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Commit 8d5a5d5c authored by Vitaly Tuzov's avatar Vitaly Tuzov
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AVX2 optimizations for FAST corner tracking provided by Victoria Zhislina

parent 110af09b
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Showing with 125 additions and 50 deletions
modules/features2d/src/fast.cpp
View file @ 8d5a5d5c
......@@ -63,6 +63,14 @@ void FAST_t(InputArray _img, std::vector<KeyPoint>& keypoints, int threshold, bo
const int quarterPatternSize = patternSize/4;
v_uint8x16 delta = v_setall_u8(0x80), t = v_setall_u8((char)threshold), K16 = v_setall_u8((char)K);
bool hasSimd = hasSIMD128();
#if CV_TRY_AVX2
__m256i delta256, t256, K16_256;
if (CV_CPU_HAS_SUPPORT_AVX2)
{
delta256 = _mm256_broadcastsi128_si256(delta.val), t256 = _mm256_broadcastsi128_si256(t.val), K16_256 = _mm256_broadcastsi128_si256(K16.val);
}
#endif
#endif
int i, j, k, pixel[25];
makeOffsets(pixel, (int)img.step, patternSize);
......@@ -100,65 +108,132 @@ void FAST_t(InputArray _img, std::vector<KeyPoint>& keypoints, int threshold, bo
{
if( patternSize == 16 )
{
for(; j < img.cols - 16 - 3; j += 16, ptr += 16)
#if CV_TRY_AVX2
if (CV_CPU_HAS_SUPPORT_AVX2)
{
v_uint8x16 v = v_load(ptr);
v_int8x16 v0 = v_reinterpret_as_s8((v + t) ^ delta);
v_int8x16 v1 = v_reinterpret_as_s8((v - t) ^ delta);
v_int8x16 x0 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[0]), delta));
v_int8x16 x1 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[quarterPatternSize]), delta));
v_int8x16 x2 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[2*quarterPatternSize]), delta));
v_int8x16 x3 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[3*quarterPatternSize]), delta));
v_int8x16 m0, m1;
m0 = (v0 < x0) & (v0 < x1);
m1 = (x0 < v1) & (x1 < v1);
m0 = m0 | ((v0 < x1) & (v0 < x2));
m1 = m1 | ((x1 < v1) & (x2 < v1));
m0 = m0 | ((v0 < x2) & (v0 < x3));
m1 = m1 | ((x2 < v1) & (x3 < v1));
m0 = m0 | ((v0 < x3) & (v0 < x0));
m1 = m1 | ((x3 < v1) & (x0 < v1));
m0 = m0 | m1;
int mask = v_signmask(m0);
if( mask == 0 )
continue;
if( (mask & 255) == 0 )
for(; j < img.cols - 32 - 3; j += 32, ptr += 32)
{
j -= 8;
ptr -= 8;
continue;
}
__m256i m0, m1;
__m256i v0 = _mm256_loadu_si256((const __m256i*)ptr);
__m256i v1 = _mm256_xor_si256(_mm256_subs_epu8(v0, t256), delta256);
v0 = _mm256_xor_si256(_mm256_adds_epu8(v0, t256), delta256);
__m256i x0 = _mm256_sub_epi8(_mm256_loadu_si256((const __m256i*)(ptr + pixel[0])), delta256);
__m256i x1 = _mm256_sub_epi8(_mm256_loadu_si256((const __m256i*)(ptr + pixel[4])), delta256);
__m256i x2 = _mm256_sub_epi8(_mm256_loadu_si256((const __m256i*)(ptr + pixel[8])), delta256);
__m256i x3 = _mm256_sub_epi8(_mm256_loadu_si256((const __m256i*)(ptr + pixel[12])), delta256);
m0 = _mm256_and_si256(_mm256_cmpgt_epi8(x0, v0), _mm256_cmpgt_epi8(x1, v0));
m1 = _mm256_and_si256(_mm256_cmpgt_epi8(v1, x0), _mm256_cmpgt_epi8(v1, x1));
m0 = _mm256_or_si256(m0, _mm256_and_si256(_mm256_cmpgt_epi8(x1, v0), _mm256_cmpgt_epi8(x2, v0)));
m1 = _mm256_or_si256(m1, _mm256_and_si256(_mm256_cmpgt_epi8(v1, x1), _mm256_cmpgt_epi8(v1, x2)));
m0 = _mm256_or_si256(m0, _mm256_and_si256(_mm256_cmpgt_epi8(x2, v0), _mm256_cmpgt_epi8(x3, v0)));
m1 = _mm256_or_si256(m1, _mm256_and_si256(_mm256_cmpgt_epi8(v1, x2), _mm256_cmpgt_epi8(v1, x3)));
m0 = _mm256_or_si256(m0, _mm256_and_si256(_mm256_cmpgt_epi8(x3, v0), _mm256_cmpgt_epi8(x0, v0)));
m1 = _mm256_or_si256(m1, _mm256_and_si256(_mm256_cmpgt_epi8(v1, x3), _mm256_cmpgt_epi8(v1, x0)));
m0 = _mm256_or_si256(m0, m1);
unsigned int mask = _mm256_movemask_epi8(m0); //unsigned is important!
