Add missing file

src/targets/gpu/kernels/include/migraphx/kernels/gemm_batcher.hpp

+#ifndef MIGRAPHX_GUARD_KERNELS_GEMM_BATCHER_HPP
+#define MIGRAPHX_GUARD_KERNELS_GEMM_BATCHER_HPP
+
+#include <migraphx/kernels/tensor_view.hpp>
+#include <migraphx/kernels/functional.hpp>
+#include <migraphx/kernels/index.hpp>
+
+namespace migraphx {
+
+template<class Shape>
+constexpr auto gemm_get_batches()
+{
+    constexpr auto lens = Shape{}.lens;
+    constexpr auto strides = Shape{}.strides;
+    constexpr auto new_lens = sequence(lens.size() - _c<2>, [](auto... is) {
+        return make_const_array(_c<lens[is]>...);
+    });
+    constexpr auto new_strides = sequence(strides.size() - _c<2>, [](auto... is) {
+        return make_const_array(_c<strides[is]>...);
+    });
+    return make_shape(new_lens, new_strides);
+}
+
+template<class Shape>
+constexpr auto gemm_get_matrix()
+{
+    constexpr auto lens = Shape{}.lens;
+    constexpr auto strides = Shape{}.strides;
+    constexpr auto m = lens.size() - _c<2>;
+    constexpr auto n = lens.size() - _c<1>;
+    constexpr auto new_lens = make_const_array(_c<lens[m]>, _c<lens[n]>);
+    constexpr auto new_strides = make_const_array(_c<strides[m]>, _c<strides[n]>);
+    return make_shape(new_lens, new_strides);
+}
+
+template<class Tensor, class T>
+constexpr auto gemm_batch_slice(Tensor t, T i)
+{
+    constexpr auto batch = gemm_get_batches<Tensor>();
+    constexpr auto matrix = gemm_get_matrix<Tensor>();
+    return make_tensor_view(t.data() + matrix.index(i), matrix);
+}
+
+template<class BlocksPerBatch, class T, class... Ts>
+constexpr auto gemm_batch_args(index idx, BlocksPerBatch bpb, T x, Ts... xs)
+{
+    return [=](auto f) {
+        // All tensors should have the same rank
+        static_assert((true and ... and (get_shape_c<T>{}.lens.size() == get_shape_c<Ts>{}.lens.size())));
+        if constexpr(get_shape_c<T>{}.lens.size() > 2)
+        {
+            // Get the first batch since all batches should have the same number of elements
+            constexpr auto batch = gemm_get_batches<T>();
+            static_assert((true and ... and (batch.elements() == gemm_get_batches<Ts>().elements())));
+            idx.group_stride(bpb * batch.elements(), [&](auto gidx) {
+                constexpr auto batch_idx = gidx / bpb;
+                f(gemm_batch_slice(x, batch_idx), gemm_batch_slice(xs, batch_idx)...);
+            });
+        }
+        else
+        {
+            f(x, xs...);    
+        }
+    };
+}
+
+} // namespace migraphx
+#endif // MIGRAPHX_GUARD_KERNELS_GEMM_BATCHER_HPP