/*
 * Copyright © 2017 Red Hat
 *
 * 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 (including the next
 * paragraph) 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 "radv_private.h"
#include "radv_shader.h"
#include "nir/nir.h"
#include "nir/nir_deref.h"

static void mark_sampler_desc(const nir_variable *var,
			      struct radv_shader_info *info)
{
	info->desc_set_used_mask |= (1 << var->data.descriptor_set);
}

static void mark_ls_output(struct radv_shader_info *info,
			   uint32_t param, int num_slots)
{
	uint64_t mask = (1ull << num_slots) - 1ull;
	info->vs.ls_outputs_written |= (mask << param);
}

static void mark_tess_output(struct radv_shader_info *info,
			     bool is_patch, uint32_t param, int num_slots)
{
	uint64_t mask = (1ull << num_slots) - 1ull;
	if (is_patch)
		info->tcs.patch_outputs_written |= (mask << param);
	else
		info->tcs.outputs_written |= (mask << param);
}

static void
get_deref_offset(nir_deref_instr *instr,
                 unsigned *const_out)
{
        nir_variable *var = nir_deref_instr_get_variable(instr);
        nir_deref_path path;
        unsigned idx_lvl = 1;

	if (var->data.compact) {
		assert(instr->deref_type == nir_deref_type_array);
		nir_const_value *v = nir_src_as_const_value(instr->arr.index);
		assert(v);
		*const_out = v->u32[0];
		return;
	}

	nir_deref_path_init(&path, instr, NULL);

	uint32_t const_offset = 0;

	for (; path.path[idx_lvl]; ++idx_lvl) {
		const struct glsl_type *parent_type = path.path[idx_lvl - 1]->type;
		if (path.path[idx_lvl]->deref_type == nir_deref_type_struct) {
			unsigned index = path.path[idx_lvl]->strct.index;

			for (unsigned i = 0; i < index; i++) {
				const struct glsl_type *ft = glsl_get_struct_field(parent_type, i);
				const_offset += glsl_count_attribute_slots(ft, false);
			}
		} else if(path.path[idx_lvl]->deref_type == nir_deref_type_array) {
			unsigned size = glsl_count_attribute_slots(path.path[idx_lvl]->type, false);
			nir_const_value *v = nir_src_as_const_value(path.path[idx_lvl]->arr.index);
			if (v)
				const_offset += v->u32[0] * size;
		} else
			unreachable("Uhandled deref type in get_deref_instr_offset");
	}

	*const_out = const_offset;

	nir_deref_path_finish(&path);
}

static void
gather_intrinsic_load_deref_info(const nir_shader *nir,
			       const nir_intrinsic_instr *instr,
			       struct radv_shader_info *info)
{
	switch (nir->info.stage) {
	case MESA_SHADER_VERTEX: {
		nir_variable *var = nir_deref_instr_get_variable(nir_instr_as_deref(instr->src[0].ssa->parent_instr));

		if (var->data.mode == nir_var_shader_in) {
			unsigned idx = var->data.location;
			uint8_t mask = nir_ssa_def_components_read(&instr->dest.ssa);

			info->vs.input_usage_mask[idx] |=
				mask << var->data.location_frac;
		}
		break;
	}
	default:
		break;
	}
}

static void
set_output_usage_mask(const nir_shader *nir, const nir_intrinsic_instr *instr,
		      uint8_t *output_usage_mask)
{
	nir_deref_instr *deref_instr =
		nir_instr_as_deref(instr->src[0].ssa->parent_instr);
	nir_variable *var = nir_deref_instr_get_variable(deref_instr);
	unsigned attrib_count = glsl_count_attribute_slots(var->type, false);
	unsigned idx = var->data.location;
	unsigned comp = var->data.location_frac;
	unsigned const_offset = 0;

	get_deref_offset(deref_instr, &const_offset);

	if (idx == VARYING_SLOT_CLIP_DIST0) {
		/* Special case for clip/cull distances because there are
		 * combined into a single array that contains both.
		 */
		output_usage_mask[idx] |= 1 << const_offset;
		return;
	}

