| /* |
| * jfdctint-neon.c - accurate integer FDCT (Arm Neon) |
| * |
| * Copyright (C) 2020, Arm Limited. All Rights Reserved. |
| * Copyright (C) 2020, D. R. Commander. All Rights Reserved. |
| * |
| * This software is provided 'as-is', without any express or implied |
| * warranty. In no event will the authors be held liable for any damages |
| * arising from the use of this software. |
| * |
| * Permission is granted to anyone to use this software for any purpose, |
| * including commercial applications, and to alter it and redistribute it |
| * freely, subject to the following restrictions: |
| * |
| * 1. The origin of this software must not be misrepresented; you must not |
| * claim that you wrote the original software. If you use this software |
| * in a product, an acknowledgment in the product documentation would be |
| * appreciated but is not required. |
| * 2. Altered source versions must be plainly marked as such, and must not be |
| * misrepresented as being the original software. |
| * 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| #define JPEG_INTERNALS |
| #include "../../jinclude.h" |
| #include "../../jpeglib.h" |
| #include "../../jsimd.h" |
| #include "../../jdct.h" |
| #include "../../jsimddct.h" |
| #include "../jsimd.h" |
| #include "align.h" |
| #include "neon-compat.h" |
| |
| #include <arm_neon.h> |
| |
| |
| /* jsimd_fdct_islow_neon() performs a slower but more accurate forward DCT |
| * (Discrete Cosine Transform) on one block of samples. It uses the same |
| * calculations and produces exactly the same output as IJG's original |
| * jpeg_fdct_islow() function, which can be found in jfdctint.c. |
| * |
| * Scaled integer constants are used to avoid floating-point arithmetic: |
| * 0.298631336 = 2446 * 2^-13 |
| * 0.390180644 = 3196 * 2^-13 |
| * 0.541196100 = 4433 * 2^-13 |
| * 0.765366865 = 6270 * 2^-13 |
| * 0.899976223 = 7373 * 2^-13 |
| * 1.175875602 = 9633 * 2^-13 |
| * 1.501321110 = 12299 * 2^-13 |
| * 1.847759065 = 15137 * 2^-13 |
| * 1.961570560 = 16069 * 2^-13 |
| * 2.053119869 = 16819 * 2^-13 |
| * 2.562915447 = 20995 * 2^-13 |
| * 3.072711026 = 25172 * 2^-13 |
| * |
| * See jfdctint.c for further details of the DCT algorithm. Where possible, |
| * the variable names and comments here in jsimd_fdct_islow_neon() match up |
| * with those in jpeg_fdct_islow(). |
| */ |
| |
| #define CONST_BITS 13 |
| #define PASS1_BITS 2 |
| |
| #define DESCALE_P1 (CONST_BITS - PASS1_BITS) |
| #define DESCALE_P2 (CONST_BITS + PASS1_BITS) |
| |
| #define F_0_298 2446 |
| #define F_0_390 3196 |
