1 // Copyright 2012 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 speed-critical encoding functions.
11 //
12 // adapted from libvpx (http://www.webmproject.org/code/)
13 
14 #include "./dsp.h"
15 
16 #if defined(WEBP_USE_NEON)
17 
18 #include <assert.h>
19 
20 #include "./neon.h"
21 #include "../enc/vp8enci.h"
22 
23 //------------------------------------------------------------------------------
24 // Transforms (Paragraph 14.4)
25 
26 // Inverse transform.
27 // This code is pretty much the same as TransformOne in the dec_neon.c, except
28 // for subtraction to *ref. See the comments there for algorithmic explanations.
29 
30 static const int16_t kC1 = 20091;
31 static const int16_t kC2 = 17734;  // half of kC2, actually. See comment above.
32 
33 // This code works but is *slower* than the inlined-asm version below
34 // (with gcc-4.6). So we disable it for now. Later, it'll be conditional to
35 // USE_INTRINSICS define.
36 // With gcc-4.8, it's a little faster speed than inlined-assembly.
37 #if defined(USE_INTRINSICS)
38 
39 // Treats 'v' as an uint8x8_t and zero extends to an int16x8_t.
ConvertU8ToS16(uint32x2_t v)40 static WEBP_INLINE int16x8_t ConvertU8ToS16(uint32x2_t v) {
41   return vreinterpretq_s16_u16(vmovl_u8(vreinterpret_u8_u32(v)));
42 }
43 
44 // Performs unsigned 8b saturation on 'dst01' and 'dst23' storing the result
45 // to the corresponding rows of 'dst'.
SaturateAndStore4x4(uint8_t * const dst,const int16x8_t dst01,const int16x8_t dst23)46 static WEBP_INLINE void SaturateAndStore4x4(uint8_t* const dst,
47                                             const int16x8_t dst01,
48                                             const int16x8_t dst23) {
49   // Unsigned saturate to 8b.
50   const uint8x8_t dst01_u8 = vqmovun_s16(dst01);
51   const uint8x8_t dst23_u8 = vqmovun_s16(dst23);
52 
53   // Store the results.
54   vst1_lane_u32((uint32_t*)(dst + 0 * BPS), vreinterpret_u32_u8(dst01_u8), 0);
55   vst1_lane_u32((uint32_t*)(dst + 1 * BPS), vreinterpret_u32_u8(dst01_u8), 1);
56   vst1_lane_u32((uint32_t*)(dst + 2 * BPS), vreinterpret_u32_u8(dst23_u8), 0);
57   vst1_lane_u32((uint32_t*)(dst + 3 * BPS), vreinterpret_u32_u8(dst23_u8), 1);
58 }
59 
Add4x4(const int16x8_t row01,const int16x8_t row23,const uint8_t * const ref,uint8_t * const dst)60 static WEBP_INLINE void Add4x4(const int16x8_t row01, const int16x8_t row23,
61                                const uint8_t* const ref, uint8_t* const dst) {
62   uint32x2_t dst01 = vdup_n_u32(0);
63   uint32x2_t dst23 = vdup_n_u32(0);
64 
65   // Load the source pixels.
66   dst01 = vld1_lane_u32((uint32_t*)(ref + 0 * BPS), dst01, 0);
67   dst23 = vld1_lane_u32((uint32_t*)(ref + 2 * BPS), dst23, 0);
68   dst01 = vld1_lane_u32((uint32_t*)(ref + 1 * BPS), dst01, 1);
69   dst23 = vld1_lane_u32((uint32_t*)(ref + 3 * BPS), dst23, 1);
70 
71   {
72     // Convert to 16b.
73     const int16x8_t dst01_s16 = ConvertU8ToS16(dst01);
74     const int16x8_t dst23_s16 = ConvertU8ToS16(dst23);
75 
76     // Descale with rounding.
77     const int16x8_t out01 = vrsraq_n_s16(dst01_s16, row01, 3);
78     const int16x8_t out23 = vrsraq_n_s16(dst23_s16, row23, 3);
79     // Add the inverse transform.
80     SaturateAndStore4x4(dst, out01, out23);
81   }
82 }
83 
Transpose8x2(const int16x8_t in0,const int16x8_t in1,int16x8x2_t * const out)84 static WEBP_INLINE void Transpose8x2(const int16x8_t in0, const int16x8_t in1,
85                                      int16x8x2_t* const out) {
86   // a0 a1 a2 a3 | b0 b1 b2 b3   => a0 b0 c0 d0 | a1 b1 c1 d1
87   // c0 c1 c2 c3 | d0 d1 d2 d3      a2 b2 c2 d2 | a3 b3 c3 d3
88   const int16x8x2_t tmp0 = vzipq_s16(in0, in1);   // a0 c0 a1 c1 a2 c2 ...
89                                                   // b0 d0 b1 d1 b2 d2 ...
90   *out = vzipq_s16(tmp0.val[0], tmp0.val[1]);
91 }
92 
TransformPass(int16x8x2_t * const rows)93 static WEBP_INLINE void TransformPass(int16x8x2_t* const rows) {
94   // {rows} = in0 | in4
95   //          in8 | in12
96   // B1 = in4 | in12
97   const int16x8_t B1 =
98       vcombine_s16(vget_high_s16(rows->val[0]), vget_high_s16(rows->val[1]));
99   // C0 = kC1 * in4 | kC1 * in12
100   // C1 = kC2 * in4 | kC2 * in12
101   const int16x8_t C0 = vsraq_n_s16(B1, vqdmulhq_n_s16(B1, kC1), 1);
102   const int16x8_t C1 = vqdmulhq_n_s16(B1, kC2);
103   const int16x4_t a = vqadd_s16(vget_low_s16(rows->val[0]),
104                                 vget_low_s16(rows->val[1]));   // in0 + in8
105   const int16x4_t b = vqsub_s16(vget_low_s16(rows->val[0]),
106                                 vget_low_s16(rows->val[1]));   // in0 - in8
107   // c = kC2 * in4 - kC1 * in12
108   // d = kC1 * in4 + kC2 * in12
109   const int16x4_t c = vqsub_s16(vget_low_s16(C1), vget_high_s16(C0));
110   const int16x4_t d = vqadd_s16(vget_low_s16(C0), vget_high_s16(C1));
111   const int16x8_t D0 = vcombine_s16(a, b);      // D0 = a | b
112   const int16x8_t D1 = vcombine_s16(d, c);      // D1 = d | c
113   const int16x8_t E0 = vqaddq_s16(D0, D1);      // a+d | b+c
114   const int16x8_t E_tmp = vqsubq_s16(D0, D1);   // a-d | b-c
115   const int16x8_t E1 = vcombine_s16(vget_high_s16(E_tmp), vget_low_s16(E_tmp));
116   Transpose8x2(E0, E1, rows);
117 }
118 
ITransformOne(const uint8_t * ref,const int16_t * in,uint8_t * dst)119 static void ITransformOne(const uint8_t* ref,
120                           const int16_t* in, uint8_t* dst) {
121   int16x8x2_t rows;
122   INIT_VECTOR2(rows, vld1q_s16(in + 0), vld1q_s16(in + 8));
123   TransformPass(&rows);
124   TransformPass(&rows);
125   Add4x4(rows.val[0], rows.val[1], ref, dst);
126 }
127 
128 #else
129 
ITransformOne(const uint8_t * ref,const int16_t * in,uint8_t * dst)130 static void ITransformOne(const uint8_t* ref,
131                           const int16_t* in, uint8_t* dst) {
132   const int kBPS = BPS;
133   const int16_t kC1C2[] = { kC1, kC2, 0, 0 };
134 
135   __asm__ volatile (
136     "vld1.16         {q1, q2}, [%[in]]           \n"
137     "vld1.16         {d0}, [%[kC1C2]]            \n"
138 
139     // d2: in[0]
140     // d3: in[8]
141     // d4: in[4]
142     // d5: in[12]
143     "vswp            d3, d4                      \n"
144 
145     // q8 = {in[4], in[12]} * kC1 * 2 >> 16
146     // q9 = {in[4], in[12]} * kC2 >> 16
147     "vqdmulh.s16     q8, q2, d0[0]               \n"
148     "vqdmulh.s16     q9, q2, d0[1]               \n"
149 
150     // d22 = a = in[0] + in[8]
151     // d23 = b = in[0] - in[8]
152     "vqadd.s16       d22, d2, d3                 \n"
153     "vqsub.s16       d23, d2, d3                 \n"
154 
155     //  q8 = in[4]/[12] * kC1 >> 16
156     "vshr.s16        q8, q8, #1                  \n"
157 
158     // Add {in[4], in[12]} back after the multiplication.
