diff options
Diffstat (limited to 'src/dsp/arm/motion_field_projection_neon.cc')
| -rw-r--r-- | src/dsp/arm/motion_field_projection_neon.cc | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/src/dsp/arm/motion_field_projection_neon.cc b/src/dsp/arm/motion_field_projection_neon.cc new file mode 100644 index 0000000..8caba7d --- /dev/null +++ b/src/dsp/arm/motion_field_projection_neon.cc @@ -0,0 +1,393 @@ +// Copyright 2020 The libgav1 Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "src/dsp/motion_field_projection.h" +#include "src/utils/cpu.h" + +#if LIBGAV1_ENABLE_NEON + +#include <arm_neon.h> + +#include <algorithm> +#include <cassert> +#include <cstddef> +#include <cstdint> + +#include "src/dsp/constants.h" +#include "src/dsp/dsp.h" +#include "src/utils/common.h" +#include "src/utils/constants.h" +#include "src/utils/types.h" + +namespace libgav1 { +namespace dsp { +namespace { + +inline int16x8_t LoadDivision(const int8x8x2_t division_table, + const int8x8_t reference_offset) { + const int8x8_t kOne = vcreate_s8(0x0100010001000100); + const int8x16_t kOneQ = vcombine_s8(kOne, kOne); + const int8x8_t t = vadd_s8(reference_offset, reference_offset); + const int8x8x2_t tt = vzip_s8(t, t); + const int8x16_t t1 = vcombine_s8(tt.val[0], tt.val[1]); + const int8x16_t idx = vaddq_s8(t1, kOneQ); + const int8x8_t idx_low = vget_low_s8(idx); + const int8x8_t idx_high = vget_high_s8(idx); + const int16x4_t d0 = vreinterpret_s16_s8(vtbl2_s8(division_table, idx_low)); + const int16x4_t d1 = vreinterpret_s16_s8(vtbl2_s8(division_table, idx_high)); + return vcombine_s16(d0, d1); +} + +inline int16x4_t MvProjection(const int16x4_t mv, const int16x4_t denominator, + const int numerator) { + const int32x4_t m0 = vmull_s16(mv, denominator); + const int32x4_t m = vmulq_n_s32(m0, numerator); + // Add the sign (0 or -1) to round towards zero. + const int32x4_t add_sign = vsraq_n_s32(m, m, 31); + return vqrshrn_n_s32(add_sign, 14); +} + +inline int16x8_t MvProjectionClip(const int16x8_t mv, + const int16x8_t denominator, + const int numerator) { + const int16x4_t mv0 = vget_low_s16(mv); + const int16x4_t mv1 = vget_high_s16(mv); + const int16x4_t s0 = MvProjection(mv0, vget_low_s16(denominator), numerator); + const int16x4_t s1 = MvProjection(mv1, vget_high_s16(denominator), numerator); + const int16x8_t projection = vcombine_s16(s0, s1); + const int16x8_t projection_mv_clamp = vdupq_n_s16(kProjectionMvClamp); + const int16x8_t clamp = vminq_s16(projection, projection_mv_clamp); + return vmaxq_s16(clamp, vnegq_s16(projection_mv_clamp)); +} + +inline int8x8_t Project_NEON(const int16x8_t delta, const int16x8_t dst_sign) { + // Add 63 to negative delta so that it shifts towards zero. + const int16x8_t delta_sign = vshrq_n_s16(delta, 15); + const uint16x8_t delta_u = vreinterpretq_u16_s16(delta); + const uint16x8_t delta_sign_u = vreinterpretq_u16_s16(delta_sign); + const uint16x8_t delta_adjust_u = vsraq_n_u16(delta_u, delta_sign_u, 10); + const int16x8_t delta_adjust = vreinterpretq_s16_u16(delta_adjust_u); + const int16x8_t offset0 = vshrq_n_s16(delta_adjust, 6); + const int16x8_t offset1 = veorq_s16(offset0, dst_sign); + const int16x8_t offset2 = vsubq_s16(offset1, dst_sign); + return vqmovn_s16(offset2); +} + +inline void GetPosition( + const int8x8x2_t division_table, const MotionVector* const mv, + const