glsl: Fix chained assignments of vector channels.
Simple shaders such as: void splat(vec2 v, float f) { v[0] = v[1] = f; } failed to compile with the following error: error: value of type vec2 cannot be assigned to variable of type float First, we would process v[1] = f, and transform: LHS: (expression float vector_extract (var_ref v) (constant int (1))) RHS: (var_ref f) into: LHS: (var_ref v) RHS: (expression vec2 vector_insert (var_ref v) (constant int (1)) (var_ref f)) Note that the LHS type is now vec2, not a float. This is surprising, but not the real problem. After emitting assignments, this ultimately becomes: (declare (temporary) vec2 assignment_tmp) (assign (xy) (var_ref assignment_tmp) (expression vec2 vector_insert (var_ref v) (constant int (1)) (var_ref f))) (assign (xy) (var_ref v) (var_ref assignment_tmp)) We would then return (var_ref assignment_tmp) as the rvalue, which has the wrong type---it should be float, but is instead a vec2. To fix this, we simply return (vector_extract (var_ref assignment_temp) <the appropriate channel>) to pull out the desired float value. Fixes Piglit's chained-assignment-with-vector-constant-index.vert and chained-assignment-with-vector-dynamic-index.vert tests. Cc: mesa-stable@lists.freedesktop.org Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74026 Reported-by:Dan Ginsburg <dang@valvesoftware.com> Reviewed-by:
Ian Romanick <ian.d.romanick@intel.com> Reviewed-by:
Matt Turner <mattst88@gmail.com> Signed-off-by:
Kenneth Graunke <kenneth@whitecape.org>
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