if (mask == 0){
continue;
}
if ((mask & 0xffff) == 0)
{
j -= 16;
ptr -= 16;
continue;
}
v_int8x16 c0 = v_setzero_s8();
v_int8x16 c1 = v_setzero_s8();
v_uint8x16 max0 = v_setzero_u8();
v_uint8x16 max1 = v_setzero_u8();
for( k = 0; k < N; k++ )
{
v_int8x16 x = v_reinterpret_as_s8(v_load((ptr + pixel[k])) ^ delta);
m0 = v0 < x;
m1 = x < v1;
__m256i c0 = _mm256_setzero_si256(), c1 = c0, max0 = c0, max1 = c0;
for (k = 0; k < N; k++)
{
__m256i x = _mm256_xor_si256(_mm256_loadu_si256((const __m256i*)(ptr + pixel[k])), delta256);
m0 = _mm256_cmpgt_epi8(x, v0);
m1 = _mm256_cmpgt_epi8(v1, x);
c0 = v_sub_wrap(c0, m0) & m0;
c1 = v_sub_wrap(c1, m1) & m1;
c0 = _mm256_and_si256(_mm256_sub_epi8(c0, m0), m0);
c1 = _mm256_and_si256(_mm256_sub_epi8(c1, m1), m1);
max0 = v_max(max0, v_reinterpret_as_u8(c0));
max1 = v_max(max1, v_reinterpret_as_u8(c1));
}
max0 = _mm256_max_epu8(max0, c0);
max1 = _mm256_max_epu8(max1, c1);
}
max0 = v_max(max0, max1);
int m = v_signmask(K16 < max0);
max0 = _mm256_max_epu8(max0, max1);
unsigned int m = _mm256_movemask_epi8(_mm256_cmpgt_epi8(max0, K16_256));
for( k = 0; m > 0 && k < 16; k++, m >>= 1 )
for (k = 0; m > 0 && k < 32; k++, m >>= 1)
if (m & 1)
{
cornerpos[ncorners++] = j + k;
if (nonmax_suppression)
curr[j + k] = (uchar)cornerScore<patternSize>(ptr + k, pixel, threshold);
}
}
} //CV_CPU_HAS_SUPPORT_AVX2
#endif
//vz if (j <= (img.cols - 27)) //it doesn't make sense using vectors for less than 8 elements
{
for (; j < img.cols - 16 - 3; j += 16, ptr += 16)
{
if(m & 1)
v_uint8x16 v = v_load(ptr);
v_int8x16 v0 = v_reinterpret_as_s8((v + t) ^ delta);
v_int8x16 v1 = v_reinterpret_as_s8((v - t) ^ delta);
v_int8x16 x0 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[0]), delta));
v_int8x16 x1 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[quarterPatternSize]), delta));
v_int8x16 x2 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[2*quarterPatternSize]), delta));
v_int8x16 x3 = v_reinterpret_as_s8(v_sub_wrap(v_load(ptr + pixel[3*quarterPatternSize]), delta));
v_int8x16 m0, m1;
m0 = (v0 < x0) & (v0 < x1);
m1 = (x0 < v1) & (x1 < v1);
m0 = m0 | ((v0 < x1) & (v0 < x2));
m1 = m1 | ((x1 < v1) & (x2 < v1));
m0 = m0 | ((v0 < x2) & (v0 < x3));
m1 = m1 | ((x2 < v1) & (x3 < v1));
m0 = m0 | ((v0 < x3) & (v0 < x0));
m1 = m1 | ((x3 < v1) & (x0 < v1));
m0 = m0 | m1;
int mask = v_signmask(m0);
if( mask == 0 )
continue;
if( (mask & 255) == 0 )
{
cornerpos[ncorners++] = j+k;
if(nonmax_suppression)
curr[j+k] = (uchar)cornerScore<patternSize>(ptr+k, pixel, threshold);
j -= 8;
ptr -= 8;
continue;
}
v_int8x16 c0 = v_setzero_s8();
v_int8x16 c1 = v_setzero_s8();
v_uint8x16 max0 = v_setzero_u8();
v_uint8x16 max1 = v_setzero_u8();
for( k = 0; k < N; k++ )
{
v_int8x16 x = v_reinterpret_as_s8(v_load((ptr + pixel[k])) ^ delta);
m0 = v0 < x;
m1 = x < v1;
c0 = v_sub_wrap(c0, m0) & m0;
c1 = v_sub_wrap(c1, m1) & m1;
max0 = v_max(max0, v_reinterpret_as_u8(c0));
max1 = v_max(max1, v_reinterpret_as_u8(c1));
}
max0 = v_max(max0, max1);
int m = v_signmask(K16 < max0);
for( k = 0; m > 0 && k < 16; k++, m >>= 1 )
{
if(m & 1)
{
cornerpos[ncorners++] = j+k;
if(nonmax_suppression)
curr[j+k] = (uchar)cornerScore<patternSize>(ptr+k, pixel, threshold);
}
}
}
}
......
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