ac/shader: scan vertex inputs usage mask

Signed-off-by: Samuel Pitoiset <[email protected]>
Reviewed-by: Bas Nieuwenhuizen <[email protected]>

2 files changed, 16 insertions, 0 deletions

diff --git a/src/amd/common/ac_shader_info.c b/src/amd/common/ac_shader_info.c
index d771cd250dc..e7132638172 100644
--- a/src/amd/common/ac_shader_info.c
+++ b/src/amd/common/ac_shader_info.c
@@ -133,6 +133,19 @@ gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
 		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);
+				info->vs.input_usage_mask[idx] |= mask;
+			}
+		}
+		break;
 	default:
 		break;
 	}
diff --git a/src/amd/common/ac_shader_info.h b/src/amd/common/ac_shader_info.h
index 59b749576aa..380c06a8551 100644
--- a/src/amd/common/ac_shader_info.h
+++ b/src/amd/common/ac_shader_info.h
@@ -24,6 +24,8 @@
 #ifndef AC_SHADER_INFO_H
 #define AC_SHADER_INFO_H
 
+#include "compiler/shader_enums.h"
+
 struct nir_shader;
 struct ac_nir_compiler_options;
 
@@ -34,6 +36,7 @@ struct ac_shader_info {
 	bool uses_invocation_id;
 	bool uses_prim_id;
 	struct {
+		uint8_t input_usage_mask[VERT_ATTRIB_MAX];
 		bool has_vertex_buffers; /* needs vertex buffers and base/start */
 		bool needs_draw_id;
 		bool needs_instance_id;