diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2ae7f5818c..f2de0e838a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -977,6 +977,7 @@ jobs:
         with:
           key: macos-${{ matrix.backend }}-minimal
           deps: testing_minimal
+          pydeps: "capstone"
           llvm: ${{ matrix.backend == 'llvm' && 'true' }}
       - name: Set env
         run: printf "${{ matrix.backend == 'llvm' && 'LLVM=1' || matrix.backend == 'cpu' && 'CPU=1' || matrix.backend == 'metal' && 'METAL=1'}}" >> $GITHUB_ENV
diff --git a/test/test_disassembly.py b/test/test_disassembly.py
new file mode 100644
index 0000000000..e908b83710
--- /dev/null
+++ b/test/test_disassembly.py
@@ -0,0 +1,21 @@
+import unittest, io
+from tinygrad import Tensor, dtypes
+from contextlib import redirect_stdout
+from tinygrad.device import Device
+from tinygrad.helpers import OSX
+from tinygrad.engine.realize import get_program
+
+class TestDisassembly(unittest.TestCase):
+  # TODO: fails on llvm. llvm.LLVMGetHostCPUName() returns "generic"
+  @unittest.skipUnless(Device.DEFAULT in ("CPU",) and OSX, "m series cpus support fp16 arithmetic")
+  def test_float16_alu(self):
+    c = Tensor([1], dtype=dtypes.float16) + Tensor([1], dtype=dtypes.float16)
+    s = c.schedule()[-1]
+    p = get_program(s.ast, Device[Device.DEFAULT].renderer)
+    lib = Device[Device.DEFAULT].compiler.compile(p.src)
+    out = io.StringIO()
+    with redirect_stdout(out): Device[Device.DEFAULT].compiler.disassemble(lib)
+    assert "fcvt" not in out.getvalue()
+
+if __name__ == "__main__":
+  unittest.main()
\ No newline at end of file
diff --git a/tinygrad/runtime/ops_cpu.py b/tinygrad/runtime/ops_cpu.py
index 2bcb1e5c64..5ebf1f8c31 100644
--- a/tinygrad/runtime/ops_cpu.py
+++ b/tinygrad/runtime/ops_cpu.py
@@ -18,7 +18,9 @@ class ClangJITCompiler(Compiler):
     # -fno-math-errno is required for __builtin_sqrt to become an instruction instead of a function call
     # x18 is a reserved platform register. It is clobbered on context switch in macos and is used to store TEB pointer in windows on arm, don't use it
     target = 'x86_64' if sys.platform == 'win32' else platform.machine()
-    args = ['-march=native', f'--target={target}-none-unknown-elf', '-O2', '-fPIC', '-ffreestanding', '-fno-math-errno', '-nostdlib', '-fno-ident']
+    # on arm march means "runs on this arch and superset" instead of "optimize for this arch". x86 march == arm mcpu
+    arch = '-march=native' if platform.machine() in ('x86_64', 'AMD64') else '-mcpu=native'
+    args = [arch, f'--target={target}-none-unknown-elf', '-O2', '-fPIC', '-ffreestanding', '-fno-math-errno', '-nostdlib', '-fno-ident']
     arch_args = ['-ffixed-x18'] if target == 'arm64' else []
     obj = subprocess.check_output([getenv("CC", 'clang'), '-c', '-x', 'c', *args, *arch_args, '-', '-o', '-'], input=src.encode('utf-8'))
     return jit_loader(obj)