xref: /aosp_15_r20/external/libaom/aom_dsp/x86/sum_squares_sse2.c (revision 77c1e3ccc04c968bd2bc212e87364f250e820521)
1 /*
2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 
12 #include <assert.h>
13 #include <emmintrin.h>
14 #include <stdio.h>
15 
16 #include "aom_dsp/x86/synonyms.h"
17 #include "aom_dsp/x86/sum_squares_sse2.h"
18 #include "config/aom_dsp_rtcd.h"
19 
xx_loadh_64(__m128i a,const void * b)20 static inline __m128i xx_loadh_64(__m128i a, const void *b) {
21   const __m128d ad = _mm_castsi128_pd(a);
22   return _mm_castpd_si128(_mm_loadh_pd(ad, (double *)b));
23 }
24 
xx_cvtsi128_si64(__m128i a)25 static inline uint64_t xx_cvtsi128_si64(__m128i a) {
26 #if AOM_ARCH_X86_64
27   return (uint64_t)_mm_cvtsi128_si64(a);
28 #else
29   {
30     uint64_t tmp;
31     _mm_storel_epi64((__m128i *)&tmp, a);
32     return tmp;
33   }
34 #endif
35 }
36 
sum_squares_i16_4x4_sse2(const int16_t * src,int stride)37 static inline __m128i sum_squares_i16_4x4_sse2(const int16_t *src, int stride) {
38   const __m128i v_val_0_w = xx_loadl_64(src + 0 * stride);
39   const __m128i v_val_2_w = xx_loadl_64(src + 2 * stride);
40   const __m128i v_val_01_w = xx_loadh_64(v_val_0_w, src + 1 * stride);
41   const __m128i v_val_23_w = xx_loadh_64(v_val_2_w, src + 3 * stride);
42   const __m128i v_sq_01_d = _mm_madd_epi16(v_val_01_w, v_val_01_w);
43   const __m128i v_sq_23_d = _mm_madd_epi16(v_val_23_w, v_val_23_w);
44 
45   return _mm_add_epi32(v_sq_01_d, v_sq_23_d);
46 }
47 
aom_sum_squares_2d_i16_4x4_sse2(const int16_t * src,int stride)48 uint64_t aom_sum_squares_2d_i16_4x4_sse2(const int16_t *src, int stride) {
49   const __m128i v_sum_0123_d = sum_squares_i16_4x4_sse2(src, stride);
50   __m128i v_sum_d =
51       _mm_add_epi32(v_sum_0123_d, _mm_srli_epi64(v_sum_0123_d, 32));
52   v_sum_d = _mm_add_epi32(v_sum_d, _mm_srli_si128(v_sum_d, 8));
53   return (uint64_t)_mm_cvtsi128_si32(v_sum_d);
54 }
55 
aom_sum_sse_2d_i16_4x4_sse2(const int16_t * src,int stride,int * sum)56 uint64_t aom_sum_sse_2d_i16_4x4_sse2(const int16_t *src, int stride, int *sum) {
57   const __m128i one_reg = _mm_set1_epi16(1);
58   const __m128i v_val_0_w = xx_loadl_64(src + 0 * stride);
59   const __m128i v_val_2_w = xx_loadl_64(src + 2 * stride);
60   __m128i v_val_01_w = xx_loadh_64(v_val_0_w, src + 1 * stride);
61   __m128i v_val_23_w = xx_loadh_64(v_val_2_w, src + 3 * stride);
62 
63   __m128i v_sum_0123_d = _mm_add_epi16(v_val_01_w, v_val_23_w);
64   v_sum_0123_d = _mm_madd_epi16(v_sum_0123_d, one_reg);
65   v_sum_0123_d = _mm_add_epi32(v_sum_0123_d, _mm_srli_si128(v_sum_0123_d, 8));
66   v_sum_0123_d = _mm_add_epi32(v_sum_0123_d, _mm_srli_si128(v_sum_0123_d, 4));
67   *sum = _mm_cvtsi128_si32(v_sum_0123_d);
68 
69   const __m128i v_sq_01_d = _mm_madd_epi16(v_val_01_w, v_val_01_w);
70   const __m128i v_sq_23_d = _mm_madd_epi16(v_val_23_w, v_val_23_w);
71   __m128i v_sq_0123_d = _mm_add_epi32(v_sq_01_d, v_sq_23_d);
72   v_sq_0123_d = _mm_add_epi32(v_sq_0123_d, _mm_srli_si128(v_sq_0123_d, 8));
73   v_sq_0123_d = _mm_add_epi32(v_sq_0123_d, _mm_srli_si128(v_sq_0123_d, 4));
74   return (uint64_t)_mm_cvtsi128_si32(v_sq_0123_d);
75 }
76 
aom_sum_squares_2d_i16_4xn_sse2(const int16_t * src,int stride,int height)77 uint64_t aom_sum_squares_2d_i16_4xn_sse2(const int16_t *src, int stride,
