2 files changed, 34 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.c b/src/gallium/auxiliary/tgsi/tgsi_scan.c
index a9aa36be46c..7d5496c9603 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.c
@@ -199,6 +199,28 @@ scan_src_operand(struct tgsi_shader_info *info,
       }
    }
 
+   if (info->processor == PIPE_SHADER_TESS_CTRL &&
+       src->Register.File == TGSI_FILE_OUTPUT) {
+      unsigned input;
+
+      if (src->Register.Indirect && src->Indirect.ArrayID)
+         input = info->output_array_first[src->Indirect.ArrayID];
+      else
+         input = src->Register.Index;
+
+      switch (info->output_semantic_name[input]) {
+      case TGSI_SEMANTIC_PATCH:
+         info->reads_perpatch_outputs = true;
+         break;
+      case TGSI_SEMANTIC_TESSINNER:
+      case TGSI_SEMANTIC_TESSOUTER:
+         info->reads_tessfactor_outputs = true;
+         break;
+      default:
+         info->reads_pervertex_outputs = true;
+      }
+   }
+
    /* check for indirect register reads */
    if (src->Register.Indirect) {
       info->indirect_files |= (1 << src->Register.File);
@@ -539,6 +561,10 @@ scan_declaration(struct tgsi_shader_info *info,
          case TGSI_SEMANTIC_SAMPLEMASK:
             info->reads_samplemask = TRUE;
             break;
+         case TGSI_SEMANTIC_TESSINNER:
+         case TGSI_SEMANTIC_TESSOUTER:
+            info->reads_tess_factors = true;
+            break;
          }
          break;
 
diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.h b/src/gallium/auxiliary/tgsi/tgsi_scan.h
index 4add2f7a7e3..e3c24e950ed 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.h
@@ -84,11 +84,19 @@ struct tgsi_shader_info
 
    uint opcode_count[TGSI_OPCODE_LAST];  /**< opcode histogram */
 
+   /**
+    * If a tessellation control shader reads outputs, this describes which ones.
+    */
+   boolean reads_pervertex_outputs;
+   boolean reads_perpatch_outputs;
+   boolean reads_tessfactor_outputs;
+
    ubyte colors_read; /**< which color components are read by the FS */
    ubyte colors_written;
    boolean reads_position; /**< does fragment shader read position? */
    boolean reads_z; /**< does fragment shader read depth? */
    boolean reads_samplemask; /**< does fragment shader read sample mask? */
+   boolean reads_tess_factors; /**< If TES reads TESSINNER or TESSOUTER */
    boolean writes_z;  /**< does fragment shader write Z value? */
    boolean writes_stencil; /**< does fragment shader write stencil value? */
    boolean writes_samplemask; /**< does fragment shader write sample mask? */