[Piglit] [PATCH] glsl-1.10: test for crash in loop analysis

[Andres Gomez]

This is:

Reviewed-by: Andres Gomez <agomez at igalia.com>

On Tue, 2019-03-19 at 14:29 +1100, Timothy Arceri wrote:
> This test for a crash in Mesa seen in an Assasins Creed Odyssey shader.
> ---
>  ...riable-iteration-limit-unroll4.shader_test | 88 +++++++++++++++++++
>  1 file changed, 88 insertions(+)
>  create mode 100644 tests/spec/glsl-1.10/execution/vs-loop-variable-iteration-limit-unroll4.shader_test
> 
> diff --git a/tests/spec/glsl-1.10/execution/vs-loop-variable-iteration-limit-unroll4.shader_test b/tests/spec/glsl-1.10/execution/vs-loop-variable-iteration-limit-unroll4.shader_test
> new file mode 100644
> index 000000000..38fdda4ca
> --- /dev/null
> +++ b/tests/spec/glsl-1.10/execution/vs-loop-variable-iteration-limit-unroll4.shader_test
> @@ -0,0 +1,88 @@
> +# This tests unrolling of a loop with a single exit point but where the
> +# exact trip count is unknown, only the max iteration count (4) is known.
> +#
> +# Here we test all possible outcomes for the loop and also add some
> +# unreachable code to make sure it is not accessible after unrolling.
> +[require]
> +GLSL >= 1.10
> +
> +[vertex shader]
> +uniform int loop_count;
> +uniform int loop_count2;
> +
> +void main()
> +{
> +  gl_Position = gl_Vertex;
> +
> +  vec4 colour = vec4(1.0, 1.0, 1.0, 1.0);
> +
> +  int i = 0;
> +  int j = 0;
> +  int x = 0;
> +
> +  /* Here we add a second && and put the known limit i < 4 in parentheses in
> +   * order to trigger a Mesa bug seen in a Assasins Creed Odyssey shader
> +   */
> +  while (x < loop_count && (i < 4 && j < loop_count2)) {
> +    if (x == 0 && i == 0)
> +      colour = vec4(0.0, 0.25, 0.0, 1.0);
> +
> +    if (x == 2 && i == 1 && j == 4)
> +      colour = vec4(0.0, 0.5, 0.0, 1.0);
> +
> +    if (x == 4 && i == 2 && j == 8)
> +      colour = vec4(0.0, 0.75, 0.0, 1.0);
> +
> +    if (x == 6 && i == 3 && j == 12)
> +      colour = vec4(0.0, 1.0, 0.0, 1.0);
> +
> +    /* This should be unreachable */
> +    if (x >= 8 || i >= 4)
> +      colour = vec4(1.0, 0.0, 0.0, 1.0);
> +
> +    i++;
> +    x+=2;
> +    j+=4;
> +  }
> +
> +  gl_FrontColor = colour;
> +}
> +
> +[fragment shader]
> +void main()
> +{
> +  gl_FragColor = gl_Color;
> +}
> +
> +[test]
> +clear color 0.5 0.5 0.5 0.5
> +
> +uniform int loop_count 0
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 1.0 1.0 1.0 1.0
> +
> +uniform int loop_count 2
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 0.0 0.25 0.0 1.0
> +
> +uniform int loop_count 4
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 0.0 0.5 0.0 1.0
> +
> +uniform int loop_count 6
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 0.0 0.75 0.0 1.0
> +
> +uniform int loop_count 8
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 0.0 1.0 0.0 1.0
> +
> +uniform int loop_count 10
> +uniform int loop_count2 16
> +draw rect -1 -1 2 2
> +probe all rgba 0.0 1.0 0.0 1.0
-- 
Br,

Andres