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Diffstat (limited to 'gfx/2d/ConvolutionFilterNEON.cpp')
| -rw-r--r-- | gfx/2d/ConvolutionFilterNEON.cpp | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/gfx/2d/ConvolutionFilterNEON.cpp b/gfx/2d/ConvolutionFilterNEON.cpp new file mode 100644 index 0000000000..9983a0681a --- /dev/null +++ b/gfx/2d/ConvolutionFilterNEON.cpp @@ -0,0 +1,287 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 2011-2016 Google Inc. +// Use of this source code is governed by a BSD-style license that can be +// found in the gfx/skia/LICENSE file. + +#include "SkConvolver.h" +#include "mozilla/Attributes.h" +#include <arm_neon.h> + +namespace skia { + +static MOZ_ALWAYS_INLINE void AccumRemainder( + const unsigned char* pixelsLeft, + const SkConvolutionFilter1D::ConvolutionFixed* filterValues, + int32x4_t& accum, int r) { + int remainder[4] = {0}; + for (int i = 0; i < r; i++) { + SkConvolutionFilter1D::ConvolutionFixed coeff = filterValues[i]; + remainder[0] += coeff * pixelsLeft[i * 4 + 0]; + remainder[1] += coeff * pixelsLeft[i * 4 + 1]; + remainder[2] += coeff * pixelsLeft[i * 4 + 2]; + remainder[3] += coeff * pixelsLeft[i * 4 + 3]; + } + int32x4_t t = {remainder[0], remainder[1], remainder[2], remainder[3]}; + accum += t; +} + +// Convolves horizontally along a single row. The row data is given in +// |srcData| and continues for the numValues() of the filter. +void convolve_horizontally_neon(const unsigned char* srcData, + const SkConvolutionFilter1D& filter, + unsigned char* outRow, bool /*hasAlpha*/) { + // Loop over each pixel on this row in the output image. + int numValues = filter.numValues(); + for (int outX = 0; outX < numValues; outX++) { + uint8x8_t coeff_mask0 = vcreate_u8(0x0100010001000100); + uint8x8_t coeff_mask1 = vcreate_u8(0x0302030203020302); + uint8x8_t coeff_mask2 = vcreate_u8(0x0504050405040504); + uint8x8_t coeff_mask3 = vcreate_u8(0x0706070607060706); + // Get the filter that determines the current output pixel. + int filterOffset, filterLength; + const SkConvolutionFilter1D::ConvolutionFixed* filterValues = + filter.FilterForValue(outX, &filterOffset, &filterLength); + + // Compute the first pixel in this row that the filter affects. It will + // touch |filterLength| pixels (4 bytes each) after this. + const unsigned char* rowToFilter = &srcData[filterOffset * 4]; + + // Apply the filter to the row to get the destination pixel in |accum|. + int32x4_t accum = vdupq_n_s32(0); + for (int filterX = 0; filterX < filterLength >> 2; filterX++) { + // Load 4 coefficients + int16x4_t coeffs, coeff0, coeff1, coeff2, coeff3; + coeffs = vld1_s16(filterValues); + coeff0 = vreinterpret_s16_u8( + vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask0)); + coeff1 = vreinterpret_s16_u8( + vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask1)); + coeff2 = vreinterpret_s16_u8( + vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask2)); + coeff3 = vreinterpret_s16_u8( + vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask3)); + + // Load pixels and calc + uint8x16_t pixels = vld1q_u8(rowToFilter); + int16x8_t p01_16 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(pixels))); + int16x8_t p23_16 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(pixels))); + + int16x4_t p0_src = vget_low_s16(p01_16); + int16x4_t p1_src = vget_high_s16(p01_16); + int16x4_t p2_src = vget_low_s16(p23_16); + int16x4_t p3_src = vget_high_s16(p23_16); + + int32x4_t p0 = vmull_s16(p0_src, coeff0); + int32x4_t p1 = vmull_s16(p1_src, coeff1); + int32x4_t p2 = vmull_s16(p2_src, coeff2); + int32x4_t p3 = vmull_s16(p3_src, coeff3); + + accum += p0; + accum += p1; + accum += p2; + accum += p3; + + // Advance the pointers + rowToFilter += 16; + filterValues += 4; + } + + int r = filterLength & 3; + if (r) { + int