78                                          int height) {
79   int r = 0;
80   __m128i v_acc_q = _mm_setzero_si128();
81   do {
82     const __m128i v_acc_d = sum_squares_i16_4x4_sse2(src, stride);
83     v_acc_q = _mm_add_epi32(v_acc_q, v_acc_d);
84     src += stride << 2;
85     r += 4;
86   } while (r < height);
87   const __m128i v_zext_mask_q = _mm_set1_epi64x(~0u);
88   __m128i v_acc_64 = _mm_add_epi64(_mm_srli_epi64(v_acc_q, 32),
89                                    _mm_and_si128(v_acc_q, v_zext_mask_q));
90   v_acc_64 = _mm_add_epi64(v_acc_64, _mm_srli_si128(v_acc_64, 8));
91   return xx_cvtsi128_si64(v_acc_64);
92 }
93 
aom_sum_sse_2d_i16_4xn_sse2(const int16_t * src,int stride,int height,int * sum)94 uint64_t aom_sum_sse_2d_i16_4xn_sse2(const int16_t *src, int stride, int height,
95                                      int *sum) {
96   int r = 0;
97   uint64_t sse = 0;
98   do {
99     int curr_sum = 0;
100     sse += aom_sum_sse_2d_i16_4x4_sse2(src, stride, &curr_sum);
101     *sum += curr_sum;
102     src += stride << 2;
103     r += 4;
104   } while (r < height);
105   return sse;
106 }
107 
108 #ifdef __GNUC__
109 // This prevents GCC/Clang from inlining this function into
110 // aom_sum_squares_2d_i16_sse2, which in turn saves some stack
111 // maintenance instructions in the common case of 4x4.
112 __attribute__((noinline))
113 #endif
114 uint64_t
aom_sum_squares_2d_i16_nxn_sse2(const int16_t * src,int stride,int width,int height)115 aom_sum_squares_2d_i16_nxn_sse2(const int16_t *src, int stride, int width,
116                                 int height) {
117   int r = 0;
118 
119   const __m128i v_zext_mask_q = _mm_set1_epi64x(~0u);
120   __m128i v_acc_q = _mm_setzero_si128();
121 
122   do {
123     __m128i v_acc_d = _mm_setzero_si128();
124     int c = 0;
125     do {
126       const int16_t *b = src + c;
127 
128       const __m128i v_val_0_w = xx_load_128(b + 0 * stride);
129       const __m128i v_val_1_w = xx_load_128(b + 1 * stride);
130       const __m128i v_val_2_w = xx_load_128(b + 2 * stride);
131       const __m128i v_val_3_w = xx_load_128(b + 3 * stride);
132 
133       const __m128i v_sq_0_d = _mm_madd_epi16(v_val_0_w, v_val_0_w);
134       const __m128i v_sq_1_d = _mm_madd_epi16(v_val_1_w, v_val_1_w);
135       const __m128i v_sq_2_d = _mm_madd_epi16(v_val_2_w, v_val_2_w);
136       const __m128i v_sq_3_d = _mm_madd_epi16(v_val_3_w, v_val_3_w);
137 
138       const __m128i v_sum_01_d = _mm_add_epi32(v_sq_0_d, v_sq_1_d);
139       const __m128i v_sum_23_d = _mm_add_epi32(v_sq_2_d, v_sq_3_d);
140 
141       const __m128i v_sum_0123_d = _mm_add_epi32(v_sum_01_d, v_sum_23_d);
142 
143       v_acc_d = _mm_add_epi32(v_acc_d, v_sum_0123_d);
144       c += 8;
145     } while (c < width);
146 
147     v_acc_q = _mm_add_epi64(v_acc_q, _mm_and_si128(v_acc_d, v_zext_mask_q));
148     v_acc_q = _mm_add_epi64(v_acc_q, _mm_srli_epi64(v_acc_d, 32));
149 
150     src += 4 * stride;
151     r += 4;
152   } while (r < height);
153 
154   v_acc_q = _mm_add_epi64(v_acc_q, _mm_srli_si128(v_acc_q, 8));
155   return xx_cvtsi128_si64(v_acc_q);
156 }
157 
158 #ifdef __GNUC__
159 // This prevents GCC/Clang from inlining this function into
160 // aom_sum_sse_2d_i16_nxn_sse2, which in turn saves some stack
161 // maintenance instructions in the common case of 4x4.
