radeonsi: make si_shader_io_get_unique_index stricter

Tested-by: Edmondo Tommasina <edmondo.tommasina@gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/gallium/drivers/radeonsi/si_shader.c

@@ -123,11 +123,9 @@ unsigned si_shader_io_get_unique_index(unsigned semantic_name, unsigned index)
 	case TGSI_SEMANTIC_GENERIC:
 		if (index <= 63-4)
 			return 4 + index;
-		else
-			/* same explanation as in the default statement,
-			 * the only user hitting this is st/nine.
-			 */
-			return 0;
+
+		assert(!"invalid generic index");
+		return 0;
 
 	/* patch indices are completely separate and thus start from 0 */
 	case TGSI_SEMANTIC_TESSOUTER:
@@ -138,11 +136,7 @@ unsigned si_shader_io_get_unique_index(unsigned semantic_name, unsigned index)
 		return 2 + index;
 
 	default:
-		/* Don't fail here. The result of this function is only used
-		 * for LS, TCS, TES, and GS, where legacy GL semantics can't
-		 * occur, but this function is called for all vertex shaders
-		 * before it's known whether LS will be compiled or not.
-		 */
+		assert(!"invalid semantic name");
 		return 0;
 	}
 }

src/gallium/drivers/radeonsi/si_state_shaders.c

@@ -1425,9 +1425,18 @@ static void *si_create_shader_selector(struct pipe_context *ctx,
 				sel->patch_outputs_written |=
 					1llu << si_shader_io_get_unique_index(name, index);
 				break;
-			default:
+
+			case TGSI_SEMANTIC_GENERIC:
+				/* don't process indices the function can't handle */
+				if (index >= 60)
+					break;
+				/* fall through */
+			case TGSI_SEMANTIC_POSITION:
+			case TGSI_SEMANTIC_PSIZE:
+			case TGSI_SEMANTIC_CLIPDIST:
 				sel->outputs_written |=
 					1llu << si_shader_io_get_unique_index(name, index);
+				break;
 			}
 		}
 		sel->esgs_itemsize = util_last_bit64(sel->outputs_written) * 16;