When the EU validator encountered an error, it would add an annotation
to the disassembly. Unfortunately, the code to insert an error assumed
that the next instruction would start at (offset + sizeof(brw_inst)),
which is not true if the instruction with an error is compacted.
This could lead to cascading disassembly errors, where we started trying
to decode the next instruction at the wrong offset, and getting lots of
scary looking output:
ERROR: Register Regioning patterns where [...]
(-f0.1.any16h) illegal(*** invalid execution size value 6 ) { align1 $7.src atomic };
(+f0.1.any16h) illegal.sat(*** invalid execution size value 6 ) { align1 $9.src AccWrEnable };
illegal(*** invalid execution size value 6 ) { align1 $11.src };
(+f0.1) illegal.sat(*** invalid execution size value 6 ) { align1 F@2 AccWrEnable };
(+f0.1) illegal.sat(*** invalid execution size value 6 ) { align1 F@2 AccWrEnable };
(+f0.1) illegal.sat(*** invalid execution size value 6 ) { align1 $15.src AccWrEnable };
illegal(*** invalid execution size value 6 ) { align1 $15.src };
(+f0.1) illegal.sat.g.f0.1(*** invalid execution size value 6 ) { align1 $13.src AccWrEnable };
Only the first instruction was actually wrong - the rest are just a
result of starting the disassembler at the wrong offset. Trash ensues!
To fix this, just pass the instruction size in a few layers so we can
record the next offset properly.
Cc: mesa-stable
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17624>
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