Add vpx_scaled_2d_neon()

BUG=webm:1419

Change-Id: I39c8033734562efc0ac0e28e7f06fa05130f9b96

5 files changed, 349 insertions, 2 deletions

diff --git a/test/convolve_test.cc b/test/convolve_test.cc
index f1a24af32..b42821373 100644
--- a/test/convolve_test.cc
+++ b/test/convolve_test.cc
@@ -1199,7 +1199,7 @@ const ConvolveFunctions convolve8_neon(
     vpx_convolve8_avg_horiz_neon, vpx_convolve8_vert_neon,
     vpx_convolve8_avg_vert_neon, vpx_convolve8_neon, vpx_convolve8_avg_neon,
     vpx_scaled_horiz_c, vpx_scaled_avg_horiz_c, vpx_scaled_vert_c,
-    vpx_scaled_avg_vert_c, vpx_scaled_2d_c, vpx_scaled_avg_2d_c, 0);
+    vpx_scaled_avg_vert_c, vpx_scaled_2d_neon, vpx_scaled_avg_2d_c, 0);
 
 const ConvolveParam kArrayConvolve_neon[] = { ALL_SIZES(convolve8_neon) };
 #endif  // CONFIG_VP9_HIGHBITDEPTH
diff --git a/vpx_dsp/arm/vpx_convolve8_neon.h b/vpx_dsp/arm/vpx_convolve8_neon.h
index 2ac865816..c1634ed55 100644
--- a/vpx_dsp/arm/vpx_convolve8_neon.h
+++ b/vpx_dsp/arm/vpx_convolve8_neon.h
@@ -47,6 +47,28 @@ static INLINE void load_u8_8x8(const uint8_t *s, const ptrdiff_t p,
   *s7 = vld1_u8(s);
 }
 
