This changes the pass to extract pinned instructions and not just unpinned
instructions when rescheduling instructions. This stops pinned instructions
from being bunched together when instructions are reinserted into the blocks
which can result in regressions with regards to cycles and instruction
counts on i965 and register use/Max Waves on AMD hardware.
In order to do this we also throw away the post-order depth-first
search linearization algorithm used to re-insert the instructions, which
itself causes possible regressions when instructions are reinserted into
a less than ideal new order (of which the bunched together pinned
instructions is one example). Instead we simply insert instructions in the
reverse order they were extracted. This will simply place instructions
that were scheduled earlier onto the end of their new block and
instructions that were scheduled later to the start of their new block.
With this everything should remain in order without the need to run
over uses.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/597>
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