1) * src_stride + SUBPEL_TAPS / 2 + 1;
 
   // horizontal
-  // Note: processing 8x8 is about 20% faster than processing row by row using
+  // Note: processing 4x8 is about 20% faster than processing row by row using
   // vld4_u8().
   do {
     load_u8_8x8(src + 2, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
@@ -141,10 +224,14 @@ static void scale_plane_2_to_1_general_neon(const uint8_t *src,
       transpose_u8_8x8(&s[6], &s[7], &s[8], &s[9], &s[10], &s[11], &s[12],
                        &s[13]);
 
-      d[0] = scale_filter(&s[0], filters);
-      d[1] = scale_filter(&s[2], filters);
-      d[2] = scale_filter(&s[4], filters);
-      d[3] = scale_filter(&s[6], filters);
+      d[0] = scale_filter(&s[0], filters);  // 00 10 20 30 40 50 60 70
+      d[1] = scale_filter(&s[2], filters);  // 01 11 21 31 41 51 61 71
+      d[2] = scale_filter(&s[4], filters);  // 02 12 22 32 42 52 62 72
+      d[3] = scale_filter(&s[6], filters);  // 03 13 23 33 43 53 63 73
+      // 00 01 02 03 40 41 42 43
+      // 10 11 12 13 50 51 52 53
+      // 20 21 22 23 60 61 62 63
+      // 30 31 32 33 70 71 72 73
       transpose_u8_8x4(&d[0], &d[1], &d[2], &d[3]);
       vst1_lane_u32((uint32_t *)(t + 0 * max_width_hor),
                     vreinterpret_u32_u8(d[0]), 0);
@@ -219,6 +306,111 @@ static void scale_plane_2_to_1_general_neon(const uint8_t *src,
   } while (x);
 }
 