	for (unsigned i = 0; i < attrib_count; i++) {
		output_usage_mask[idx + i + const_offset] |=
			instr->const_index[0] << comp;
	}
}

static void
gather_intrinsic_store_deref_info(const nir_shader *nir,
				const nir_intrinsic_instr *instr,
				struct radv_shader_info *info)
{
	nir_variable *var = nir_deref_instr_get_variable(nir_instr_as_deref(instr->src[0].ssa->parent_instr));

	if (var->data.mode == nir_var_shader_out) {
		unsigned idx = var->data.location;

		switch (nir->info.stage) {
		case MESA_SHADER_VERTEX:
			set_output_usage_mask(nir, instr,
					      info->vs.output_usage_mask);
			break;
		case MESA_SHADER_GEOMETRY:
			set_output_usage_mask(nir, instr,
					      info->gs.output_usage_mask);
			break;
		case MESA_SHADER_TESS_EVAL:
			set_output_usage_mask(nir, instr,
					      info->tes.output_usage_mask);
			break;
		case MESA_SHADER_TESS_CTRL: {
			unsigned param = shader_io_get_unique_index(idx);
			const struct glsl_type *type = var->type;

			if (!var->data.patch)
				type = glsl_get_array_element(var->type);

			unsigned slots =
				var->data.compact ? DIV_ROUND_UP(glsl_get_length(type), 4)
						  : glsl_count_attribute_slots(type, false);

			if (idx == VARYING_SLOT_CLIP_DIST0)
				slots = (nir->info.clip_distance_array_size +
					 nir->info.cull_distance_array_size > 4) ? 2 : 1;

			mark_tess_output(info, var->data.patch, param, slots);
			break;
		}
		default:
			break;
		}
	}
}

static void
gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
		      struct radv_shader_info *info)
{
	switch (instr->intrinsic) {
	case nir_intrinsic_interp_deref_at_sample:
		info->ps.needs_sample_positions = true;
		break;
	case nir_intrinsic_load_draw_id:
		info->vs.needs_draw_id = true;
		break;
	case nir_intrinsic_load_instance_id:
		info->vs.needs_instance_id = true;
		break;
	case nir_intrinsic_load_num_work_groups:
		info->cs.uses_grid_size = true;
		break;
	case nir_intrinsic_load_local_invocation_id:
	case nir_intrinsic_load_work_group_id: {
		unsigned mask = nir_ssa_def_components_read(&instr->dest.ssa);
		while (mask) {
			unsigned i = u_bit_scan(&mask);

			if (instr->intrinsic == nir_intrinsic_load_work_group_id)
				info->cs.uses_block_id[i] = true;
			else
				info->cs.uses_thread_id[i] = true;
		}
		break;
	}
	case nir_intrinsic_load_local_invocation_index:
	case nir_intrinsic_load_subgroup_id:
	case nir_intrinsic_load_num_subgroups:
		info->cs.uses_local_invocation_idx = true;
		break;
	case nir_intrinsic_load_sample_id:
		info->ps.force_persample = true;
		break;
	case nir_intrinsic_load_sample_pos:
		info->ps.force_persample = true;
		break;
	case nir_intrinsic_load_view_index:
		info->needs_multiview_view_index = true;
		if (nir->info.stage == MESA_SHADER_FRAGMENT)
			info->ps.layer_input = true;
		break;
	case nir_intrinsic_load_invocation_id:
		info->uses_invocation_id = true;
		break;
	case nir_intrinsic_load_primitive_id:
		info->uses_prim_id = true;
		break;
	case nir_intrinsic_load_push_constant:
		info->loads_push_constants = true;
		break;
	case nir_intrinsic_vulkan_resource_index:
		info->desc_set_used_mask |= (1 << nir_intrinsic_desc_set(instr));
		break;
	case nir_intrinsic_image_deref_load:
	case nir_intrinsic_image_deref_store:
	case nir_intrinsic_image_deref_atomic_add:
	case nir_intrinsic_image_deref_atomic_min:
	case nir_intrinsic_image_deref_atomic_max:
	case nir_intrinsic_image_deref_atomic_and:
	case nir_intrinsic_image_deref_atomic_or:
	case nir_intrinsic_image_deref_atomic_xor:
	case nir_intrinsic_image_deref_atomic_exchange:
	case nir_intrinsic_image_deref_atomic_comp_swap:
	case nir_intrinsic_image_deref_size: {
		nir_variable *var = nir_deref_instr_get_variable(nir_instr_as_deref(instr->src[0].ssa->parent_instr));
		const struct glsl_type *type = glsl_without_array(var->type);

