1 files changed, 122 insertions, 0 deletions
diff --git a/media/libwebp/src/dsp/cost_neon.c b/media/libwebp/src/dsp/cost_neon.c
new file mode 100644
index 0000000000..8cc8ce58aa
--- /dev/null
+++ b/media/libwebp/src/dsp/cost_neon.c
@@ -0,0 +1,122 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING 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.
+// -----------------------------------------------------------------------------
+//
+// ARM NEON version of cost functions
+
+#include "src/dsp/dsp.h"
+
+#if defined(WEBP_USE_NEON)
+
+#include "src/dsp/neon.h"
+#include "src/enc/cost_enc.h"
+
+static const uint8_t position[16] = { 1, 2,  3,  4,  5,  6,  7,  8,
+                                      9, 10, 11, 12, 13, 14, 15, 16 };
+
+static void SetResidualCoeffs_NEON(const int16_t* const coeffs,
+                                   VP8Residual* const res) {
+  const int16x8_t minus_one = vdupq_n_s16(-1);
+  const int16x8_t coeffs_0 = vld1q_s16(coeffs);
+  const int16x8_t coeffs_1 = vld1q_s16(coeffs + 8);
+  const uint16x8_t eob_0 = vtstq_s16(coeffs_0, minus_one);
+  const uint16x8_t eob_1 = vtstq_s16(coeffs_1, minus_one);
+  const uint8x16_t eob = vcombine_u8(vqmovn_u16(eob_0), vqmovn_u16(eob_1));
+  const uint8x16_t masked = vandq_u8(eob, vld1q_u8(position));
+
+#ifdef __aarch64__
+  res->last = vmaxvq_u8(masked) - 1;
+#else
+  const uint8x8_t eob_8x8 = vmax_u8(vget_low_u8(masked), vget_high_u8(masked));
+  const uint16x8_t eob_16x8 = vmovl_u8(eob_8x8);
+  const uint16x4_t eob_16x4 =
+      vmax_u16(vget_low_u16(eob_16x8), vget_high_u16(eob_16x8));
+  const uint32x4_t eob_32x4 = vmovl_u16(eob_16x4);
+  uint32x2_t eob_32x2 =
+      vmax_u32(vget_low_u32(eob_32x4), vget_high_u32(eob_32x4));
+  eob_32x2 = vpmax_u32(eob_32x2, eob_32x2);
+
+  vst1_lane_s32(&res->last, vreinterpret_s32_u32(eob_32x2), 0);
+  --res->last;
+#endif  // __aarch64__
+
+  res->coeffs = coeffs;
+}
+
+static int GetResidualCost_NEON(int ctx0, const VP8Residual* const res) {
+  uint8_t levels[16], ctxs[16];
+  uint16_t abs_levels[16];
+  int n = res->first;
+  // should be prob[VP8EncBands[n]], but it's equivalent for n=0 or 1
+  const int p0 = res->prob[n][ctx0][0];
+  CostArrayPtr const costs = res->costs;
+  const uint16_t* t = costs[n][ctx0];
+  // bit_cost(1, p0) is already incorporated in t[] tables, but only if ctx != 0
+  // (as required by the syntax). For ctx0 == 0, we need to add it here or it'll
+  // be missing during the loop.
+  int cost = (ctx0 == 0) ? VP8BitCost(1, p0) : 0;
+
+  if (res->last < 0) {
+    return VP8BitCost(0, p0);
+  }
+
+  {   // precompute clamped levels and contexts, packed to 8b.
+    const uint8x16_t kCst2 = vdupq_n_u8(2);
+    const uint8x16_t kCst67 = vdupq_n_u8(MAX_VARIABLE_LEVEL);
+    const int16x8_t c0 = vld1q_s16(res->coeffs);
+    const int16x8_t c1 = vld1q_s16(res->coeffs + 8);
+    const uint16x8_t E0 = vreinterpretq_u16_s16(vabsq_s16(c0));
+    const uint16x8_t E1 = vreinterpretq_u16_s16(vabsq_s16(c1));
+    const uint8x16_t F = vcombine_u8(vqmovn_u16(E0), vqmovn_u16(E1));
+    const uint8x16_t G = vminq_u8(F, kCst2);   // context = 0,1,2
+    const uint8x16_t H = vminq_u8(F, kCst67);  // clamp_level in [0..67]
+
+    vst1q_u8(ctxs, G);
+    vst1q_u8(levels, H);
+
+    vst1q_u16(abs_levels, E0);
+    vst1q_u16(abs_levels + 8, E1);
+  }
+  for (; n < res->last; ++n) {
+    const int ctx = ctxs[n];
+    const int level = levels[n];
+    const int flevel = abs_levels[n];   // full level
+    cost += VP8LevelFixedCosts[flevel] + t[level];  // simplified VP8LevelCost()
+    t = costs[n + 1][ctx];
+  }
+  // Last coefficient is always non-zero
+  {
+    const int level = levels[n];
+    const int flevel = abs_levels[n];
+    assert(flevel != 0);
+    cost += VP8LevelFixedCosts[flevel] + t[level];
+    if (n < 15) {
+      const int b = VP8EncBands[n + 1];
+      const int ctx = ctxs[n];
+      const int last_p0 = res->prob[b][ctx][0];
+      cost += VP8BitCost(0, last_p0);
+    }
+  }
+  return cost;
+}
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8EncDspCostInitNEON(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspCostInitNEON(void) {
+  VP8SetResidualCoeffs = SetResidualCoeffs_NEON;
+  VP8GetResidualCost = GetResidualCost_NEON;
+}
+
+#else  // !WEBP_USE_NEON
+
+WEBP_DSP_INIT_STUB(VP8EncDspCostInitNEON)
+
+#endif  // WEBP_USE_NEON