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1 /*
2  *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include <smmintrin.h> /* SSE4.1 */
12 
13 #include "./vp8_rtcd.h"
14 #include "vp8/encoder/block.h"
15 #include "vpx_ports/bitops.h" /* get_lsb */
16 #include "vpx_ports/compiler_attributes.h"
17 
18 // Unsigned shift overflow is disabled for the use of ~1U << eob with ymask.
vp8_regular_quantize_b_sse4_1(BLOCK * b,BLOCKD * d)19 VPX_NO_UNSIGNED_SHIFT_CHECK void vp8_regular_quantize_b_sse4_1(BLOCK *b,
20                                                                BLOCKD *d) {
21   int eob = -1;
22   short *zbin_boost_ptr = b->zrun_zbin_boost;
23   __m128i zbin_boost0 = _mm_load_si128((__m128i *)(zbin_boost_ptr));
24   __m128i zbin_boost1 = _mm_load_si128((__m128i *)(zbin_boost_ptr + 8));
25   __m128i x0, x1, y0, y1, x_minus_zbin0, x_minus_zbin1, dqcoeff0, dqcoeff1;
26   __m128i quant_shift0 = _mm_load_si128((__m128i *)(b->quant_shift));
27   __m128i quant_shift1 = _mm_load_si128((__m128i *)(b->quant_shift + 8));
28   __m128i z0 = _mm_load_si128((__m128i *)(b->coeff));
29   __m128i z1 = _mm_load_si128((__m128i *)(b->coeff + 8));
30   __m128i zbin_extra = _mm_cvtsi32_si128(b->zbin_extra);
31   __m128i zbin0 = _mm_load_si128((__m128i *)(b->zbin));
32   __m128i zbin1 = _mm_load_si128((__m128i *)(b->zbin + 8));
33   __m128i round0 = _mm_load_si128((__m128i *)(b->round));
34   __m128i round1 = _mm_load_si128((__m128i *)(b->round + 8));
35   __m128i quant0 = _mm_load_si128((__m128i *)(b->quant));
36   __m128i quant1 = _mm_load_si128((__m128i *)(b->quant + 8));
37   __m128i dequant0 = _mm_load_si128((__m128i *)(d->dequant));
38   __m128i dequant1 = _mm_load_si128((__m128i *)(d->dequant + 8));
39   __m128i qcoeff0, qcoeff1, t0, t1, x_shuf0, x_shuf1;
40   uint32_t mask, ymask;
41   DECLARE_ALIGNED(16, static const uint8_t,
42                   zig_zag_mask[16]) = { 0, 1,  4,  8,  5, 2,  3,  6,
43                                         9, 12, 13, 10, 7, 11, 14, 15 };
44   DECLARE_ALIGNED(16, uint16_t, qcoeff[16]) = { 0 };
45 
46   /* Duplicate to all lanes. */
47   zbin_extra = _mm_shufflelo_epi16(zbin_extra, 0);
48   zbin_extra = _mm_unpacklo_epi16(zbin_extra, zbin_extra);
49 
50   /* x = abs(z) */
51   x0 = _mm_abs_epi16(z0);
52   x1 = _mm_abs_epi16(z1);
53 
54   /* zbin[] + zbin_extra */
55   zbin0 = _mm_add_epi16(zbin0, zbin_extra);
56   zbin1 = _mm_add_epi16(zbin1, zbin_extra);
57 
58   /* In C x is compared to zbin where zbin = zbin[] + boost + extra. Rebalance
59    * the equation because boost is the only value which can change:
60    * x - (zbin[] + extra) >= boost */
61   x_minus_zbin0 = _mm_sub_epi16(x0, zbin0);
62   x_minus_zbin1 = _mm_sub_epi16(x1, zbin1);
63 
64   /* All the remaining calculations are valid whether they are done now with
65    * simd or later inside the loop one at a time. */
66   x0 = _mm_add_epi16(x0, round0);
67   x1 = _mm_add_epi16(x1, round1);
68 
69   y0 = _mm_mulhi_epi16(x0, quant0);