| #define F_0_541 4433 |
| #define F_0_765 6270 |
| #define F_0_899 7373 |
| #define F_1_175 9633 |
| #define F_1_501 12299 |
| #define F_1_847 15137 |
| #define F_1_961 16069 |
| #define F_2_053 16819 |
| #define F_2_562 20995 |
| #define F_3_072 25172 |
| |
| |
| ALIGN(16) static const int16_t jsimd_fdct_islow_neon_consts[] = { |
| F_0_298, -F_0_390, F_0_541, F_0_765, |
| -F_0_899, F_1_175, F_1_501, -F_1_847, |
| -F_1_961, F_2_053, -F_2_562, F_3_072 |
| }; |
| |
| void jsimd_fdct_islow_neon(DCTELEM *data) |
| { |
| /* Load DCT constants. */ |
| #ifdef HAVE_VLD1_S16_X3 |
| const int16x4x3_t consts = vld1_s16_x3(jsimd_fdct_islow_neon_consts); |
| #else |
| /* GCC does not currently support the intrinsic vld1_<type>_x3(). */ |
| const int16x4_t consts1 = vld1_s16(jsimd_fdct_islow_neon_consts); |
| const int16x4_t consts2 = vld1_s16(jsimd_fdct_islow_neon_consts + 4); |
| const int16x4_t consts3 = vld1_s16(jsimd_fdct_islow_neon_consts + 8); |
| const int16x4x3_t consts = { { consts1, consts2, consts3 } }; |
| #endif |
| |
| /* Load an 8x8 block of samples into Neon registers. De-interleaving loads |
| * are used, followed by vuzp to transpose the block such that we have a |
| * column of samples per vector - allowing all rows to be processed at once. |
| */ |
| int16x8x4_t s_rows_0123 = vld4q_s16(data); |
| int16x8x4_t s_rows_4567 = vld4q_s16(data + 4 * DCTSIZE); |
| |
| int16x8x2_t cols_04 = vuzpq_s16(s_rows_0123.val[0], s_rows_4567.val[0]); |
| int16x8x2_t cols_15 = vuzpq_s16(s_rows_0123.val[1], s_rows_4567.val[1]); |
| int16x8x2_t cols_26 = vuzpq_s16(s_rows_0123.val[2], s_rows_4567.val[2]); |
| int16x8x2_t cols_37 = vuzpq_s16(s_rows_0123.val[3], s_rows_4567.val[3]); |
| |
| int16x8_t col0 = cols_04.val[0]; |
| int16x8_t col1 = cols_15.val[0]; |
| int16x8_t col2 = cols_26.val[0]; |
| int16x8_t col3 = cols_37.val[0]; |
| int16x8_t col4 = cols_04.val[1]; |
| int16x8_t col5 = cols_15.val[1]; |
| int16x8_t col6 = cols_26.val[1]; |
| int16x8_t col7 = cols_37.val[1]; |
| |
| /* Pass 1: process rows. */ |
| |
| int16x8_t tmp0 = vaddq_s16(col0, col7); |
| int16x8_t tmp7 = vsubq_s16(col0, col7); |
| int16x8_t tmp1 = vaddq_s16(col1, col6); |
| int16x8_t tmp6 = vsubq_s16(col1, col6); |
| int16x8_t tmp2 = vaddq_s16(col2, col5); |
| int16x8_t tmp5 = vsubq_s16(col2, col5); |
| int16x8_t tmp3 = vaddq_s16(col3, col4); |
| int16x8_t tmp4 = vsubq_s16(col3, col4); |
| |
| /* Even part */ |
| int16x8_t tmp10 = vaddq_s16(tmp0, tmp3); |
| int16x8_t tmp13 = vsubq_s16(tmp0, tmp3); |
| int16x8_t tmp11 = vaddq_s16(tmp1, tmp2); |
| int16x8_t tmp12 = vsubq_s16(tmp1, tmp2); |