int numerator, const int x8_start, const int x8_end, const int x8, + const int8x8_t r_offsets, const int8x8_t source_reference_type8, + const int8x8_t skip_r, const int8x8_t y8_floor8, const int8x8_t y8_ceiling8, + const int16x8_t d_sign, const int delta, int8x8_t* const r, + int8x8_t* const position_y8, int8x8_t* const position_x8, + int64_t* const skip_64, int32x4_t mvs[2]) { + const auto* const mv_int = reinterpret_cast<const int32_t*>(mv + x8); + *r = vtbl1_s8(r_offsets, source_reference_type8); + const int16x8_t denorm = LoadDivision(division_table, source_reference_type8); + int16x8_t projection_mv[2]; + mvs[0] = vld1q_s32(mv_int + 0); + mvs[1] = vld1q_s32(mv_int + 4); + // Deinterlace x and y components + const int16x8_t mv0 = vreinterpretq_s16_s32(mvs[0]); + const int16x8_t mv1 = vreinterpretq_s16_s32(mvs[1]); + const int16x8x2_t mv_yx = vuzpq_s16(mv0, mv1); + // numerator could be 0. + projection_mv[0] = MvProjectionClip(mv_yx.val[0], denorm, numerator); + projection_mv[1] = MvProjectionClip(mv_yx.val[1], denorm, numerator); + // Do not update the motion vector if the block position is not valid or + // if position_x8 is outside the current range of x8_start and x8_end. + // Note that position_y8 will always be within the range of y8_start and + // y8_end. + // After subtracting the base, valid projections are within 8-bit. + *position_y8 = Project_NEON(projection_mv[0], d_sign); + const int8x8_t position_x = Project_NEON(projection_mv[1], d_sign); + const int8x8_t k01234567 = vcreate_s8(uint64_t{0x0706050403020100}); + *position_x8 = vqadd_s8(position_x, k01234567); + const int8x16_t position_xy = vcombine_s8(*position_x8, *position_y8); + const int x8_floor = std::max( + x8_start - x8, delta - kProjectionMvMaxHorizontalOffset); // [-8, 8] + const int x8_ceiling = std::min( + x8_end - x8, delta + 8 + kProjectionMvMaxHorizontalOffset); // [0, 16] + const int8x8_t x8_floor8 = vdup_n_s8(x8_floor); + const int8x8_t x8_ceiling8 = vdup_n_s8(x8_ceiling); + const int8x16_t floor_xy = vcombine_s8(x8_floor8, y8_floor8); + const int8x16_t ceiling_xy = vcombine_s8(x8_ceiling8, y8_ceiling8); + const uint8x16_t underflow = vcltq_s8(position_xy, floor_xy); + const uint8x16_t overflow = vcgeq_s8(position_xy, ceiling_xy); + const int8x16_t out = vreinterpretq_s8_u8(vorrq_u8(underflow, overflow)); + const int8x8_t skip_low = vorr_s8(skip_r, vget_low_s8(out)); + const int8x8_t skip = vorr_s8(skip_low, vget_high_s8(out)); + *skip_64 = vget_lane_s64(vreinterpret_s64_s8(skip), 0); +} + +template <int idx> +inline void Store(const int16x8_t position, const int8x8_t reference_offset, + const int32x4_t mv, int8_t* dst_reference_offset, + MotionVector* dst_mv) { + const ptrdiff_t offset = vgetq_lane_s16(position, idx); + auto* const d_mv = reinterpret_cast<int32_t*>(&dst_mv[offset]); + vst1q_lane_s32(d_mv, mv, idx & 3); + vst1_lane_s8(&dst_reference_offset[offset], reference_offset, idx); +} + +template <int idx> +inline void CheckStore(const int8_t* skips, const int16x8_t position, + const int8x8_t reference_offset, const int32x4_t mv, + int8_t* dst_reference_offset, MotionVector* dst_mv) { + if (skips[idx] == 0) { + Store<idx>(position, reference_offset, mv, dst_reference_offset, dst_mv); + } +} + +// 7.9.2. +void MotionFieldProjectionKernel_NEON(const ReferenceInfo& reference_info, + const int