add AVX option to cmake build system

build/CMakeLists.txt

@@ -8,6 +8,7 @@ project ( "i2pd" )
 
 # configurale options
 option(WITH_AESNI     "Use AES-NI instructions set" OFF)
+option(WITH_AVX       "Use AVX instructions" OFF)
 option(WITH_HARDENING "Use hardening compiler flags" OFF)
 option(WITH_LIBRARY   "Build library" ON)
 option(WITH_BINARY    "Build binary" ON)
@@ -213,6 +214,10 @@ if (WITH_AESNI)
   add_definitions ( -DAESNI )
 endif()
 
+if (WITH_AVX)
+  set ( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mavx" )
+endif()
+
 if (WITH_ADDRSANITIZER)
   if (NOT MSVC)
     set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address -fno-omit-frame-pointer" )
@@ -379,6 +384,7 @@ message(STATUS "Compiler path      : ${CMAKE_CXX_COMPILER}")
 message(STATUS "Install prefix:    : ${CMAKE_INSTALL_PREFIX}")
 message(STATUS "Options:")
 message(STATUS "  AESNI            : ${WITH_AESNI}")
+message(STATUS "  AVX              : ${WITH_AVX}")
 message(STATUS "  HARDENING        : ${WITH_HARDENING}")
 message(STATUS "  LIBRARY          : ${WITH_LIBRARY}")
 message(STATUS "  BINARY           : ${WITH_BINARY}")