jfdctfst-altivec.c (4527B)
1 /* 2 * AltiVec optimizations for libjpeg-turbo 3 * 4 * Copyright (C) 2014, D. R. Commander. All Rights Reserved. 5 * 6 * This software is provided 'as-is', without any express or implied 7 * warranty. In no event will the authors be held liable for any damages 8 * arising from the use of this software. 9 * 10 * Permission is granted to anyone to use this software for any purpose, 11 * including commercial applications, and to alter it and redistribute it 12 * freely, subject to the following restrictions: 13 * 14 * 1. The origin of this software must not be misrepresented; you must not 15 * claim that you wrote the original software. If you use this software 16 * in a product, an acknowledgment in the product documentation would be 17 * appreciated but is not required. 18 * 2. Altered source versions must be plainly marked as such, and must not be 19 * misrepresented as being the original software. 20 * 3. This notice may not be removed or altered from any source distribution. 21 */ 22 23 /* FAST INTEGER FORWARD DCT 24 * 25 * This is similar to the SSE2 implementation, except that we left-shift the 26 * constants by 1 less bit (the -1 in CONST_SHIFT.) This is because 27 * vec_madds(arg1, arg2, arg3) generates the 16-bit saturated sum of: 28 * the elements in arg3 + the most significant 17 bits of 29 * (the elements in arg1 * the elements in arg2). 30 */ 31 32 #include "jsimd_altivec.h" 33 34 35 #define F_0_382 98 /* FIX(0.382683433) */ 36 #define F_0_541 139 /* FIX(0.541196100) */ 37 #define F_0_707 181 /* FIX(0.707106781) */ 38 #define F_1_306 334 /* FIX(1.306562965) */ 39 40 #define CONST_BITS 8 41 #define PRE_MULTIPLY_SCALE_BITS 2 42 #define CONST_SHIFT (16 - PRE_MULTIPLY_SCALE_BITS - CONST_BITS - 1) 43 44 45 #define DO_FDCT() { \ 46 /* Even part */ \ 47 \ 48 tmp10 = vec_add(tmp0, tmp3); \ 49 tmp13 = vec_sub(tmp0, tmp3); \ 50 tmp11 = vec_add(tmp1, tmp2); \ 51 tmp12 = vec_sub(tmp1, tmp2); \ 52 \ 53 out0 = vec_add(tmp10, tmp11); \ 54 out4 = vec_sub(tmp10, tmp11); \ 55 \ 56 z1 = vec_add(tmp12, tmp13); \ 57 z1 = vec_sl(z1, pre_multiply_scale_bits); \ 58 z1 = vec_madds(z1, pw_0707, pw_zero); \ 59 \ 60 out2 = vec_add(tmp13, z1); \ 61 out6 = vec_sub(tmp13, z1); \ 62 \ 63 /* Odd part */ \ 64 \ 65 tmp10 = vec_add(tmp4, tmp5); \ 66 tmp11 = vec_add(tmp5, tmp6); \ 67 tmp12 = vec_add(tmp6, tmp7); \ 68 \ 69 tmp10 = vec_sl(tmp10, pre_multiply_scale_bits); \ 70 tmp12 = vec_sl(tmp12, pre_multiply_scale_bits); \ 71 z5 = vec_sub(tmp10, tmp12); \ 72 z5 = vec_madds(z5, pw_0382, pw_zero); \ 73 \ 74 z2 = vec_madds(tmp10, pw_0541, z5); \ 75 z4 = vec_madds(tmp12, pw_1306, z5); \ 76 \ 77 tmp11 = vec_sl(tmp11, pre_multiply_scale_bits); \ 78 z3 = vec_madds(tmp11, pw_0707, pw_zero); \ 79 \ 80 z11 = vec_add(tmp7, z3); \ 81 z13 = vec_sub(tmp7, z3); \ 82 \ 83 out5 = vec_add(z13, z2); \ 84 out3 = vec_sub(z13, z2); \ 85 out1 = vec_add(z11, z4); \ 86 out7 = vec_sub(z11, z4); \ 87 } 88 89 90 void jsimd_fdct_ifast_altivec(DCTELEM *data) 91 { 92 __vector short row0, row1, row2, row3, row4, row5, row6, row7, 93 col0, col1, col2, col3, col4, col5, col6, col7, 94 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp10, tmp11, tmp12, tmp13, 95 z1, z2, z3, z4, z5, z11, z13, 96 out0, out1, out2, out3, out4, out5, out6, out7; 97 98 /* Constants */ 99 __vector short pw_zero = { __8X(0) }, 100 pw_0382 = { __8X(F_0_382 << CONST_SHIFT) }, 101 pw_0541 = { __8X(F_0_541 << CONST_SHIFT) }, 102 pw_0707 = { __8X(F_0_707 << CONST_SHIFT) }, 103 pw_1306 = { __8X(F_1_306 << CONST_SHIFT) }; 104 __vector unsigned short 105 pre_multiply_scale_bits = { __8X(PRE_MULTIPLY_SCALE_BITS) }; 106 107 /* Pass 1: process rows */ 108 109 row0 = vec_ld(0, data); 110 row1 = vec_ld(16, data); 111 row2 = vec_ld(32, data); 112 row3 = vec_ld(48, data); 113 row4 = vec_ld(64, data); 114 row5 = vec_ld(80, data); 115 row6 = vec_ld(96, data); 116 row7 = vec_ld(112, data); 117 118 TRANSPOSE(row, col); 119 120 tmp0 = vec_add(col0, col7); 121 tmp7 = vec_sub(col0, col7); 122 tmp1 = vec_add(col1, col6); 123 tmp6 = vec_sub(col1, col6); 124 tmp2 = vec_add(col2, col5); 125 tmp5 = vec_sub(col2, col5); 126 tmp3 = vec_add(col3, col4); 127 tmp4 = vec_sub(col3, col4); 128 129 DO_FDCT(); 130 131 /* Pass 2: process columns */ 132 133 TRANSPOSE(out, row); 134 135 tmp0 = vec_add(row0, row7); 136 tmp7 = vec_sub(row0, row7); 137 tmp1 = vec_add(row1, row6); 138 tmp6 = vec_sub(row1, row6); 139 tmp2 = vec_add(row2, row5); 140 tmp5 = vec_sub(row2, row5); 141 tmp3 = vec_add(row3, row4); 142 tmp4 = vec_sub(row3, row4); 143 144 DO_FDCT(); 145 146 vec_st(out0, 0, data); 147 vec_st(out1, 16, data); 148 vec_st(out2, 32, data); 149 vec_st(out3, 48, data); 150 vec_st(out4, 64, data); 151 vec_st(out5, 80, data); 152 vec_st(out6, 96, data); 153 vec_st(out7, 112, data); 154 }