| |
| col0 = vshlq_n_s16(vaddq_s16(tmp10, tmp11), PASS1_BITS); |
| col4 = vshlq_n_s16(vsubq_s16(tmp10, tmp11), PASS1_BITS); |
| |
| int16x8_t tmp12_add_tmp13 = vaddq_s16(tmp12, tmp13); |
| int32x4_t z1_l = |
| vmull_lane_s16(vget_low_s16(tmp12_add_tmp13), consts.val[0], 2); |
| int32x4_t z1_h = |
| vmull_lane_s16(vget_high_s16(tmp12_add_tmp13), consts.val[0], 2); |
| |
| int32x4_t col2_scaled_l = |
| vmlal_lane_s16(z1_l, vget_low_s16(tmp13), consts.val[0], 3); |
| int32x4_t col2_scaled_h = |
| vmlal_lane_s16(z1_h, vget_high_s16(tmp13), consts.val[0], 3); |
| col2 = vcombine_s16(vrshrn_n_s32(col2_scaled_l, DESCALE_P1), |
| vrshrn_n_s32(col2_scaled_h, DESCALE_P1)); |
| |
| int32x4_t col6_scaled_l = |
| vmlal_lane_s16(z1_l, vget_low_s16(tmp12), consts.val[1], 3); |
| int32x4_t col6_scaled_h = |
| vmlal_lane_s16(z1_h, vget_high_s16(tmp12), consts.val[1], 3); |
| col6 = vcombine_s16(vrshrn_n_s32(col6_scaled_l, DESCALE_P1), |
| vrshrn_n_s32(col6_scaled_h, DESCALE_P1)); |
| |
| /* Odd part */ |
| int16x8_t z1 = vaddq_s16(tmp4, tmp7); |
| int16x8_t z2 = vaddq_s16(tmp5, tmp6); |
| int16x8_t z3 = vaddq_s16(tmp4, tmp6); |
| int16x8_t z4 = vaddq_s16(tmp5, tmp7); |
| /* sqrt(2) * c3 */ |
| int32x4_t z5_l = vmull_lane_s16(vget_low_s16(z3), consts.val[1], 1); |
| int32x4_t z5_h = vmull_lane_s16(vget_high_s16(z3), consts.val[1], 1); |
| z5_l = vmlal_lane_s16(z5_l, vget_low_s16(z4), consts.val[1], 1); |
| z5_h = vmlal_lane_s16(z5_h, vget_high_s16(z4), consts.val[1], 1); |
| |
| /* sqrt(2) * (-c1+c3+c5-c7) */ |
| int32x4_t tmp4_l = vmull_lane_s16(vget_low_s16(tmp4), consts.val[0], 0); |
| int32x4_t tmp4_h = vmull_lane_s16(vget_high_s16(tmp4), consts.val[0], 0); |
| /* sqrt(2) * ( c1+c3-c5+c7) */ |
| int32x4_t tmp5_l = vmull_lane_s16(vget_low_s16(tmp5), consts.val[2], 1); |
| int32x4_t tmp5_h = vmull_lane_s16(vget_high_s16(tmp5), consts.val[2], 1); |
| /* sqrt(2) * ( c1+c3+c5-c7) */ |
| int32x4_t tmp6_l = vmull_lane_s16(vget_low_s16(tmp6), consts.val[2], 3); |
| int32x4_t tmp6_h = vmull_lane_s16(vget_high_s16(tmp6), consts.val[2], 3); |
| /* sqrt(2) * ( c1+c3-c5-c7) */ |
| int32x4_t tmp7_l = vmull_lane_s16(vget_low_s16(tmp7), consts.val[1], 2); |
| int32x4_t tmp7_h = vmull_lane_s16(vget_high_s16(tmp7), consts.val[1], 2); |
| |
| /* sqrt(2) * (c7-c3) */ |
| z1_l = vmull_lane_s16(vget_low_s16(z1), consts.val[1], 0); |
| z1_h = vmull_lane_s16(vget_high_s16(z1), consts.val[1], 0); |
| /* sqrt(2) * (-c1-c3) */ |
| int32x4_t z2_l = vmull_lane_s16(vget_low_s16(z2), consts.val[2], 2); |
| int32x4_t z2_h = vmull_lane_s16(vget_high_s16(z2), consts.val[2], 2); |
