Add an easy way for package builders to disable native cpu optimizations

CMakeLists.txt

@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.1)
 
 option(WITH_GDB "WITH_GDB" OFF)
 option(WITHOUT_LLVM "WITHOUT_LLVM" OFF)
+option(USE_NATIVE_INSTRUCTIONS "USE_NATIVE_INSTRUCTIONS makes rpcs3 compile with -march=native, which is useful for local builds, but not good for packages." ON)
 
 if (WITH_GDB)
 	add_definitions(-DWITH_GDB_DEBUGGER)

README.md

@@ -101,6 +101,9 @@ This Builds RPCS3 with support for debugging PS3 games using gdb.
 - ```-DUSE_VULKAN=ON/OFF``` (default = *ON*)  
 This builds RPCS3 with Vulkan support.
 
+- ```-DUSE_NATIVE_INSTRUCTIONS=ON/OFF``` (default = *ON*)  
+This builds rpcs3 with -march=native, which is useful for local builds, but not good for packages.
+
 ## License
 
 Most files are licensed under the terms of GNU GPLv2 License, see LICENSE file for details. Some files may be licensed differently, check appropriate file headers for details.

rpcs3/CMakeLists.txt

@@ -108,7 +108,7 @@ if(NOT MSVC)
 
 	add_compile_options(-msse -msse2 -mcx16 -mrtm)
 
-	if(NOT DEFINED ENV{TRAVIS})
+	if(NOT DEFINED ENV{TRAVIS} AND USE_NATIVE_INSTRUCTIONS)
 		add_compile_options(-march=native)
 	endif()