/* * 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 } } }