| /* sqrt(2) * (-c3-c5) */ |
| int32x4_t z3_l = vmull_lane_s16(vget_low_s16(z3), consts.val[2], 0); |
| int32x4_t z3_h = vmull_lane_s16(vget_high_s16(z3), consts.val[2], 0); |
| /* sqrt(2) * (c5-c3) */ |
| int32x4_t z4_l = vmull_lane_s16(vget_low_s16(z4), consts.val[0], 1); |
| int32x4_t z4_h = vmull_lane_s16(vget_high_s16(z4), consts.val[0], 1); |
| |
| z3_l = vaddq_s32(z3_l, z5_l); |
| z3_h = vaddq_s32(z3_h, z5_h); |
| z4_l = vaddq_s32(z4_l, z5_l); |
| z4_h = vaddq_s32(z4_h, z5_h); |
| |
| tmp4_l = vaddq_s32(tmp4_l, z1_l); |
| tmp4_h = vaddq_s32(tmp4_h, z1_h); |
| tmp4_l = vaddq_s32(tmp4_l, z3_l); |
| tmp4_h = vaddq_s32(tmp4_h, z3_h); |
| col7 = vcombine_s16(vrshrn_n_s32(tmp4_l, DESCALE_P1), |
| vrshrn_n_s32(tmp4_h, DESCALE_P1)); |
| |
| tmp5_l = vaddq_s32(tmp5_l, z2_l); |
| tmp5_h = vaddq_s32(tmp5_h, z2_h); |
| tmp5_l = vaddq_s32(tmp5_l, z4_l); |
| tmp5_h = vaddq_s32(tmp5_h, z4_h); |
| col5 = vcombine_s16(vrshrn_n_s32(tmp5_l, DESCALE_P1), |
| vrshrn_n_s32(tmp5_h, DESCALE_P1)); |
| |
| tmp6_l = vaddq_s32(tmp6_l, z2_l); |
| tmp6_h = vaddq_s32(tmp6_h, z2_h); |
| tmp6_l = vaddq_s32(tmp6_l, z3_l); |
| tmp6_h = vaddq_s32(tmp6_h, z3_h); |
| col3 = vcombine_s16(vrshrn_n_s32(tmp6_l, DESCALE_P1), |
| vrshrn_n_s32(tmp6_h, DESCALE_P1)); |
| |
| tmp7_l = vaddq_s32(tmp7_l, z1_l); |
| tmp7_h = vaddq_s32(tmp7_h, z1_h); |
| tmp7_l = vaddq_s32(tmp7_l, z4_l); |
| tmp7_h = vaddq_s32(tmp7_h, z4_h); |
| col1 = vcombine_s16(vrshrn_n_s32(tmp7_l, DESCALE_P1), |
| vrshrn_n_s32(tmp7_h, DESCALE_P1)); |
| |
| /* Transpose to work on columns in pass 2. */ |
| int16x8x2_t cols_01 = vtrnq_s16(col0, col1); |
| int16x8x2_t cols_23 = vtrnq_s16(col2, col3); |
| int16x8x2_t cols_45 = vtrnq_s16(col4, col5); |
| int16x8x2_t cols_67 = vtrnq_s16(col6, col7); |
| |
| int32x4x2_t cols_0145_l = vtrnq_s32(vreinterpretq_s32_s16(cols_01.val[0]), |
| vreinterpretq_s32_s16(cols_45.val[0])); |
| int32x4x2_t cols_0145_h = vtrnq_s32(vreinterpretq_s32_s16(cols_01.val[1]), |
| vreinterpretq_s32_s16(cols_45.val[1])); |
| int32x4x2_t cols_2367_l = vtrnq_s32(vreinterpretq_s32_s16(cols_23.val[0]), |
| vreinterpretq_s32_s16(cols_67.val[0])); |
| int32x4x2_t cols_2367_h = vtrnq_s32(vreinterpretq_s32_s16(cols_23.val[1]), |
| vreinterpretq_s32_s16(cols_67.val[1])); |
| |
| int32x4x2_t rows_04 = vzipq_s32(cols_0145_l.val[0], cols_2367_l.val[0]); |
| int32x4x2_t rows_15 = vzipq_s32(cols_0145_h.val[0], cols_2367_h.val[0]); |
| int32x4x2_t rows_26 = vzipq_s32(cols_0145_l.val[1], cols_2367_l.val[1]); |
| int32x4x2_t rows_37 = vzipq_s32(cols_0145_h.val[1], cols_2367_h.val[1]); |