159     "vqadd.s16       q8, q2, q8                  \n"
160 
161     // d20 = c = in[4]*kC2 - in[12]*kC1
162     // d21 = d = in[4]*kC1 + in[12]*kC2
163     "vqsub.s16       d20, d18, d17               \n"
164     "vqadd.s16       d21, d19, d16               \n"
165 
166     // d2 = tmp[0] = a + d
167     // d3 = tmp[1] = b + c
168     // d4 = tmp[2] = b - c
169     // d5 = tmp[3] = a - d
170     "vqadd.s16       d2, d22, d21                \n"
171     "vqadd.s16       d3, d23, d20                \n"
172     "vqsub.s16       d4, d23, d20                \n"
173     "vqsub.s16       d5, d22, d21                \n"
174 
175     "vzip.16         q1, q2                      \n"
176     "vzip.16         q1, q2                      \n"
177 
178     "vswp            d3, d4                      \n"
179 
180     // q8 = {tmp[4], tmp[12]} * kC1 * 2 >> 16
181     // q9 = {tmp[4], tmp[12]} * kC2 >> 16
182     "vqdmulh.s16     q8, q2, d0[0]               \n"
183     "vqdmulh.s16     q9, q2, d0[1]               \n"
184 
185     // d22 = a = tmp[0] + tmp[8]
186     // d23 = b = tmp[0] - tmp[8]
187     "vqadd.s16       d22, d2, d3                 \n"
188     "vqsub.s16       d23, d2, d3                 \n"
189 
190     "vshr.s16        q8, q8, #1                  \n"
191     "vqadd.s16       q8, q2, q8                  \n"
192 
193     // d20 = c = in[4]*kC2 - in[12]*kC1
194     // d21 = d = in[4]*kC1 + in[12]*kC2
195     "vqsub.s16       d20, d18, d17               \n"
196     "vqadd.s16       d21, d19, d16               \n"
197 
198     // d2 = tmp[0] = a + d
199     // d3 = tmp[1] = b + c
200     // d4 = tmp[2] = b - c
201     // d5 = tmp[3] = a - d
202     "vqadd.s16       d2, d22, d21                \n"
203     "vqadd.s16       d3, d23, d20                \n"
204     "vqsub.s16       d4, d23, d20                \n"
205     "vqsub.s16       d5, d22, d21                \n"
206 
207     "vld1.32         d6[0], [%[ref]], %[kBPS]    \n"
208     "vld1.32         d6[1], [%[ref]], %[kBPS]    \n"
209     "vld1.32         d7[0], [%[ref]], %[kBPS]    \n"
210     "vld1.32         d7[1], [%[ref]], %[kBPS]    \n"
211 
212     "sub         %[ref], %[ref], %[kBPS], lsl #2 \n"
213 
214     // (val) + 4 >> 3
215     "vrshr.s16       d2, d2, #3                  \n"
216     "vrshr.s16       d3, d3, #3                  \n"
217     "vrshr.s16       d4, d4, #3                  \n"
218     "vrshr.s16       d5, d5, #3                  \n"
219 
220     "vzip.16         q1, q2                      \n"
221     "vzip.16         q1, q2                      \n"
222 
223     // Must accumulate before saturating
224     "vmovl.u8        q8, d6                      \n"
225     "vmovl.u8        q9, d7                      \n"
226 
227     "vqadd.s16       q1, q1, q8                  \n"
228     "vqadd.s16       q2, q2, q9                  \n"
229 
230     "vqmovun.s16     d0, q1                      \n"
231     "vqmovun.s16     d1, q2                      \n"
232 
233     "vst1.32         d0[0], [%[dst]], %[kBPS]    \n"
234     "vst1.32         d0[1], [%[dst]], %[kBPS]    \n"
235     "vst1.32         d1[0], [%[dst]], %[kBPS]    \n"
236     "vst1.32         d1[1], [%[dst]]             \n"
237 
238     : [in] "+r"(in), [dst] "+r"(dst)               // modified registers
239     : [kBPS] "r"(kBPS), [kC1C2] "r"(kC1C2), [ref] "r"(ref)  // constants
240     : "memory", "q0", "q1", "q2", "q8", "q9", "q10", "q11"  // clobbered
241   );
242 }
243 
244 #endif    // USE_INTRINSICS
245 
ITransform(const uint8_t * ref,const int16_t * in,uint8_t * dst,int do_two)246 static void ITransform(const uint8_t* ref,
247                        const int16_t* in, uint8_t* dst, int do_two) {
248   ITransformOne(ref, in, dst);
249   if (do_two) {
250     ITransformOne(ref + 4, in + 16, dst + 4);
251   }
252 }
253 
254 // Load all 4x4 pixels into a single uint8x16_t variable.
Load4x4(const uint8_t * src)255 static uint8x16_t Load4x4(const uint8_t* src) {
256   uint32x4_t out = vdupq_n_u32(0);
257   out = vld1q_lane_u32((const uint32_t*)(src + 0 * BPS), out, 0);
258   out = vld1q_lane_u32((const uint32_t*)(src + 1 * BPS), out, 1);
259   out = vld1q_lane_u32((const uint32_t*)(src + 2 * BPS), out, 2);
260   out = vld1q_lane_u32((const uint32_t*)(src + 3 * BPS), out, 3);
261   return vreinterpretq_u8_u32(out);
262 }
263 
264 // Forward transform.