162 __attribute__((noinline))
163 #endif
164 uint64_t
aom_sum_sse_2d_i16_nxn_sse2(const int16_t * src,int stride,int width,int height,int * sum)165 aom_sum_sse_2d_i16_nxn_sse2(const int16_t *src, int stride, int width,
166                             int height, int *sum) {
167   int r = 0;
168   uint64_t result;
169   const __m128i zero_reg = _mm_setzero_si128();
170   const __m128i one_reg = _mm_set1_epi16(1);
171 
172   __m128i v_sse_total = zero_reg;
173   __m128i v_sum_total = zero_reg;
174 
175   do {
176     int c = 0;
177     __m128i v_sse_row = zero_reg;
178     do {
179       const int16_t *b = src + c;
180 
181       __m128i v_val_0_w = xx_load_128(b + 0 * stride);
182       __m128i v_val_1_w = xx_load_128(b + 1 * stride);
183       __m128i v_val_2_w = xx_load_128(b + 2 * stride);
184       __m128i v_val_3_w = xx_load_128(b + 3 * stride);
185 
186       const __m128i v_sq_0_d = _mm_madd_epi16(v_val_0_w, v_val_0_w);
187       const __m128i v_sq_1_d = _mm_madd_epi16(v_val_1_w, v_val_1_w);
188       const __m128i v_sq_2_d = _mm_madd_epi16(v_val_2_w, v_val_2_w);
189       const __m128i v_sq_3_d = _mm_madd_epi16(v_val_3_w, v_val_3_w);
190       const __m128i v_sq_01_d = _mm_add_epi32(v_sq_0_d, v_sq_1_d);
191       const __m128i v_sq_23_d = _mm_add_epi32(v_sq_2_d, v_sq_3_d);
192       const __m128i v_sq_0123_d = _mm_add_epi32(v_sq_01_d, v_sq_23_d);
193       v_sse_row = _mm_add_epi32(v_sse_row, v_sq_0123_d);
194 
195       const __m128i v_sum_01 = _mm_add_epi16(v_val_0_w, v_val_1_w);
196       const __m128i v_sum_23 = _mm_add_epi16(v_val_2_w, v_val_3_w);
197       __m128i v_sum_0123_d = _mm_add_epi16(v_sum_01, v_sum_23);
198       v_sum_0123_d = _mm_madd_epi16(v_sum_0123_d, one_reg);
199       v_sum_total = _mm_add_epi32(v_sum_total, v_sum_0123_d);
200 
201       c += 8;
202     } while (c < width);
203 
204     const __m128i v_sse_row_low = _mm_unpacklo_epi32(v_sse_row, zero_reg);
205     const __m128i v_sse_row_hi = _mm_unpackhi_epi32(v_sse_row, zero_reg);
206     v_sse_row = _mm_add_epi64(v_sse_row_low, v_sse_row_hi);
207     v_sse_total = _mm_add_epi64(v_sse_total, v_sse_row);
208     src += 4 * stride;
209     r += 4;
210   } while (r < height);
211 
212   v_sum_total = _mm_add_epi32(v_sum_total, _mm_srli_si128(v_sum_total, 8));
213   v_sum_total = _mm_add_epi32(v_sum_total, _mm_srli_si128(v_sum_total, 4));
214   *sum += _mm_cvtsi128_si32(v_sum_total);
215 
216   v_sse_total = _mm_add_epi64(v_sse_total, _mm_srli_si128(v_sse_total, 8));
217   xx_storel_64(&result, v_sse_total);
218   return result;
219 }
220 
aom_sum_squares_2d_i16_sse2(const int16_t * src,int stride,int width,int height)221 uint64_t aom_sum_squares_2d_i16_sse2(const int16_t *src, int stride, int width,
222                                      int height) {
223   // 4 elements per row only requires half an XMM register, so this
224   // must be a special case, but also note that over 75% of all calls
225   // are with size == 4, so it is also the common case.
