| /* |
| * AltiVec optimizations for libjpeg-turbo |
| * |
| * Copyright (C) 2015, 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. |
| */ |
| |
| /* This file is included by jdcolor-altivec.c */ |
| |
| |
| void jsimd_ycc_rgb_convert_altivec (JDIMENSION out_width, JSAMPIMAGE input_buf, |
| JDIMENSION input_row, |
| JSAMPARRAY output_buf, int num_rows) |
| { |
| JSAMPROW outptr, inptr0, inptr1, inptr2; |
| int pitch = out_width * RGB_PIXELSIZE, num_cols; |
| #if __BIG_ENDIAN__ |
| int offset; |
| #endif |
| unsigned char __attribute__((aligned(16))) tmpbuf[RGB_PIXELSIZE * 16]; |
| |
| __vector unsigned char rgb0, rgb1, rgb2, rgbx0, rgbx1, rgbx2, rgbx3, |
| y, cb, cr; |
| #if __BIG_ENDIAN__ |
| __vector unsigned char edgel, edgeh, edges, out0, out1, out2, out3; |
| #if RGB_PIXELSIZE == 4 |
| __vector unsigned char out4; |
| #endif |
| #endif |
| #if RGB_PIXELSIZE == 4 |
| __vector unsigned char rgb3; |
| #endif |
| __vector short rg0, rg1, rg2, rg3, bx0, bx1, bx2, bx3, yl, yh, cbl, cbh, |
| crl, crh, rl, rh, gl, gh, bl, bh, g0w, g1w, g2w, g3w; |
| __vector int g0, g1, g2, g3; |
| |
| /* Constants |
| * NOTE: The >> 1 is to compensate for the fact that vec_madds() returns 17 |
| * high-order bits, not 16. |
| */ |
| __vector short pw_f0402 = { __8X(F_0_402 >> 1) }, |
| pw_mf0228 = { __8X(-F_0_228 >> 1) }, |
| pw_mf0344_f0285 = { __4X2(-F_0_344, F_0_285) }, |
| pw_one = { __8X(1) }, pw_255 = { __8X(255) }, |
| pw_cj = { __8X(CENTERJSAMPLE) }; |
| __vector int pd_onehalf = { __4X(ONE_HALF) }; |
| __vector unsigned char pb_zero = { __16X(0) }, |
| #if __BIG_ENDIAN__ |
| shift_pack_index = {0,1,4,5,8,9,12,13,16,17,20,21,24,25,28,29}; |
| #else |
| shift_pack_index = {2,3,6,7,10,11,14,15,18,19,22,23,26,27,30,31}; |
| #endif |
| |
| while (--num_rows >= 0) { |
| inptr0 = input_buf[0][input_row]; |
| inptr1 = input_buf[1][input_row]; |
| inptr2 = input_buf[2][input_row]; |
| input_row++; |
| outptr = *output_buf++; |
| |
| for (num_cols = pitch; num_cols > 0; |
| num_cols -= RGB_PIXELSIZE * 16, outptr += RGB_PIXELSIZE * 16, |
| inptr0 += 16, inptr1 += 16, inptr2 += 16) { |
| |
| y = vec_ld(0, inptr0); |
| /* NOTE: We have to use vec_merge*() here because vec_unpack*() doesn't |
| * support unsigned vectors. |
| */ |
| yl = (__vector signed short)VEC_UNPACKHU(y); |
| yh = (__vector signed short)VEC_UNPACKLU(y); |
| |
| cb = vec_ld(0, inptr1); |
| cbl = (__vector signed short)VEC_UNPACKHU(cb); |
| cbh = (__vector signed short)VEC_UNPACKLU(cb); |
| cbl = vec_sub(cbl, pw_cj); |
| cbh = vec_sub(cbh, pw_cj); |
| |
| cr = vec_ld(0, inptr2); |
| crl = (__vector signed short)VEC_UNPACKHU(cr); |
| crh = (__vector signed short)VEC_UNPACKLU(cr); |
| crl = vec_sub(crl, pw_cj); |
| crh = vec_sub(crh, pw_cj); |
| |
| /* (Original) |
| * R = Y + 1.40200 * Cr |
| * G = Y - 0.34414 * Cb - 0.71414 * Cr |
| * B = Y + 1.77200 * Cb |
| * |
| * (This implementation) |
| * R = Y + 0.40200 * Cr + Cr |
| * G = Y - 0.34414 * Cb + 0.28586 * Cr - Cr |
| * B = Y - 0.22800 * Cb + Cb + Cb |
| */ |
| bl = vec_add(cbl, cbl); |
| bh = vec_add(cbh, cbh); |