265 
266 #if defined(USE_INTRINSICS)
267 
Transpose4x4_S16(const int16x4_t A,const int16x4_t B,const int16x4_t C,const int16x4_t D,int16x8_t * const out01,int16x8_t * const out32)268 static WEBP_INLINE void Transpose4x4_S16(const int16x4_t A, const int16x4_t B,
269                                          const int16x4_t C, const int16x4_t D,
270                                          int16x8_t* const out01,
271                                          int16x8_t* const out32) {
272   const int16x4x2_t AB = vtrn_s16(A, B);
273   const int16x4x2_t CD = vtrn_s16(C, D);
274   const int32x2x2_t tmp02 = vtrn_s32(vreinterpret_s32_s16(AB.val[0]),
275                                      vreinterpret_s32_s16(CD.val[0]));
276   const int32x2x2_t tmp13 = vtrn_s32(vreinterpret_s32_s16(AB.val[1]),
277                                      vreinterpret_s32_s16(CD.val[1]));
278   *out01 = vreinterpretq_s16_s64(
279       vcombine_s64(vreinterpret_s64_s32(tmp02.val[0]),
280                    vreinterpret_s64_s32(tmp13.val[0])));
281   *out32 = vreinterpretq_s16_s64(
282       vcombine_s64(vreinterpret_s64_s32(tmp13.val[1]),
283                    vreinterpret_s64_s32(tmp02.val[1])));
284 }
285 
DiffU8ToS16(const uint8x8_t a,const uint8x8_t b)286 static WEBP_INLINE int16x8_t DiffU8ToS16(const uint8x8_t a,
287                                          const uint8x8_t b) {
288   return vreinterpretq_s16_u16(vsubl_u8(a, b));
289 }
290 
FTransform(const uint8_t * src,const uint8_t * ref,int16_t * out)291 static void FTransform(const uint8_t* src, const uint8_t* ref,
292                        int16_t* out) {
293   int16x8_t d0d1, d3d2;   // working 4x4 int16 variables
294   {
295     const uint8x16_t S0 = Load4x4(src);
296     const uint8x16_t R0 = Load4x4(ref);
297     const int16x8_t D0D1 = DiffU8ToS16(vget_low_u8(S0), vget_low_u8(R0));
298     const int16x8_t D2D3 = DiffU8ToS16(vget_high_u8(S0), vget_high_u8(R0));
299     const int16x4_t D0 = vget_low_s16(D0D1);
300     const int16x4_t D1 = vget_high_s16(D0D1);
301     const int16x4_t D2 = vget_low_s16(D2D3);
302     const int16x4_t D3 = vget_high_s16(D2D3);
303     Transpose4x4_S16(D0, D1, D2, D3, &d0d1, &d3d2);
304   }
305   {    // 1rst pass
306     const int32x4_t kCst937 = vdupq_n_s32(937);
307     const int32x4_t kCst1812 = vdupq_n_s32(1812);
308     const int16x8_t a0a1 = vaddq_s16(d0d1, d3d2);   // d0+d3 | d1+d2   (=a0|a1)
309     const int16x8_t a3a2 = vsubq_s16(d0d1, d3d2);   // d0-d3 | d1-d2   (=a3|a2)
310     const int16x8_t a0a1_2 = vshlq_n_s16(a0a1, 3);
311     const int16x4_t tmp0 = vadd_s16(vget_low_s16(a0a1_2),
312                                     vget_high_s16(a0a1_2));
313     const int16x4_t tmp2 = vsub_s16(vget_low_s16(a0a1_2),
314                                     vget_high_s16(a0a1_2));
315     const int32x4_t a3_2217 = vmull_n_s16(vget_low_s16(a3a2), 2217);
316     const int32x4_t a2_2217 = vmull_n_s16(vget_high_s16(a3a2), 2217);
317     const int32x4_t a2_p_a3 = vmlal_n_s16(a2_2217, vget_low_s16(a3a2), 5352);
318     const int32x4_t a3_m_a2 = vmlsl_n_s16(a3_2217, vget_high_s16(a3a2), 5352);
319     const int16x4_t tmp1 = vshrn_n_s32(vaddq_s32(a2_p_a3, kCst1812), 9);
320     const int16x4_t tmp3 = vshrn_n_s32(vaddq_s32(a3_m_a2, kCst937), 9);
321     Transpose4x4_S16(tmp0, tmp1, tmp2, tmp3, &d0d1, &d3d2);
322   }
323   {    // 2nd pass
324     // the (1<<16) addition is for the replacement: a3!=0  <-> 1-(a3==0)
325     const int32x4_t kCst12000 = vdupq_n_s32(12000 + (1 << 16));
326     const int32x4_t kCst51000 = vdupq_n_s32(51000);
327     const int16x8_t a0a1 = vaddq_s16(d0d1, d3d2);   // d0+d3 | d1+d2   (=a0|a1)
328     const int16x8_t a3a2 = vsubq_s16(d0d1, d3d2);   // d0-d3 | d1-d2   (=a3|a2)
329     const int16x4_t a0_k7 = vadd_s16(vget_low_s16(a0a1), vdup_n_s16(7));
330     const int16x4_t out0 = vshr_n_s16(vadd_s16(a0_k7, vget_high_s16(a0a1)), 4);
331     const int16x4_t out2 = vshr_n_s16(vsub_s16(a0_k7, vget_high_s16(a0a1)), 4);
332     const int32x4_t a3_2217 = vmull_n_s16(vget_low_s16(a3a2), 2217);
333     const int32x4_t a2_2217 = vmull_n_s16(vget_high_s16(a3a2), 2217);
334     const int32x4_t a2_p_a3 = vmlal_n_s16(a2_2217, vget_low_s16(a3a2), 5352);
335     const int32x4_t a3_m_a2 = vmlsl_n_s16(a3_2217, vget_high_s16(a3a2), 5352);
336     const int16x4_t tmp1 = vaddhn_s32(a2_p_a3, kCst12000);
337     const int16x4_t out3 = vaddhn_s32(a3_m_a2, kCst51000);
338     const int16x4_t a3_eq_0 =
339         vreinterpret_s16_u16(vceq_s16(vget_low_s16(a3a2), vdup_n_s16(0)));
340     const int16x4_t out1 = vadd_s16(tmp1, a3_eq_0);
341     vst1_s16(out +  0, out0);
342     vst1_s16(out +  4, out1);
343     vst1_s16(out +  8, out2);
344     vst1_s16(out + 12, out3);
345   }
346 }
347 
348 #else
349 
350 // adapted from vp8/encoder/arm/neon/shortfdct_neon.asm
351 static const int16_t kCoeff16[] = {
352   5352,  5352,  5352, 5352, 2217,  2217,  2217, 2217
353 };
354 static const int32_t kCoeff32[] = {
355    1812,  1812,  1812,  1812,
356     937,   937,   937,   937,
357   12000, 12000, 12000, 12000,
358   51000, 51000, 51000, 51000
359 };
360 
FTransform(const uint8_t * src,const uint8_t * ref,int16_t * out)361 static void FTransform(const uint8_t* src, const uint8_t* ref,
362                        int16_t* out) {
363   const int kBPS = BPS;
364   const uint8_t* src_ptr = src;
365   const uint8_t* ref_ptr = ref;
366   const int16_t* coeff16 = kCoeff16;
367   const int32_t* coeff32 = kCoeff32;
368 
369   __asm__ volatile (
370     // load src into q4, q5 in high half
371     "vld1.8 {d8},  [%[src_ptr]], %[kBPS]      \n"
372     "vld1.8 {d10}, [%[src_ptr]], %[kBPS]      \n"
373     "vld1.8 {d9},  [%[src_ptr]], %[kBPS]      \n"
374     "vld1.8 {d11}, [%[src_ptr]]               \n"
375 
376     // load ref into q6, q7 in high half
377     "vld1.8 {d12}, [%[ref_ptr]], %[kBPS]      \n"
378     "vld1.8 {d14}, [%[ref_ptr]], %[kBPS]      \n"
379     "vld1.8 {d13}, [%[ref_ptr]], %[kBPS]      \n"
380     "vld1.8 {d15}, [%[ref_ptr]]               \n"
381 
382     // Pack the high values in to q4 and q6
383     "vtrn.32     q4, q5                       \n"
384     "vtrn.32     q6, q7                       \n"
385 
386     // d[0-3] = src - ref
387     "vsubl.u8    q0, d8, d12                  \n"
388     "vsubl.u8    q1, d9, d13                  \n"
389 
390     // load coeff16 into q8(d16=5352, d17=2217)
391     "vld1.16     {q8}, [%[coeff16]]           \n"
392 
393     // load coeff32 high half into q9 = 1812, q10 = 937
394     "vld1.32     {q9, q10}, [%[coeff32]]!     \n"
395 
396     // load coeff32 low half into q11=12000, q12=51000
397     "vld1.32     {q11,q12}, [%[coeff32]]      \n"