remainder_offset = (filterOffset + filterLength - r) * 4; + AccumRemainder(srcData + remainder_offset, filterValues, accum, r); + } + + // Bring this value back in range. All of the filter scaling factors + // are in fixed point with kShiftBits bits of fractional part. + accum = vshrq_n_s32(accum, SkConvolutionFilter1D::kShiftBits); + + // Pack and store the new pixel. + int16x4_t accum16 = vqmovn_s32(accum); + uint8x8_t accum8 = vqmovun_s16(vcombine_s16(accum16, accum16)); + vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow), + vreinterpret_u32_u8(accum8), 0); + outRow += 4; + } +} + +// Does vertical convolution to produce one output row. The filter values and +// length are given in the first two parameters. These are applied to each +// of the rows pointed to in the |sourceDataRows| array, with each row +// being |pixelWidth| wide. +// +// The output must have room for |pixelWidth * 4| bytes. +template <bool hasAlpha> +static void ConvolveVertically( + const SkConvolutionFilter1D::ConvolutionFixed* filterValues, + int filterLength, unsigned char* const* sourceDataRows, int pixelWidth, + unsigned char* outRow) { + int width = pixelWidth & ~3; + + // Output four pixels per iteration (16 bytes). + for (int outX = 0; outX < width; outX += 4) { + // Accumulated result for each pixel. 32 bits per RGBA channel. + int32x4_t accum0 = vdupq_n_s32(0); + int32x4_t accum1 = vdupq_n_s32(0); + int32x4_t accum2 = vdupq_n_s32(0); + int32x4_t accum3 = vdupq_n_s32(0); + + // Convolve with one filter coefficient per iteration. + for (int filterY = 0; filterY < filterLength; filterY++) { + // Duplicate the filter coefficient 4 times. + // [16] cj cj cj cj + int16x4_t coeff16 = vdup_n_s16(filterValues[filterY]); + + // Load four pixels (16 bytes) together. + // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0 + uint8x16_t src8 = vld1q_u8(&sourceDataRows[filterY][outX << 2]); + + int16x8_t src16_01 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(src8))); + int16x8_t src16_23 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(src8))); + int16x4_t src16_0 = vget_low_s16(src16_01); + int16x4_t src16_1 = vget_high_s16(src16_01); + int16x4_t src16_2 = vget_low_s16(src16_23); + int16x4_t src16_3 = vget_high_s16(src16_23); + + accum0 += vmull_s16(src16_0, coeff16); + accum1 += vmull_s16(src16_1, coeff16); + accum2 += vmull_s16(src16_2, coeff16); + accum3 += vmull_s16(src16_3, coeff16); + } + + // Shift right for fixed point implementation. + accum0 = vshrq_n_s32(accum0, SkConvolutionFilter1D::kShiftBits); + accum1 = vshrq_n_s32(accum1, SkConvolutionFilter1D::kShiftBits); + accum2 = vshrq_n_s32(accum2, SkConvolutionFilter1D::kShiftBits); + accum3 = vshrq_n_s32(accum3, SkConvolutionFilter1D::kShiftBits); + + // Packing 32 bits |accum| to 16 bits per channel (signed saturation). + // [16] a1 b1 g1 r1 a0 b0 g0 r0 + int16x8_t accum16_0 = vcombine_s16(vqmovn_s32(accum0), vqmovn_s32(accum1)); + // [16] a3 b3 g3 r3 a2 b2 g2 r2 + int16x8_t accum16_1 = vcombine_s16(vqmovn_s32(accum2), vqmovn_s32(accum3)); + + // Packing 16 bits |accum| to 8 bits per channel (unsigned saturation). + // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0 + uint8x16_t accum8 = + vcombine_u8(vqmovun_s16(accum16_0), vqmovun_s16(accum16_1)); + + if (hasAlpha) { + // Compute the max(ri, gi, bi) for each pixel. + // [8] xx a3 b3 g3 xx a2 b2 g2 xx a1 b1 g1 xx a0 b0 g0 + uint8x16_t a = + vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 8)); + // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0 + uint8x16_t b = vmaxq_u8(a, accum8); // Max of r and g + // [8] xx xx a3 b3 xx xx a2 b2 xx xx a1 b1 xx xx a0 b0 + a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 16)); + // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0 + b = vmaxq_u8(a, b); // Max of r and g and