		enum glsl_sampler_dim dim = glsl_get_sampler_dim(type);
		if (dim == GLSL_SAMPLER_DIM_SUBPASS ||
		    dim == GLSL_SAMPLER_DIM_SUBPASS_MS) {
			info->ps.layer_input = true;
			info->ps.uses_input_attachments = true;
		}
		mark_sampler_desc(var, info);

		if (nir_intrinsic_image_deref_store ||
		    nir_intrinsic_image_deref_atomic_add ||
		    nir_intrinsic_image_deref_atomic_min ||
		    nir_intrinsic_image_deref_atomic_max ||
		    nir_intrinsic_image_deref_atomic_and ||
		    nir_intrinsic_image_deref_atomic_or ||
		    nir_intrinsic_image_deref_atomic_xor ||
		    nir_intrinsic_image_deref_atomic_exchange ||
		    nir_intrinsic_image_deref_atomic_comp_swap) {
			if (nir->info.stage == MESA_SHADER_FRAGMENT)
				info->ps.writes_memory = true;
		}
		break;
	}
	case nir_intrinsic_store_ssbo:
	case nir_intrinsic_ssbo_atomic_add:
	case nir_intrinsic_ssbo_atomic_imin:
	case nir_intrinsic_ssbo_atomic_umin:
	case nir_intrinsic_ssbo_atomic_imax:
	case nir_intrinsic_ssbo_atomic_umax:
	case nir_intrinsic_ssbo_atomic_and:
	case nir_intrinsic_ssbo_atomic_or:
	case nir_intrinsic_ssbo_atomic_xor:
	case nir_intrinsic_ssbo_atomic_exchange:
	case nir_intrinsic_ssbo_atomic_comp_swap:
		if (nir->info.stage == MESA_SHADER_FRAGMENT)
			info->ps.writes_memory = true;
		break;
	case nir_intrinsic_load_deref:
		gather_intrinsic_load_deref_info(nir, instr, info);
		break;
	case nir_intrinsic_store_deref:
		gather_intrinsic_store_deref_info(nir, instr, info);
		break;
	default:
		break;
	}
}

static void
gather_tex_info(const nir_shader *nir, const nir_tex_instr *instr,
		struct radv_shader_info *info)
{
	for (unsigned i = 0; i < instr->num_srcs; i++) {
		switch (instr->src[i].src_type) {
		case nir_tex_src_texture_deref:
			mark_sampler_desc(nir_deref_instr_get_variable(nir_src_as_deref(instr->src[i].src)), info);
			break;
		case nir_tex_src_sampler_deref:
			mark_sampler_desc(nir_deref_instr_get_variable(nir_src_as_deref(instr->src[i].src)), info);
			break;
		default:
			break;
		}
	}
}

static void
gather_info_block(const nir_shader *nir, const nir_block *block,
		  struct radv_shader_info *info)
{
	nir_foreach_instr(instr, block) {
		switch (instr->type) {
		case nir_instr_type_intrinsic:
			gather_intrinsic_info(nir, nir_instr_as_intrinsic(instr), info);
			break;
		case nir_instr_type_tex:
			gather_tex_info(nir, nir_instr_as_tex(instr), info);
			break;
		default:
			break;
		}
	}
}