398 
399     // part 1
400     // Transpose. Register dN is the same as dN in C
401     "vtrn.32         d0, d2                   \n"
402     "vtrn.32         d1, d3                   \n"
403     "vtrn.16         d0, d1                   \n"
404     "vtrn.16         d2, d3                   \n"
405 
406     "vadd.s16        d4, d0, d3               \n" // a0 = d0 + d3
407     "vadd.s16        d5, d1, d2               \n" // a1 = d1 + d2
408     "vsub.s16        d6, d1, d2               \n" // a2 = d1 - d2
409     "vsub.s16        d7, d0, d3               \n" // a3 = d0 - d3
410 
411     "vadd.s16        d0, d4, d5               \n" // a0 + a1
412     "vshl.s16        d0, d0, #3               \n" // temp[0+i*4] = (a0+a1) << 3
413     "vsub.s16        d2, d4, d5               \n" // a0 - a1
414     "vshl.s16        d2, d2, #3               \n" // (temp[2+i*4] = (a0-a1) << 3
415 
416     "vmlal.s16       q9, d7, d16              \n" // a3*5352 + 1812
417     "vmlal.s16       q10, d7, d17             \n" // a3*2217 + 937
418     "vmlal.s16       q9, d6, d17              \n" // a2*2217 + a3*5352 + 1812
419     "vmlsl.s16       q10, d6, d16             \n" // a3*2217 + 937 - a2*5352
420 
421     // temp[1+i*4] = (d2*2217 + d3*5352 + 1812) >> 9
422     // temp[3+i*4] = (d3*2217 + 937 - d2*5352) >> 9
423     "vshrn.s32       d1, q9, #9               \n"
424     "vshrn.s32       d3, q10, #9              \n"
425 
426     // part 2
427     // transpose d0=ip[0], d1=ip[4], d2=ip[8], d3=ip[12]
428     "vtrn.32         d0, d2                   \n"
429     "vtrn.32         d1, d3                   \n"
430     "vtrn.16         d0, d1                   \n"
431     "vtrn.16         d2, d3                   \n"
432 
433     "vmov.s16        d26, #7                  \n"
434 
435     "vadd.s16        d4, d0, d3               \n" // a1 = ip[0] + ip[12]
436     "vadd.s16        d5, d1, d2               \n" // b1 = ip[4] + ip[8]
437     "vsub.s16        d6, d1, d2               \n" // c1 = ip[4] - ip[8]
438     "vadd.s16        d4, d4, d26              \n" // a1 + 7
439     "vsub.s16        d7, d0, d3               \n" // d1 = ip[0] - ip[12]
440 
441     "vadd.s16        d0, d4, d5               \n" // op[0] = a1 + b1 + 7
442     "vsub.s16        d2, d4, d5               \n" // op[8] = a1 - b1 + 7
443 
444     "vmlal.s16       q11, d7, d16             \n" // d1*5352 + 12000
445     "vmlal.s16       q12, d7, d17             \n" // d1*2217 + 51000
446 
447     "vceq.s16        d4, d7, #0               \n"
448 
449     "vshr.s16        d0, d0, #4               \n"
450     "vshr.s16        d2, d2, #4               \n"
451 
452     "vmlal.s16       q11, d6, d17             \n" // c1*2217 + d1*5352 + 12000
453     "vmlsl.s16       q12, d6, d16             \n" // d1*2217 - c1*5352 + 51000
454 
455     "vmvn            d4, d4                   \n" // !(d1 == 0)
456     // op[4] = (c1*2217 + d1*5352 + 12000)>>16
457     "vshrn.s32       d1, q11, #16             \n"
458     // op[4] += (d1!=0)
459     "vsub.s16        d1, d1, d4               \n"
460     // op[12]= (d1*2217 - c1*5352 + 51000)>>16
461     "vshrn.s32       d3, q12, #16             \n"
462 
463     // set result to out array
464     "vst1.16         {q0, q1}, [%[out]]   \n"
465     : [src_ptr] "+r"(src_ptr), [ref_ptr] "+r"(ref_ptr),
466       [coeff32] "+r"(coeff32)          // modified registers
467     : [kBPS] "r"(kBPS), [coeff16] "r"(coeff16),
468       [out] "r"(out)                   // constants
469     : "memory", "q0", "q1", "q2", "q3", "q4", "q5", "q6", "q7", "q8", "q9",
470       "q10", "q11", "q12", "q13"       // clobbered
471   );
472 }
473 
474 #endif
475 
476 #define LOAD_LANE_16b(VALUE, LANE) do {             \
477   (VALUE) = vld1_lane_s16(src, (VALUE), (LANE));    \
478   src += stride;                                    \
479 } while (0)
480 
FTransformWHT(const int16_t * src,int16_t * out)481 static void FTransformWHT(const int16_t* src, int16_t* out) {
482   const int stride = 16;
483   const int16x4_t zero = vdup_n_s16(0);
484   int32x4x4_t tmp0;
485   int16x4x4_t in;
486   INIT_VECTOR4(in, zero, zero, zero, zero);
487   LOAD_LANE_16b(in.val[0], 0);
488   LOAD_LANE_16b(in.val[1], 0);
489   LOAD_LANE_16b(in.val[2], 0);
490   LOAD_LANE_16b(in.val[3], 0);
491   LOAD_LANE_16b(in.val[0], 1);
492   LOAD_LANE_16b(in.val[1], 1);
493   LOAD_LANE_16b(in.val[2], 1);
494   LOAD_LANE_16b(in.val[3], 1);
495   LOAD_LANE_16b(in.val[0], 2);
496   LOAD_LANE_16b(in.val[1], 2);
497   LOAD_LANE_16b(in.val[2], 2);
498   LOAD_LANE_16b(in.val[3], 2);
499   LOAD_LANE_16b(in.val[0], 3);
500   LOAD_LANE_16b(in.val[1], 3);
501   LOAD_LANE_16b(in.val[2], 3);
502   LOAD_LANE_16b(in.val[3], 3);
503 
504   {
505     // a0 = in[0 * 16] + in[2 * 16]
506     // a1 = in[1 * 16] + in[3 * 16]
507     // a2 = in[1 * 16] - in[3 * 16]
508     // a3 = in[0 * 16] - in[2 * 16]
509     const int32x4_t a0 = vaddl_s16(in.val[0], in.val[2]);
510     const int32x4_t a1 = vaddl_s16(in.val[1], in.val[3]);
511     const int32x4_t a2 = vsubl_s16(in.val[1], in.val[3]);
512     const int32x4_t a3 = vsubl_s16(in.val[0], in.val[2]);
513     tmp0.val[0] = vaddq_s32(a0, a1);
514     tmp0.val[1] = vaddq_s32(a3, a2);
515     tmp0.val[2] = vsubq_s32(a3, a2);
516     tmp0.val[3] = vsubq_s32(a0, a1);
517   }
518   {
519     const int32x4x4_t tmp1 = Transpose4x4(tmp0);
520     // a0 = tmp[0 + i] + tmp[ 8 + i]
521     // a1 = tmp[4 + i] + tmp[12 + i]
522     // a2 = tmp[4 + i] - tmp[12 + i]
523     // a3 = tmp[0 + i] - tmp[ 8 + i]
524     const int32x4_t a0 = vaddq_s32(tmp1.val[0], tmp1.val[2]);
525     const int32x4_t a1 = vaddq_s32(tmp1.val[1], tmp1.val[3]);
526     const int32x4_t a2 = vsubq_s32(tmp1.val[1], tmp1.val[3]);
527     const int32x4_t a3 = vsubq_s32(tmp1.val[0], tmp1.val[2]);
528     const int32x4_t b0 = vhaddq_s32(a0, a1);  // (a0 + a1) >> 1
529     const int32x4_t b1 = vhaddq_s32(a3, a2);  // (a3 + a2) >> 1
530     const int32x4_t b2 = vhsubq_s32(a3, a2);  // (a3 - a2) >> 1
531     const int32x4_t b3 = vhsubq_s32(a0, a1);  // (a0 - a1) >> 1
532     const int16x4_t out0 = vmovn_s32(b0);
533     const int16x4_t out1 = vmovn_s32(b1);
534     const int16x4_t out2 = vmovn_s32(b2);
535     const int16x4_t out3 = vmovn_s32(b3);
536 
537     vst1_s16(out +  0, out0);
538     vst1_s16(out +  4, out1);
539     vst1_s16(out +  8, out2);
540     vst1_s16(out + 12, out3);
541   }
542 }
543 #undef LOAD_LANE_16b
544 
545 //------------------------------------------------------------------------------
546 // Texture distortion
547 //
548 // We try to match the spectral content (weighted) between source and
549 // reconstructed samples.