226   if (LIKELY(width == 4 && height == 4)) {
227     return aom_sum_squares_2d_i16_4x4_sse2(src, stride);
228   } else if (LIKELY(width == 4 && (height & 3) == 0)) {
229     return aom_sum_squares_2d_i16_4xn_sse2(src, stride, height);
230   } else if (LIKELY((width & 7) == 0 && (height & 3) == 0)) {
231     // Generic case
232     return aom_sum_squares_2d_i16_nxn_sse2(src, stride, width, height);
233   } else {
234     return aom_sum_squares_2d_i16_c(src, stride, width, height);
235   }
236 }
237 
aom_sum_sse_2d_i16_sse2(const int16_t * src,int src_stride,int width,int height,int * sum)238 uint64_t aom_sum_sse_2d_i16_sse2(const int16_t *src, int src_stride, int width,
239                                  int height, int *sum) {
240   if (LIKELY(width == 4 && height == 4)) {
241     return aom_sum_sse_2d_i16_4x4_sse2(src, src_stride, sum);
242   } else if (LIKELY(width == 4 && (height & 3) == 0)) {
243     return aom_sum_sse_2d_i16_4xn_sse2(src, src_stride, height, sum);
244   } else if (LIKELY((width & 7) == 0 && (height & 3) == 0)) {
245     // Generic case
246     return aom_sum_sse_2d_i16_nxn_sse2(src, src_stride, width, height, sum);
247   } else {
248     return aom_sum_sse_2d_i16_c(src, src_stride, width, height, sum);
249   }
250 }
251 
252 //////////////////////////////////////////////////////////////////////////////
253 // 1D version
254 //////////////////////////////////////////////////////////////////////////////
255 
aom_sum_squares_i16_64n_sse2(const int16_t * src,uint32_t n)256 static uint64_t aom_sum_squares_i16_64n_sse2(const int16_t *src, uint32_t n) {
257   const __m128i v_zext_mask_q = _mm_set1_epi64x(~0u);
258   __m128i v_acc0_q = _mm_setzero_si128();
259   __m128i v_acc1_q = _mm_setzero_si128();
260 
261   const int16_t *const end = src + n;
262 
263   assert(n % 64 == 0);
264 
265   while (src < end) {
266     const __m128i v_val_0_w = xx_load_128(src);
267     const __m128i v_val_1_w = xx_load_128(src + 8);
268     const __m128i v_val_2_w = xx_load_128(src + 16);
269     const __m128i v_val_3_w = xx_load_128(src + 24);
270     const __m128i v_val_4_w = xx_load_128(src + 32);
271     const __m128i v_val_5_w = xx_load_128(src + 40);
272     const __m128i v_val_6_w = xx_load_128(src + 48);
273     const __m128i v_val_7_w = xx_load_128(src + 56);
274 
275     const __m128i v_sq_0_d = _mm_madd_epi16(v_val_0_w, v_val_0_w);
276     const __m128i v_sq_1_d = _mm_madd_epi16(v_val_1_w, v_val_1_w);
277     const __m128i v_sq_2_d = _mm_madd_epi16(v_val_2_w, v_val_2_w);
278     const __m128i v_sq_3_d = _mm_madd_epi16(v_val_3_w, v_val_3_w);
279     const __m128i v_sq_4_d = _mm_madd_epi16(v_val_4_w, v_val_4_w);
280     const __m128i v_sq_5_d = _mm_madd_epi16(v_val_5_w, v_val_5_w);
281     const __m128i v_sq_6_d = _mm_madd_epi16(v_val_6_w, v_val_6_w);
282     const __m128i v_sq_7_d = _mm_madd_epi16(v_val_7_w, v_val_7_w);
283 
284     const __m128i v_sum_01_d = _mm_add_epi32(v_sq_0_d, v_sq_1_d);
285     const __m128i v_sum_23_d = _mm_add_epi32(v_sq_2_d, v_sq_3_d);
286     const __m128i v_sum_45_d = _mm_add_epi32(v_sq_4_d, v_sq_5_d);
287     const __m128i v_sum_67_d = _mm_add_epi32(v_sq_6_d, v_sq_7_d);
288 
289     const __m128i v_sum_0123_d = _mm_add_epi32(v_sum_01_d, v_sum_23_d);
290     const __m128i v_sum_4567_d = _mm_add_epi32(v_sum_45_d, v_sum_67_d);
291 
292     const __m128i v_sum_d = _mm_add_epi32(v_sum_0123_d, v_sum_4567_d);
293 
294     v_acc0_q = _mm_add_epi64(v_acc0_q, _mm_and_si128(v_sum_d, v_zext_mask_q));