static void
gather_info_input_decl_vs(const nir_shader *nir, const nir_variable *var,
			  struct radv_shader_info *info)
{
	int idx = var->data.location;

	if (idx >= VERT_ATTRIB_GENERIC0 && idx <= VERT_ATTRIB_GENERIC15)
		info->vs.has_vertex_buffers = true;
}

static void
gather_info_input_decl_ps(const nir_shader *nir, const nir_variable *var,
			  struct radv_shader_info *info)
{
	unsigned attrib_count = glsl_count_attribute_slots(var->type, false);
	const struct glsl_type *type = glsl_without_array(var->type);
	int idx = var->data.location;

	switch (idx) {
	case VARYING_SLOT_PNTC:
		info->ps.has_pcoord = true;
		break;
	case VARYING_SLOT_PRIMITIVE_ID:
		info->ps.prim_id_input = true;
		break;
	case VARYING_SLOT_LAYER:
		info->ps.layer_input = true;
		break;
	case VARYING_SLOT_CLIP_DIST0:
		info->ps.num_input_clips_culls = attrib_count;
		break;
	default:
		break;
	}

	if (glsl_get_base_type(type) == GLSL_TYPE_FLOAT) {
		if (var->data.sample)
			info->ps.force_persample = true;
	}
}

static void
gather_info_input_decl(const nir_shader *nir, const nir_variable *var,
		       struct radv_shader_info *info)
{
	switch (nir->info.stage) {
	case MESA_SHADER_VERTEX:
		gather_info_input_decl_vs(nir, var, info);
		break;
	case MESA_SHADER_FRAGMENT:
		gather_info_input_decl_ps(nir, var, info);
		break;
	default:
		break;
	}
}

static void
gather_info_output_decl_ls(const nir_shader *nir, const nir_variable *var,
			   struct radv_shader_info *info)
{
	int idx = var->data.location;
	unsigned param = shader_io_get_unique_index(idx);
	int num_slots = glsl_count_attribute_slots(var->type, false);
	if (idx == VARYING_SLOT_CLIP_DIST0)
		num_slots = (nir->info.clip_distance_array_size + nir->info.cull_distance_array_size > 4) ? 2 : 1;
	mark_ls_output(info, param, num_slots);
}

static void
gather_info_output_decl_ps(const nir_shader *nir, const nir_variable *var,
			   struct radv_shader_info *info)
{
	int idx = var->data.location;

	switch (idx) {
	case FRAG_RESULT_DEPTH:
		info->ps.writes_z = true;
		break;
	case FRAG_RESULT_STENCIL:
		info->ps.writes_stencil = true;
		break;
	case FRAG_RESULT_SAMPLE_MASK:
		info->ps.writes_sample_mask = true;
		break;
	default:
		break;
	}
}

static void
gather_info_output_decl(const nir_shader *nir, const nir_variable *var,
			struct radv_shader_info *info,
			const struct radv_nir_compiler_options *options)
{
	switch (nir->info.stage) {
	case MESA_SHADER_FRAGMENT:
		gather_info_output_decl_ps(nir, var, info);
		break;
	case MESA_SHADER_VERTEX:
		if (options->key.vs.as_ls)
			gather_info_output_decl_ls(nir, var, info);
		break;
	default:
		break;
	}
}

void
radv_nir_shader_info_pass(const struct nir_shader *nir,
			  const struct radv_nir_compiler_options *options,
			  struct radv_shader_info *info)
{
	struct nir_function *func =
		(struct nir_function *)exec_list_get_head_const(&nir->functions);

	if (options->layout && options->layout->dynamic_offset_count)
		info->loads_push_constants = true;

	nir_foreach_variable(variable, &nir->inputs)
		gather_info_input_decl(nir, variable, info);

	nir_foreach_block(block, func->impl) {
		gather_info_block(nir, block, info);
	}

	nir_foreach_variable(variable, &nir->outputs)
		gather_info_output_decl(nir, variable, info, options);
}