70   y1 = _mm_mulhi_epi16(x1, quant1);
71 
72   y0 = _mm_add_epi16(y0, x0);
73   y1 = _mm_add_epi16(y1, x1);
74 
75   /* Instead of shifting each value independently we convert the scaling
76    * factor with 1 << (16 - shift) so we can use multiply/return high half. */
77   y0 = _mm_mulhi_epi16(y0, quant_shift0);
78   y1 = _mm_mulhi_epi16(y1, quant_shift1);
79 
80   /* Restore the sign. */
81   y0 = _mm_sign_epi16(y0, z0);
82   y1 = _mm_sign_epi16(y1, z1);
83 
84   {
85     const __m128i zig_zag_i16_0 =
86         _mm_setr_epi8(0, 1, 2, 3, 8, 9, 14, 15, 10, 11, 4, 5, 6, 7, 12, 13);
87     const __m128i zig_zag_i16_1 =
88         _mm_setr_epi8(0, 1, 6, 7, 8, 9, 2, 3, 14, 15, 4, 5, 10, 11, 12, 13);
89 
90     /* The first part of the zig zag needs a value
91      * from x_minus_zbin1 and vice versa. */
92     t1 = _mm_alignr_epi8(x_minus_zbin1, x_minus_zbin1, 2);
93     t0 = _mm_blend_epi16(x_minus_zbin0, t1, 0x80);
94     t1 = _mm_blend_epi16(t1, x_minus_zbin0, 0x80);
95     x_shuf0 = _mm_shuffle_epi8(t0, zig_zag_i16_0);
96     x_shuf1 = _mm_shuffle_epi8(t1, zig_zag_i16_1);
97   }
98 
99   /* Check if y is nonzero and put it in zig zag order. */
100   t0 = _mm_packs_epi16(y0, y1);
101   t0 = _mm_cmpeq_epi8(t0, _mm_setzero_si128());
102   t0 = _mm_shuffle_epi8(t0, _mm_load_si128((const __m128i *)zig_zag_mask));
103   ymask = _mm_movemask_epi8(t0) ^ 0xffff;
104 
105   for (;;) {
106     t0 = _mm_cmpgt_epi16(zbin_boost0, x_shuf0);
107     t1 = _mm_cmpgt_epi16(zbin_boost1, x_shuf1);
108     t0 = _mm_packs_epi16(t0, t1);
109     mask = _mm_movemask_epi8(t0);
110     mask = ~mask & ymask;
111     if (!mask) break;
112     /* |eob| will contain the index of the next found element where:
113      * boost[i - old_eob - 1] <= x[zigzag[i]] && y[zigzag[i]] != 0 */
114     eob = get_lsb(mask);
115     /* Need to clear the mask from processed elements so that
116      * they are no longer counted in the next iteration. */
117     ymask &= ~1U << eob;
118     /* It's safe to read ahead of this buffer if struct VP8_COMP has at
119      * least 32 bytes before the zrun_zbin_boost_* fields (it has 384).
120      * Any data read outside of the buffer is masked by the updated |ymask|. */
121     zbin_boost0 = _mm_loadu_si128((__m128i *)(zbin_boost_ptr - eob - 1));
122     zbin_boost1 = _mm_loadu_si128((__m128i *)(zbin_boost_ptr - eob + 7));
123     qcoeff[zig_zag_mask[eob]] = 0xffff;
124   }
125 
126   qcoeff0 = _mm_load_si128((__m128i *)(qcoeff));
127   qcoeff1 = _mm_load_si128((__m128i *)(qcoeff + 8));
128   qcoeff0 = _mm_and_si128(qcoeff0, y0);
129   qcoeff1 = _mm_and_si128(qcoeff1, y1);
130 
131   _mm_store_si128((__m128i *)(d->qcoeff), qcoeff0);
132   _mm_store_si128((__m128i *)(d->qcoeff + 8), qcoeff1);
133 
134   dqcoeff0 = _mm_mullo_epi16(qcoeff0, dequant0);
135   dqcoeff1 = _mm_mullo_epi16(qcoeff1, dequant1);
136 
137   _mm_store_si128((__m128i *)(d->dqcoeff), dqcoeff0);
138   _mm_store_si128((__m128i *)(d->dqcoeff + 8), dqcoeff1);
139 
140   *d->eob = eob + 1;
141 }
142