+static INLINE void load_u8_16x8(const uint8_t *s, const ptrdiff_t p,
+                                uint8x16_t *const s0, uint8x16_t *const s1,
+                                uint8x16_t *const s2, uint8x16_t *const s3,
+                                uint8x16_t *const s4, uint8x16_t *const s5,
+                                uint8x16_t *const s6, uint8x16_t *const s7) {
+  *s0 = vld1q_u8(s);
+  s += p;
+  *s1 = vld1q_u8(s);
+  s += p;
+  *s2 = vld1q_u8(s);
+  s += p;
+  *s3 = vld1q_u8(s);
+  s += p;
+  *s4 = vld1q_u8(s);
+  s += p;
+  *s5 = vld1q_u8(s);
+  s += p;
+  *s6 = vld1q_u8(s);
+  s += p;
+  *s7 = vld1q_u8(s);
+}
+
 static INLINE int16x4_t convolve8_4(const int16x4_t s0, const int16x4_t s1,
                                     const int16x4_t s2, const int16x4_t s3,
                                     const int16x4_t s4, const int16x4_t s5,
diff --git a/vpx_dsp/arm/vpx_scaled_convolve8_neon.c b/vpx_dsp/arm/vpx_scaled_convolve8_neon.c
new file mode 100644
index 000000000..8edf8a66e
--- /dev/null
+++ b/vpx_dsp/arm/vpx_scaled_convolve8_neon.c
@@ -0,0 +1,324 @@
+/*
+ *  Copyright (c) 2017 The WebM 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 <arm_neon.h>
+#include <assert.h>
+#include <string.h>
+
+#include "./vpx_config.h"
+#include "./vpx_dsp_rtcd.h"
+#include "vpx/vpx_integer.h"
+#include "vpx_dsp/arm/transpose_neon.h"
+#include "vpx_dsp/arm/vpx_convolve8_neon.h"
+#include "vpx_ports/mem.h"
+
+static INLINE void scaledconvolve_horiz_w4(
+    const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
+    const ptrdiff_t dst_stride, const InterpKernel *const x_filters,
+    const int x0_q4, const int x_step_q4, const int w, const int h) {
+  DECLARE_ALIGNED(16, uint8_t, temp[4 * 4]);
+  int x, y, z;
+
+  src -= SUBPEL_TAPS / 2 - 1;
+
+  y = h;
+  do {
+    int x_q4 = x0_q4;
+    x = 0;
+    do {
+      // process 4 src_x steps
+      for (z = 0; z < 4; ++z) {
+        const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
+        if (x_q4 & SUBPEL_MASK) {
+          const int16x8_t filters = vld1q_s16(x_filters[x_q4 & SUBPEL_MASK]);
+          const int16x4_t filter3 = vdup_lane_s16(vget_low_s16(filters), 3);
+          const int16x4_t filter4 = vdup_lane_s16(vget_high_s16(filters), 0);
+          uint8x8_t s[8], d;
+          int16x8_t ss[4];
+          int16x4_t t[8], tt;
+
+          load_u8_8x4(src_x, src_stride, &s[0], &s[1], &s[2], &s[3]);
+          transpose_u8_8x4(&s[0], &s[1], &s[2], &s[3]);
+
+          ss[0] = vreinterpretq_s16_u16(vmovl_u8(s[0]));
+          ss[1] = vreinterpretq_s16_u16(vmovl_u8(s[1]));
+          ss[2] = vreinterpretq_s16_u16(vmovl_u8(s[2]));
+          ss[3] = vreinterpretq_s16_u16(vmovl_u8(s[3]));
+          t[0] = vget_low_s16(ss[0]);
+          t[1] = vget_low_s16(ss[1]);
+          t[2] = vget_low_s16(ss[2]);
+          t[3] = vget_low_s16(ss[3]);
+          t[4] = vget_high_s16(ss[0]);
+          t[5] = vget_high_s16(ss[1]);
+          t[6] = vget_high_s16(ss[2]);
+          t[7] = vget_high_s16(ss[3]);
+
+          tt = convolve8_4(t[0], t[1], t[2], t[3], t[4], t[5], t[6], t[7],
+                           filters, filter3, filter4);
+          d = vqrshrun_n_s16(vcombine_s16(tt, tt), 7);
+          vst1_lane_u32((uint32_t *)&temp[4 * z], vreinterpret_u32_u8(d), 0);
+        } else {
+          int i;
+          for (i = 0; i < 4; ++i) {
+            temp[z * 4 + i] = src_x[i * src_stride + 3];
+          }
+        }
+        x_q4 += x_step_q4;
+      }
+
+      // transpose the 4x4 filters values back to dst
+      {
+        const uint8x8x4_t d4 = vld4_u8(temp);
+        vst1_lane_u32((uint32_t *)&dst[x + 0 * dst_stride],
+                      vreinterpret_u32_u8(d4.val[0]), 0);
+        vst1_lane_u32((uint32_t *)&dst[x + 1 * dst_stride],
+                      vreinterpret_u32_u8(d4.val[1]), 0);
+        vst1_lane_u32((uint32_t *)&dst[x + 2 * dst_stride],
+                      vreinterpret_u32_u8(d4.val[2]), 0);
+        vst1_lane_u32((uint32_t *)&dst[x + 3 * dst_stride],
+                      vreinterpret_u32_u8(d4.val[3]), 0);
+      }
+      x += 4;
+    } while (x < w);
+
+    src += src_stride * 4;
+    dst += dst_stride * 4;
+    y -= 4;
+  } while (y > 0);
+}
+
+static INLINE void scaledconvolve_horiz_w8(
+    const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
+    const ptrdiff_t dst_stride, const InterpKernel *const x_filters,
+    const int x0_q4, const int x_step_q4, const int w, const int h) {
