ref: fedcf83f333820cfbcc8c35f2b0117bb1c08599e
dir: /vpx_dsp/arm/idct32x32_34_add_neon.c/
/* * Copyright (c) 2016 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 "./vpx_config.h" #include "./vpx_dsp_rtcd.h" #include "vpx_dsp/arm/idct_neon.h" #include "vpx_dsp/arm/transpose_neon.h" #include "vpx_dsp/txfm_common.h" // Only for the first pass of the _34_ variant. Since it only uses values from // the top left 8x8 it can safely assume all the remaining values are 0 and skip // an awful lot of calculations. In fact, only the first 6 columns make the cut. // None of the elements in the 7th or 8th column are used so it skips any calls // to input[67] too. // In C this does a single row of 32 for each call. Here it transposes the top // left 8x8 to allow using SIMD. // vp9/common/vp9_scan.c:vp9_default_iscan_32x32 arranges the first 34 non-zero // coefficients as follows: // 0 1 2 3 4 5 6 7 // 0 0 2 5 10 17 25 // 1 1 4 8 15 22 30 // 2 3 7 12 18 28 // 3 6 11 16 23 31 // 4 9 14 19 29 // 5 13 20 26 // 6 21 27 33 // 7 24 32 static void idct32_6_neon(const tran_low_t *input, int16_t *output) { int16x8_t in[8], s1[32], s2[32], s3[32]; in[0] = load_tran_low_to_s16q(input); input += 32; in[1] = load_tran_low_to_s16q(input); input += 32; in[2] = load_tran_low_to_s16q(input); input += 32; in[3] = load_tran_low_to_s16q(input); input += 32; in[4] = load_tran_low_to_s16q(input); input += 32; in[5] = load_tran_low_to_s16q(input); input += 32; in[6] = load_tran_low_to_s16q(input); input += 32; in[7] = load_tran_low_to_s16q(input); transpose_s16_8x8(&in[0], &in[1], &in[2], &in[3], &in[4], &in[5], &in[6], &in[7]); // stage 1 // input[1] * cospi_31_64 - input[31] * cospi_1_64 (but input[31] == 0) s1[16] = multiply_shift_and_narrow_s16(in[1], cospi_31_64); // input[1] * cospi_1_64 + input[31] * cospi_31_64 (but input[31] == 0) s1[31] = multiply_shift_and_narrow_s16(in[1], cospi_1_64); s1[20] = multiply_shift_and_narrow_s16(in[5], cospi_27_64); s1[27] = multiply_shift_and_narrow_s16(in[5], cospi_5_64); s1[23] = multiply_shift_and_narrow_s16(in[3], -cospi_29_64); s1[24] = multiply_shift_and_narrow_s16(in[3], cospi_3_64); // stage 2 s2[8] = multiply_shift_and_narrow_s16(in[2], cospi_30_64); s2[15] = multiply_shift_and_narrow_s16(in[2], cospi_2_64); // stage 3 s1[4] = multiply_shift_and_narrow_s16(in[4], cospi_28_64); s1[7] = multiply_shift_and_narrow_s16(in[4], cospi_4_64); s1[17] = multiply_accumulate_shift_and_narrow_s16(s1[16], -cospi_4_64, s1[31], cospi_28_64); s1[30] = multiply_accumulate_shift_and_narrow_s16(s1[16], cospi_28_64, s1[31], cospi_4_64); s1[21] = multiply_accumulate_shift_and_narrow_s16(s1[20], -cospi_20_64, s1[27], cospi_12_64); s1[26] = multiply_accumulate_shift_and_narrow_s16(s1[20], cospi_12_64, s1[27], cospi_20_64); s1[22] = multiply_accumulate_shift_and_narrow_s16(s1[23], -cospi_12_64, s1[24], -cospi_20_64); s1[25] = multiply_accumulate_shift_and_narrow_s16(s1[23], -cospi_20_64, s1[24], cospi_12_64); // stage 