diff options
Diffstat (limited to 'third_party/aom/av1/encoder/x86/corner_match_sse4.c')
-rw-r--r-- | third_party/aom/av1/encoder/x86/corner_match_sse4.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/x86/corner_match_sse4.c b/third_party/aom/av1/encoder/x86/corner_match_sse4.c new file mode 100644 index 000000000..179da0d28 --- /dev/null +++ b/third_party/aom/av1/encoder/x86/corner_match_sse4.c @@ -0,0 +1,91 @@ +#include <stdlib.h> +#include <memory.h> +#include <math.h> +#include <assert.h> + +#include <smmintrin.h> + +#include "./av1_rtcd.h" +#include "aom_ports/mem.h" +#include "av1/encoder/corner_match.h" + +DECLARE_ALIGNED(16, static const uint8_t, byte_mask[16]) = { + 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 0, 0, 0 +}; +#if MATCH_SZ != 13 +#error "Need to change byte_mask in corner_match_sse4.c if MATCH_SZ != 13" +#endif + +/* Compute corr(im1, im2) * MATCH_SZ * stddev(im1), where the + correlation/standard deviation are taken over MATCH_SZ by MATCH_SZ windows + of each image, centered at (x1, y1) and (x2, y2) respectively. +*/ +double compute_cross_correlation_sse4_1(unsigned char *im1, int stride1, int x1, + int y1, unsigned char *im2, int stride2, + int x2, int y2) { + int i; + // 2 16-bit partial sums in lanes 0, 4 (== 2 32-bit partial sums in lanes 0, + // 2) + __m128i sum1_vec = _mm_setzero_si128(); + __m128i sum2_vec = _mm_setzero_si128(); + // 4 32-bit partial sums of squares + __m128i sumsq2_vec = _mm_setzero_si128(); + __m128i cross_vec = _mm_setzero_si128(); + + const __m128i mask = _mm_load_si128((__m128i *)byte_mask); + const __m128i zero = _mm_setzero_si128(); + + im1 += (y1 - MATCH_SZ_BY2) * stride1 + (x1 - MATCH_SZ_BY2); + im2 += (y2 - MATCH_SZ_BY2) * stride2 + (x2 - MATCH_SZ_BY2); + + for (i = 0; i < MATCH_SZ; ++i) { + const __m128i v1 = + _mm_and_si128(_mm_loadu_si128((__m128i *)&im1[i * stride1]), mask); + const __m128i v2 = + _mm_and_si128(_mm_loadu_si128((__m128i *)&im2[i * stride2]), mask); + + // Using the 'sad' intrinsic here is a bit faster than adding + // v1_l + v1_r and v2_l + v2_r, plus it avoids the need for a 16->32 bit + // conversion step later, for a net speedup of ~10% + sum1_vec = _mm_add_epi16(sum1_vec, _mm_sad_epu8(v1, zero)); + sum2_vec = _mm_add_epi16(sum2_vec, _mm_sad_epu8(v2, zero)); + + const __m128i v1_l = _mm_cvtepu8_epi16(v1); + const __m128i v1_r = _mm_cvtepu8_epi16(_mm_srli_si128(v1, 8)); + const __m128i v2_l = _mm_cvtepu8_epi16(v2); + const __m128i v2_r = _mm_cvtepu8_epi16(_mm_srli_si128(v2, 8)); + + sumsq2_vec = _mm_add_epi32( + sumsq2_vec, + _mm_add_epi32(_mm_madd_epi16(v2_l, v2_l), _mm_madd_epi16(v2_r, v2_r))); + cross_vec = _mm_add_epi32( + cross_vec, + _mm_add_epi32(_mm_madd_epi16(v1_l, v2_l), _mm_madd_epi16(v1_r, v2_r))); + } + + // Now we can treat the four registers (sum1_vec, sum2_vec, sumsq2_vec, + // cross_vec) + // as holding 4 32-bit elements each, which we want to sum horizontally. + // We do this by transposing and then summing vertically. + __m128i tmp_0 = _mm_unpacklo_epi32(sum1_vec, sum2_vec); + __m128i tmp_1 = _mm_unpackhi_epi32(sum1_vec, sum2_vec); + __m128i tmp_2 = _mm_unpacklo_epi32(sumsq2_vec, cross_vec); + __m128i tmp_3 = _mm_unpackhi_epi32(sumsq2_vec, cross_vec); + + __m128i tmp_4 = _mm_unpacklo_epi64(tmp_0, tmp_2); + __m128i tmp_5 = _mm_unpackhi_epi64(tmp_0, tmp_2); + __m128i tmp_6 = _mm_unpacklo_epi64(tmp_1, tmp_3); + __m128i tmp_7 = _mm_unpackhi_epi64(tmp_1, tmp_3); + + __m128i res = + _mm_add_epi32(_mm_add_epi32(tmp_4, tmp_5), _mm_add_epi32(tmp_6, tmp_7)); + + int sum1 = _mm_extract_epi32(res, 0); + int sum2 = _mm_extract_epi32(res, 1); + int sumsq2 = _mm_extract_epi32(res, 2); + int cross = _mm_extract_epi32(res, 3); + + int var2 = sumsq2 * MATCH_SZ_SQ - sum2 * sum2; + int cov = cross * MATCH_SZ_SQ - sum1 * sum2; + return cov / sqrt((double)var2); +} |