Adding support to not native x86 systems for external libraries (#732)

- Filtering of x86 specific directive at both `Makefile` and `setup.py`
level. Former needed for libraries that integrate Stim at the binary
level (e.g. PyMatching).
- Replacing `sys` with `platform` to gain access to additional
information on the OS and CPU architecture.
- Wrapped up with a function the extensions that shall be built for a
specific architecture.

CMakeLists.txt

@@ -21,14 +21,19 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY out)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY out)
 
 # Convert desired SIMD_WIDTH into machine architecture flags.
-if(NOT(SIMD_WIDTH))
-    set(MACHINE_FLAG "-march=native")
-elseif(SIMD_WIDTH EQUAL 256)
-    set(MACHINE_FLAG "-mavx2" "-msse2")
-elseif(SIMD_WIDTH EQUAL 128)
-    set(MACHINE_FLAG "-mno-avx2" "-msse2")
-elseif(SIMD_WIDTH EQUAL 64)
-    set(MACHINE_FLAG "-mno-avx2" "-mno-sse2")
+
+if (CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|I386|ARM64)$")
+    if(NOT(SIMD_WIDTH))
+        set(MACHINE_FLAG "-march=native")
+    elseif(SIMD_WIDTH EQUAL 256)
+        set(MACHINE_FLAG "-mavx2" "-msse2")
+    elseif(SIMD_WIDTH EQUAL 128)
+        set(MACHINE_FLAG "-mno-avx2" "-msse2")
+    elseif(SIMD_WIDTH EQUAL 64)
+        set(MACHINE_FLAG "-mno-avx2" "-mno-sse2")
+    endif()
+else ()
+    set(MACHINE_FLAG "")
 endif()
 
 # make changes to file_lists trigger a reconfigure

setup.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import sys
+import platform
 
 from setuptools import setup, Extension
 import glob
@@ -27,7 +27,7 @@
 
 __version__ = '1.14.dev0'
 
-if sys.platform.startswith('win'):
+if platform.system().startswith('Win'):
     common_compile_args = [
         '/std:c++20',
         '/O2',
@@ -97,6 +97,17 @@
 with open('glue/python/README.md', encoding='UTF-8') as f:
     long_description = f.read()
 
+def _get_extensions():
+    archs=["x86", "i686", "i386", "amd64"]
+    if any(_ext in platform.processor().lower() for _ext in archs):
+        # NOTE: disabled until https://github.com/quantumlib/Stim/issues/432 is fixed
+        # stim_avx2,
+        return [stim_detect_machine_architecture, stim_polyfill,
+                # stim_avx2,
+                stim_sse2]
+    else:
+        return [stim_detect_machine_architecture, stim_polyfill]
+
 setup(
     name='stim',
     version=__version__,
@@ -107,13 +118,7 @@
     description='A fast library for analyzing with quantum stabilizer circuits.',
     long_description=long_description,
     long_description_content_type='text/markdown',
-    ext_modules=[
-        stim_detect_machine_architecture,
-        stim_polyfill,
-        stim_sse2,
-        # NOTE: disabled until https://github.com/quantumlib/Stim/issues/432 is fixed
-        # stim_avx2,
-    ],
+    ext_modules=_get_extensions(),
     python_requires='>=3.6.0',
     packages=['stim'],
     package_dir={'stim': 'glue/python/src/stim'},