| |
| int16x8_t row0 = vreinterpretq_s16_s32(rows_04.val[0]); |
| int16x8_t row1 = vreinterpretq_s16_s32(rows_15.val[0]); |
| int16x8_t row2 = vreinterpretq_s16_s32(rows_26.val[0]); |
| int16x8_t row3 = vreinterpretq_s16_s32(rows_37.val[0]); |
| int16x8_t row4 = vreinterpretq_s16_s32(rows_04.val[1]); |
| int16x8_t row5 = vreinterpretq_s16_s32(rows_15.val[1]); |
| int16x8_t row6 = vreinterpretq_s16_s32(rows_26.val[1]); |
| int16x8_t row7 = vreinterpretq_s16_s32(rows_37.val[1]); |
| |
| /* Pass 2: process columns. */ |
| |
| tmp0 = vaddq_s16(row0, row7); |
| tmp7 = vsubq_s16(row0, row7); |
| tmp1 = vaddq_s16(row1, row6); |
| tmp6 = vsubq_s16(row1, row6); |
| tmp2 = vaddq_s16(row2, row5); |
| tmp5 = vsubq_s16(row2, row5); |
| tmp3 = vaddq_s16(row3, row4); |
| tmp4 = vsubq_s16(row3, row4); |
| |
| /* Even part */ |
| tmp10 = vaddq_s16(tmp0, tmp3); |
| tmp13 = vsubq_s16(tmp0, tmp3); |
| tmp11 = vaddq_s16(tmp1, tmp2); |
| tmp12 = vsubq_s16(tmp1, tmp2); |
| |
| row0 = vrshrq_n_s16(vaddq_s16(tmp10, tmp11), PASS1_BITS); |
| row4 = vrshrq_n_s16(vsubq_s16(tmp10, tmp11), PASS1_BITS); |
| |
| tmp12_add_tmp13 = vaddq_s16(tmp12, tmp13); |
| z1_l = vmull_lane_s16(vget_low_s16(tmp12_add_tmp13), consts.val[0], 2); |
| z1_h = vmull_lane_s16(vget_high_s16(tmp12_add_tmp13), consts.val[0], 2); |
| |
| int32x4_t row2_scaled_l = |
| vmlal_lane_s16(z1_l, vget_low_s16(tmp13), consts.val[0], 3); |
| int32x4_t row2_scaled_h = |
| vmlal_lane_s16(z1_h, vget_high_s16(tmp13), consts.val[0], 3); |
| row2 = vcombine_s16(vrshrn_n_s32(row2_scaled_l, DESCALE_P2), |
| vrshrn_n_s32(row2_scaled_h, DESCALE_P2)); |
| |
| int32x4_t row6_scaled_l = |
| vmlal_lane_s16(z1_l, vget_low_s16(tmp12), consts.val[1], 3); |
| int32x4_t row6_scaled_h = |
| vmlal_lane_s16(z1_h, vget_high_s16(tmp12), consts.val[1], 3); |
| row6 = vcombine_s16(vrshrn_n_s32(row6_scaled_l, DESCALE_P2), |
| vrshrn_n_s32(row6_scaled_h, DESCALE_P2)); |
| |
| /* Odd part */ |
| z1 = vaddq_s16(tmp4, tmp7); |
| z2 = vaddq_s16(tmp5, tmp6); |
| z3 = vaddq_s16(tmp4, tmp6); |
| z4 = vaddq_s16(tmp5, tmp7); |
| /* sqrt(2) * c3 */ |
| z5_l = vmull_lane_s16(vget_low_s16(z3), consts.val[1], 1); |
| z5_h = vmull_lane_s16(vget_high_s16(z3), consts.val[1], 1); |
| z5_l = vmlal_lane_s16(z5_l, vget_low_s16(z4), consts.val[1], 1); |
| z5_h = vmlal_lane_s16(z5_h, vget_high_s16(z4), consts.val[1], 1); |
| |
| /* sqrt(2) * (-c1+c3+c5-c7) */ |
| tmp4_l = vmull_lane_s16(vget_low_s16(tmp4), consts.val[0], 0); |
| tmp4_h = vmull_lane_s16(vget_high_s16(tmp4), consts.val[0], 0); |
| /* sqrt(2) * ( c1+c3-c5+c7) */ |