+  DECLARE_ALIGNED(16, uint8_t, temp[8 * 8]);
+  int x, y, z;
+  src -= SUBPEL_TAPS / 2 - 1;
+
+  // This function processes 8x8 areas. The intermediate height is not always
+  // a multiple of 8, so force it to be a multiple of 8 here.
+  y = (h + 7) & ~7;
+
+  do {
+    int x_q4 = x0_q4;
+    x = 0;
+    do {
+      uint8x8_t d[8];
+      // process 8 src_x steps
+      for (z = 0; z < 8; ++z) {
+        const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
+
+        if (x_q4 & SUBPEL_MASK) {
+          const int16x8_t filters = vld1q_s16(x_filters[x_q4 & SUBPEL_MASK]);
+          uint8x8_t s[8];
+          load_u8_8x8(src_x, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4],
+                      &s[5], &s[6], &s[7]);
+          transpose_u8_8x8(&s[0], &s[1], &s[2], &s[3], &s[4], &s[5], &s[6],
+                           &s[7]);
+          d[0] = scale_filter_8(s, filters);
+          vst1_u8(&temp[8 * z], d[0]);
+        } else {
+          int i;
+          for (i = 0; i < 8; ++i) {
+            temp[z * 8 + i] = src_x[i * src_stride + 3];
+          }
+        }
+        x_q4 += x_step_q4;
+      }
+
+      // transpose the 8x8 filters values back to dst
+      load_u8_8x8(temp, 8, &d[0], &d[1], &d[2], &d[3], &d[4], &d[5], &d[6],
+                  &d[7]);
+      transpose_u8_8x8(&d[0], &d[1], &d[2], &d[3], &d[4], &d[5], &d[6], &d[7]);
+      vst1_u8(&dst[x + 0 * dst_stride], d[0]);
+      vst1_u8(&dst[x + 1 * dst_stride], d[1]);
+      vst1_u8(&dst[x + 2 * dst_stride], d[2]);
+      vst1_u8(&dst[x + 3 * dst_stride], d[3]);
+      vst1_u8(&dst[x + 4 * dst_stride], d[4]);
+      vst1_u8(&dst[x + 5 * dst_stride], d[5]);
+      vst1_u8(&dst[x + 6 * dst_stride], d[6]);
+      vst1_u8(&dst[x + 7 * dst_stride], d[7]);
+      x += 8;
+    } while (x < w);
+
+    src += src_stride * 8;
+    dst += dst_stride * 8;
+  } while (y -= 8);
+}
+
+static INLINE void scaledconvolve_vert_w4(
+    const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
+    const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
+    const int y0_q4, const int y_step_q4, const int w, const int h) {
+  int y;
+  int y_q4 = y0_q4;
+
+  src -= src_stride * (SUBPEL_TAPS / 2 - 1);
+  y = h;
+  do {
+    const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
+
+    if (y_q4 & SUBPEL_MASK) {
+      const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
+      const int16x4_t filter3 = vdup_lane_s16(vget_low_s16(filters), 3);
+      const int16x4_t filter4 = vdup_lane_s16(vget_high_s16(filters), 0);
+      uint8x8_t s[8], d;
+      int16x4_t t[8], tt;
+
+      load_u8_8x8(src_y, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
+                  &s[6], &s[7]);
+      t[0] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[0])));
+      t[1] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[1])));
+      t[2] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[2])));
+      t[3] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[3])));
+      t[4] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[4])));
+      t[5] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[5])));
+      t[6] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[6])));
+      t[7] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[7])));
+
+      tt = convolve8_4(t[0], t[1], t[2], t[3], t[4], t[5], t[6], t[7], filters,
+                       filter3, filter4);
+      d = vqrshrun_n_s16(vcombine_s16(tt, tt), 7);
+      vst1_lane_u32((uint32_t *)dst, vreinterpret_u32_u8(d), 0);
+    } else {
+      memcpy(dst, &src_y[3 * src_stride], w);
+    }
+
+    dst += dst_stride;
+    y_q4 += y_step_q4;
+  } while (--y);
+}
+
+static INLINE void scaledconvolve_vert_w8(
+    const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
+    const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
+    const int y0_q4, const int y_step_q4, const int w, const int h) {
+  int y;
+  int y_q4 = y0_q4;
+
+  src -= src_stride * (SUBPEL_TAPS / 2 - 1);
+  y = h;
+  do {
+    const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
+    if (y_q4 & SUBPEL_MASK) {
+      const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
+      uint8x8_t s[8], d;
+      load_u8_8x8(src_y, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
+                  &s[6], &s[7]);
+      d = scale_filter_8(s, filters);
+      vst1_u8(dst, d);
+    } else {
+      memcpy(dst, &src_y[3 * src_stride], w);
+    }
+    dst += dst_stride;
