core: rework code locality

- to reduce binaries size of FFmpeg Windows wrapper
- MinGW linker doesn't support -ffunction-sections (used for FFmpeg Windows wrapper)
- move code to improve locality with its used dependencies
- move UMat::dot() to matmul.dispatch.cpp (Mat::dot() is already there)
- move UMat::inv() to lapack.cpp
- move UMat::mul() to arithm.cpp
- move UMat:eye() to matrix_operations.cpp (near setIdentity() implementation)
- move normalize(): convert_scale.cpp => norm.cpp
- move convertAndUnrollScalar(): arithm.cpp => copy.cpp
- move scalarToRawData(): array.cpp => copy.cpp
- move transpose(): matrix_operations.cpp => matrix_transform.cpp
- move flip(), rotate(): copy.cpp => matrix_transform.cpp (rotate90 uses flip and transpose)
- add 'OPENCV_CORE_EXCLUDE_C_API' CMake variable to exclude compilation of C-API functions from the core module
- matrix_wrap.cpp: add compile-time checks for CUDA/OpenGL calls
- the steps above allow to reduce FFmpeg wrapper size for ~1.5Mb (initial size of OpenCV part is about 3Mb)

modules/core/src/matmul.dispatch.cpp

@@ -999,8 +999,79 @@ double Mat::dot(InputArray _mat) const
     return r;
 }
 
+
+#ifdef HAVE_OPENCL
+
+static bool ocl_dot( InputArray _src1, InputArray _src2, double & res )
+{
+    UMat src1 = _src1.getUMat().reshape(1), src2 = _src2.getUMat().reshape(1);
+
+    int type = src1.type(), depth = CV_MAT_DEPTH(type),
+            kercn = ocl::predictOptimalVectorWidth(src1, src2);
+    bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0;
+
+    if ( !doubleSupport && depth == CV_64F )
+        return false;
+
+    int dbsize = ocl::Device::getDefault().maxComputeUnits();
+    size_t wgs = ocl::Device::getDefault().maxWorkGroupSize();
+    int ddepth = std::max(CV_32F, depth);
+
+    int wgs2_aligned = 1;
+    while (wgs2_aligned < (int)wgs)
+        wgs2_aligned <<= 1;
+    wgs2_aligned >>= 1;
+
+    char cvt[40];
+    ocl::Kernel k("reduce", ocl::core::reduce_oclsrc,
+                  format("-D srcT=%s -D srcT1=%s -D dstT=%s -D dstTK=%s -D ddepth=%d -D convertToDT=%s -D OP_DOT "
+                         "-D WGS=%d -D WGS2_ALIGNED=%d%s%s%s -D kercn=%d",
+                         ocl::typeToStr(CV_MAKE_TYPE(depth, kercn)), ocl::typeToStr(depth),
+                         ocl::typeToStr(ddepth), ocl::typeToStr(CV_MAKE_TYPE(ddepth, kercn)),
+                         ddepth, ocl::convertTypeStr(depth, ddepth, kercn, cvt),
+                         (int)wgs, wgs2_aligned, doubleSupport ? " -D DOUBLE_SUPPORT" : "",
+                         _src1.isContinuous() ? " -D HAVE_SRC_CONT" : "",
+                         _src2.isContinuous() ? " -D HAVE_SRC2_CONT" : "", kercn));
+    if (k.empty())
+        return false;
+
+    UMat db(1, dbsize, ddepth);
+
+    ocl::KernelArg src1arg = ocl::KernelArg::ReadOnlyNoSize(src1),
+            src2arg = ocl::KernelArg::ReadOnlyNoSize(src2),
+            dbarg = ocl::KernelArg::PtrWriteOnly(db);
+
+    k.args(src1arg, src1.cols, (int)src1.total(), dbsize, dbarg, src2arg);
+
+    size_t globalsize = dbsize * wgs;
+    if (k.run(1, &globalsize, &wgs, true))
+    {
+        res = sum(db.getMat(ACCESS_READ))[0];
+        return true;
+    }
+    return false;
+}
+
+#endif
+
+double UMat::dot(InputArray m) const
+{
+    CV_INSTRUMENT_REGION();
+
+    CV_Assert(m.sameSize(*this) && m.type() == type());
+
+#ifdef HAVE_OPENCL
+    double r = 0;
+    CV_OCL_RUN_(dims <= 2, ocl_dot(*this, m, r), r)
+#endif
+
+    return getMat(ACCESS_READ).dot(m);
+}
+
 }  // namespace cv::
 
+
+#ifndef OPENCV_EXCLUDE_C_API
 /****************************************************************************************\
 *                                    Earlier API                                         *
 \****************************************************************************************/
@@ -1225,4 +1296,6 @@ cvBackProjectPCA( const CvArr* proj_arr, const CvArr* avg_arr,
     CV_Assert(dst0.data == dst.data);
 }
 
+#endif  // OPENCV_EXCLUDE_C_API
+
 /* End of file. */