On 19 May 2012 13:05, Jose Fonseca <<a href="mailto:jfonseca@vmware.com" target="_blank">jfonseca@vmware.com</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Good find and nice test IMO. Jose </blockquote><div> Thanks, Jose. Can I consider that a "reviewed-by"? </div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <div><div class="h5"> ----- Original Message ----- > As of 5/19/12, Mesa's constant propagation optimization pass fails to > properly account for the behaviour of array indexing applied to > vectors. If v is a vector and i is an integer, it assumes that > > v[i] = ...; > > kills the x component of v. This is not necessarily the case--it > might kill any component of v, depending on the value of i. > --- > ...-vector-indexing-kills-all-channels.shader_test | 39 > +++++++++++++++++++ > ...-vector-indexing-kills-all-channels.shader_test | 41 > ++++++++++++++++++++ > 2 files changed, 80 insertions(+), 0 deletions(-) > create mode 100644 > tests/spec/glsl-1.10/execution/fs-vector-indexing-kills-all-channels.shader_test > create mode 100644 > tests/spec/glsl-1.10/execution/vs-vector-indexing-kills-all-channels.shader_test > > diff --git > a/tests/spec/glsl-1.10/execution/fs-vector-indexing-kills-all-channels.shader_test > b/tests/spec/glsl-1.10/execution/fs-vector-indexing-kills-all-channels.shader_test > new file mode 100644 > index 0000000..b22405a > --- /dev/null > +++ > b/tests/spec/glsl-1.10/execution/fs-vector-indexing-kills-all-channels.shader_test > @@ -0,0 +1,39 @@ > +# This test exercises a bug in mesa as of 5/19.12: constant > +# propagation fails to detect that array indexing into a vector > might > +# kill any component of the vector. > + > +[vertex shader] > +void main() > +{ > + gl_Position = gl_Vertex; > +} > + > +[fragment shader] > +#define RED vec4(1.0, 0.0, 0.0, 0.0) > +#define GREEN vec4(0.0, 1.0, 0.0, 0.0) > + > +uniform int three; > +uniform float five; > + > +void main() > +{ > + vec4 v = vec4(1.0, 2.0, 3.0, 4.0); > + > + // If the bug is present, constant propagation will see a scalar > on > + // the RHS, and incorrectly conclude that therefore only v.x is > + // killed. > + v[three] = five; > + > + vec4 color = v.a == 5.0 ? GREEN : RED; > + > + // If the bug is present, then index and new_value will be > optimized > + // away, making shader_runner fail to assign uniforms. To avoid > + // that, multiply color by (five - three - 1.0). > + gl_FragColor = color * (five - float(three) - 1.0); > +} > + > +[test] > +uniform int three 3 > +uniform float five 5.0 > +draw rect -1 -1 2 2 > +probe all rgba 0.0 1.0 0.0 0.0 > diff --git > a/tests/spec/glsl-1.10/execution/vs-vector-indexing-kills-all-channels.shader_test > b/tests/spec/glsl-1.10/execution/vs-vector-indexing-kills-all-channels.shader_test > new file mode 100644 > index 0000000..6838f78 > --- /dev/null > +++ > b/tests/spec/glsl-1.10/execution/vs-vector-indexing-kills-all-channels.shader_test > @@ -0,0 +1,41 @@ > +# This test exercises a bug in mesa as of 5/19/12: constant > +# propagation fails to detect that array indexing into a vector > might > +# kill any component of the vector. > + > +[vertex shader] > +#define RED vec4(1.0, 0.0, 0.0, 0.0) > +#define GREEN vec4(0.0, 1.0, 0.0, 0.0) > + > +uniform int three; > +uniform float five; > + > +void main() > +{ > + gl_Position = gl_Vertex; > + > + vec4 v = vec4(1.0, 2.0, 3.0, 4.0); > + > + // If the bug is present, constant propagation will see a scalar > on > + // the RHS, and incorrectly conclude that therefore only v.x is > + // killed. > + v[three] = five; > + > + vec4 color = v.a == 5.0 ? GREEN : RED; > + > + // If the bug is present, then index and new_value will be > optimized > + // away, making shader_runner fail to assign uniforms. To avoid > + // that, multiply color by (five - three - 1.0). > + gl_FrontColor = color * (five - float(three) - 1.0); > +} > + > +[fragment shader] > +void main() > +{ > + gl_FragColor = gl_Color; > +} > + > +[test] > +uniform int three 3 > +uniform float five 5.0 > +draw rect -1 -1 2 2 > +probe all rgba 0.0 1.0 0.0 0.0 > -- > 1.7.7.6 > </div></div>> _______________________________________________ > Piglit mailing list > <a href="mailto:Piglit@lists.freedesktop.org">Piglit@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/piglit" target="_blank">http://lists.freedesktop.org/mailman/listinfo/piglit</a> > </blockquote></div>