tgsi/scan: record if a shader writes the position output

Tested-by: Edmondo Tommasina <[email protected]>
Reviewed-by: Nicolai Hähnle <[email protected]>

2 files changed, 3 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.c b/src/gallium/auxiliary/tgsi/tgsi_scan.c
index f0dba0b1bda..84d64568c4b 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.c
@@ -575,6 +575,8 @@ scan_declaration(struct tgsi_shader_info *info,
          case TGSI_SEMANTIC_POSITION:
             if (procType == PIPE_SHADER_FRAGMENT)
                info->writes_z = true;
+            else
+               info->writes_position = true;
             break;
          }
          break;
diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.h b/src/gallium/auxiliary/tgsi/tgsi_scan.h
index 602a8703d50..fe503e8ba36 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.h
@@ -110,6 +110,7 @@ struct tgsi_shader_info
    boolean uses_primid;
    boolean uses_frontface;
    boolean uses_invocationid;
+   boolean writes_position;
    boolean writes_psize;
    boolean writes_clipvertex;
    boolean writes_viewport_index;