fix

mlx/ops.cpp

@@ -2864,8 +2864,7 @@ array matmul(
   }
 
   // complex matmul using Karatsuba's Algorithm
-
-  if (a.dtype() == complex64 && b.dtype() == complex64) {
+  if (a.dtype() == complex64 || b.dtype() == complex64) {
     // Extract real and imaginary parts
     auto a_real = real(a, s);
     auto a_imag = imag(a, s);

python/tests/test_blas.py

@@ -1210,13 +1210,6 @@ class TestBlas(mlx_tests.MLXTestCase):
         self.assertTrue(np.allclose(c, c_np))
 
         # Test addmm
-        M = 16
-        K = 50
-        N = 32
-
-        def rand(shape):
-            return mx.random.uniform(shape=shape) + 1j * mx.random.uniform(shape=shape)
-
         a = rand((M, K))
         b = rand((K, N))
         c = rand((M, N))
@@ -1224,6 +1217,13 @@ class TestBlas(mlx_tests.MLXTestCase):
         out_np = 2.0 * np.matmul(a, b) + 2.0 * c
         self.assertTrue(np.allclose(out, out_np))
 
+        # complex with real
+        a = rand((M, K)).real
+        b = rand((K, N))
+        c = mx.matmul(a, b)
+        c_np = np.matmul(a, b)
+        self.assertTrue(np.allclose(out, out_np))
+
 
 if __name__ == "__main__":
     unittest.main()