Added RISC-V backend of universal intrinsics

modules/core/include/opencv2/core/cv_cpu_dispatch.h

@@ -170,6 +170,7 @@
 
 #if defined CV_CPU_COMPILE_RVV
 #  define CV_RVV 1
+#  include <riscv_vector.h>
 #endif
 
 #endif // CV_ENABLE_INTRINSICS && !CV_DISABLE_OPTIMIZATION && !__CUDACC__

modules/core/include/opencv2/core/hal/intrin.hpp

@@ -202,7 +202,7 @@ using namespace CV_CPU_OPTIMIZATION_HAL_NAMESPACE;
 #   undef CV_RVV
 #endif
 
-#if (CV_SSE2 || CV_NEON || CV_VSX || CV_MSA || CV_WASM_SIMD) && !defined(CV_FORCE_SIMD128_CPP)
+#if (CV_SSE2 || CV_NEON || CV_VSX || CV_MSA || CV_WASM_SIMD || CV_RVV) && !defined(CV_FORCE_SIMD128_CPP)
 #define CV__SIMD_FORWARD 128
 #include "opencv2/core/hal/intrin_forward.hpp"
 #endif

platforms/linux/riscv64-gcc.toolchain.cmake

@@ -0,0 +1,20 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR riscv64)
+
+set(RISCV_GCC_INSTALL_ROOT /opt/RISCV CACHE PATH "Path to GCC for RISC-V cross compiler installation directory")
+set(CMAKE_SYSROOT ${RISCV_GCC_INSTALL_ROOT}/sysroot CACHE PATH "RISC-V sysroot")
+
+set(CMAKE_C_COMPILER ${RISCV_GCC_INSTALL_ROOT}/bin/riscv64-unknown-linux-gnu-gcc)
+set(CMAKE_CXX_COMPILER ${RISCV_GCC_INSTALL_ROOT}/bin/riscv64-unknown-linux-gnu-g++)
+
+# Don't run the linker on compiler check
+set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
+
+set(CMAKE_C_FLAGS "-march=rv64gcv_zvqmac ${CMAKE_C_FLAGS}")
+set(CMAKE_CXX_FLAGS "-march=rv64gcv_zvqmac ${CXX_FLAGS}")
+
+set(CMAKE_FIND_ROOT_PATH ${CMAKE_SYSROOT})
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)