more options for march=native

README.md

@@ -51,17 +51,17 @@ brew install libomp
 And then reinstall this package: `pip install --force-reinstall hpfrec`.
 
 ** *
-**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:
+**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 (by e.g. using AVX instructions if available), 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 either by (a) defining an environment variable `DONT_SET_MARCH=1`, or by (b) manually supplying compilation `CFLAGS` as an environment variable with something related to architecture. For maximum compatibility (but slowest speed), it's possible to do something like this:
 
 ```
-export CFLAGS="-msse2"
+export DONT_SET_MARCH=1
 pip install hpfrec
 ```
 
-or for creating wheels:
+or, for forcing a maximum-compatibility x86-64 binary:
 ```
-export CFLAGS="-msse2"
-python setup.py bwheel
+export CFLAGS="-march=x86-64"
+pip install hpfrec
 ```
 ** *
 

setup.py

@@ -21,7 +21,7 @@ def build_extensions(self):
 			for e in self.extensions:
 				e.extra_compile_args += ['/openmp', '/O2', '/fp:fast']
 		else:
-			if not self.check_cflags_contain_arch():
+			if not self.check_for_variable_dont_set_march() and not self.check_cflags_contain_arch():
 				self.add_march_native()
 			self.add_openmp_linkage()
 			self.add_no_math_errno()
@@ -43,6 +43,9 @@ def check_cflags_contain_arch(self):
 					return True
 		return False
 
+	def check_for_variable_dont_set_march(self):
+		return "DONT_SET_MARCH" in os.environ
+
 	def add_march_native(self):
 		arg_march_native = "-march=native"
 		arg_mcpu_native = "-mcpu=native"