550 
551 // This code works but is *slower* than the inlined-asm version below
552 // (with gcc-4.6). So we disable it for now. Later, it'll be conditional to
553 // USE_INTRINSICS define.
554 // With gcc-4.8, it's only slightly slower than the inlined.
555 #if defined(USE_INTRINSICS)
556 
557 // Zero extend an uint16x4_t 'v' to an int32x4_t.
ConvertU16ToS32(uint16x4_t v)558 static WEBP_INLINE int32x4_t ConvertU16ToS32(uint16x4_t v) {
559   return vreinterpretq_s32_u32(vmovl_u16(v));
560 }
561 
562 // Does a regular 4x4 transpose followed by an adjustment of the upper columns
563 // in the inner rows to restore the source order of differences,
564 // i.e., a0 - a1 | a3 - a2.
DistoTranspose4x4(const int32x4x4_t rows)565 static WEBP_INLINE int32x4x4_t DistoTranspose4x4(const int32x4x4_t rows) {
566   int32x4x4_t out = Transpose4x4(rows);
567   // restore source order in the columns containing differences.
568   const int32x2_t r1h = vget_high_s32(out.val[1]);
569   const int32x2_t r2h = vget_high_s32(out.val[2]);
570   out.val[1] = vcombine_s32(vget_low_s32(out.val[1]), r2h);
571   out.val[2] = vcombine_s32(vget_low_s32(out.val[2]), r1h);
572   return out;
573 }
574 
DistoHorizontalPass(const uint8x8_t r0r1,const uint8x8_t r2r3)575 static WEBP_INLINE int32x4x4_t DistoHorizontalPass(const uint8x8_t r0r1,
576                                                    const uint8x8_t r2r3) {
577   // a0 = in[0] + in[2] | a1 = in[1] + in[3]
578   const uint16x8_t a0a1 = vaddl_u8(r0r1, r2r3);
579   // a3 = in[0] - in[2] | a2 = in[1] - in[3]
580   const uint16x8_t a3a2 = vsubl_u8(r0r1, r2r3);
581   const int32x4_t tmp0 = vpaddlq_s16(vreinterpretq_s16_u16(a0a1));  // a0 + a1
582   const int32x4_t tmp1 = vpaddlq_s16(vreinterpretq_s16_u16(a3a2));  // a3 + a2
583   // no pairwise subtraction; reorder to perform tmp[2]/tmp[3] calculations.
584   // a0a0 a3a3 a0a0 a3a3 a0a0 a3a3 a0a0 a3a3
585   // a1a1 a2a2 a1a1 a2a2 a1a1 a2a2 a1a1 a2a2
586   const int16x8x2_t transpose =
587       vtrnq_s16(vreinterpretq_s16_u16(a0a1), vreinterpretq_s16_u16(a3a2));
588   // tmp[3] = a0 - a1 | tmp[2] = a3 - a2
589   const int32x4_t tmp32_1 = vsubl_s16(vget_low_s16(transpose.val[0]),
590                                       vget_low_s16(transpose.val[1]));
591   const int32x4_t tmp32_2 = vsubl_s16(vget_high_s16(transpose.val[0]),
592                                       vget_high_s16(transpose.val[1]));
593   // [0]: tmp[3] [1]: tmp[2]
594   const int32x4x2_t split = vtrnq_s32(tmp32_1, tmp32_2);
595   const int32x4x4_t res = { { tmp0, tmp1, split.val[1], split.val[0] } };
596   return res;
597 }
598 
DistoVerticalPass(const int32x4x4_t rows)599 static WEBP_INLINE int32x4x4_t DistoVerticalPass(const int32x4x4_t rows) {
600   // a0 = tmp[0 + i] + tmp[8 + i];
601   const int32x4_t a0 = vaddq_s32(rows.val[0], rows.val[1]);
602   // a1 = tmp[4 + i] + tmp[12+ i];
603   const int32x4_t a1 = vaddq_s32(rows.val[2], rows.val[3]);
604   // a2 = tmp[4 + i] - tmp[12+ i];
605   const int32x4_t a2 = vsubq_s32(rows.val[2], rows.val[3]);
606   // a3 = tmp[0 + i] - tmp[8 + i];
607   const int32x4_t a3 = vsubq_s32(rows.val[0], rows.val[1]);
608   const int32x4_t b0 = vqabsq_s32(vaddq_s32(a0, a1));  // abs(a0 + a1)
609   const int32x4_t b1 = vqabsq_s32(vaddq_s32(a3, a2));  // abs(a3 + a2)
610   const int32x4_t b2 = vabdq_s32(a3, a2);              // abs(a3 - a2)
611   const int32x4_t b3 = vabdq_s32(a0, a1);              // abs(a0 - a1)
612   const int32x4x4_t res = { { b0, b1, b2, b3 } };
613   return res;
614 }
615 
616 // Calculate the weighted sum of the rows in 'b'.
DistoSum(const int32x4x4_t b,const int32x4_t w0,const int32x4_t w1,const int32x4_t w2,const int32x4_t w3)617 static WEBP_INLINE int64x1_t DistoSum(const int32x4x4_t b,
618                                       const int32x4_t w0, const int32x4_t w1,
619                                       const int32x4_t w2, const int32x4_t w3) {
620   const int32x4_t s0 = vmulq_s32(w0, b.val[0]);
621   const int32x4_t s1 = vmlaq_s32(s0, w1, b.val[1]);
622   const int32x4_t s2 = vmlaq_s32(s1, w2, b.val[2]);
623   const int32x4_t s3 = vmlaq_s32(s2, w3, b.val[3]);
624   const int64x2_t sum1 = vpaddlq_s32(s3);
625   const int64x1_t sum2 = vadd_s64(vget_low_s64(sum1), vget_high_s64(sum1));
626   return sum2;
627 }
628 
629 #define LOAD_LANE_32b(src, VALUE, LANE) \
630     (VALUE) = vld1q_lane_u32((const uint32_t*)(src), (VALUE), (LANE))
631 
632 // Hadamard transform
633 // Returns the weighted sum of the absolute value of transformed coefficients.
