Initial changes for jit gather implementation

Taken from gatherND.cpp and modified so we include the axis parameter as opposed
to the batch_dims attribute.

Should always exist since we default this to zero when no axis is provided from
the instruction

Work in progress for the .hpp jit side.

src/targets/gpu/jit/gather.cpp

+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015-2022 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <migraphx/gpu/compiler.hpp>
+#include <migraphx/make_op.hpp>
+#include <migraphx/gpu/context.hpp>
+
+#include <migraphx/gpu/compile_hip_code_object.hpp>
+#include <migraphx/gpu/compile_hip.hpp>
+
+namespace migraphx {
+inline namespace MIGRAPHX_INLINE_NS {
+namespace gpu {
+
+// NOLINTNEXTLINE
+static const char* const gather_kernel = R"__migraphx__(
+#include <migraphx/kernels/gathernd.hpp>
+#include <migraphx/kernels/ops.hpp>
+#include <migraphx/kernels/integral_constant.hpp>
+#include <migraphx/kernels/generic_constant.hpp>
+#include <args.hpp>
+
+namespace migraphx {
+
+extern "C" {
+
+__global__ void gather_kernel(void* in_data, void* in_indices, void* output) 
+{
+    make_tensors()(in_data, in_indices, output)([](auto&&... xs) { 
+        auto settings = make_gather_settings(MIGRAPHX_MAKE_CONSTANT(int64_t{AXIS}));
+        gather(xs..., settings); 
+    });
+}
+
+}
+
+} // namespace migraphx
+
+)__migraphx__";
+
+struct gathernd_compiler : compiler<gathernd_compiler>
+{
+    std::vector<std::string> names() const { return {"gather"}; }
+
+    operation compile_op(context& ctx, const std::vector<shape>& inputs, const value& v) const
+    {
+        hip_compile_options options;
+        const auto& out_s = inputs.back();
+        options.set_launch_params(v, compute_global_for(ctx, out_s.elements()));
+        options.inputs         = inputs;
+        options.output         = out_s;
+        options.kernel_name    = "gather_kernel";
+        options.virtual_inputs = inputs;
+
+        // axis attribute
+        assert(v.contains("axis"));
+        auto axis = v.at("axis").to<int64_t>();
+        options.params += " -DAXIS=" + std::to_string(axis);
+
+        return compile_hip_code_object(gather_kernel, options);
+    }
+
+    compiler_replace compile(context& ctx, instruction_ref ins, const operation& op) const
+    {
+        return replace(compile_op(ctx, to_shapes(ins->inputs()), op.to_value()));
+    }
+};
+
+} // namespace gpu
+} // namespace MIGRAPHX_INLINE_NS
+} // namespace migraphx

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

+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015-2022 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MIGRAPHX_GUARD_KERNELS_GATHERND_HPP
+#define MIGRAPHX_GUARD_KERNELS_GATHERND_HPP
+
+#include <migraphx/kernels/index.hpp>
+#include <migraphx/kernels/algorithm.hpp>
+
+namespace migraphx {
+
+template <class T>
+struct gather_settings
+{
+    T axes{};
+};
+
+template <class... Ts>
+constexpr gather_settings<Ts...> make_gather_settings(Ts... xs)
+{
+    return {xs...};
+}
+
+template <class T, class U, class V, class Settings>
+__device__ void gather(const T& data_t, const U& indices_t, const V& output_t, Settings s)
+{
+    auto ind           = make_index();
+    auto axis          = s.axis;
+    auto output_shape  = output_t.get_shape();
+    auto indices_shape = indices_t.get_shape();
+    auto data_shape    = data_t.get_shape();
+
+    auto axis_dim_size = data_shape.lens().at(axis);
+
+    auto indices_shape_lens = indices_shape.lens;
+    auto data_shape_lens    = data_shape.lens;
+
+    const auto* indices_ptr = indices_t.data();
+    auto* output_ptr        = output_t.data();
+
+    ind.global_stride(output_shape.elements(), [&](auto i) {
+
+    });
+}
+
+} // namespace migraphx
+#endif