295     v_acc1_q = _mm_add_epi64(v_acc1_q, _mm_srli_epi64(v_sum_d, 32));
296 
297     src += 64;
298   }
299 
300   v_acc0_q = _mm_add_epi64(v_acc0_q, v_acc1_q);
301   v_acc0_q = _mm_add_epi64(v_acc0_q, _mm_srli_si128(v_acc0_q, 8));
302   return xx_cvtsi128_si64(v_acc0_q);
303 }
304 
aom_sum_squares_i16_sse2(const int16_t * src,uint32_t n)305 uint64_t aom_sum_squares_i16_sse2(const int16_t *src, uint32_t n) {
306   if (n % 64 == 0) {
307     return aom_sum_squares_i16_64n_sse2(src, n);
308   } else if (n > 64) {
309     const uint32_t k = n & ~63u;
310     return aom_sum_squares_i16_64n_sse2(src, k) +
311            aom_sum_squares_i16_c(src + k, n - k);
312   } else {
313     return aom_sum_squares_i16_c(src, n);
314   }
315 }
316 
317 // Accumulate sum of 16-bit elements in the vector
mm_accumulate_epi16(__m128i vec_a)318 static inline int32_t mm_accumulate_epi16(__m128i vec_a) {
319   __m128i vtmp = _mm_srli_si128(vec_a, 8);
320   vec_a = _mm_add_epi16(vec_a, vtmp);
321   vtmp = _mm_srli_si128(vec_a, 4);
322   vec_a = _mm_add_epi16(vec_a, vtmp);
323   vtmp = _mm_srli_si128(vec_a, 2);
324   vec_a = _mm_add_epi16(vec_a, vtmp);
325   return _mm_extract_epi16(vec_a, 0);
326 }
327 
328 // Accumulate sum of 32-bit elements in the vector
mm_accumulate_epi32(__m128i vec_a)329 static inline int32_t mm_accumulate_epi32(__m128i vec_a) {
330   __m128i vtmp = _mm_srli_si128(vec_a, 8);
331   vec_a = _mm_add_epi32(vec_a, vtmp);
332   vtmp = _mm_srli_si128(vec_a, 4);
333   vec_a = _mm_add_epi32(vec_a, vtmp);
334   return _mm_cvtsi128_si32(vec_a);
335 }
336 
aom_var_2d_u8_sse2(uint8_t * src,int src_stride,int width,int height)337 uint64_t aom_var_2d_u8_sse2(uint8_t *src, int src_stride, int width,
338                             int height) {
339   uint8_t *srcp;
340   uint64_t s = 0, ss = 0;
341   __m128i vzero = _mm_setzero_si128();
342   __m128i v_acc_sum = vzero;
343   __m128i v_acc_sqs = vzero;
344   int i, j;
345 
346   // Process 16 elements in a row
347   for (i = 0; i < width - 15; i += 16) {
348     srcp = src + i;
349     // Process 8 columns at a time
350     for (j = 0; j < height - 7; j += 8) {
351       __m128i vsrc[8];
352       for (int k = 0; k < 8; k++) {
353         vsrc[k] = _mm_loadu_si128((__m128i *)srcp);
354         srcp += src_stride;
355       }
356       for (int k = 0; k < 8; k++) {
357         __m128i vsrc0 = _mm_unpacklo_epi8(vsrc[k], vzero);
358         __m128i vsrc1 = _mm_unpackhi_epi8(vsrc[k], vzero);
359         v_acc_sum = _mm_add_epi16(v_acc_sum, vsrc0);
360         v_acc_sum = _mm_add_epi16(v_acc_sum, vsrc1);
361 
362         __m128i vsqs0 = _mm_madd_epi16(vsrc0, vsrc0);
363         __m128i vsqs1 = _mm_madd_epi16(vsrc1, vsrc1);
364         v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs0);
365         v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs1);
366       }
367 
368       // Update total sum and clear the vectors
369       s += mm_accumulate_epi16(v_acc_sum);
370       ss += mm_accumulate_epi32(v_acc_sqs);
371       v_acc_sum = vzero;
372       v_acc_sqs = vzero;
373     }
374 
375     // Process remaining rows (height not a multiple of 8)
376     for (; j < height; j++) {
377       __m128i vsrc = _mm_loadu_si128((__m128i *)srcp);
378       __m128i vsrc0 = _mm_unpacklo_epi8(vsrc, vzero);
379       __m128i vsrc1 = _mm_unpackhi_epi8(vsrc, vzero);
380       v_acc_sum = _mm_add_epi16(v_acc_sum, vsrc0);