Disto4x4(const uint8_t * const a,const uint8_t * const b,const uint16_t * const w)634 static int Disto4x4(const uint8_t* const a, const uint8_t* const b,
635                     const uint16_t* const w) {
636   uint32x4_t d0d1 = { 0, 0, 0, 0 };
637   uint32x4_t d2d3 = { 0, 0, 0, 0 };
638   LOAD_LANE_32b(a + 0 * BPS, d0d1, 0);  // a00 a01 a02 a03
639   LOAD_LANE_32b(a + 1 * BPS, d0d1, 1);  // a10 a11 a12 a13
640   LOAD_LANE_32b(b + 0 * BPS, d0d1, 2);  // b00 b01 b02 b03
641   LOAD_LANE_32b(b + 1 * BPS, d0d1, 3);  // b10 b11 b12 b13
642   LOAD_LANE_32b(a + 2 * BPS, d2d3, 0);  // a20 a21 a22 a23
643   LOAD_LANE_32b(a + 3 * BPS, d2d3, 1);  // a30 a31 a32 a33
644   LOAD_LANE_32b(b + 2 * BPS, d2d3, 2);  // b20 b21 b22 b23
645   LOAD_LANE_32b(b + 3 * BPS, d2d3, 3);  // b30 b31 b32 b33
646 
647   {
648     // a00 a01 a20 a21 a10 a11 a30 a31 b00 b01 b20 b21 b10 b11 b30 b31
649     // a02 a03 a22 a23 a12 a13 a32 a33 b02 b03 b22 b23 b12 b13 b32 b33
650     const uint16x8x2_t tmp =
651         vtrnq_u16(vreinterpretq_u16_u32(d0d1), vreinterpretq_u16_u32(d2d3));
652     const uint8x16_t d0d1u8 = vreinterpretq_u8_u16(tmp.val[0]);
653     const uint8x16_t d2d3u8 = vreinterpretq_u8_u16(tmp.val[1]);
654     const int32x4x4_t hpass_a = DistoHorizontalPass(vget_low_u8(d0d1u8),
655                                                     vget_low_u8(d2d3u8));
656     const int32x4x4_t hpass_b = DistoHorizontalPass(vget_high_u8(d0d1u8),
657                                                     vget_high_u8(d2d3u8));
658     const int32x4x4_t tmp_a = DistoTranspose4x4(hpass_a);
659     const int32x4x4_t tmp_b = DistoTranspose4x4(hpass_b);
660     const int32x4x4_t vpass_a = DistoVerticalPass(tmp_a);
661     const int32x4x4_t vpass_b = DistoVerticalPass(tmp_b);
662     const int32x4_t w0 = ConvertU16ToS32(vld1_u16(w + 0));
663     const int32x4_t w1 = ConvertU16ToS32(vld1_u16(w + 4));
664     const int32x4_t w2 = ConvertU16ToS32(vld1_u16(w + 8));
665     const int32x4_t w3 = ConvertU16ToS32(vld1_u16(w + 12));
666     const int64x1_t sum1 = DistoSum(vpass_a, w0, w1, w2, w3);
667     const int64x1_t sum2 = DistoSum(vpass_b, w0, w1, w2, w3);
668     const int32x2_t diff = vabd_s32(vreinterpret_s32_s64(sum1),
669                                     vreinterpret_s32_s64(sum2));
670     const int32x2_t res = vshr_n_s32(diff, 5);
671     return vget_lane_s32(res, 0);
672   }
673 }
674 
675 #undef LOAD_LANE_32b
676 
677 #else
678 
679 // Hadamard transform
680 // Returns the weighted sum of the absolute value of transformed coefficients.
Disto4x4(const uint8_t * const a,const uint8_t * const b,const uint16_t * const w)681 static int Disto4x4(const uint8_t* const a, const uint8_t* const b,
682                     const uint16_t* const w) {
683   const int kBPS = BPS;
684   const uint8_t* A = a;
685   const uint8_t* B = b;
686   const uint16_t* W = w;
687   int sum;
688   __asm__ volatile (
689     "vld1.32         d0[0], [%[a]], %[kBPS]   \n"
690     "vld1.32         d0[1], [%[a]], %[kBPS]   \n"
691     "vld1.32         d2[0], [%[a]], %[kBPS]   \n"
692     "vld1.32         d2[1], [%[a]]            \n"
693 
694     "vld1.32         d1[0], [%[b]], %[kBPS]   \n"
695     "vld1.32         d1[1], [%[b]], %[kBPS]   \n"
696     "vld1.32         d3[0], [%[b]], %[kBPS]   \n"
697     "vld1.32         d3[1], [%[b]]            \n"
698 
699     // a d0/d2, b d1/d3
700     // d0/d1: 01 01 01 01
701     // d2/d3: 23 23 23 23
702     // But: it goes 01 45 23 67
703     // Notice the middle values are transposed
704     "vtrn.16         q0, q1                   \n"
705 
706     // {a0, a1} = {in[0] + in[2], in[1] + in[3]}
707     "vaddl.u8        q2, d0, d2               \n"
708     "vaddl.u8        q10, d1, d3              \n"
709     // {a3, a2} = {in[0] - in[2], in[1] - in[3]}
710     "vsubl.u8        q3, d0, d2               \n"
711     "vsubl.u8        q11, d1, d3              \n"
712 
713     // tmp[0] = a0 + a1
714     "vpaddl.s16      q0, q2                   \n"
715     "vpaddl.s16      q8, q10                  \n"
716 
717     // tmp[1] = a3 + a2
718     "vpaddl.s16      q1, q3                   \n"
719     "vpaddl.s16      q9, q11                  \n"
720 
721     // No pair subtract
722     // q2 = {a0, a3}
723     // q3 = {a1, a2}
724     "vtrn.16         q2, q3                   \n"
725     "vtrn.16         q10, q11                 \n"
726 
727     // {tmp[3], tmp[2]} = {a0 - a1, a3 - a2}
728     "vsubl.s16       q12, d4, d6              \n"
729     "vsubl.s16       q13, d5, d7              \n"
730     "vsubl.s16       q14, d20, d22            \n"
731     "vsubl.s16       q15, d21, d23            \n"
732 
733     // separate tmp[3] and tmp[2]
734     // q12 = tmp[3]
735     // q13 = tmp[2]
736     "vtrn.32         q12, q13                 \n"
737     "vtrn.32         q14, q15                 \n"
738 
739     // Transpose tmp for a
740     "vswp            d1, d26                  \n" // vtrn.64
741     "vswp            d3, d24                  \n" // vtrn.64
742     "vtrn.32         q0, q1                   \n"
743     "vtrn.32         q13, q12                 \n"
744 
745     // Transpose tmp for b
746     "vswp            d17, d30                 \n" // vtrn.64
747     "vswp            d19, d28                 \n" // vtrn.64
748     "vtrn.32         q8, q9                   \n"
749     "vtrn.32         q15, q14                 \n"
750 
751     // The first Q register is a, the second b.
752     // q0/8 tmp[0-3]
753     // q13/15 tmp[4-7]
754     // q1/9 tmp[8-11]
755     // q12/14 tmp[12-15]
756 
757     // These are still in 01 45 23 67 order. We fix it easily in the addition
758     // case but the subtraction propagates them.
759     "vswp            d3, d27                  \n"
760     "vswp            d19, d31                 \n"
761 
762     // a0 = tmp[0] + tmp[8]
763     "vadd.s32        q2, q0, q1               \n"
764     "vadd.s32        q3, q8, q9               \n"
765 
766     // a1 = tmp[4] + tmp[12]
767     "vadd.s32        q10, q13, q12            \n"
768     "vadd.s32        q11, q15, q14            \n"
769 
770     // a2 = tmp[4] - tmp[12]
771     "vsub.s32        q13, q13, q12            \n"
772     "vsub.s32        q15, q15, q14            \n"
773 
774     // a3 = tmp[0] - tmp[8]
775     "vsub.s32        q0, q0, q1               \n"
776     "vsub.s32        q8, q8, q9               \n"
777 
778     // b0 = a0 + a1
779     "vadd.s32        q1, q2, q10              \n"
780     "vadd.s32        q9, q3, q11              \n"
781 
782     // b1 = a3 + a2
783     "vadd.s32        q12, q0, q13             \n"
784     "vadd.s32        q14, q8, q15             \n"
785 
786     // b2 = a3 - a2
787     "vsub.s32        q0, q0, q13              \n"
788     "vsub.s32        q8, q8, q15              \n"
789 
790     // b3 = a0 - a1
791     "vsub.s32        q2, q2, q10              \n"
792     "vsub.s32        q3, q3, q11              \n"
793 
794     "vld1.64         {q10, q11}, [%[w]]       \n"
795 
796     // abs(b0)
797     "vabs.s32        q1, q1                   \n"
798     "vabs.s32        q9, q9                   \n"
799     // abs(b1)
800     "vabs.s32        q12, q12                 \n"
801     "vabs.s32        q14, q14                 \n"
802     // abs(b2)
803     "vabs.s32        q0, q0                   \n"
804     "vabs.s32        q8, q8                   \n"
805     // abs(b3)
806     "vabs.s32        q2, q2                   \n"
807     "vabs.s32        q3, q3                   \n"
808 
809     // expand w before using.
