radv/meta: reduce vertex buffer usage in clear shaders

For depth clears we have to pass the depth in the 2nd
component, we can use push constants for some of this
later to drop the vertex buffer completely

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/amd/vulkan/radv_meta.c

@@ -417,7 +417,7 @@ radv_meta_save_graphics_reset_vport_scissor_novertex(struct radv_meta_saved_stat
 	cmd_buffer->state.dirty |= dirty_state;
 }
 
-nir_ssa_def *radv_meta_gen_rect_vertices(nir_builder *vs_b)
+nir_ssa_def *radv_meta_gen_rect_vertices_comp2(nir_builder *vs_b, nir_ssa_def *comp2)
 {
 
 	nir_intrinsic_instr *vertex_id = nir_intrinsic_instr_create(vs_b->shader, nir_intrinsic_load_vertex_id_zero_base);
@@ -443,9 +443,14 @@ nir_ssa_def *radv_meta_gen_rect_vertices(nir_builder *vs_b)
 	comp[1] = nir_bcsel(vs_b, c1cmp,
 			    nir_imm_float(vs_b, -1.0),
 			    nir_imm_float(vs_b, 1.0));
-	comp[2] = nir_imm_float(vs_b, 0.0);
+	comp[2] = comp2;
 	comp[3] = nir_imm_float(vs_b, 1.0);
 	nir_ssa_def *outvec = nir_vec(vs_b, comp, 4);
 
 	return outvec;
 }
+
+nir_ssa_def *radv_meta_gen_rect_vertices(nir_builder *vs_b)
+{
+	return radv_meta_gen_rect_vertices_comp2(vs_b, nir_imm_float(vs_b, 0.0));
+}

src/amd/vulkan/radv_meta.h

@@ -226,7 +226,7 @@ void radv_blit_to_prime_linear(struct radv_cmd_buffer *cmd_buffer,
 #include "nir_builder.h"
 
 nir_ssa_def *radv_meta_gen_rect_vertices(nir_builder *vs_b);
-
+nir_ssa_def *radv_meta_gen_rect_vertices_comp2(nir_builder *vs_b, nir_ssa_def *comp2);
 #ifdef __cplusplus
 }
 #endif

src/amd/vulkan/radv_meta_clear.c

@@ -27,15 +27,14 @@
 
 #include "util/format_rgb9e5.h"
 #include "vk_format.h"
+
 /** Vertex attributes for color clears.  */
 struct color_clear_vattrs {
-	float position[2];
 	VkClearColorValue color;
 };
 
 /** Vertex attributes for depthstencil clears.  */
 struct depthstencil_clear_vattrs {
-	float position[2];
 	float depth_clear;
 };
 
@@ -62,11 +61,6 @@ build_color_shaders(struct nir_shader **out_vs,
 	const struct glsl_type *position_type = glsl_vec4_type();
 	const struct glsl_type *color_type = glsl_vec4_type();
 
-	nir_variable *vs_in_pos =
-		nir_variable_create(vs_b.shader, nir_var_shader_in, position_type,
-				    "a_position");
-	vs_in_pos->data.location = VERT_ATTRIB_GENERIC0;
-
 	nir_variable *vs_out_pos =
 		nir_variable_create(vs_b.shader, nir_var_shader_out, position_type,
 				    "gl_Position");
@@ -75,7 +69,7 @@ build_color_shaders(struct nir_shader **out_vs,
 	nir_variable *vs_in_color =
 		nir_variable_create(vs_b.shader, nir_var_shader_in, color_type,
 				    "a_color");
-	vs_in_color->data.location = VERT_ATTRIB_GENERIC1;
+	vs_in_color->data.location = VERT_ATTRIB_GENERIC0;
 
 	nir_variable *vs_out_color =
 		nir_variable_create(vs_b.shader, nir_var_shader_out, color_type,
@@ -94,7 +88,9 @@ build_color_shaders(struct nir_shader **out_vs,
 				    "f_color");
 	fs_out_color->data.location = FRAG_RESULT_DATA0 + frag_output;
 
-	nir_copy_var(&vs_b, vs_out_pos, vs_in_pos);
+	nir_ssa_def *outvec = radv_meta_gen_rect_vertices(&vs_b);
+
+	nir_store_var(&vs_b, vs_out_pos, outvec, 0xf);
 	nir_copy_var(&vs_b, vs_out_color, vs_in_color);
 	nir_copy_var(&fs_b, fs_out_color, fs_in_color);
 
