freedreno/ir3: Drop the max_const on a6xx to 512.
The GLES blob on the p3a limits constlen to 512 between VS and FS across a6xx gpu ids (615, 630, 640, and 650). Experimentally, exceeding that limit in any one stage results in rendering corruption or GPU hangs (though my most detailed testing had a loop limit in a uniform, so that may the cause of the hang). Clamp the limit we use inside of a shader so we don't exceed it within a stage. This commit doesn't resovle limiting inter-stage. Experimentally, I've found that I can push up to a total of ~768 vec4s between VS and FS on a630, with or without uniform updates between each draw. We'll need to do some shader key-based limiting of constlen at draw time to respect that limit, but that's left for future work, and this commit is enough for the google earth case that initiated this work. Part-of: <!5273>
Showing with 4 additions and 1 deletion