810     "vmovl.u16       q13, d20                 \n"
811     "vmovl.u16       q15, d21                 \n"
812 
813     // w[0] * abs(b0)
814     "vmul.u32        q1, q1, q13              \n"
815     "vmul.u32        q9, q9, q13              \n"
816 
817     // w[4] * abs(b1)
818     "vmla.u32        q1, q12, q15             \n"
819     "vmla.u32        q9, q14, q15             \n"
820 
821     // expand w before using.
822     "vmovl.u16       q13, d22                 \n"
823     "vmovl.u16       q15, d23                 \n"
824 
825     // w[8] * abs(b1)
826     "vmla.u32        q1, q0, q13              \n"
827     "vmla.u32        q9, q8, q13              \n"
828 
829     // w[12] * abs(b1)
830     "vmla.u32        q1, q2, q15              \n"
831     "vmla.u32        q9, q3, q15              \n"
832 
833     // Sum the arrays
834     "vpaddl.u32      q1, q1                   \n"
835     "vpaddl.u32      q9, q9                   \n"
836     "vadd.u64        d2, d3                   \n"
837     "vadd.u64        d18, d19                 \n"
838 
839     // Hadamard transform needs 4 bits of extra precision (2 bits in each
840     // direction) for dynamic raw. Weights w[] are 16bits at max, so the maximum
841     // precision for coeff is 8bit of input + 4bits of Hadamard transform +
842     // 16bits for w[] + 2 bits of abs() summation.
843     //
844     // This uses a maximum of 31 bits (signed). Discarding the top 32 bits is
845     // A-OK.
846 
847     // sum2 - sum1
848     "vsub.u32        d0, d2, d18              \n"
849     // abs(sum2 - sum1)
850     "vabs.s32        d0, d0                   \n"
851     // abs(sum2 - sum1) >> 5
852     "vshr.u32        d0, #5                   \n"
853 
854     // It would be better to move the value straight into r0 but I'm not
855     // entirely sure how this works with inline assembly.
856     "vmov.32         %[sum], d0[0]            \n"
857 
858     : [sum] "=r"(sum), [a] "+r"(A), [b] "+r"(B), [w] "+r"(W)
859     : [kBPS] "r"(kBPS)
860     : "memory", "q0", "q1", "q2", "q3", "q4", "q5", "q6", "q7", "q8", "q9",
861       "q10", "q11", "q12", "q13", "q14", "q15"  // clobbered
862   ) ;
863 
864   return sum;
865 }
866 
867 #endif  // USE_INTRINSICS
868 
Disto16x16(const uint8_t * const a,const uint8_t * const b,const uint16_t * const w)869 static int Disto16x16(const uint8_t* const a, const uint8_t* const b,
870                       const uint16_t* const w) {
871   int D = 0;
872   int x, y;
873   for (y = 0; y < 16 * BPS; y += 4 * BPS) {
874     for (x = 0; x < 16; x += 4) {
875       D += Disto4x4(a + x + y, b + x + y, w);
876     }
877   }
878   return D;
879 }
880 
881 //------------------------------------------------------------------------------
882 
CollectHistogram(const uint8_t * ref,const uint8_t * pred,int start_block,int end_block,VP8Histogram * const histo)883 static void CollectHistogram(const uint8_t* ref, const uint8_t* pred,
884                              int start_block, int end_block,
885                              VP8Histogram* const histo) {
886   const uint16x8_t max_coeff_thresh = vdupq_n_u16(MAX_COEFF_THRESH);
887   int j;
888   for (j = start_block; j < end_block; ++j) {
889     int16_t out[16];
890     FTransform(ref + VP8DspScan[j], pred + VP8DspScan[j], out);
891     {
892       int k;
893       const int16x8_t a0 = vld1q_s16(out + 0);
894       const int16x8_t b0 = vld1q_s16(out + 8);
895       const uint16x8_t a1 = vreinterpretq_u16_s16(vabsq_s16(a0));
896       const uint16x8_t b1 = vreinterpretq_u16_s16(vabsq_s16(b0));
897       const uint16x8_t a2 = vshrq_n_u16(a1, 3);
898       const uint16x8_t b2 = vshrq_n_u16(b1, 3);
899       const uint16x8_t a3 = vminq_u16(a2, max_coeff_thresh);
900       const uint16x8_t b3 = vminq_u16(b2, max_coeff_thresh);
901       vst1q_s16(out + 0, vreinterpretq_s16_u16(a3));
902       vst1q_s16(out + 8, vreinterpretq_s16_u16(b3));
903       // Convert coefficients to bin.
904       for (k = 0; k < 16; ++k) {
905         histo->distribution[out[k]]++;
906       }
907     }
908   }
909 }
910 
911 //------------------------------------------------------------------------------
912 
AccumulateSSE16(const uint8_t * const a,const uint8_t * const b,uint32x4_t * const sum)913 static WEBP_INLINE void AccumulateSSE16(const uint8_t* const a,
914                                         const uint8_t* const b,
915                                         uint32x4_t* const sum) {
916   const uint8x16_t a0 = vld1q_u8(a);
917   const uint8x16_t b0 = vld1q_u8(b);
918   const uint8x16_t abs_diff = vabdq_u8(a0, b0);
919   uint16x8_t prod = vmull_u8(vget_low_u8(abs_diff), vget_low_u8(abs_diff));
920   prod = vmlal_u8(prod, vget_high_u8(abs_diff), vget_high_u8(abs_diff));
921   *sum = vpadalq_u16(*sum, prod);      // pair-wise add and accumulate
922 }
923 
924 // Horizontal sum of all four uint32_t values in 'sum'.
SumToInt(uint32x4_t sum)925 static int SumToInt(uint32x4_t sum) {
926   const uint64x2_t sum2 = vpaddlq_u32(sum);
927   const uint64_t sum3 = vgetq_lane_u64(sum2, 0) + vgetq_lane_u64(sum2, 1);
928   return (int)sum3;
929 }
930 
SSE16x16(const uint8_t * a,const uint8_t * b)931 static int SSE16x16(const uint8_t* a, const uint8_t* b) {
932   uint32x4_t sum = vdupq_n_u32(0);
933   int y;
934   for (y = 0; y < 16; ++y) {
935     AccumulateSSE16(a + y * BPS, b + y * BPS, &sum);
936   }
937   return SumToInt(sum);
938 }
939 
SSE16x8(const uint8_t * a,const uint8_t * b)940 static int SSE16x8(const uint8_t* a, const uint8_t* b) {
941   uint32x4_t sum = vdupq_n_u32(0);
942   int y;
943   for (y = 0; y < 8; ++y) {
944     AccumulateSSE16(a + y * BPS, b + y * BPS, &sum);
945   }
946   return SumToInt(sum);
947 }
948 
SSE8x8(const uint8_t * a,const uint8_t * b)949 static int SSE8x8(const uint8_t* a, const uint8_t* b) {
950   uint32x4_t sum = vdupq_n_u32(0);
951   int y;
952   for (y = 0; y < 8; ++y) {
953     const uint8x8_t a0 = vld1_u8(a + y * BPS);
954     const uint8x8_t b0 = vld1_u8(b + y * BPS);
955     const uint8x8_t abs_diff = vabd_u8(a0, b0);
956     const uint16x8_t prod = vmull_u8(abs_diff, abs_diff);
957     sum = vpadalq_u16(sum, prod);
958   }
959   return SumToInt(sum);
960 }
961 
SSE4x4(const uint8_t * a,const uint8_t * b)962 static int SSE4x4(const uint8_t* a, const uint8_t* b) {
963   const uint8x16_t a0 = Load4x4(a);
964   const uint8x16_t b0 = Load4x4(b);
965   const uint8x16_t abs_diff = vabdq_u8(a0, b0);
966   uint16x8_t prod = vmull_u8(vget_low_u8(abs_diff), vget_low_u8(abs_diff));
967   prod = vmlal_u8(prod, vget_high_u8(abs_diff), vget_high_u8(abs_diff));
968   return SumToInt(vpaddlq_u16(prod));
969 }
970 
971 //------------------------------------------------------------------------------
972 
973 // Compilation with gcc-4.6.x is problematic for now.