reference_to_current_with_sign, + const int dst_sign, const int y8_start, + const int y8_end, const int x8_start, + const int x8_end, + TemporalMotionField* const motion_field) { + const ptrdiff_t stride = motion_field->mv.columns(); + // The column range has to be offset by kProjectionMvMaxHorizontalOffset since + // coordinates in that range could end up being position_x8 because of + // projection. + const int adjusted_x8_start = + std::max(x8_start - kProjectionMvMaxHorizontalOffset, 0); + const int adjusted_x8_end = std::min( + x8_end + kProjectionMvMaxHorizontalOffset, static_cast<int>(stride)); + const int adjusted_x8_end8 = adjusted_x8_end & ~7; + const int leftover = adjusted_x8_end - adjusted_x8_end8; + const int8_t* const reference_offsets = + reference_info.relative_distance_to.data(); + const bool* const skip_references = reference_info.skip_references.data(); + const int16_t* const projection_divisions = + reference_info.projection_divisions.data(); + const ReferenceFrameType* source_reference_types = + &reference_info.motion_field_reference_frame[y8_start][0]; + const MotionVector* mv = &reference_info.motion_field_mv[y8_start][0]; + int8_t* dst_reference_offset = motion_field->reference_offset[y8_start]; + MotionVector* dst_mv = motion_field->mv[y8_start]; + const int16x8_t d_sign = vdupq_n_s16(dst_sign); + + static_assert(sizeof(int8_t) == sizeof(bool), ""); + static_assert(sizeof(int8_t) == sizeof(ReferenceFrameType), ""); + static_assert(sizeof(int32_t) == sizeof(MotionVector), ""); + assert(dst_sign == 0 || dst_sign == -1); + assert(stride == motion_field->reference_offset.columns()); + assert((y8_start & 7) == 0); + assert((adjusted_x8_start & 7) == 0); + // The final position calculation is represented with int16_t. Valid + // position_y8 from its base is at most 7. After considering the horizontal + // offset which is at most |stride - 1|, we have the following assertion, + // which means this optimization works for frame width up to 32K (each + // position is a 8x8 block). + assert(8 * stride <= 32768); + const int8x8_t skip_reference = + vld1_s8(reinterpret_cast<const int8_t*>(skip_references)); + const int8x8_t r_offsets = vld1_s8(reference_offsets); + const int8x16_t table = vreinterpretq_s8_s16(vld1q_s16(projection_divisions)); + int8x8x2_t division_table; + division_table.val[0] = vget_low_s8(table); + division_table.val[1] = vget_high_s8(table); + + int y8 = y8_start; + do { + const int y8_floor = (y8 & ~7) - y8; // [-7, 0] + const int y8_ceiling = std::min(y8_end - y8, y8_floor + 8); // [1, 8] + const int8x8_t y8_floor8 = vdup_n_s8(y8_floor); + const int8x8_t y8_ceiling8 = vdup_n_s8(y8_ceiling); + int x8; + + for (x8 = adjusted_x8_start; x8 < adjusted_x8_end8; x8 += 8) { + const int8x8_t source_reference_type8 = + vld1_s8(reinterpret_cast<const int8_t*>(source_reference_types + x8)); + const int8x8_t skip_r = vtbl1_s8(skip_reference, source_reference_type8); + const int64_t early_skip = vget_lane_s64(vreinterpret_s64_s8(skip_r), 0); + // Early termination #1 if all are skips. Chance is typically ~30-40%. + if (early_skip == -1) continue; + int64_t skip_64; + int8x8_t r, position_x8, position_y8; + int32x4_t mvs[2]; + GetPosition(division_table, mv, reference_to_current_with_sign, x8_start, + x8_end, x8, r_offsets, source_reference_type8, skip_r, + y8_floor8, y8_ceiling8, d_sign, 