Handle zero epsilon

src/include/migraphx/match/layernorm.hpp

@@ -48,10 +48,10 @@ struct layernorm_matcher
 
     auto layernorm_onnx() const
     {
+        auto add_eps = f("add")(either_arg(0, 1)(variance(), is_constant().bind("eps")));
         return f("div")(arg(0)(x_minus_mean()),
 
-                        arg(1)(skip_broadcasts(f("sqrt")(arg(0)(
-                            f("add")(either_arg(0, 1)(variance(), is_constant().bind("eps"))))))));
+                        arg(1)(skip_broadcasts(f("sqrt")(arg(0)(match::any_of(add_eps, variance()))))));
     }
 
     auto matcher() const { return layernorm_onnx(); }

src/targets/gpu/prefuse_ops.cpp

@@ -104,7 +104,9 @@ struct find_add_layernorm
     {
         auto ins     = r.result;
         auto add_ins = r.instructions["add"];
-        auto eps     = r.instructions["eps"]->eval().at<float>();
+        float eps = 0;
+        if (contains(r.instructions, "eps"))
+            eps     = r.instructions["eps"]->eval().at<float>();
 
         m.replace_instruction(ins, add_layernorm{eps}, add_ins->inputs());
     }