intel/compiler: Add a uses_firstvertex flag

Reviewed-by: Kenneth Graunke <[email protected]>

2 files changed, 5 insertions, 0 deletions

diff --git a/src/intel/compiler/brw_compiler.h b/src/intel/compiler/brw_compiler.h
index 875b2936fd8..24196248b8e 100644
--- a/src/intel/compiler/brw_compiler.h
+++ b/src/intel/compiler/brw_compiler.h
@@ -978,6 +978,7 @@ struct brw_vs_prog_data {
    bool uses_vertexid;
    bool uses_instanceid;
    bool uses_basevertex;
+   bool uses_firstvertex;
    bool uses_baseinstance;
    bool uses_drawid;
 };
diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp
index 218925ccb12..9459d61af6c 100644
--- a/src/intel/compiler/brw_vec4.cpp
+++ b/src/intel/compiler/brw_vec4.cpp
@@ -2837,6 +2837,10 @@ brw_compile_vs(const struct brw_compiler *compiler, void *log_data,
       prog_data->uses_basevertex = true;
 
    if (shader->info.system_values_read &
+       BITFIELD64_BIT(SYSTEM_VALUE_FIRST_VERTEX))
+      prog_data->uses_firstvertex = true;
+
+   if (shader->info.system_values_read &
        BITFIELD64_BIT(SYSTEM_VALUE_BASE_INSTANCE))
       prog_data->uses_baseinstance = true;