0, &r, &position_y8, + &position_x8, &skip_64, mvs); + // Early termination #2 if all are skips. + // Chance is typically ~15-25% after Early termination #1. + if (skip_64 == -1) continue; + const int16x8_t p_y = vmovl_s8(position_y8); + const int16x8_t p_x = vmovl_s8(position_x8); + const int16x8_t pos = vmlaq_n_s16(p_x, p_y, stride); + const int16x8_t position = vaddq_s16(pos, vdupq_n_s16(x8)); + if (skip_64 == 0) { + // Store all. Chance is typically ~70-85% after Early termination #2. + Store<0>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<1>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<2>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<3>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<4>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<5>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<6>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<7>(position, r, mvs[1], dst_reference_offset, dst_mv); + } else { + // Check and store each. + // Chance is typically ~15-30% after Early termination #2. + // The compiler is smart enough to not create the local buffer skips[]. + int8_t skips[8]; + memcpy(skips, &skip_64, sizeof(skips)); + CheckStore<0>(skips, position, r, mvs[0], dst_reference_offset, dst_mv); + CheckStore<1>(skips, position, r, mvs[0], dst_reference_offset, dst_mv); + CheckStore<2>(skips, position, r, mvs[0], dst_reference_offset, dst_mv); + CheckStore<3>(skips, position, r, mvs[0], dst_reference_offset, dst_mv); + CheckStore<4>(skips, position, r, mvs[1], dst_reference_offset, dst_mv); + CheckStore<5>(skips, position, r, mvs[1], dst_reference_offset, dst_mv); + CheckStore<6>(skips, position, r, mvs[1], dst_reference_offset, dst_mv); + CheckStore<7>(skips, position, r, mvs[1], dst_reference_offset, dst_mv); + } + } + + // The following leftover processing cannot be moved out of the do...while + // loop. Doing so may change the result storing orders of the same position. + if (leftover > 0) { + // Use SIMD only when leftover is at least 4, and there are at least 8 + // elements in a row. + if (leftover >= 4 && adjusted_x8_start < adjusted_x8_end8) { + // Process the last 8 elements to avoid loading invalid memory. Some + // elements may have been processed in the above loop, which is OK. + const int delta = 8 - leftover; + x8 = adjusted_x8_end - 8; + const int8x8_t source_reference_type8 = vld1_s8( + reinterpret_cast<const int8_t*>(source_reference_types + x8)); + const int8x8_t skip_r = + vtbl1_s8(skip_reference, source_reference_type8); + const int64_t early_skip = + vget_lane_s64(vreinterpret_s64_s8(skip_r), 0); + // Early termination #1 if all are skips. + if (early_skip != -1) { + int64_t skip_64; + int8x8_t r, position_x8, position_y8; + int32x4_t mvs[2]; + GetPosition(division_table, mv, reference_to_current_with_sign, + x8_start, x8_end, x8, r_offsets, source_reference_type8, + skip_r, y8_floor8, y8_ceiling8, d_sign, delta, &r, + &position_y8, &position_x8, &skip_64, mvs); + // Early termination #2 if all are skips. + if (skip_64 != -1) { + const int16x8_t p_y = vmovl_s8(position_y8); + const int16x8_t p_x = vmovl_s8(position_x8); + const int16x8_t pos = vmlaq_n_s16(p_x, p_y, stride); + const int16x8_t position = vaddq_s16(pos, vdupq_n_s16(x8)); + // Store up to 7 elements since leftover is at most 7. + if (skip_64 == 0) { + // Store