Merge pull request #833 from Sonicadvance1/add_perf_warning

Adds x86-64 host performance warning

.github/workflows/ccpp.yml

@@ -45,7 +45,7 @@ jobs:
       # Note the current convention is to use the -S and -B options here to specify source
       # and build directories, but this is only available with CMake 3.13 and higher.
       # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
-      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -G Ninja -DENABLE_LTO=False -DENABLE_ASSERTIONS=True
+      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -G Ninja -DENABLE_LTO=False -DENABLE_ASSERTIONS=True -DENABLE_X86_HOST_DEBUG=True
 
     - name: Build
       working-directory: ${{runner.workspace}}/build

CMakeLists.txt

@@ -83,6 +83,14 @@ set (CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fomit-frame-pointer")
 set (CMAKE_LINKER_FLAGS_RELEASE "${CMAKE_LINKER_FLAGS_RELEASE} -fomit-frame-pointer")
 
 if (CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
+  option(ENABLE_X86_HOST_DEBUG "Enables compiling on x86_64 host" FALSE)
+  if (NOT ENABLE_X86_HOST_DEBUG)
+    message(FATAL_ERROR
+      " Be warned: FEX isn't optimized for x86_64 hosts!\n"
+      " Support for x86_64 hosts is only for debugging and convenience!\n"
+      " Don't expect amazing performance or optimal code generation!\n"
+      " Pass -DENABLE_X86_HOST_DEBUG=True to bypass this message!")
+  endif()
   set(_M_X86_64 1)
   add_definitions(-D_M_X86_64=1)
   set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mcx16")