4 s1[0] = multiply_shift_and_narrow_s16(in[0], cospi_16_64); s2[9] = multiply_accumulate_shift_and_narrow_s16(s2[8], -cospi_8_64, s2[15], cospi_24_64); s2[14] = multiply_accumulate_shift_and_narrow_s16(s2[8], cospi_24_64, s2[15], cospi_8_64); s2[20] = vsubq_s16(s1[23], s1[20]); s2[21] = vsubq_s16(s1[22], s1[21]); s2[22] = vaddq_s16(s1[21], s1[22]); s2[23] = vaddq_s16(s1[20], s1[23]); s2[24] = vaddq_s16(s1[24], s1[27]); s2[25] = vaddq_s16(s1[25], s1[26]); s2[26] = vsubq_s16(s1[25], s1[26]); s2[27] = vsubq_s16(s1[24], s1[27]); // stage 5 s1[5] = sub_multiply_shift_and_narrow_s16(s1[7], s1[4], cospi_16_64); s1[6] = add_multiply_shift_and_narrow_s16(s1[4], s1[7], cospi_16_64); s1[18] = multiply_accumulate_shift_and_narrow_s16(s1[17], -cospi_8_64, s1[30], cospi_24_64); s1[29] = multiply_accumulate_shift_and_narrow_s16(s1[17], cospi_24_64, s1[30], cospi_8_64); s1[19] = multiply_accumulate_shift_and_narrow_s16(s1[16], -cospi_8_64, s1[31], cospi_24_64); s1[28] = multiply_accumulate_shift_and_narrow_s16(s1[16], cospi_24_64, s1[31], cospi_8_64); s1[20] = multiply_accumulate_shift_and_narrow_s16(s2[20], -cospi_24_64, s2[27], -cospi_8_64); s1[27] = multiply_accumulate_shift_and_narrow_s16(s2[20], -cospi_8_64, s2[27], cospi_24_64); s1[21] = multiply_accumulate_shift_and_narrow_s16(s2[21], -cospi_24_64, s2[26], -cospi_8_64); s1[26] = multiply_accumulate_shift_and_narrow_s16(s2[21], -cospi_8_64, s2[26], cospi_24_64); // stage 6 s2[0] = vaddq_s16(s1[0], s1[7]); s2[1] = vaddq_s16(s1[0], s1[6]); s2[2] = vaddq_s16(s1[0], s1[5]); s2[3] = vaddq_s16(s1[0], s1[4]); s2[4] = vsubq_s16(s1[0], s1[4]); s2[5] = vsubq_s16(s1[0], s1[5]); s2[6] = vsubq_s16(s1[0], s1[6]); s2[7] = vsubq_s16(s1[0], s1[7]); s2[10] = sub_multiply_shift_and_narrow_s16(s2[14], s2[9], cospi_16_64); s2[13] = add_multiply_shift_and_narrow_s16(s2[9], s2[14], cospi_16_64); s2[11] = sub_multiply_shift_and_narrow_s16(s2[15], s2[8], cospi_16_64); s2[12] = add_multiply_shift_and_narrow_s16(s2[8], s2[15], cospi_16_64); s2[16] = vaddq_s16(s1[16], s2[23]); s2[17] = vaddq_s16(s1[17], s2[22]); s2[18] = vaddq_s16(s1[18], s1[21]); s2[19] = vaddq_s16(s1[19], s1[20]); s2[20] = vsubq_s16(s1[19], s1[20]); s2[21] = vsubq_s16(s1[18], s1[21]); s2[22] = vsubq_s16(s1[17], s2[22]); s2[23] = vsubq_s16(s1[16], s2[23]); s3[24] = vsubq_s16(s1[31], s2[24]); s3[25] = vsubq_s16(s1[30], s2[25]); s3[26] = vsubq_s16(s1[29], s1[26]); s3[27] = vsubq_s16(s1[28], s1[27]); s2[28] = vaddq_s16(s1[27], s1[28]); s2[29] = vaddq_s16(s1[26], s1[29]); s2[30] = vaddq_s16(s2[25], s1[30]); s2[31] = vaddq_s16(s2[24], s1[31]); // stage 7 