st/glsl_to_nir: gather next_stage in shader_info

Reviewed-by: Marek Olšák <[email protected]>

2 files changed, 20 insertions, 0 deletions

diff --git a/src/compiler/shader_info.h b/src/compiler/shader_info.h
index 737e9cffa86..ababe520b2d 100644
--- a/src/compiler/shader_info.h
+++ b/src/compiler/shader_info.h
@@ -64,6 +64,11 @@ typedef struct shader_info {
    /** The shader stage, such as MESA_SHADER_VERTEX. */
    gl_shader_stage stage;
 
+   /** The shader stage in a non SSO linked program that follows this stage,
+     * such as MESA_SHADER_FRAGMENT.
+     */
+   gl_shader_stage next_stage;
+
    /* Number of textures used by this shader */
    unsigned num_textures;
    /* Number of uniform buffers used by this shader */
diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 2cd1d97baec..f2d4b184d67 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -362,6 +362,21 @@ st_glsl_to_nir(struct st_context *st, struct gl_program *prog,
 
    nir_shader *nir = glsl_to_nir(shader_program, stage, options);
 
+   /* Set the next shader stage hint for VS and TES. */
+   if (!nir->info.separate_shader &&
+       (nir->info.stage == MESA_SHADER_VERTEX ||
+        nir->info.stage == MESA_SHADER_TESS_EVAL)) {
+
+      unsigned prev_stages = (1 << (prog->info.stage + 1)) - 1;
+      unsigned stages_mask =
+         ~prev_stages & shader_program->data->linked_stages;
+
+      nir->info.next_stage = stages_mask ?
+         (gl_shader_stage) ffs(stages_mask) : MESA_SHADER_FRAGMENT;
+   } else {
+      nir->info.next_stage = MESA_SHADER_FRAGMENT;
+   }
+
    nir_variable_mode mask =
       (nir_variable_mode) (nir_var_shader_in | nir_var_shader_out);
    nir_remove_dead_variables(nir, mask);