Recognize backwards dependencies in GLSL loops

[libs/gl.git] / tests / glsl / unused_variable_removal_iteration.glsl

diff --git a/tests/glsl/unused_variable_removal_iteration.glsl b/tests/glsl/unused_variable_removal_iteration.glsl
new file mode 100644 (file)
index 0000000..fc1782b
--- /dev/null
+++ b/tests/glsl/unused_variable_removal_iteration.glsl
@@ -0,0 +1,77 @@
+uniform Params
+{
+       float start_height;
+       float max_height;
+       float min_height;
+       float step_size;
+};
+
+#pragma MSP stage(vertex)
+layout(location=0) in vec4 position;
+void main()
+{
+       gl_Position = position;
+       out vec3 dir = vec3(position.xy, 1.0);
+}
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec4 frag_color;
+void main()
+{
+       vec3 ndir = normalize(dir);
+       vec3 pos = vec3(0.0, 0.0, start_height);
+       float luminance = 0.0;
+       float extinction = 0.0;
+       while(true)
+       {
+               if(pos.z<min_height || pos.z>max_height)
+                       break;
+
+               float density = exp(pos.z/-1000.0);
+               luminance += density*exp(-extinction);
+
+               extinction += density*step_size;
+               pos += ndir*step_size;
+       }
+
+       frag_color = vec4(vec3(luminance), 1.0);
+}
+
+/* Expected output: vertex
+layout(location=0) in vec4 position;
+layout(location=0) out vec3 dir;
+void main()
+{
+       gl_Position = position;
+       dir = vec3(position.xy, 1.0);
+}
+*/
+
+/* Expected output: fragment
+layout(binding=80) uniform Params
+{
+       float start_height;
+       float max_height;
+       float min_height;
+       float step_size;
+};
+layout(location=0) out vec4 frag_color;
+layout(location=0) in vec3 dir;
+void main()
+{
+       vec3 ndir = normalize(dir);
+       vec3 pos = vec3(0.0, 0.0, start_height);
+       float luminance = 0.0;
+       float extinction = 0.0;
+       while(true)
+       {
+               if(pos.z<min_height || pos.z>max_height)
+                       break;
+               float density = exp(pos.z/-1000.0);
+               luminance += density*exp(-extinction);
+               extinction += density*step_size;
+               pos += ndir*step_size;
+       }
+       frag_color = vec4(vec3(luminance), 1.0);
+}
+*/