Add loop test to demonstrate bug in r300 compiler

This is based on the existing vs-loop-complex-unroll-with-else-break
test, however this one can't be unrolled and demonstrates an issue
with copy propagation in r300 compiler.

More details in: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6467

Signed-off-by: Pavel Ondračka <pavel.ondracka@gmail.com>
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/piglit/-/merge_requests/694>

1 files changed, 57 insertions, 0 deletions

diff --git a/tests/spec/glsl-1.10/execution/vs-loop-complex-with-else-break.shader_test b/tests/spec/glsl-1.10/execution/vs-loop-complex-with-else-break.shader_test
new file mode 100644
index 000000000..43430071b
--- /dev/null
+++ b/tests/spec/glsl-1.10/execution/vs-loop-complex-with-else-break.shader_test
@@ -0,0 +1,57 @@
+# This tests a bug in the r300 compiler where it was too aggresive
+# with optimizations (copy propagation) of movs in loops.
+#
+# See: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6467
+[require]
+GLSL >= 1.10
+
+[vertex shader]
+uniform int loop_count;
+uniform int limit;
+
+void main()
+{
+  gl_Position = gl_Vertex;
+
+  vec4 colour = vec4(1.0, 1.0, 1.0, 1.0);
+  for (int i = 0; i < loop_count; i++) {
+
+     if (i > limit) {
+        colour = vec4(1.0, 0.0, 0.0, 1.0);
+     }
+
+     if (i <= limit) {
+        colour = vec4(0.0, 1.0, 0.0, 1.0);
+     } else {
+        break;
+     }
+  }
+
+  gl_FrontColor = colour;
+}
+
+[fragment shader]
+void main()
+{
+  gl_FragColor = gl_Color;
+}
+
+[test]
+clear color 0.5 0.5 0.5 0.5
+
+uniform int limit 1
+uniform int loop_count 3
+draw rect -1 -1 2 2
+probe all rgba 1.0 0.0 0.0 1.0
+
+uniform int loop_count 2
+draw rect -1 -1 2 2
+probe all rgba 0.0 1.0 0.0 1.0
+
+uniform int loop_count 1
+draw rect -1 -1 2 2
+probe all rgba 0.0 1.0 0.0 1.0
+
+uniform int loop_count 0
+draw rect -1 -1 2 2
+probe all rgba 1.0 1.0 1.0 1.0