st/glsl_to_nir: fix edgeflag passthrough

We have to mark the additional shader input as used, otherwise it will
be eliminated, and we have to setup its index correctly.

This is a bit of a hack, but so is everything surrounding edgeflag
passthrough.

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

2 files changed, 6 insertions, 1 deletions

diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index 524eefa236c..89f78884389 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -92,6 +92,9 @@ st_nir_assign_vs_in_locations(struct gl_program *prog, nir_shader *nir)
       }
    }
 
+   /* bit of a hack, mirroring st_translate_vertex_program */
+   input_to_index[VERT_ATTRIB_EDGEFLAG] = num_inputs;
+
    nir->num_inputs = 0;
    nir_foreach_variable_safe(var, &nir->inputs) {
       attr = var->data.location;
diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index eb44fc57b57..6b6d41536cf 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -557,8 +557,10 @@ st_create_vp_variant(struct st_context *st,
       vpv->tgsi.ir.nir = nir_shader_clone(NULL, stvp->tgsi.ir.nir);
       if (key->clamp_color)
          NIR_PASS_V(vpv->tgsi.ir.nir, nir_lower_clamp_color_outputs);
-      if (key->passthrough_edgeflags)
+      if (key->passthrough_edgeflags) {
          NIR_PASS_V(vpv->tgsi.ir.nir, nir_lower_passthrough_edgeflags);
+         vpv->num_inputs++;
+      }
 
       st_finalize_nir(st, &stvp->Base, vpv->tgsi.ir.nir);