+    y_q4 += y_step_q4;
+  } while (--y);
+}
+
+static INLINE void scaledconvolve_vert_w16(
+    const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
+    const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
+    const int y0_q4, const int y_step_q4, const int w, const int h) {
+  int x, y;
+  int y_q4 = y0_q4;
+
+  src -= src_stride * (SUBPEL_TAPS / 2 - 1);
+  y = h;
+  do {
+    const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
+    if (y_q4 & SUBPEL_MASK) {
+      x = 0;
+      do {
+        const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
+        uint8x16_t ss[8];
+        uint8x8_t s[8], d[2];
+        load_u8_16x8(src_y, src_stride, &ss[0], &ss[1], &ss[2], &ss[3], &ss[4],
+                     &ss[5], &ss[6], &ss[7]);
+        s[0] = vget_low_u8(ss[0]);
+        s[1] = vget_low_u8(ss[1]);
+        s[2] = vget_low_u8(ss[2]);
+        s[3] = vget_low_u8(ss[3]);
+        s[4] = vget_low_u8(ss[4]);
+        s[5] = vget_low_u8(ss[5]);
+        s[6] = vget_low_u8(ss[6]);
+        s[7] = vget_low_u8(ss[7]);
+        d[0] = scale_filter_8(s, filters);
+
+        s[0] = vget_high_u8(ss[0]);
+        s[1] = vget_high_u8(ss[1]);
+        s[2] = vget_high_u8(ss[2]);
+        s[3] = vget_high_u8(ss[3]);
+        s[4] = vget_high_u8(ss[4]);
+        s[5] = vget_high_u8(ss[5]);
+        s[6] = vget_high_u8(ss[6]);
+        s[7] = vget_high_u8(ss[7]);
+        d[1] = scale_filter_8(s, filters);
+        vst1q_u8(&dst[x], vcombine_u8(d[0], d[1]));
+        src_y += 16;
+        x += 16;
+      } while (x < w);
+    } else {
+      memcpy(dst, &src_y[3 * src_stride], w);
+    }
+    dst += dst_stride;
+    y_q4 += y_step_q4;
+  } while (--y);
+}
+
+void vpx_scaled_2d_neon(const uint8_t *src, ptrdiff_t src_stride, uint8_t *dst,
+                        ptrdiff_t dst_stride, const InterpKernel *filter,
+                        int x0_q4, int x_step_q4, int y0_q4, int y_step_q4,
+                        int w, int h) {
+  // Note: Fixed size intermediate buffer, temp, places limits on parameters.
+  // 2d filtering proceeds in 2 steps:
+  //   (1) Interpolate horizontally into an intermediate buffer, temp.
+  //   (2) Interpolate temp vertically to derive the sub-pixel result.
+  // Deriving the maximum number of rows in the temp buffer (135):
+  // --Smallest scaling factor is x1/2 ==> y_step_q4 = 32 (Normative).
+  // --Largest block size is 64x64 pixels.
+  // --64 rows in the downscaled frame span a distance of (64 - 1) * 32 in the
+  //   original frame (in 1/16th pixel units).
+  // --Must round-up because block may be located at sub-pixel position.
+  // --Require an additional SUBPEL_TAPS rows for the 8-tap filter tails.
+  // --((64 - 1) * 32 + 15) >> 4 + 8 = 135.
+  // --Require an additional 8 rows for the horiz_w8 transpose tail.
+  // When calling in frame scaling function, the smallest scaling factor is x1/4
+  // ==> y_step_q4 = 64. Since w and h are at most 16, the temp buffer is still
+  // big enough.
+  DECLARE_ALIGNED(16, uint8_t, temp[(135 + 8) * 64]);
+  const int intermediate_height =
+      (((h - 1) * y_step_q4 + y0_q4) >> SUBPEL_BITS) + SUBPEL_TAPS;
+
+  assert(w <= 64);
+  assert(h <= 64);
+  assert(y_step_q4 <= 32 || (y_step_q4 <= 64 && h <= 32));
+  assert(x_step_q4 <= 64);
+
+  if (w >= 8) {
+    scaledconvolve_horiz_w8(src - src_stride * (SUBPEL_TAPS / 2 - 1),
+                            src_stride, temp, 64, filter, x0_q4, x_step_q4, w,
+                            intermediate_height);
+  } else {
+    scaledconvolve_horiz_w4(src - src_stride * (SUBPEL_TAPS / 2 - 1),
+                            src_stride, temp, 64, filter, x0_q4, x_step_q4, w,
+                            intermediate_height);
+  }
+
+  if (w >= 16) {
+    scaledconvolve_vert_w16(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
+                            dst_stride, filter, y0_q4, y_step_q4, w, h);
+  } else if (w == 8) {
+    scaledconvolve_vert_w8(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
+                           dst_stride, filter, y0_q4, y_step_q4, w, h);
+  } else {
+    scaledconvolve_vert_w4(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
+                           dst_stride, filter, y0_q4, y_step_q4, w, h);
+  }
+}
diff --git a/vpx_dsp/vpx_dsp.mk b/vpx_dsp/vpx_dsp.mk
index d242c1a91..dd6f84bbf 100644
--- a/vpx_dsp/vpx_dsp.mk
+++ b/vpx_dsp/vpx_dsp.mk
@@ -106,6 +106,7 @@ DSP_SRCS-$(HAVE_NEON)  += arm/highbd_vpx_convolve_neon.c
 endif
 
