freedreno,tu,ir3: Update SP_FS_PREFETCH,SP_FS_PREFETCH_CNTL regs and DCE ij_pix if possible
- Found that
GATHER4*
ops could be prefetched - tested that they work but haven't implemented them. Would requirenir_texop_tex_prefetch
to store which op to prefetch or to having severalnir_texop_*_prefetch
ops. Note: wasn't able to coerce blob to emit gather4 prefetch. -
SP_FS_PREFETCH_CNTL.IJ_WRITE_DISABLE
- prevents ij from being written allowing to DCE it. -
SP_FS_PREFETCH_CNTL.WRITE_COLOR_TO_OUTPUT
- prefetch would entirely bypass FS and write straight into output somehow. Looks like optimization, but blob doesn't use it. - Still a few mystery regs left.