381       v_acc_sum = _mm_add_epi16(v_acc_sum, vsrc1);
382 
383       __m128i vsqs0 = _mm_madd_epi16(vsrc0, vsrc0);
384       __m128i vsqs1 = _mm_madd_epi16(vsrc1, vsrc1);
385       v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs0);
386       v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs1);
387 
388       srcp += src_stride;
389     }
390 
391     // Update total sum and clear the vectors
392     s += mm_accumulate_epi16(v_acc_sum);
393     ss += mm_accumulate_epi32(v_acc_sqs);
394     v_acc_sum = vzero;
395     v_acc_sqs = vzero;
396   }
397 
398   // Process the remaining area using C
399   srcp = src;
400   for (int k = 0; k < height; k++) {
401     for (int m = i; m < width; m++) {
402       uint8_t val = srcp[m];
403       s += val;
404       ss += val * val;
405     }
406     srcp += src_stride;
407   }
408   return (ss - s * s / (width * height));
409 }
410 
411 #if CONFIG_AV1_HIGHBITDEPTH
aom_var_2d_u16_sse2(uint8_t * src,int src_stride,int width,int height)412 uint64_t aom_var_2d_u16_sse2(uint8_t *src, int src_stride, int width,
413                              int height) {
414   uint16_t *srcp1 = CONVERT_TO_SHORTPTR(src), *srcp;
415   uint64_t s = 0, ss = 0;
416   __m128i vzero = _mm_setzero_si128();
417   __m128i v_acc_sum = vzero;
418   __m128i v_acc_sqs = vzero;
419   int i, j;
420 
421   // Process 8 elements in a row
422   for (i = 0; i < width - 8; i += 8) {
423     srcp = srcp1 + i;
424     // Process 8 columns at a time
425     for (j = 0; j < height - 8; j += 8) {
426       __m128i vsrc[8];
427       for (int k = 0; k < 8; k++) {
428         vsrc[k] = _mm_loadu_si128((__m128i *)srcp);
429         srcp += src_stride;
430       }
431       for (int k = 0; k < 8; k++) {
432         __m128i vsrc0 = _mm_unpacklo_epi16(vsrc[k], vzero);
433         __m128i vsrc1 = _mm_unpackhi_epi16(vsrc[k], vzero);
434         v_acc_sum = _mm_add_epi32(vsrc0, v_acc_sum);
435         v_acc_sum = _mm_add_epi32(vsrc1, v_acc_sum);
436 
437         __m128i vsqs0 = _mm_madd_epi16(vsrc[k], vsrc[k]);
438         v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs0);
439       }
440 
441       // Update total sum and clear the vectors
442       s += mm_accumulate_epi32(v_acc_sum);
443       ss += mm_accumulate_epi32(v_acc_sqs);
444       v_acc_sum = vzero;
445       v_acc_sqs = vzero;
446     }
447 
448     // Process remaining rows (height not a multiple of 8)
449     for (; j < height; j++) {
450       __m128i vsrc = _mm_loadu_si128((__m128i *)srcp);
451       __m128i vsrc0 = _mm_unpacklo_epi16(vsrc, vzero);
452       __m128i vsrc1 = _mm_unpackhi_epi16(vsrc, vzero);
453       v_acc_sum = _mm_add_epi32(vsrc0, v_acc_sum);
454       v_acc_sum = _mm_add_epi32(vsrc1, v_acc_sum);
455 
456       __m128i vsqs0 = _mm_madd_epi16(vsrc, vsrc);
457       v_acc_sqs = _mm_add_epi32(v_acc_sqs, vsqs0);
458       srcp += src_stride;
459     }
460 
461     // Update total sum and clear the vectors
462     s += mm_accumulate_epi32(v_acc_sum);
463     ss += mm_accumulate_epi32(v_acc_sqs);
464     v_acc_sum = vzero;
465     v_acc_sqs = vzero;
466   }
467 
468   // Process the remaining area using C
469   srcp = srcp1;
470   for (int k = 0; k < height; k++) {
471     for (int m = i; m < width; m++) {
472       uint16_t val = srcp[m];
473       s += val;
474       ss += val * val;
475     }
476     srcp += src_stride;
477   }
478   return (ss - s * s / (width * height));
479 }
480 #endif  // CONFIG_AV1_HIGHBITDEPTH
481