| bl = vec_madds(bl, pw_mf0228, pw_one); |
| bh = vec_madds(bh, pw_mf0228, pw_one); |
| bl = vec_sra(bl, (__vector unsigned short)pw_one); |
| bh = vec_sra(bh, (__vector unsigned short)pw_one); |
| bl = vec_add(bl, cbl); |
| bh = vec_add(bh, cbh); |
| bl = vec_add(bl, cbl); |
| bh = vec_add(bh, cbh); |
| bl = vec_add(bl, yl); |
| bh = vec_add(bh, yh); |
| |
| rl = vec_add(crl, crl); |
| rh = vec_add(crh, crh); |
| rl = vec_madds(rl, pw_f0402, pw_one); |
| rh = vec_madds(rh, pw_f0402, pw_one); |
| rl = vec_sra(rl, (__vector unsigned short)pw_one); |
| rh = vec_sra(rh, (__vector unsigned short)pw_one); |
| rl = vec_add(rl, crl); |
| rh = vec_add(rh, crh); |
| rl = vec_add(rl, yl); |
| rh = vec_add(rh, yh); |
| |
| g0w = vec_mergeh(cbl, crl); |
| g1w = vec_mergel(cbl, crl); |
| g0 = vec_msums(g0w, pw_mf0344_f0285, pd_onehalf); |
| g1 = vec_msums(g1w, pw_mf0344_f0285, pd_onehalf); |
| g2w = vec_mergeh(cbh, crh); |
| g3w = vec_mergel(cbh, crh); |
| g2 = vec_msums(g2w, pw_mf0344_f0285, pd_onehalf); |
| g3 = vec_msums(g3w, pw_mf0344_f0285, pd_onehalf); |
| /* Clever way to avoid 4 shifts + 2 packs. This packs the high word from |
| * each dword into a new 16-bit vector, which is the equivalent of |
| * descaling the 32-bit results (right-shifting by 16 bits) and then |
| * packing them. |
| */ |
| gl = vec_perm((__vector short)g0, (__vector short)g1, shift_pack_index); |
| gh = vec_perm((__vector short)g2, (__vector short)g3, shift_pack_index); |
| gl = vec_sub(gl, crl); |
| gh = vec_sub(gh, crh); |
| gl = vec_add(gl, yl); |
| gh = vec_add(gh, yh); |
| |
| rg0 = vec_mergeh(rl, gl); |
| bx0 = vec_mergeh(bl, pw_255); |
| rg1 = vec_mergel(rl, gl); |
| bx1 = vec_mergel(bl, pw_255); |
| rg2 = vec_mergeh(rh, gh); |
| bx2 = vec_mergeh(bh, pw_255); |
| rg3 = vec_mergel(rh, gh); |
| bx3 = vec_mergel(bh, pw_255); |
| |
| rgbx0 = vec_packsu(rg0, bx0); |
| rgbx1 = vec_packsu(rg1, bx1); |
| rgbx2 = vec_packsu(rg2, bx2); |
| rgbx3 = vec_packsu(rg3, bx3); |
| |
| #if RGB_PIXELSIZE == 3 |
| /* rgbx0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 X0 B1 X1 B2 X2 B3 X3 |
| * rgbx1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 X4 B5 X5 B6 X6 B7 X7 |
| * rgbx2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 X8 B9 X9 Ba Xa Bb Xb |
| * rgbx3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Xc Bd Xd Be Xe Bf Xf |
| * |
| * rgb0 = R0 G0 B0 R1 G1 B1 R2 G2 B2 R3 G3 B3 R4 G4 B4 R5 |
| * rgb1 = G5 B5 R6 G6 B6 R7 G7 B7 R8 G8 B8 R9 G9 B9 Ra Ga |
| * rgb2 = Ba Rb Gb Bb Rc Gc Bc Rd Gd Bd Re Ge Be Rf Gf Bf |
| */ |
| rgb0 = vec_perm(rgbx0, rgbx1, (__vector unsigned char)RGB_INDEX0); |
| rgb1 = vec_perm(rgbx1, rgbx2, (__vector unsigned char)RGB_INDEX1); |
| rgb2 = vec_perm(rgbx2, rgbx3, (__vector unsigned char)RGB_INDEX2); |
| #else |
| /* rgbx0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 X0 B1 X1 B2 X2 B3 X3 |
| * rgbx1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 X4 B5 X5 B6 X6 B7 X7 |
| * rgbx2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 X8 B9 X9 Ba Xa Bb Xb |
| * rgbx3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Xc Bd Xd Be Xe Bf Xf |
