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Thanks a lot. Now, this section became clear to me. It also became clear why there is a two prefetch tiles, not just one.

beannaich wrote:Of these 34 fetches, only 33 are ever actually used in rendering

Why 33? (in line 32 tiles)

I'm just starting out, trying to understand.
Are you sure that the cycle (NT-> AT-> LBG-> HBG) should continue to tick 256 (32 cycles), and not to 240 (30 cycles)?
Indeed, in the previous line had been done two cycles.