s1[0] = vaddq_s16(s2[0], s2[15]); s1[1] = vaddq_s16(s2[1], s2[14]); s1[2] = vaddq_s16(s2[2], s2[13]); s1[3] = vaddq_s16(s2[3], s2[12]); s1[4] = vaddq_s16(s2[4], s2[11]); s1[5] = vaddq_s16(s2[5], s2[10]); s1[6] = vaddq_s16(s2[6], s2[9]); s1[7] = vaddq_s16(s2[7], s2[8]); s1[8] = vsubq_s16(s2[7], s2[8]); s1[9] = vsubq_s16(s2[6], s2[9]); s1[10] = vsubq_s16(s2[5], s2[10]); s1[11] = vsubq_s16(s2[4], s2[11]); s1[12] = vsubq_s16(s2[3], s2[12]); s1[13] = vsubq_s16(s2[2], s2[13]); s1[14] = vsubq_s16(s2[1], s2[14]); s1[15] = vsubq_s16(s2[0], s2[15]); s1[20] = sub_multiply_shift_and_narrow_s16(s3[27], s2[20], cospi_16_64); s1[27] = add_multiply_shift_and_narrow_s16(s2[20], s3[27], cospi_16_64); s1[21] = sub_multiply_shift_and_narrow_s16(s3[26], s2[21], cospi_16_64); s1[26] = add_multiply_shift_and_narrow_s16(s2[21], s3[26], cospi_16_64); s1[22] = sub_multiply_shift_and_narrow_s16(s3[25], s2[22], cospi_16_64); s1[25] = add_multiply_shift_and_narrow_s16(s2[22], s3[25], cospi_16_64); s1[23] = sub_multiply_shift_and_narrow_s16(s3[24], s2[23], cospi_16_64); s1[24] = add_multiply_shift_and_narrow_s16(s2[23], s3[24], cospi_16_64); // final stage vst1q_s16(output, vaddq_s16(s1[0], s2[31])); output += 8; vst1q_s16(output, vaddq_s16(s1[1], s2[30])); output += 8; vst1q_s16(output, vaddq_s16(s1[2], s2[29])); output += 8; vst1q_s16(output, vaddq_s16(s1[3], s2[28])); output += 8; vst1q_s16(output, vaddq_s16(s1[4], s1[27])); output += 8; vst1q_s16(output, vaddq_s16(s1[5], s1[26])); output += 8; vst1q_s16(output, vaddq_s16(s1[6], s1[25])); output += 8; vst1q_s16(output, vaddq_s16(s1[7], s1[24])); output += 8; vst1q_s16(output, vaddq_s16(s1[8], s1[23])); output += 8; vst1q_s16(output, vaddq_s16(s1[9], s1[22])); output += 8; vst1q_s16(output, vaddq_s16(s1[10], s1[21])); output += 8; vst1q_s16(output, vaddq_s16(s1[11], s1[20])); output += 8; vst1q_s16(output, vaddq_s16(s1[12], s2[19])); output += 8; vst1q_s16(output, vaddq_s16(s1[13], s2[18])); output += 8; vst1q_s16(output, vaddq_s16(s1[14], s2[17])); output += 8; vst1q_s16(output, vaddq_s16(s1[15], s2[16])); output += 8; vst1q_s16(output, vsubq_s16(s1[15], s2[16])); output += 8; vst1q_s16(output, vsubq_s16(s1[14], s2[17])); output += 8; vst1q_s16(output, vsubq_s16(s1[13], s2[18])); output += 8; vst1q_s16(output, vsubq_s16(s1[12], s2[19])); output += 8; vst1q_s16(output, vsubq_s16(s1[11], s1[20])); output += 8; vst1q_s16(output, vsubq_s16(s1[10], s1[21])); output += 8; vst1q_s16(output, vsubq_s16(s1[9], s1[22])); output += 8; vst1q_s16(output, vsubq_s16(s1[8], s1[23])); output += 8; vst1q_s16(output, vsubq_s16(s1[7], s1[24])); output += 8; vst1q_s16(output, vsubq_s16(s1[6], s1[25])); output += 8; vst1q_s16(output, vsubq_s16(s1[5], s1[26])); output += 8; vst1q_s16(output, vsubq_s16(s1[4], s1[27])); output += 8; vst1q_s16(output, vsubq_s16(s1[3], s2[28])); output += 8; vst1q_s16(output, vsubq_s16(s1[2], s2[29])); output += 8; vst1q_s16(output, vsubq_s16(s1[1], s2[30])); output += 8; vst1q_s16(output, vsubq_s16(s1[0], s2[31])); } static void idct32_8_neon(const int16_t *input, uint8_t *output, int stride) { int16x8_t in[8], s1[32], s2[32], s3[32], out[8]; load_and_transpose_s16_8x8(input, 8, &in[0], &in[1], &in[2], &in[3], &in[4], &in[5], &in[6], &in[7]); // stage 1 s1[16] = multiply_shift_and_narrow_s16(in[1], cospi_31_64); s1[31] = multiply_shift_and_narrow_s16(in[1], cospi_1_64); // Different for _8_ s1[19] = multiply_shift_and_narrow_s16(in[7], -cospi_25_64); s1[28] = multiply_shift_and_narrow_s16(in[7], cospi_7_64); s1[20] = multiply_shift_and_narrow_s16(in[5], cospi_27_64); s1[27] = multiply_shift_and_narrow_s16(in[5], cospi_5_64); s1[23] = multiply_shift_and_narrow_s16(in[3], -cospi_29_64); s1[24] = multiply_shift_and_narrow_s16(in[3], cospi_3_64); // stage 2 s2[8] = multiply_shift_and_narrow_s16(in[2], cospi_30_64); s2[15] = multiply_shift_and_narrow_s16(in[2], cospi_2_64); s2[11] = multiply_shift_and_narrow_s16(in[6], -cospi_26_64); s2[12] = multiply_shift_and_narrow_s16(in[6], cospi_6_64); // stage 3 s1[4] = multiply_shift_and_narrow_s16(in[4], cospi_28_64); s1[7] = multiply_shift_and_narrow_s16(in[4], cospi_4_64); s1[17] = multiply_accumulate_shift_and_narrow_s16(s1[16], -cospi_4_64, s1[31], cospi_28_64); s1[30] = multiply_accumulate_shift_and_narrow_s16(s1[16], cospi_28_64, s1[31], cospi_4_64); // Different for _8_ s1[18] = multiply_accumulate_shift_and_narrow_s16(s1[19], -cospi_28_64, s1[28], -cospi_4_64); s1[29] = multiply_accumulate_shift_and_narrow_s16(s1[19], -cospi_4_64, s1[28], cospi_28_64); s1[21] = multiply_accumulate_shift_and_narrow_s16(s1[20], -cospi_20_64, s1[27], cospi_12_64); s1[26] = multiply_accumulate_shift_and_narrow_s16(s1[20], cospi_12_64, s1[27], cospi_20_64); s1[22] = multiply_accumulate_shift_and_narrow_s16(s1[23], -cospi_12_64, s1[24], -cospi_20_64); s1[25] = multiply_accumulate_shift_and_narrow_s16(s1[23], -cospi_20_64, s1[24], cospi_12_64); // stage 4 s1[0] = multiply_shift_and_narrow_s16(in[0], cospi_16_64); s2[9] = multiply_accumulate_shift_and_narrow_s16(s2[8], -cospi_8_64, s2[15], cospi_24_64); s2[14] = multiply_accumulate_shift_and_narrow_s16(s2[8], cospi_24_64, s2[15], cospi_8_64); s2[10] = multiply_accumulate_shift_and_narrow_s16(s2[11], -cospi_24_64, s2[12], -cospi_8_64); s2[13] = multiply_accumulate_shift_and_narrow_s16(s2[11], -cospi_8_64, s2[12], cospi_24_64); s2[16] = vaddq_s16(s1[16], s1[19]); s2[17] = vaddq_s16(s1[17], s1[18]); s2[18] = vsubq_s16(s1[17], s1[18]); s2[19] = vsubq_s16(s1[16], s1[19]); s2[20] = vsubq_s16(s1[23], s1[20]); s2[21] = vsubq_s16(s1[22], s1[21]); s2[22] = vaddq_s16(s1[21], s1[22]); s2[23] = vaddq_s16(s1[20], s1[23]); s2[24] = vaddq_s16(s1[24], s1[27]); s2[25] = vaddq_s16(s1[25], s1[26]); s2[26] = vsubq_s16(s1[25], s1[26]); s2[27] = vsubq_s16(s1[24], s1[27]); s2[28] = vsubq_s16(s1[31], s1[28]); s2[29] = vsubq_s16(s1[30], s1[29]); s2[30] = vaddq_s16(s1[29], s1[30]); s2[31] = vaddq_s16(s1[28], s1[31]); // stage 