Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/core/include/opencv2/core/core_c.h

@@ -48,16 +48,19 @@
 #include "opencv2/core/types_c.h"
 
 #ifdef __cplusplus
-#  ifdef _MSC_VER
-/* disable warning C4190: 'function' has C-linkage specified, but returns UDT 'typename'
-                          which is incompatible with C
+/* disable MSVC warning C4190 / clang-cl -Wreturn-type-c-linkage:
+       'function' has C-linkage specified, but returns UDT 'typename'
+       which is incompatible with C
 
    It is OK to disable it because we only extend few plain structures with
    C++ constructors for simpler interoperability with C++ API of the library
 */
-#    pragma warning(disable:4190)
-#  elif defined __clang__ && __clang_major__ >= 3
+#  if defined(__clang__)
+     // handle clang on Linux and clang-cl (i. e. clang on Windows) first
 #    pragma GCC diagnostic ignored "-Wreturn-type-c-linkage"
+#  elif defined(_MSC_VER)
+     // then handle MSVC
+#    pragma warning(disable:4190)
 #  endif
 #endif
 

modules/core/include/opencv2/core/utils/fp_control.private.hpp

@@ -0,0 +1,29 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef OPENCV_CORE_FP_CONTROL_UTILS_PRIVATE_HPP
+#define OPENCV_CORE_FP_CONTROL_UTILS_PRIVATE_HPP
+
+#include "fp_control_utils.hpp"
+
+#if OPENCV_SUPPORTS_FP_DENORMALS_HINT == 0
+  // disabled
+#elif defined(OPENCV_IMPL_FP_HINTS)
+  // custom
+#elif defined(OPENCV_IMPL_FP_HINTS_X86)
+  // custom
+#elif defined(__SSE__) || defined(__SSE2__) || defined(_M_X64) || (defined(_M_IX86_FP) && _M_IX86_FP >= 1)
+  #include <xmmintrin.h>
+  #define OPENCV_IMPL_FP_HINTS_X86 1
+  #define OPENCV_IMPL_FP_HINTS 1
+#endif
+
+#ifndef OPENCV_IMPL_FP_HINTS
+#define OPENCV_IMPL_FP_HINTS 0
+#endif
+#ifndef OPENCV_IMPL_FP_HINTS_X86
+#define OPENCV_IMPL_FP_HINTS_X86 0
+#endif
+
+#endif // OPENCV_CORE_FP_CONTROL_UTILS_PRIVATE_HPP

modules/core/include/opencv2/core/utils/fp_control_utils.hpp

@@ -0,0 +1,69 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef OPENCV_CORE_FP_CONTROL_UTILS_HPP
+#define OPENCV_CORE_FP_CONTROL_UTILS_HPP
+
+namespace cv {
+
+namespace details {
+
+struct FPDenormalsModeState
+{
+    uint32_t reserved[16];  // 64-bytes
+};  // FPDenormalsModeState
+
+CV_EXPORTS void setFPDenormalsIgnoreHint(bool ignore, CV_OUT FPDenormalsModeState& state);
+CV_EXPORTS int saveFPDenormalsState(CV_OUT FPDenormalsModeState& state);
+CV_EXPORTS bool restoreFPDenormalsState(const FPDenormalsModeState& state);
+
+class FPDenormalsIgnoreHintScope
+{
+public:
+    inline explicit FPDenormalsIgnoreHintScope(bool ignore = true)
+    {
+        details::setFPDenormalsIgnoreHint(ignore, saved_state);
+    }
+
+    inline explicit FPDenormalsIgnoreHintScope(const FPDenormalsModeState& state)
+    {
+        details::saveFPDenormalsState(saved_state);
+        details::restoreFPDenormalsState(state);
+    }
+
+    inline ~FPDenormalsIgnoreHintScope()
+    {
+        details::restoreFPDenormalsState(saved_state);
+    }
+
+protected:
+    FPDenormalsModeState saved_state;
+};  // FPDenormalsIgnoreHintScope
+
+class FPDenormalsIgnoreHintScopeNOOP
+{
+public:
+    inline FPDenormalsIgnoreHintScopeNOOP(bool ignore = true) { CV_UNUSED(ignore); }
+    inline FPDenormalsIgnoreHintScopeNOOP(const FPDenormalsModeState& state) { CV_UNUSED(state); }
+    inline ~FPDenormalsIgnoreHintScopeNOOP() { }
+};  // FPDenormalsIgnoreHintScopeNOOP
+
+}  // namespace details
+
+
+// Should depend on target compilation architecture only
+// Note: previously added archs should NOT be removed to preserve ABI compatibility
+#if defined(OPENCV_SUPPORTS_FP_DENORMALS_HINT)
+  // preserve configuration overloading through ports
+#elif defined(__i386__) || defined(__x86_64__) || defined(_M_X64) || defined(_X86_)
+typedef details::FPDenormalsIgnoreHintScope FPDenormalsIgnoreHintScope;
+#define OPENCV_SUPPORTS_FP_DENORMALS_HINT 1
+#else
+#define OPENCV_SUPPORTS_FP_DENORMALS_HINT 0
+typedef details::FPDenormalsIgnoreHintScopeNOOP FPDenormalsIgnoreHintScope;
+#endif
+
+}  // namespace cv
+
+#endif // OPENCV_CORE_FP_CONTROL_UTILS_HPP