+static void scale_plane_4_to_1_general_neon(const uint8_t *src,
+                                            const int src_stride, uint8_t *dst,
+                                            const int dst_stride, const int w,
+                                            const int h,
+                                            const int16_t *const coef,
+                                            uint8_t *const temp_buffer) {
+  const int max_width_hor = (w + 1) & ~1;
+  const int max_width_ver = (w + 7) & ~7;
+  const int max_height_hor = (4 * h + SUBPEL_TAPS - 2 + 7) & ~7;
+  const int max_height_ver = (h + 1) & ~1;
+  const int16x8_t filters = vld1q_s16(coef);
+  int x, y = max_height_hor;
+  uint8_t *t = temp_buffer;
+  uint8x8_t s[12], d[2];
+
+  assert(w && h);
+
+  src -= (SUBPEL_TAPS / 2 - 1) * src_stride + SUBPEL_TAPS / 2 + 3;
+
+  // horizontal
+  // Note: processing 2x8 is about 20% faster than processing row by row using
+  // vld4_u8().
+  do {
+    load_u8_8x8(src + 4, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
+                &s[6], &s[7]);
+    transpose_u8_4x8(&s[0], &s[1], &s[2], &s[3], s[4], s[5], s[6], s[7]);
+    x = max_width_hor;
+
+    do {
+      uint8x8x2_t dd;
+      src += 8;
+      load_u8_8x8(src, src_stride, &s[4], &s[5], &s[6], &s[7], &s[8], &s[9],
+                  &s[10], &s[11]);
+      transpose_u8_8x8(&s[4], &s[5], &s[6], &s[7], &s[8], &s[9], &s[10],
+                       &s[11]);
+
+      d[0] = scale_filter(&s[0], filters);  // 00 10 20 30 40 50 60 70
+      d[1] = scale_filter(&s[4], filters);  // 01 11 21 31 41 51 61 71
+      // dd.val[0]: 00 01 20 21 40 41 60 61
+      // dd.val[1]: 10 11 30 31 50 51 70 71
+      dd = vtrn_u8(d[0], d[1]);
+      vst1_lane_u16((uint16_t *)(t + 0 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[0]), 0);
+      vst1_lane_u16((uint16_t *)(t + 1 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[1]), 0);
+      vst1_lane_u16((uint16_t *)(t + 2 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[0]), 1);
+      vst1_lane_u16((uint16_t *)(t + 3 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[1]), 1);
+      vst1_lane_u16((uint16_t *)(t + 4 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[0]), 2);
+      vst1_lane_u16((uint16_t *)(t + 5 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[1]), 2);
+      vst1_lane_u16((uint16_t *)(t + 6 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[0]), 3);
+      vst1_lane_u16((uint16_t *)(t + 7 * max_width_hor),
+                    vreinterpret_u16_u8(dd.val[1]), 3);
+
+      s[0] = s[8];
+      s[1] = s[9];
+      s[2] = s[10];
+      s[3] = s[11];
+
+      t += 2;
+      x -= 2;
+    } while (x);
+    src += 8 * src_stride - 4 * max_width_hor;
+    t += 7 * max_width_hor;
+    y -= 8;
+  } while (y);
+
+  // vertical
+  x = max_width_ver;
+  t = temp_buffer;
+  do {
+    load_u8_8x4(t, max_width_hor, &s[0], &s[1], &s[2], &s[3]);
+    t += 4 * max_width_hor;
+    y = max_height_ver;
+
+    do {
+      load_u8_8x8(t, max_width_hor, &s[4], &s[5], &s[6], &s[7], &s[8], &s[9],
+                  &s[10], &s[11]);
+      t += 8 * max_width_hor;
+
+      d[0] = scale_filter(&s[0], filters);
+      d[1] = scale_filter(&s[4], filters);
+      vst1_u8(dst + 0 * dst_stride, d[0]);
+      vst1_u8(dst + 1 * dst_stride, d[1]);
+
+      s[0] = s[8];
+      s[1] = s[9];
+      s[2] = s[10];
+      s[3] = s[11];
+
+      dst += 2 * dst_stride;
+      y -= 2;
+    } while (y);
+    t -= max_width_hor * (4 * max_height_ver + 4);
+    t += 8;
+    dst -= max_height_ver * dst_stride;
+    dst += 8;
+    x -= 8;
+  } while (x);
+}
+
 void vp9_scale_and_extend_frame_neon(const YV12_BUFFER_CONFIG *src,
                                      YV12_BUFFER_CONFIG *dst,
                                      INTERP_FILTER filter_type,
@@ -277,6 +469,52 @@ void vp9_scale_and_extend_frame_neon(const YV12_BUFFER_CONFIG *src,
         scaled = 0;
       }
     }
+  } else if (4 * dst_w == src_w && 4 * dst_h == src_h) {
+    scaled = 1;
+    if (phase_scaler == 0) {
+      scale_plane_4_to_1_phase_0_neon(src->y_buffer, src->y_stride,
+                                      dst->y_buffer, dst->y_stride, dst_w,
+                                      dst_h);
+      scale_plane_4_to_1_phase_0_neon(src->u_buffer, src->uv_stride,
+                                      dst->u_buffer, dst->uv_stride, dst_uv_w,
+                                      dst_uv_h);
+      scale_plane_4_to_1_phase_0_neon(src->v_buffer, src->uv_stride,
+                                      dst->v_buffer, dst->uv_stride, dst_uv_w,
+                                      dst_uv_h);
+    } else if (filter_type == BILINEAR) {
+      const int16_t c0 = vp9_filter_kernels[BILINEAR][phase_scaler][3];
+      const int16_t c1 = vp9_filter_kernels[BILINEAR][phase_scaler][4];
+      scale_plane_4_to_1_bilinear_phase_non_0_neon(src->y_buffer, src->y_stride,
+                                                   dst->y_buffer, dst->y_stride,
+                                                   dst_w, dst_h, c0, c1);
+      scale_plane_4_to_1_bilinear_phase_non_0_neon(
+          src->u_buffer, src->uv_stride, dst->u_buffer, dst->uv_stride,
+          dst_uv_w, dst_uv_h, c0, c1);
+      scale_plane_4_to_1_bilinear_phase_non_0_neon(
+          src->v_buffer, src->uv_stride, dst->v_buffer, dst->uv_stride,
+          dst_uv_w, dst_uv_h, c0, c1);
+    } else {
+      const int buffer_max_width = (dst_w + 1) & ~1;
+      const int buffer_max_height = (4 * dst_h + SUBPEL_TAPS - 2 + 7) & ~7;
+      uint8_t *const temp_buffer =
+          (uint8_t *)malloc(buffer_max_width * buffer_max_height);
+      if (temp_buffer) {
+        scale_plane_4_to_1_general_neon(
+            src->y_buffer, src->y_stride, dst->y_buffer, dst->y_stride, dst_w,
+            dst_h, vp9_filter_kernels[filter_type][phase_scaler], temp_buffer);
+        scale_plane_4_to_1_general_neon(
+            src->u_buffer, src->uv_stride, dst->u_buffer, dst->uv_stride,
+            dst_uv_w, dst_uv_h, vp9_filter_kernels[filter_type][phase_scaler],
+            temp_buffer);
+        scale_plane_4_to_1_general_neon(
+            src->v_buffer, src->uv_stride, dst->v_buffer, dst->uv_stride,
+            dst_uv_w, dst_uv_h, vp9_filter_kernels[filter_type][phase_scaler],
+            temp_buffer);
+        free(temp_buffer);
+      } else {
+        scaled = 0;
+      }
+    }
   }
 
