mirror/opencv
1
0
Fork 0
mirror of https://github.com/opencv/opencv.git synced 2025-08-05 22:19:14 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Precompute the divisor to ensure that no kind of compiler would process it on the fly at each call.

Browse Source
This commit is contained in:
Pierre-Emmanuel Viel 2020-07-01 18:52:05 +02:00
parent a84afb6334
commit 327f92cc46
1 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
modules/flann/include/opencv2/flann/dist.h
View File

@ -506,7 +506,7 @@ struct Hamming2
const uint64_t* pa = reinterpret_cast<const uint64_t*>(a);
const uint64_t* pb = reinterpret_cast<const uint64_t*>(b);
ResultType result = 0;
size /= (sizeof(uint64_t)/sizeof(unsigned char));
size /= long_word_size_;
for(size_t i = 0; i < size; ++i ) {
result += popcnt64(*pa ^ *pb);
++pa;
@ -516,7 +516,7 @@ struct Hamming2
const uint32_t* pa = reinterpret_cast<const uint32_t*>(a);
const uint32_t* pb = reinterpret_cast<const uint32_t*>(b);
ResultType result = 0;
size /= (sizeof(uint32_t)/sizeof(unsigned char));
size /= long_word_size_;
for(size_t i = 0; i < size; ++i ) {
result += popcnt32(*pa ^ *pb);
++pa;
@ -525,6 +525,13 @@ struct Hamming2
#endif
return result;
}
private:
#ifdef FLANN_PLATFORM_64_BIT
static const size_t long_word_size_ = sizeof(uint64_t)/sizeof(unsigned char);
#else
static const size_t long_word_size_ = sizeof(uint32_t)/sizeof(unsigned char);
#endif
};