| tmp5_l = vmull_lane_s16(vget_low_s16(tmp5), consts.val[2], 1); |
| tmp5_h = vmull_lane_s16(vget_high_s16(tmp5), consts.val[2], 1); |
| /* sqrt(2) * ( c1+c3+c5-c7) */ |
| tmp6_l = vmull_lane_s16(vget_low_s16(tmp6), consts.val[2], 3); |
| tmp6_h = vmull_lane_s16(vget_high_s16(tmp6), consts.val[2], 3); |
| /* sqrt(2) * ( c1+c3-c5-c7) */ |
| tmp7_l = vmull_lane_s16(vget_low_s16(tmp7), consts.val[1], 2); |
| tmp7_h = vmull_lane_s16(vget_high_s16(tmp7), consts.val[1], 2); |
| |
| /* sqrt(2) * (c7-c3) */ |
| z1_l = vmull_lane_s16(vget_low_s16(z1), consts.val[1], 0); |
| z1_h = vmull_lane_s16(vget_high_s16(z1), consts.val[1], 0); |
| /* sqrt(2) * (-c1-c3) */ |
| z2_l = vmull_lane_s16(vget_low_s16(z2), consts.val[2], 2); |
| z2_h = vmull_lane_s16(vget_high_s16(z2), consts.val[2], 2); |
| /* sqrt(2) * (-c3-c5) */ |
| z3_l = vmull_lane_s16(vget_low_s16(z3), consts.val[2], 0); |
| z3_h = vmull_lane_s16(vget_high_s16(z3), consts.val[2], 0); |
| /* sqrt(2) * (c5-c3) */ |
| z4_l = vmull_lane_s16(vget_low_s16(z4), consts.val[0], 1); |
| z4_h = vmull_lane_s16(vget_high_s16(z4), consts.val[0], 1); |
| |
| z3_l = vaddq_s32(z3_l, z5_l); |
| z3_h = vaddq_s32(z3_h, z5_h); |
| z4_l = vaddq_s32(z4_l, z5_l); |
| z4_h = vaddq_s32(z4_h, z5_h); |
| |
| tmp4_l = vaddq_s32(tmp4_l, z1_l); |
| tmp4_h = vaddq_s32(tmp4_h, z1_h); |
| tmp4_l = vaddq_s32(tmp4_l, z3_l); |
| tmp4_h = vaddq_s32(tmp4_h, z3_h); |
| row7 = vcombine_s16(vrshrn_n_s32(tmp4_l, DESCALE_P2), |
| vrshrn_n_s32(tmp4_h, DESCALE_P2)); |
| |
| tmp5_l = vaddq_s32(tmp5_l, z2_l); |
| tmp5_h = vaddq_s32(tmp5_h, z2_h); |
| tmp5_l = vaddq_s32(tmp5_l, z4_l); |
| tmp5_h = vaddq_s32(tmp5_h, z4_h); |
| row5 = vcombine_s16(vrshrn_n_s32(tmp5_l, DESCALE_P2), |
| vrshrn_n_s32(tmp5_h, DESCALE_P2)); |
| |
| tmp6_l = vaddq_s32(tmp6_l, z2_l); |
| tmp6_h = vaddq_s32(tmp6_h, z2_h); |
| tmp6_l = vaddq_s32(tmp6_l, z3_l); |
| tmp6_h = vaddq_s32(tmp6_h, z3_h); |
| row3 = vcombine_s16(vrshrn_n_s32(tmp6_l, DESCALE_P2), |
| vrshrn_n_s32(tmp6_h, DESCALE_P2)); |
| |
| tmp7_l = vaddq_s32(tmp7_l, z1_l); |
| tmp7_h = vaddq_s32(tmp7_h, z1_h); |
| tmp7_l = vaddq_s32(tmp7_l, z4_l); |
| tmp7_h = vaddq_s32(tmp7_h, z4_h); |
| row1 = vcombine_s16(vrshrn_n_s32(tmp7_l, DESCALE_P2), |
| vrshrn_n_s32(tmp7_h, DESCALE_P2)); |
| |
| vst1q_s16(data + 0 * DCTSIZE, row0); |
| vst1q_s16(data + 1 * DCTSIZE, row1); |
| vst1q_s16(data + 2 * DCTSIZE, row2); |
| vst1q_s16(data + 3 * DCTSIZE, row3); |
| vst1q_s16(data + 4 * DCTSIZE, row4); |
| vst1q_s16(data + 5 * DCTSIZE, row5); |
| vst1q_s16(data + 6 * DCTSIZE, row6); |
| vst1q_s16(data + 7 * DCTSIZE, row7); |
| } |
