fix mcpu on os x (apache#7276)

python/tvm/micro/compiler.py

@@ -106,6 +106,12 @@ def _target_from_sources(cls, sources):
     }
 
     def _autodetect_toolchain_prefix(self, target):
+        # Treat absence of -mcpu as if -mcpu=native is specified. The gcc shipped with OS X
+        # complains if -mcpu=native is given, so this approach allows model targets to avoid
+        # specifying this flag e.g. for tutorials.
+        if "mcpu" not in target.attrs:
+            return self.TOOLCHAIN_PREFIX_BY_CPU_REGEX["native"]
+
         matches = []
         for regex, prefix in self.TOOLCHAIN_PREFIX_BY_CPU_REGEX.items():
             if re.match(regex, target.attrs["mcpu"]):

python/tvm/target/target.py

@@ -232,7 +232,7 @@ def micro(model="unknown", options=None):
         Additional options
     """
     trans_table = {
-        "host": ["-mcpu=native"],
+        "host": [],
         "stm32f746xx": ["-mcpu=cortex-m7", "-march=armv7e-m"],
     }
     opts = _merge_opts(

tests/python/unittest/test_link_params.py

@@ -347,7 +347,7 @@ def test_crt_link_params():
         mod, param_init = _make_mod_and_params(dtype)
         rand_input = _make_random_tensor(dtype, INPUT_SHAPE)
         main_func = mod["main"]
-        target = "c -mcpu=native --system-lib --runtime=c --link-params"
+        target = "c --system-lib --runtime=c --link-params"
         with tvm.transform.PassContext(opt_level=3, config={"tir.disable_vectorize": True}):
             graph_json, lib, params = tvm.relay.build(mod, target, params=param_init)
             assert set(params.keys()) == {"p0", "p1"}  # NOTE: op folded