brw_wm_iz.c sets the c->runtime_check_aads flag, which the old backend used to use, but the new one doesn't. I'm guessing this means we're missing some crazy workaround and broke Gen4.
Some stuff was done with this. Is this now fixed? Probably fixed by 6e61892aea542593875ebb8ae209af18bbad84bd.
The irony...I reported this in November 2012, forgot about it, and re-reported it in May 2014. But yes, Iago fixed this.
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