5 s1[5] = sub_multiply_shift_and_narrow_s16(s1[7], s1[4], cospi_16_64); s1[6] = add_multiply_shift_and_narrow_s16(s1[4], s1[7], cospi_16_64); s1[8] = vaddq_s16(s2[8], s2[11]); s1[9] = vaddq_s16(s2[9], s2[10]); s1[10] = vsubq_s16(s2[9], s2[10]); s1[11] = vsubq_s16(s2[8], s2[11]); s1[12] = vsubq_s16(s2[15], s2[12]); s1[13] = vsubq_s16(s2[14], s2[13]); s1[14] = vaddq_s16(s2[13], s2[14]); s1[15] = vaddq_s16(s2[12], s2[15]); s1[18] = multiply_accumulate_shift_and_narrow_s16(s2[18], -cospi_8_64, s2[29], cospi_24_64); s1[29] = multiply_accumulate_shift_and_narrow_s16(s2[18], cospi_24_64, s2[29], cospi_8_64); s1[19] = multiply_accumulate_shift_and_narrow_s16(s2[19], -cospi_8_64, s2[28], cospi_24_64); s1[28] = multiply_accumulate_shift_and_narrow_s16(s2[19], cospi_24_64, s2[28], cospi_8_64); s1[20] = multiply_accumulate_shift_and_narrow_s16(s2[20], -cospi_24_64, s2[27], -cospi_8_64); s1[27] = multiply_accumulate_shift_and_narrow_s16(s2[20], -cospi_8_64, s2[27], cospi_24_64); s1[21] = multiply_accumulate_shift_and_narrow_s16(s2[21], -cospi_24_64, s2[26], -cospi_8_64); s1[26] = multiply_accumulate_shift_and_narrow_s16(s2[21], -cospi_8_64, s2[26], cospi_24_64); // stage 6 s2[0] = vaddq_s16(s1[0], s1[7]); s2[1] = vaddq_s16(s1[0], s1[6]); s2[2] = vaddq_s16(s1[0], s1[5]); s2[3] = vaddq_s16(s1[0], s1[4]); s2[4] = vsubq_s16(s1[0], s1[4]); s2[5] = vsubq_s16(s1[0], s1[5]); s2[6] = vsubq_s16(s1[0], s1[6]); s2[7] = vsubq_s16(s1[0], s1[7]); s2[10] = sub_multiply_shift_and_narrow_s16(s1[13], s1[10], cospi_16_64); s2[13] = add_multiply_shift_and_narrow_s16(s1[10], s1[13], cospi_16_64); s2[11] = sub_multiply_shift_and_narrow_s16(s1[12], s1[11], cospi_16_64); s2[12] = add_multiply_shift_and_narrow_s16(s1[11], s1[12], cospi_16_64); s1[16] = vaddq_s16(s2[16], s2[23]); s1[17] = vaddq_s16(s2[17], s2[22]); s2[18] = vaddq_s16(s1[18], s1[21]); s2[19] = vaddq_s16(s1[19], s1[20]); s2[20] = vsubq_s16(s1[19], s1[20]); s2[21] = vsubq_s16(s1[18], s1[21]); s1[22] = vsubq_s16(s2[17], s2[22]); s1[23] = vsubq_s16(s2[16], s2[23]); s3[24] = vsubq_s16(s2[31], s2[24]); s3[25] = vsubq_s16(s2[30], s2[25]); s3[26] = vsubq_s16(s1[29], s1[26]); s3[27] = vsubq_s16(s1[28], s1[27]); s2[28] = vaddq_s16(s1[27], s1[28]); s2[29] = vaddq_s16(s1[26], s1[29]); s2[30] = vaddq_s16(s2[25], s2[30]); s2[31] = vaddq_s16(s2[24], s2[31]); // stage 7 