change multinomial_dyn_test to send 0-size seed input. This triggers auto seed

src/onnx/parse_multinomial.cpp

@@ -75,6 +75,8 @@ struct parse_multinomial : op_parser<parse_multinomial>
         {
             shape s0 = args[0]->get_shape();
             // TODO: Use literal if batch size is fixed
+            // TODO: Add second argument for seed (an Migraphx rule, not Onnx) if Onnx seed not given
+            //   It will be a literal with a shape of 0 size
             if(s0.dynamic())
             {
                 //  Dynamic batch_size will be taken from args[0].  Other contents of input are

test/ref_ops_test.cpp

@@ -5311,6 +5311,12 @@ TEST_CASE(multinomial_dyn_test)
     migraphx::shape rs{migraphx::shape::float_type, {{1, 2}, {2, sample_size + 1}}};
     auto input = mm->add_parameter("Input_1", rs);
 
+    // Runtime randomization seed
+    // To seed the rand_uniform, we can provide a value by literal or input,
+    // or we can pass it a 0-size shape in which case it will auto-seed.
+    migraphx::shape seed_shape{migraphx::shape::uint32_type, {migraphx::shape::dynamic_dimension{0, 1}}};    
+    auto seed_input = mm->add_parameter("Seed", seed_shape);
+
     // Shape of the probability distribution, which also defines the number of categories
     migraphx::shape s{migraphx::shape::float_type, {{1, 1}, {5, 6}}};
     std::vector<int> dist{15, 25, 15, 25, 20};
@@ -5332,18 +5338,12 @@ TEST_CASE(multinomial_dyn_test)
     cdf = mm->add_instruction(
         migraphx::make_op("prefix_scan_sum", {{"axis", 1}, {"exclusive", false}}), cdf);
 
-    // To seed the rand_uniform, we can provide a value by literal or input,
-    // or we can pass it a 0-size shape in which case it will auto-seed.
-    migraphx::shape seed_shape{migraphx::shape::uint32_type, {0}};
-    std::vector<int32_t> seed_data = {};
-    auto seed_input                = mm->add_literal(migraphx::literal(seed_shape, seed_data));
-
     auto randoms = mm->add_instruction(migraphx::make_op("rand_uniform",
                                                          {
                                                              {"seed", seed},
                                                          }),
                                        input,
-                                       seed_input); // <==some_seed is something user-supplied
+                                       seed_input);
     mm->add_instruction(migraphx::make_op("multinomial"), cdf, randoms);
 
     p.compile(migraphx::make_target("ref"));
@@ -5354,6 +5354,11 @@ TEST_CASE(multinomial_dyn_test)
     migraphx::shape input_fixed_shape2{migraphx::shape::float_type, {1, 5}};
     migraphx::parameter_map params0;
     params0["Input_1"] = migraphx::argument(input_fixed_shape1, dummy.data());
+
+    migraphx::shape seed_fixed_shape{migraphx::shape::uint32_type, {0}};
+    std::vector<uint32_t> seed_data = {};
+    params0["Seed"] = migraphx::argument(seed_fixed_shape, seed_data.data());
+    
     params0["Input_2"] = migraphx::argument(input_fixed_shape2, data.data());
     auto result        = p.eval(params0).back();