Fix bugs in calculating indices

src/targets/gpu/device/include/migraphx/gpu/device/nary.hpp

@@ -122,6 +122,8 @@ template <class F, class... Arguments>
 void nary_double_broadcast_vec_impl(
     hipStream_t stream, F f, argument result, argument barg1, argument barg2, Arguments... args)
 {
+    assert(barg1.get_shape().broadcasted());
+    assert(barg2.get_shape().broadcasted());
     assert(barg1.get_shape() == barg2.get_shape());
     const auto& output_shape = result.get_shape();
     const auto& b_shape      = barg1.get_shape();
@@ -161,7 +163,7 @@ void nary_double_broadcast_vec_impl(
                 {
                     auto bidx = ((i * vec_size) % bdim_next_stride) / bdim_stride;
                     auto b1   = bp[bidx];
-                    auto b2   = bp[bidx + bdim_vec_len];
+                    auto b2   = bp[bidx + bdim_len];
                     auto out  = output.data()[i];
                     for(std::size_t j = 0; j < vec_size; j++)
                     {
@@ -177,6 +179,8 @@ template <class F, class... Arguments>
 void nary_double_broadcast_impl(
     hipStream_t stream, F f, argument result, argument barg1, argument barg2, Arguments... args)
 {
+    assert(barg1.get_shape().broadcasted());
+    assert(barg2.get_shape().broadcasted());
     assert(barg1.get_shape() == barg2.get_shape());
     const auto& output_shape = result.get_shape();
     const auto& b_shape      = barg1.get_shape();
@@ -348,12 +352,13 @@ inline auto nary(hipStream_t stream, argument result, argument arg, argument bar
 template <class... Arguments>
 auto nary(hipStream_t stream, argument result, Arguments... args)
 {
+    static_assert(sizeof...(args) > 2, "Args needs to be greater than 2");
     return [=](auto f) {
         auto barg1     = back_args(args...);
         bool fallback1 = pop_back_args(args...)([&](auto&&... args2) {
             auto barg2 = back_args(args2...);
             bool fallback2 =
-                barg2.get_shape() == barg1.get_shape() and barg2.get_shape().broadcasted() and
+                barg2.get_shape() != barg1.get_shape() or not barg2.get_shape().broadcasted() or
                 pop_back_args(args2...)([&](auto&&... args3) {
                     bool divisible_by_4 = false;
                     if(broadcastable(divisible_by_4, 1024, result, barg2, args3...))