974 #if !defined(WORK_AROUND_GCC)
975 
Quantize(int16_t * const in,const VP8Matrix * const mtx,int offset)976 static int16x8_t Quantize(int16_t* const in,
977                           const VP8Matrix* const mtx, int offset) {
978   const uint16x8_t sharp = vld1q_u16(&mtx->sharpen_[offset]);
979   const uint16x8_t q = vld1q_u16(&mtx->q_[offset]);
980   const uint16x8_t iq = vld1q_u16(&mtx->iq_[offset]);
981   const uint32x4_t bias0 = vld1q_u32(&mtx->bias_[offset + 0]);
982   const uint32x4_t bias1 = vld1q_u32(&mtx->bias_[offset + 4]);
983 
984   const int16x8_t a = vld1q_s16(in + offset);                // in
985   const uint16x8_t b = vreinterpretq_u16_s16(vabsq_s16(a));  // coeff = abs(in)
986   const int16x8_t sign = vshrq_n_s16(a, 15);                 // sign
987   const uint16x8_t c = vaddq_u16(b, sharp);                  // + sharpen
988   const uint32x4_t m0 = vmull_u16(vget_low_u16(c), vget_low_u16(iq));
989   const uint32x4_t m1 = vmull_u16(vget_high_u16(c), vget_high_u16(iq));
990   const uint32x4_t m2 = vhaddq_u32(m0, bias0);
991   const uint32x4_t m3 = vhaddq_u32(m1, bias1);     // (coeff * iQ + bias) >> 1
992   const uint16x8_t c0 = vcombine_u16(vshrn_n_u32(m2, 16),
993                                      vshrn_n_u32(m3, 16));   // QFIX=17 = 16+1
994   const uint16x8_t c1 = vminq_u16(c0, vdupq_n_u16(MAX_LEVEL));
995   const int16x8_t c2 = veorq_s16(vreinterpretq_s16_u16(c1), sign);
996   const int16x8_t c3 = vsubq_s16(c2, sign);                  // restore sign
997   const int16x8_t c4 = vmulq_s16(c3, vreinterpretq_s16_u16(q));
998   vst1q_s16(in + offset, c4);
999   assert(QFIX == 17);  // this function can't work as is if QFIX != 16+1
1000   return c3;
1001 }
1002 
1003 static const uint8_t kShuffles[4][8] = {
1004   { 0,   1,  2,  3,  8,  9, 16, 17 },
1005   { 10, 11,  4,  5,  6,  7, 12, 13 },
1006   { 18, 19, 24, 25, 26, 27, 20, 21 },
1007   { 14, 15, 22, 23, 28, 29, 30, 31 }
1008 };
1009 
QuantizeBlock(int16_t in[16],int16_t out[16],const VP8Matrix * const mtx)1010 static int QuantizeBlock(int16_t in[16], int16_t out[16],
1011                          const VP8Matrix* const mtx) {
1012   const int16x8_t out0 = Quantize(in, mtx, 0);
1013   const int16x8_t out1 = Quantize(in, mtx, 8);
1014   uint8x8x4_t shuffles;
1015   // vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use
1016   // non-standard versions there.
1017 #if defined(__APPLE__) && defined(__aarch64__) && \
1018     defined(__apple_build_version__) && (__apple_build_version__< 6020037)
1019   uint8x16x2_t all_out;
1020   INIT_VECTOR2(all_out, vreinterpretq_u8_s16(out0), vreinterpretq_u8_s16(out1));
1021   INIT_VECTOR4(shuffles,
1022                vtbl2q_u8(all_out, vld1_u8(kShuffles[0])),
1023                vtbl2q_u8(all_out, vld1_u8(kShuffles[1])),
1024                vtbl2q_u8(all_out, vld1_u8(kShuffles[2])),
1025                vtbl2q_u8(all_out, vld1_u8(kShuffles[3])));
1026 #else
1027   uint8x8x4_t all_out;
1028   INIT_VECTOR4(all_out,
1029                vreinterpret_u8_s16(vget_low_s16(out0)),
1030                vreinterpret_u8_s16(vget_high_s16(out0)),
1031                vreinterpret_u8_s16(vget_low_s16(out1)),
1032                vreinterpret_u8_s16(vget_high_s16(out1)));
1033   INIT_VECTOR4(shuffles,
1034                vtbl4_u8(all_out, vld1_u8(kShuffles[0])),
1035                vtbl4_u8(all_out, vld1_u8(kShuffles[1])),
1036                vtbl4_u8(all_out, vld1_u8(kShuffles[2])),
1037                vtbl4_u8(all_out, vld1_u8(kShuffles[3])));
1038 #endif
1039   // Zigzag reordering
1040   vst1_u8((uint8_t*)(out +  0), shuffles.val[0]);
1041   vst1_u8((uint8_t*)(out +  4), shuffles.val[1]);
1042   vst1_u8((uint8_t*)(out +  8), shuffles.val[2]);
1043   vst1_u8((uint8_t*)(out + 12), shuffles.val[3]);
1044   // test zeros
1045   if (*(uint64_t*)(out +  0) != 0) return 1;
1046   if (*(uint64_t*)(out +  4) != 0) return 1;
1047   if (*(uint64_t*)(out +  8) != 0) return 1;
1048   if (*(uint64_t*)(out + 12) != 0) return 1;
1049   return 0;
1050 }
1051 
1052 #endif   // !WORK_AROUND_GCC
1053 
1054 #endif   // WEBP_USE_NEON
1055 
1056 //------------------------------------------------------------------------------
1057 // Entry point
1058 
1059 extern void VP8EncDspInitNEON(void);
1060 
VP8EncDspInitNEON(void)1061 void VP8EncDspInitNEON(void) {
1062 #if defined(WEBP_USE_NEON)
1063   VP8ITransform = ITransform;
1064   VP8FTransform = FTransform;
1065 
1066   VP8FTransformWHT = FTransformWHT;
1067 
1068   VP8TDisto4x4 = Disto4x4;
1069   VP8TDisto16x16 = Disto16x16;
1070   VP8CollectHistogram = CollectHistogram;
1071   VP8SSE16x16 = SSE16x16;
1072   VP8SSE16x8 = SSE16x8;
1073   VP8SSE8x8 = SSE8x8;
1074   VP8SSE4x4 = SSE4x4;
1075 #if !defined(WORK_AROUND_GCC)
1076   VP8EncQuantizeBlock = QuantizeBlock;
1077 #endif
1078 #endif   // WEBP_USE_NEON
1079 }
1080