add option to override march=native

README.md

@@ -39,6 +39,21 @@ The variants implemented here are based on multiple oracle calls (building a ser
 
 **Note: Python 2 is not supported and package will fail to run on Python 2.7**
 
+** *
+**IMPORTANT:** the setup script will try to add compilation flag `-march=native`. This instructs the compiler to tune the package for the CPU in which it is being installed, but the result might not be usable in other computers. If building a binary wheel of this package or putting it into a docker image which will be used in different machines, this can be overriden by manually supplying compilation `CFLAGS` as an environment variable with something related to architecture. For maximum compatibility (but slowest speed), assuming `x86-64` computers, it's possible to do something like this:
+
+```
+export CFLAGS="-msse2"
+pip install costsensitive
+```
+
+or for creating wheels:
+```
+export CFLAGS="-msse2"
+python setup.py bwheel
+```
+** *
+
 
 * R:
 

setup.py

@@ -22,7 +22,8 @@ def build_extensions(self):
 			for e in self.extensions:
 				e.extra_compile_args = ['/O2']
 		else:
-			self.add_march_native()
+			if not self.check_cflags_contain_arch():
+				self.add_march_native()
 			self.add_openmp_linkage()
 
 			for e in self.extensions:
@@ -32,6 +33,14 @@ def build_extensions(self):
 
 		build_ext.build_extensions(self)
 
+	def check_cflags_contain_arch(self):
+		if "CFLAGS" in os.environ:
+			arch_list = ["-march", "-mcpu", "-mtune", "-msse", "-msse2", "-msse3", "-mssse3", "-msse4", "-msse4a", "-msse4.1", "-msse4.2", "-mavx", "-mavx2"]
+			for flag in arch_list:
+				if flag in os.environ["CFLAGS"]:
+					return True
+		return False
+
 	def add_march_native(self):
 		arg_march_native = "-march=native"
 		arg_mcpu_native = "-mcpu=native"
@@ -106,7 +115,7 @@ def test_supports_compile_arg(self, comm):
 	 'cython'
 	],
 	python_requires = ">=3",
-	version = '0.1.2.13-2',
+	version = '0.1.2.13-3',
 	description = 'Reductions for Cost-Sensitive Multi-Class Classification',
 	author = 'David Cortes',
 	author_email = 'david.cortes.rivera@gmail.com',