@@ -277,21 +273,14 @@ create_color_pipeline(struct radv_device *device,
 				.inputRate = VK_VERTEX_INPUT_RATE_VERTEX
 			},
 		},
-		.vertexAttributeDescriptionCount = 2,
+		.vertexAttributeDescriptionCount = 1,
 		.pVertexAttributeDescriptions = (VkVertexInputAttributeDescription[]) {
 			{
-				/* Position */
+				/* Color */
 				.location = 0,
 				.binding = 0,
-				.format = VK_FORMAT_R32G32_SFLOAT,
-				.offset = offsetof(struct color_clear_vattrs, position),
-			},
-			{
-				/* Color */
-				.location = 1,
-				.binding = 0,
 				.format = VK_FORMAT_R32G32B32A32_SFLOAT,
-				.offset = offsetof(struct color_clear_vattrs, color),
+				.offset = 0,
 			},
 		},
 	};
@@ -409,24 +398,12 @@ emit_color_clear(struct radv_cmd_buffer *cmd_buffer,
 
 	const struct color_clear_vattrs vertex_data[3] = {
 		{
-			.position = {
-				-1.0,
-				-1.0,
-			},
 			.color = clear_value,
 		},
 		{
-			.position = {
-				-1.0,
-				1.0,
-			},
 			.color = clear_value,
 		},
 		{
-			.position = {
-				1.0,
-				-1.0,
-			},
 			.color = clear_value,
 		},
 	};
@@ -486,19 +463,21 @@ build_depthstencil_shader(struct nir_shader **out_vs, struct nir_shader **out_fs
 
 	vs_b.shader->info->name = ralloc_strdup(vs_b.shader, "meta_clear_depthstencil_vs");
 	fs_b.shader->info->name = ralloc_strdup(fs_b.shader, "meta_clear_depthstencil_fs");
-	const struct glsl_type *position_type = glsl_vec4_type();
+	const struct glsl_type *position_out_type = glsl_vec4_type();
+	const struct glsl_type *position_type = glsl_float_type();
 
 	nir_variable *vs_in_pos =
-		nir_variable_create(vs_b.shader, nir_var_shader_in, position_type,
-				    "a_position");
+               nir_variable_create(vs_b.shader, nir_var_shader_in, position_type,
+                                   "a_position");
 	vs_in_pos->data.location = VERT_ATTRIB_GENERIC0;
 
 	nir_variable *vs_out_pos =
-		nir_variable_create(vs_b.shader, nir_var_shader_out, position_type,
+		nir_variable_create(vs_b.shader, nir_var_shader_out, position_out_type,
 				    "gl_Position");
 	vs_out_pos->data.location = VARYING_SLOT_POS;
 
-	nir_copy_var(&vs_b, vs_out_pos, vs_in_pos);
+	nir_ssa_def *outvec = radv_meta_gen_rect_vertices_comp2(&vs_b, nir_load_var(&vs_b, vs_in_pos));
+	nir_store_var(&vs_b, vs_out_pos, outvec, 0xf);
 
 	const struct glsl_type *layer_type = glsl_int_type();
 	nir_variable *vs_out_layer =
@@ -576,8 +555,8 @@ create_depthstencil_pipeline(struct radv_device *device,
 				/* Position */
 				.location = 0,
 				.binding = 0,
-				.format = VK_FORMAT_R32G32B32_SFLOAT,
-				.offset = offsetof(struct depthstencil_clear_vattrs, position),
+				.format = VK_FORMAT_R32_SFLOAT,
+				.offset = 0,
 			},
 		},
 	};
@@ -695,24 +674,12 @@ emit_depthstencil_clear(struct radv_cmd_buffer *cmd_buffer,
 
 	const struct depthstencil_clear_vattrs vertex_data[3] = {
 		{
-			.position = {
-				-1.0,
-				-1.0
-			},
 			.depth_clear = clear_value.depth,
 		},
 		{
-			.position = {
-				-1.0,
-				1.0,
-			},
 			.depth_clear = clear_value.depth,
 		},
 		{
-			.position = {
-				1.0,
-				-1.0,
-			},
 			.depth_clear = clear_value.depth,
 		},
 	};