fix android pack build

cmake/OpenCVCompilerOptions.cmake

@@ -369,3 +369,18 @@ if(MSVC)
     ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4589) # Constructor of abstract class 'cv::ORB' ignores initializer for virtual base class 'cv::Algorithm'
   endif()
 endif()
+
+if(NOT OPENCV_FP16_DISABLE)
+  try_compile(__VALID_FP16
+    "${OpenCV_BINARY_DIR}"
+    "${OpenCV_SOURCE_DIR}/cmake/checks/fp16.cpp"
+    COMPILE_DEFINITIONS "-DCHECK_FP16"
+    OUTPUT_VARIABLE TRY_OUT
+    )
+  if(NOT __VALID_FP16)
+    message(STATUS "FP16: Compiler support is not available")
+  else()
+    message(STATUS "FP16: Compiler support is available")
+    set(HAVE_FP16 1)
+  endif()
+endif()

cmake/checks/fp16.cpp

+#include <stdio.h>
+
+#if defined __F16C__ || (defined _MSC_VER && _MSC_VER >= 1700)
+#include <immintrin.h>
+int test()
+{
+    const float src[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    short dst[8];
+    __m128 v_src = _mm_load_ps(src);
+    __m128i v_dst = _mm_cvtps_ph(v_src, 0);
+    _mm_storel_epi64((__m128i*)dst, v_dst);
+    return (int)dst[0];
+}
+#elif defined __GNUC__ && (defined __arm__ || defined __aarch64__)
+#include "arm_neon.h"
+int test()
+{
+    const float src[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    short dst[8];
+    float32x4_t v_src = *(float32x4_t*)src;
+    float16x4_t v_dst = vcvt_f16_f32(v_src);
+    *(float16x4_t*)dst = v_dst;
+    return (int)dst[0];
+}
+#else
+#error "FP16 is not supported"
+#endif
+
+int main()
+{
+  printf("%d\n", test());
+  return 0;
+}

cmake/templates/cvconfig.h.in

@@ -203,3 +203,6 @@
 
 /* Lapack */
 #cmakedefine HAVE_LAPACK
+
+/* FP16 */
+#cmakedefine HAVE_FP16

modules/core/include/opencv2/core/cvdef.h

@@ -193,7 +193,7 @@ enum CpuFeatures {
 #    endif
 #    define CV_POPCNT 1
 #  endif
-#  if defined __F16C__ || (defined _MSC_VER && _MSC_VER >= 1700)
+#  if defined HAVE_FP16 && (defined __F16C__ || (defined _MSC_VER && _MSC_VER >= 1700))
 #    include <immintrin.h>
 #    define CV_FP16 1
 #  endif
@@ -219,7 +219,7 @@ enum CpuFeatures {
 
 #if (defined WIN32 || defined _WIN32) && defined(_M_ARM)
 # include <Intrin.h>
-# include "arm_neon.h"
+# include <arm_neon.h>
 # define CV_NEON 1
 # define CPU_HAS_NEON_FEATURE (true)
 #elif defined(__ARM_NEON__) || (defined (__ARM_NEON) && defined(__aarch64__))
@@ -227,8 +227,12 @@ enum CpuFeatures {
 #  define CV_NEON 1
 #endif
 
-#if defined __GNUC__ && ((defined (__arm__) && (__ARM_FP & 0x2)) || defined(__aarch64__))
-#    define CV_FP16 1
+#if defined(__ARM_NEON__) || defined(__aarch64__)
+#  include <arm_neon.h>
+#endif
+
+#if defined HAVE_FP16 && defined __GNUC__
+#  define CV_FP16 1
 #endif
 
 #if defined __GNUC__ && defined __arm__ && (defined __ARM_PCS_VFP || defined __ARM_VFPV3__ || defined __ARM_NEON__) && !defined __SOFTFP__

modules/core/src/convert.cpp

@@ -4591,6 +4591,8 @@ cvtScaleHalf_<float, short>( const float* src, size_t sstep, short* dst, size_t
                     float16x4_t v_dst = vcvt_f16_f32(v_src);
 
                     *(float16x4_t*)(dst + x) = v_dst;
+#else
+#error "Configuration error"
 #endif
                 }
 #endif
@@ -4643,6 +4645,8 @@ cvtScaleHalf_<short, float>( const short* src, size_t sstep, float* dst, size_t
                     float32x4_t v_dst = vcvt_f32_f16(v_src);
 
                     *(float32x4_t*)(dst + x) = v_dst;
+#else
+#error "Configuration error"
 #endif
                 }
 #endif

modules/imgproc/src/thresh.cpp

@@ -43,6 +43,23 @@
 #include "precomp.hpp"
 #include "opencl_kernels_imgproc.hpp"
 
+#if CV_NEON && defined(__aarch64__)
+#include <arm_neon.h>
+namespace cv {
+// Workaround with missing definitions of vreinterpretq_u64_f64/vreinterpretq_f64_u64
+template <typename T> static inline
+uint64x2_t vreinterpretq_u64_f64(T a)
+{
+    return (uint64x2_t) a;
+}
+template <typename T> static inline
+float64x2_t vreinterpretq_f64_u64(T a)
+{
+    return (float64x2_t) a;
+}
+} // namespace cv
+#endif
+
 namespace cv
 {