1 // Copyright 2018 Google Inc. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the COPYING file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS. All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 // -----------------------------------------------------------------------------
9 //
10 // ARM NEON version of cost functions
11
12 #include "src/dsp/dsp.h"
13
14 #if defined(WEBP_USE_NEON)
15
16 #include "src/dsp/neon.h"
17 #include "src/enc/cost_enc.h"
18
19 static const uint8_t position[16] = { 1, 2, 3, 4, 5, 6, 7, 8,
20 9, 10, 11, 12, 13, 14, 15, 16 };
21
SetResidualCoeffs_NEON(const int16_t * const coeffs,VP8Residual * const res)22 static void SetResidualCoeffs_NEON(const int16_t* const coeffs,
23 VP8Residual* const res) {
24 const int16x8_t minus_one = vdupq_n_s16(-1);
25 const int16x8_t coeffs_0 = vld1q_s16(coeffs);
26 const int16x8_t coeffs_1 = vld1q_s16(coeffs + 8);
27 const uint16x8_t eob_0 = vtstq_s16(coeffs_0, minus_one);
28 const uint16x8_t eob_1 = vtstq_s16(coeffs_1, minus_one);
29 const uint8x16_t eob = vcombine_u8(vqmovn_u16(eob_0), vqmovn_u16(eob_1));
30 const uint8x16_t masked = vandq_u8(eob, vld1q_u8(position));
31
32 #ifdef __aarch64__
33 res->last = vmaxvq_u8(masked) - 1;
34 #else
35 const uint8x8_t eob_8x8 = vmax_u8(vget_low_u8(masked), vget_high_u8(masked));
36 const uint16x8_t eob_16x8 = vmovl_u8(eob_8x8);
37 const uint16x4_t eob_16x4 =
38 vmax_u16(vget_low_u16(eob_16x8), vget_high_u16(eob_16x8));
39 const uint32x4_t eob_32x4 = vmovl_u16(eob_16x4);
40 uint32x2_t eob_32x2 =
41 vmax_u32(vget_low_u32(eob_32x4), vget_high_u32(eob_32x4));
42 eob_32x2 = vpmax_u32(eob_32x2, eob_32x2);
43
44 vst1_lane_s32(&res->last, vreinterpret_s32_u32(eob_32x2), 0);
45 --res->last;
46 #endif // __aarch64__
47
48 res->coeffs = coeffs;
49 }
50
GetResidualCost_NEON(int ctx0,const VP8Residual * const res)51 static int GetResidualCost_NEON(int ctx0, const VP8Residual* const res) {
52 uint8_t levels[16], ctxs[16];
53 uint16_t abs_levels[16];
54 int n = res->first;
55 // should be prob[VP8EncBands[n]], but it's equivalent for n=0 or 1
56 const int p0 = res->prob[n][ctx0][0];
57 CostArrayPtr const costs = res->costs;
58 const uint16_t* t = costs[n][ctx0];
59 // bit_cost(1, p0) is already incorporated in t[] tables, but only if ctx != 0
60 // (as required by the syntax). For ctx0 == 0, we need to add it here or it'll
61 // be missing during the loop.
62 int cost = (ctx0 == 0) ? VP8BitCost(1, p0) : 0;
63
64 if (res->last < 0) {
65 return VP8BitCost(0, p0);
66 }
67
68 { // precompute clamped levels and contexts, packed to 8b.
69 const uint8x16_t kCst2 = vdupq_n_u8(2);
70 const uint8x16_t kCst67 = vdupq_n_u8(MAX_VARIABLE_LEVEL);
71 const int16x8_t c0 = vld1q_s16(res->coeffs);
72 const int16x8_t c1 = vld1q_s16(res->coeffs + 8);
73 const uint16x8_t E0 = vreinterpretq_u16_s16(vabsq_s16(c0));
74 const uint16x8_t E1 = vreinterpretq_u16_s16(vabsq_s16(c1));
75 const uint8x16_t F = vcombine_u8(vqmovn_u16(E0), vqmovn_u16(E1));
76 const uint8x16_t G = vminq_u8(F, kCst2); // context = 0,1,2
77 const uint8x16_t H = vminq_u8(F, kCst67); // clamp_level in [0..67]
78
79 vst1q_u8(ctxs, G);
80 vst1q_u8(levels, H);
81
82 vst1q_u16(abs_levels, E0);
83 vst1q_u16(abs_levels + 8, E1);
84 }
85 for (; n < res->last; ++n) {
86 const int ctx = ctxs[n];
87 const int level = levels[n];
88 const int flevel = abs_levels[n]; // full level
89 cost += VP8LevelFixedCosts[flevel] + t[level]; // simplified VP8LevelCost()
90 t = costs[n + 1][ctx];
91 }
92 // Last coefficient is always non-zero
93 {
94 const int level = levels[n];
95 const int flevel = abs_levels[n];
96 assert(flevel != 0);
97 cost += VP8LevelFixedCosts[flevel] + t[level];
98 if (n < 15) {
99 const int b = VP8EncBands[n + 1];
100 const int ctx = ctxs[n];
101 const int last_p0 = res->prob[b][ctx][0];
102 cost += VP8BitCost(0, last_p0);
103 }
104 }
105 return cost;
106 }
107
108 //------------------------------------------------------------------------------
109 // Entry point
110
111 extern void VP8EncDspCostInitNEON(void);
112
VP8EncDspCostInitNEON(void)113 WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspCostInitNEON(void) {
114 VP8SetResidualCoeffs = SetResidualCoeffs_NEON;
115 VP8GetResidualCost = GetResidualCost_NEON;
116 }
117
118 #else // !WEBP_USE_NEON
119
120 WEBP_DSP_INIT_STUB(VP8EncDspCostInitNEON)
121
122 #endif // WEBP_USE_NEON
123