draw: Implement support for primitive id

We were largely ignoring primitive id.

Signed-off-by: Zack Rusin <[email protected]>
Reviewed-by: José Fonseca <[email protected]>

2 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
index 5764847acb5..558a8dd7dd8 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
@@ -155,6 +155,7 @@ struct lp_tgsi_info
 struct lp_bld_tgsi_system_values {
    LLVMValueRef instance_id;
    LLVMValueRef vertex_id;
+   LLVMValueRef prim_id;
 };
 
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
index 54f3fd9f8f8..e802d5b1b62 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
@@ -929,6 +929,11 @@ emit_fetch_system_value(
       atype = TGSI_TYPE_UNSIGNED;
       break;
 
+   case TGSI_SEMANTIC_PRIMID:
+      res = bld->system_values.prim_id;
+      atype = TGSI_TYPE_UNSIGNED;
+      break;
+
    default:
       assert(!"unexpected semantic in emit_fetch_system_value");
       res = bld_base->base.zero;