/*
 * 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"

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_var *deref, unsigned *const_out)
{
	nir_deref *tail = &deref->deref;
	unsigned const_offset = 0;

	if (deref->var->data.compact) {
		assert(tail->child->deref_type == nir_deref_type_array);
		assert(glsl_type_is_scalar(glsl_without_array(deref->var->type)));

		nir_deref_array *deref_array = nir_deref_as_array(tail->child);
		/* We always lower indirect dereferences for "compact" array vars. */
		assert(deref_array->deref_array_type == nir_deref_array_type_direct);

		*const_out = deref_array->base_offset;
		return;
	}

	while (tail->child != NULL) {
		const struct glsl_type *parent_type = tail->type;
		tail = tail->child;

		if (tail->deref_type == nir_deref_type_array) {
			nir_deref_array *deref_array = nir_deref_as_array(tail);
			unsigned size = glsl_count_attribute_slots(tail->type, false);

			const_offset += size * deref_array->base_offset;
		} else if (tail->deref_type == nir_deref_type_struct) {
			nir_deref_struct *deref_struct = nir_deref_as_struct(tail);

			for (unsigned i = 0; i < deref_struct->index; i++) {
				const struct glsl_type *ft = glsl_get_struct_field(parent_type, i);
				const_offset += glsl_count_attribute_slots(ft, false);
			}
		} else
			unreachable("unsupported deref type");
	}

	*const_out = const_offset;
}

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_var_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_var_load:
	case nir_intrinsic_image_var_store:
	case nir_intrinsic_image_var_atomic_add:
	case nir_intrinsic_image_var_atomic_min:
	case nir_intrinsic_image_var_atomic_max:
	case nir_intrinsic_image_var_atomic_and:
	case nir_intrinsic_image_var_atomic_or:
	case nir_intrinsic_image_var_atomic_xor:
	case nir_intrinsic_image_var_atomic_exchange:
	case nir_intrinsic_image_var_atomic_comp_swap:
	case nir_intrinsic_image_var_size: {
		const struct glsl_type *type = instr->variables[0]->var->type;
		if(instr->variables[0]->deref.child)
			type = instr->variables[0]->deref.child->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(instr->variables[0]->var, info);

		if (nir_intrinsic_image_var_store ||
		    nir_intrinsic_image_var_atomic_add ||
		    nir_intrinsic_image_var_atomic_min ||
		    nir_intrinsic_image_var_atomic_max ||
		    nir_intrinsic_image_var_atomic_and ||
		    nir_intrinsic_image_var_atomic_or ||
		    nir_intrinsic_image_var_atomic_xor ||
		    nir_intrinsic_image_var_atomic_exchange ||
		    nir_intrinsic_image_var_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_var:
		if (nir->info.stage == MESA_SHADER_VERTEX) {
			nir_deref_var *dvar = instr->variables[0];
			nir_variable *var = dvar->var;

			if (var->data.mode == nir_var_shader_in) {
				unsigned idx = var->data.location;
				uint8_t mask =
					nir_ssa_def_components_read(&instr->dest.ssa) << var->data.location_frac;
				info->vs.input_usage_mask[idx] |= mask;
			}
		}
		break;
	case nir_intrinsic_store_var: {
		nir_deref_var *dvar = instr->variables[0];
		nir_variable *var = dvar->var;

		if (var->data.mode == nir_var_shader_out) {
			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(dvar, &const_offset);

			if (nir->info.stage == MESA_SHADER_VERTEX) {
				for (unsigned i = 0; i < attrib_count; i++) {
					info->vs.output_usage_mask[idx + i + const_offset] |=
						instr->const_index[0] << comp;
				}
			} else if (nir->info.stage == MESA_SHADER_TESS_EVAL) {
				for (unsigned i = 0; i < attrib_count; i++) {
					info->tes.output_usage_mask[idx + i + const_offset] |=
						instr->const_index[0] << comp;
				}
			} else if (nir->info.stage == 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_tex_info(const nir_shader *nir, const nir_tex_instr *instr,
		struct radv_shader_info *info)
{
	if (instr->sampler)
		mark_sampler_desc(instr->sampler->var, info);
	if (instr->texture)
		mark_sampler_desc(instr->texture->var, info);
}

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)
{
	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;
	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->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);
}