 DSP_SRCS-$(HAVE_SSE2)  += x86/vpx_convolve_copy_sse2.asm
+DSP_SRCS-$(HAVE_NEON)  += arm/vpx_scaled_convolve8_neon.c
 
 ifeq ($(HAVE_NEON_ASM),yes)
 DSP_SRCS-yes += arm/vpx_convolve_copy_neon_asm$(ASM)
diff --git a/vpx_dsp/vpx_dsp_rtcd_defs.pl b/vpx_dsp/vpx_dsp_rtcd_defs.pl
index 4b3141dbd..ae4481456 100644
--- a/vpx_dsp/vpx_dsp_rtcd_defs.pl
+++ b/vpx_dsp/vpx_dsp_rtcd_defs.pl
@@ -365,7 +365,7 @@ add_proto qw/void vpx_convolve8_avg_vert/, "const uint8_t *src, ptrdiff_t src_st
 specialize qw/vpx_convolve8_avg_vert sse2 ssse3 neon dspr2 msa vsx/;
 
 add_proto qw/void vpx_scaled_2d/, "const uint8_t *src, ptrdiff_t src_stride, uint8_t *dst, ptrdiff_t dst_stride, const InterpKernel *filter, int x0_q4, int x_step_q4, int y0_q4, int y_step_q4, int w, int h";
-specialize qw/vpx_scaled_2d ssse3/;
+specialize qw/vpx_scaled_2d ssse3 neon/;
 
 add_proto qw/void vpx_scaled_horiz/, "const uint8_t *src, ptrdiff_t src_stride, uint8_t *dst, ptrdiff_t dst_stride, const InterpKernel *filter, int x0_q4, int x_step_q4, int y0_q4, int y_step_q4, int w, int h";