* use universal intrinsic instead of raw intrinsic
  * add 2 channels de-interleave on x86 platform
  * add v_int32x4 version of v_muladd
  * add accumulate version of v_dotprod based on the commit from seiko2plus on bf1852d
  * remove some verify check in performance test
  * avoid the out of boundary access and keep the performance

* fix #9720

* Add regression test

* Fix calculation method for scale

* Solves #11156

* Check file size for all file format. Disable APPEND if file is empty

* Add test for APPEND mode

with implementation of functions with multiple output formats

* Fix #10948

* Add test code

* Fixed build error

* Add value zero

* eigen: test cleanup

  * loosen some test threshold mainly for integer types
  * use relative error for floating points result
  * avoid division by zero by following the comment
  * fix the indentation

* Make <array> #ifdef true for MSVC

I think MSVC had `std::array` for quite a while (possibly going back as far as VS 2012, but it's definitely there in 2015 and 2017. So I think `_MSC_VER` `1900` is a safe bet. Probably `1800` and maybe even `1700` could work as well but I can't test that locally.

* fix test

Found via `codespell`

* cmake: add ocv_get_smart_file_name() macro

* cmake: avoid adding files for unavailable dispatch modes

* Add new Mat constructor

* Fix build error

* Fix build error

* Fixed the code about 4 comments

* Fixed three comments

* delete previous local declaration

* fix build error

- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers

* remove raw SSE2/NEON implementation from convert.cpp
  * remove raw implementation from Cvt_SIMD
  * remove raw implementation from cvtScale_SIMD
  * remove raw implementation from cvtScaleAbs_SIMD
  * remove duplicated implementation cvt_<float, short>
  * remove duplicated implementation cvtScale_<short, short, float>
  * add "from double" version of Cvt_SIMD
  * modify the condition of test ConvertScaleAbs

* Update convert.cpp

fixed crash in cvtScaleAbs(8s=>8u)

* fixed compile error on Win32

* fixed several test failures because of accuracy loss in cvtScale(int=>int)

* fixed NEON implementation of v_cvt_f64(int=>double) intrinsic

* another attempt to fix test failures

* keep trying to fix the test failures and just introduced compile warnings

* fixed one remaining test (subtractScalar)

- CV_L2 -> relative NORM_L2
- eigenEps: 1e-6 ==> 1e-4
- evalEps: 1e-6 ==> 1e-5
- evecEps: 1e-3 ==> 5e-3
- RNG seed: 12345
- drop non-informative legacy test code (ts->printf, etc)

SPIR kernels are located in opencv_extra

- Use EXPECT_TRUE instead of EXPECT_EQ for comparing NULL in xlc
- Added support for int64 to vec_promote in xlc, clang
- Fixed v_rotate_right in xlc

Universal Intrinsics: aligned v_pack behavior on different platforms, fixed 64-bit register on ARM, added more saturate_cast variants

* add accuracy test and performance check for matmul
  * add performance tests for transform and dotProduct
  * add test Core_TransformLargeTest for 8u version of transform

* remove raw SSE2/NEON implementation from matmul.cpp
  * use universal intrinsic instead of raw intrinsic
  * remove unused templated function
  * add v_matmuladd which multiply 3x3 matrix and add 3x1 vector
  * add v_rotate_left/right in universal intrinsic
  * suppress intrinsic on some function and platform
  * add pure SW implementation of new universal intrinsics
  * add test for new universal intrinsics

* core: prevent memory access after the end of buffer

* fix perf tests

The original template based mat ptr for indexing is not implemented,
add the similar implementation as uchar type, but cast to
user-defined type from the uchar pointer.