b. + // [8] max3 00 00 00 max2 00 00 00 max1 00 00 00 max0 00 00 00 + b = vreinterpretq_u8_u32(vshlq_n_u32(vreinterpretq_u32_u8(b), 24)); + + // Make sure the value of alpha channel is always larger than maximum + // value of color channels. + accum8 = vmaxq_u8(b, accum8); + } else { + // Set value of alpha channels to 0xFF. + accum8 = vreinterpretq_u8_u32(vreinterpretq_u32_u8(accum8) | + vdupq_n_u32(0xFF000000)); + } + + // Store the convolution result (16 bytes) and advance the pixel pointers. + vst1q_u8(outRow, accum8); + outRow += 16; + } + + // Process the leftovers when the width of the output is not divisible + // by 4, that is at most 3 pixels. + int r = pixelWidth & 3; + if (r) { + int32x4_t accum0 = vdupq_n_s32(0); + int32x4_t accum1 = vdupq_n_s32(0); + int32x4_t accum2 = vdupq_n_s32(0); + + for (int filterY = 0; filterY < filterLength; ++filterY) { + int16x4_t coeff16 = vdup_n_s16(filterValues[filterY]); + + // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0 + uint8x16_t src8 = vld1q_u8(&sourceDataRows[filterY][width << 2]); + + int16x8_t src16_01 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(src8))); + int16x8_t src16_23 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(src8))); + int16x4_t src16_0 = vget_low_s16(src16_01); + int16x4_t src16_1 = vget_high_s16(src16_01); + int16x4_t src16_2 = vget_low_s16(src16_23); + + accum0 += vmull_s16(src16_0, coeff16); + accum1 += vmull_s16(src16_1, coeff16); + accum2 += vmull_s16(src16_2, coeff16); + } + + accum0 = vshrq_n_s32(accum0, SkConvolutionFilter1D::kShiftBits); + accum1 = vshrq_n_s32(accum1, SkConvolutionFilter1D::kShiftBits); + accum2 = vshrq_n_s32(accum2, SkConvolutionFilter1D::kShiftBits); + + int16x8_t accum16_0 = vcombine_s16(vqmovn_s32(accum0), vqmovn_s32(accum1)); + int16x8_t accum16_1 = vcombine_s16(vqmovn_s32(accum2), vqmovn_s32(accum2)); + + uint8x16_t accum8 = + vcombine_u8(vqmovun_s16(accum16_0), vqmovun_s16(accum16_1)); + + if (hasAlpha) { + // Compute the max(ri, gi, bi) for each pixel. + // [8] xx a3 b3 g3 xx a2 b2 g2 xx a1 b1 g1 xx a0 b0 g0 + uint8x16_t a = + vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 8)); + // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0 + uint8x16_t b = vmaxq_u8(a, accum8); // Max of r and g + // [8] xx xx a3 b3 xx xx a2 b2 xx xx a1 b1 xx xx a0 b0 + a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 16)); + // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0 + b = vmaxq_u8(a, b); // Max of r and g and b. + // [8] max3 00 00 00 max2 00 00 00 max1 00 00 00 max0 00 00 00 + b = vreinterpretq_u8_u32(vshlq_n_u32(vreinterpretq_u32_u8(b), 24)); + // Make sure the value of alpha channel is always larger than maximum + // value of color channels. + accum8 = vmaxq_u8(b, accum8); + } else { + // Set value of alpha channels to 0xFF. + accum8 = vreinterpretq_u8_u32(vreinterpretq_u32_u8(accum8) | + vdupq_n_u32(0xFF000000)); + } + + switch (r) { + case 1: + vst1q_lane_u32(reinterpret_cast<uint32_t*>(outRow), + vreinterpretq_u32_u8(accum8), 0); + break; + case 2: + vst1_u32(reinterpret_cast<uint32_t*>(outRow), + vreinterpret_u32_u8(vget_low_u8(accum8))); + break; + case 3: + vst1_u32(reinterpret_cast<uint32_t*>(outRow), + vreinterpret_u32_u8(vget_low_u8(accum8))); + vst1q_lane_u32(reinterpret_cast<uint32_t*>(outRow + 8), + vreinterpretq_u32_u8(accum8), 2); + break; + } + } +} + +void convolve_vertically_neon( + const SkConvolutionFilter1D::ConvolutionFixed* filterValues, + int filterLength, unsigned char* const* sourceDataRows, int pixelWidth, + unsigned char* outRow, bool hasAlpha) { + if (hasAlpha) { + ConvolveVertically<true>(filterValues, filterLength, sourceDataRows, + pixelWidth, outRow); + } else { + ConvolveVertically<false>(filterValues, filterLength, sourceDataRows, + pixelWidth, outRow); + } +} + +} // namespace skia |