s1[0] = vaddq_s16(s2[0], s1[15]); s1[1] = vaddq_s16(s2[1], s1[14]); s1[2] = vaddq_s16(s2[2], s2[13]); s1[3] = vaddq_s16(s2[3], s2[12]); s1[4] = vaddq_s16(s2[4], s2[11]); s1[5] = vaddq_s16(s2[5], s2[10]); s1[6] = vaddq_s16(s2[6], s1[9]); s1[7] = vaddq_s16(s2[7], s1[8]); s1[8] = vsubq_s16(s2[7], s1[8]); s1[9] = vsubq_s16(s2[6], s1[9]); s1[10] = vsubq_s16(s2[5], s2[10]); s1[11] = vsubq_s16(s2[4], s2[11]); s1[12] = vsubq_s16(s2[3], s2[12]); s1[13] = vsubq_s16(s2[2], s2[13]); s1[14] = vsubq_s16(s2[1], s1[14]); s1[15] = vsubq_s16(s2[0], s1[15]); s1[20] = sub_multiply_shift_and_narrow_s16(s3[27], s2[20], cospi_16_64); s1[27] = add_multiply_shift_and_narrow_s16(s2[20], s3[27], cospi_16_64); s1[21] = sub_multiply_shift_and_narrow_s16(s3[26], s2[21], cospi_16_64); s1[26] = add_multiply_shift_and_narrow_s16(s2[21], s3[26], cospi_16_64); s2[22] = sub_multiply_shift_and_narrow_s16(s3[25], s1[22], cospi_16_64); s1[25] = add_multiply_shift_and_narrow_s16(s1[22], s3[25], cospi_16_64); s2[23] = sub_multiply_shift_and_narrow_s16(s3[24], s1[23], cospi_16_64); s1[24] = add_multiply_shift_and_narrow_s16(s1[23], s3[24], cospi_16_64); // final stage out[0] = vaddq_s16(s1[0], s2[31]); out[1] = vaddq_s16(s1[1], s2[30]); out[2] = vaddq_s16(s1[2], s2[29]); out[3] = vaddq_s16(s1[3], s2[28]); out[4] = vaddq_s16(s1[4], s1[27]); out[5] = vaddq_s16(s1[5], s1[26]); out[6] = vaddq_s16(s1[6], s1[25]); out[7] = vaddq_s16(s1[7], s1[24]); add_and_store_u8_s16(out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7], output, stride); out[0] = vaddq_s16(s1[8], s2[23]); out[1] = vaddq_s16(s1[9], s2[22]); out[2] = vaddq_s16(s1[10], s1[21]); out[3] = vaddq_s16(s1[11], s1[20]); out[4] = vaddq_s16(s1[12], s2[19]); out[5] = vaddq_s16(s1[13], s2[18]); out[6] = vaddq_s16(s1[14], s1[17]); out[7] = vaddq_s16(s1[15], s1[16]); add_and_store_u8_s16(out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7], output + (8 * stride), stride); out[0] = vsubq_s16(s1[15], s1[16]); out[1] = vsubq_s16(s1[14], s1[17]); out[2] = vsubq_s16(s1[13], s2[18]); out[3] = vsubq_s16(s1[12], s2[19]); out[4] = vsubq_s16(s1[11], s1[20]); out[5] = vsubq_s16(s1[10], s1[21]); out[6] = vsubq_s16(s1[9], s2[22]); out[7] = vsubq_s16(s1[8], s2[23]); add_and_store_u8_s16(out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7], output + (16 * stride), stride); out[0] = vsubq_s16(s1[7], s1[24]); out[1] = vsubq_s16(s1[6], s1[25]); out[2] = vsubq_s16(s1[5], s1[26]); out[3] = vsubq_s16(s1[4], s1[27]); out[4] = vsubq_s16(s1[3], s2[28]); out[5] = vsubq_s16(s1[2], s2[29]); out[6] = vsubq_s16(s1[1], s2[30]); out[7] = vsubq_s16(s1[0], s2[31]); add_and_store_u8_s16(out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7], output + (24 * stride), stride); } void vpx_idct32x32_34_add_neon(const tran_low_t *input, uint8_t *dest, int stride) { int i; int16_t temp[32 * 8]; int16_t *t = temp; idct32_6_neon(input, t); for (i = 0; i < 32; i += 8) { idct32_8_neon(t, dest, stride); t += (8 * 8); dest += 8; } }