   if (scaled) {
diff --git a/vpx_dsp/arm/vpx_convolve8_neon.c b/vpx_dsp/arm/vpx_convolve8_neon.c
index 01de14d8a..1325569fc 100644
--- a/vpx_dsp/arm/vpx_convolve8_neon.c
+++ b/vpx_dsp/arm/vpx_convolve8_neon.c
@@ -30,18 +30,6 @@
 // instructions. This optimization is much faster in speed unit test, but slowed
 // down the whole decoder by 5%.
 
-static INLINE void load_u8_8x4(const uint8_t *s, const ptrdiff_t p,
-                               uint8x8_t *const s0, uint8x8_t *const s1,
-                               uint8x8_t *const s2, uint8x8_t *const s3) {
-  *s0 = vld1_u8(s);
-  s += p;
-  *s1 = vld1_u8(s);
-  s += p;
-  *s2 = vld1_u8(s);
-  s += p;
-  *s3 = vld1_u8(s);
-}
-
 static INLINE void store_u8_8x8(uint8_t *s, const ptrdiff_t p,
                                 const uint8x8_t s0, const uint8x8_t s1,
                                 const uint8x8_t s2, const uint8x8_t s3,
diff --git a/vpx_dsp/arm/vpx_convolve8_neon.h b/vpx_dsp/arm/vpx_convolve8_neon.h
index a086d481f..0f3b2c970 100644
--- a/vpx_dsp/arm/vpx_convolve8_neon.h
+++ b/vpx_dsp/arm/vpx_convolve8_neon.h
@@ -13,6 +13,18 @@
 #include "./vpx_config.h"
 #include "./vpx_dsp_rtcd.h"
 
+static INLINE void load_u8_8x4(const uint8_t *s, const ptrdiff_t p,
+                               uint8x8_t *const s0, uint8x8_t *const s1,
+                               uint8x8_t *const s2, uint8x8_t *const s3) {
+  *s0 = vld1_u8(s);
+  s += p;
+  *s1 = vld1_u8(s);
+  s += p;
+  *s2 = vld1_u8(s);
+  s += p;
+  *s3 = vld1_u8(s);
+}
+
 static INLINE void load_u8_8x8(const uint8_t *s, const ptrdiff_t p,
                                uint8x8_t *const s0, uint8x8_t *const s1,
                                uint8x8_t *const s2, uint8x8_t *const s3,