arb_tessellation_shader: split barrier-switch test

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

2 files changed, 45 insertions, 0 deletions

diff --git a/tests/spec/arb_tessellation_shader/compiler/barrier-switch-always.tesc b/tests/spec/arb_tessellation_shader/compiler/barrier-switch-always.tesc
new file mode 100644
index 000000000..ad8baca0b
--- /dev/null
+++ b/tests/spec/arb_tessellation_shader/compiler/barrier-switch-always.tesc
@@ -0,0 +1,43 @@
+// [config]
+// expect_result: fail
+// glsl_version: 1.50
+// require_extensions: GL_ARB_tessellation_shader
+// check_link: true
+// [end config]
+
+/**
+ * From issue 42:
+ *
+ *   As a result, we choose a heavy-handed approach in which we only allow
+ *   calls to barrier() inside main().  Even within main, barrier() calls are
+ *   forbidden inside loops (even those that turn out to have constant loop
+ *   counts and don't execute "break" or "continue" statements), if
+ *   statements, or after a return statement.
+ *
+ * Further, from the spec text:
+ *
+ *   In particular, barrier() may not be called inside
+ *   a switch statement, in either sub-statement of an if statement, inside a
+ *   do, for, or while loop, or at any point after a return statement in the
+ *   function main().
+ *
+ * Technically, we should disallow this usage of barrier() inside the always-taken
+ * default case -- but this is an interesting edge case for Mesa's compiler, which
+ * at this time does not express switch statements in the IR, and so an always-taken
+ * default case is indistinguishable from code outside the switch.
+ */
+
+#version 150
+#extension GL_ARB_tessellation_shader: require
+layout(vertices = 3) out;
+uniform int val;
+
+void main() {
+    gl_out[gl_InvocationID].gl_Position = vec4(0.0);
+    switch (val) {
+    default:
+        barrier();
+    }
+    gl_TessLevelOuter = float[4](1.0, 1.0, 1.0, 1.0);
+    gl_TessLevelInner = float[2](1.0, 1.0);
+}
diff --git a/tests/spec/arb_tessellation_shader/compiler/barrier-switch.tesc b/tests/spec/arb_tessellation_shader/compiler/barrier-switch.tesc
index e08b7e392..2cc2cfdc6 100644
--- a/tests/spec/arb_tessellation_shader/compiler/barrier-switch.tesc
+++ b/tests/spec/arb_tessellation_shader/compiler/barrier-switch.tesc
@@ -30,6 +30,8 @@ uniform int val;
 void main() {
     gl_out[gl_InvocationID].gl_Position = vec4(0.0);
     switch (val) {
+    case 1:
+        break;
     default:
         barrier();
     }