all. + Store<1>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<2>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<3>(position, r, mvs[0], dst_reference_offset, dst_mv); + Store<4>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<5>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<6>(position, r, mvs[1], dst_reference_offset, dst_mv); + Store<7>(position, r, mvs[1], dst_reference_offset, dst_mv); + } else { + // Check and store each. + // The compiler is smart enough to not create the local buffer + // skips[]. + int8_t skips[8]; + memcpy(skips, &skip_64, sizeof(skips)); + CheckStore<1>(skips, position, r, mvs[0], dst_reference_offset, + dst_mv); + CheckStore<2>(skips, position, r, mvs[0], dst_reference_offset, + dst_mv); + CheckStore<3>(skips, position, r, mvs[0], dst_reference_offset, + dst_mv); + CheckStore<4>(skips, position, r, mvs[1], dst_reference_offset, + dst_mv); + CheckStore<5>(skips, position, r, mvs[1], dst_reference_offset, + dst_mv); + CheckStore<6>(skips, position, r, mvs[1], dst_reference_offset, + dst_mv); + CheckStore<7>(skips, position, r, mvs[1], dst_reference_offset, + dst_mv); + } + } + } + } else { + for (; x8 < adjusted_x8_end; ++x8) { + const int source_reference_type = source_reference_types[x8]; + if (skip_references[source_reference_type]) continue; + MotionVector projection_mv; + // reference_to_current_with_sign could be 0. + GetMvProjection(mv[x8], reference_to_current_with_sign, + projection_divisions[source_reference_type], + &projection_mv); + // Do not update the motion vector if the block position is not valid + // or if position_x8 is outside the current range of x8_start and + // x8_end. Note that position_y8 will always be within the range of + // y8_start and y8_end. + const int position_y8 = Project(0, projection_mv.mv[0], dst_sign); + if (position_y8 < y8_floor || position_y8 >= y8_ceiling) continue; + const int x8_base = x8 & ~7; + const int x8_floor = + std::max(x8_start, x8_base - kProjectionMvMaxHorizontalOffset); + const int x8_ceiling = + std::min(x8_end, x8_base + 8 + kProjectionMvMaxHorizontalOffset); + const int position_x8 = Project(x8, projection_mv.mv[1], dst_sign); + if (position_x8 < x8_floor || position_x8 >= x8_ceiling) continue; + dst_mv[position_y8 * stride + position_x8] = mv[x8]; + dst_reference_offset[position_y8 * stride + position_x8] = + reference_offsets[source_reference_type]; + } + } + } + + source_reference_types += stride; + mv += stride; + dst_reference_offset += stride; + dst_mv += stride; + } while (++y8 < y8_end); +} + +void Init8bpp() { + Dsp* const dsp = dsp_internal::GetWritableDspTable(kBitdepth8); + assert(dsp != nullptr); + dsp->motion_field_projection_kernel = MotionFieldProjectionKernel_NEON; +} + +#if LIBGAV1_MAX_BITDEPTH >= 10 +void Init10bpp() { + Dsp* const dsp = dsp_internal::GetWritableDspTable(kBitdepth10); + assert(dsp != nullptr); + dsp->motion_field_projection_kernel = MotionFieldProjectionKernel_NEON; +} +#endif + +} // namespace + +void MotionFieldProjectionInit_NEON() { + Init8bpp(); +#if LIBGAV1_MAX_BITDEPTH >= 10 + Init10bpp(); +#endif +} + +} // namespace dsp +} // namespace libgav1 + +#else // !LIBGAV1_ENABLE_NEON +namespace libgav1 { +namespace dsp { + +void MotionFieldProjectionInit_NEON() {} + +} // namespace dsp +} // namespace libgav1 +#endif // LIBGAV1_ENABLE_NEON |