| * |
| * rgb0 = R0 G0 B0 X0 R1 G1 B1 X1 R2 G2 B2 X2 R3 G3 B3 X3 |
| * rgb1 = R4 G4 B4 X4 R5 G5 B5 X5 R6 G6 B6 X6 R7 G7 B7 X7 |
| * rgb2 = R8 G8 B8 X8 R9 G9 B9 X9 Ra Ga Ba Xa Rb Gb Bb Xb |
| * rgb3 = Rc Gc Bc Xc Rd Gd Bd Xd Re Ge Be Xe Rf Gf Bf Xf |
| */ |
| rgb0 = vec_perm(rgbx0, rgbx0, (__vector unsigned char)RGB_INDEX); |
| rgb1 = vec_perm(rgbx1, rgbx1, (__vector unsigned char)RGB_INDEX); |
| rgb2 = vec_perm(rgbx2, rgbx2, (__vector unsigned char)RGB_INDEX); |
| rgb3 = vec_perm(rgbx3, rgbx3, (__vector unsigned char)RGB_INDEX); |
| #endif |
| |
| #if __BIG_ENDIAN__ |
| offset = (size_t)outptr & 15; |
| if (offset) { |
| __vector unsigned char unaligned_shift_index; |
| int bytes = num_cols + offset; |
| |
| if (bytes < (RGB_PIXELSIZE + 1) * 16 && (bytes & 15)) { |
| /* Slow path to prevent buffer overwrite. Since there is no way to |
| * write a partial AltiVec register, overwrite would occur on the |
| * last chunk of the last image row if the right edge is not on a |
| * 16-byte boundary. It could also occur on other rows if the bytes |
| * per row is low enough. Since we can't determine whether we're on |
| * the last image row, we have to assume every row is the last. |
| */ |
| vec_st(rgb0, 0, tmpbuf); |
| vec_st(rgb1, 16, tmpbuf); |
| vec_st(rgb2, 32, tmpbuf); |
| #if RGB_PIXELSIZE == 4 |
| vec_st(rgb3, 48, tmpbuf); |
| #endif |
| memcpy(outptr, tmpbuf, min(num_cols, RGB_PIXELSIZE * 16)); |
| } else { |
| /* Fast path */ |
| unaligned_shift_index = vec_lvsl(0, outptr); |
| edgel = vec_ld(0, outptr); |
| edgeh = vec_ld(min(num_cols - 1, RGB_PIXELSIZE * 16), outptr); |
| edges = vec_perm(edgeh, edgel, unaligned_shift_index); |
| unaligned_shift_index = vec_lvsr(0, outptr); |
| out0 = vec_perm(edges, rgb0, unaligned_shift_index); |
| out1 = vec_perm(rgb0, rgb1, unaligned_shift_index); |
| out2 = vec_perm(rgb1, rgb2, unaligned_shift_index); |
| #if RGB_PIXELSIZE == 4 |
| out3 = vec_perm(rgb2, rgb3, unaligned_shift_index); |
| out4 = vec_perm(rgb3, edges, unaligned_shift_index); |
| #else |
| out3 = vec_perm(rgb2, edges, unaligned_shift_index); |
| #endif |
| vec_st(out0, 0, outptr); |
| if (bytes > 16) |
| vec_st(out1, 16, outptr); |
| if (bytes > 32) |
| vec_st(out2, 32, outptr); |
| if (bytes > 48) |
| vec_st(out3, 48, outptr); |
| #if RGB_PIXELSIZE == 4 |
| if (bytes > 64) |
| vec_st(out4, 64, outptr); |
| #endif |
| } |
| } else { |
| #endif /* __BIG_ENDIAN__ */ |
| if (num_cols < RGB_PIXELSIZE * 16 && (num_cols & 15)) { |
| /* Slow path */ |
| VEC_ST(rgb0, 0, tmpbuf); |
| VEC_ST(rgb1, 16, tmpbuf); |
| VEC_ST(rgb2, 32, tmpbuf); |
| #if RGB_PIXELSIZE == 4 |
| VEC_ST(rgb3, 48, tmpbuf); |
| #endif |
| memcpy(outptr, tmpbuf, min(num_cols, RGB_PIXELSIZE * 16)); |
| } else { |
| /* Fast path */ |
| VEC_ST(rgb0, 0, outptr); |
| if (num_cols > 16) |
| VEC_ST(rgb1, 16, outptr); |
| if (num_cols > 32) |
| VEC_ST(rgb2, 32, outptr); |
| #if RGB_PIXELSIZE == 4 |
| if (num_cols > 48) |
| VEC_ST(rgb3, 48, outptr); |
| #endif |
| } |
| #if __BIG_ENDIAN__ |
| } |
| #endif |
| } |
| } |
| } |
