JIT: Don't run fgComputeBlockWeights in MinOpts
#110451
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cc @dotnet/jit-contrib, @AndyAyersMS PTAL. Small MinOpts diffs from what looks like different block placement: This seems to stem from some blocks (not) being marked as rarely-run now, leading |
AndyAyersMS
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Dec 6, 2024
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Block weights don't seem particularly useful in MinOpts. Skipping
fgComputeBlockWeightswhen we aren't optimizing had few diffs locally, so this looks like an opportunity to save some TP.(As an aside, I suspect we can soon replace
fgComputeBlockWeightsandoptSetBlockWeightswith profile synthesis. After the existing flow opt and unreachable block removal passes, I think we ought to compute the loop data structures, run profile synthesis, and then run loop opts. Since earlier phases don't seem too dependent on profile fidelity, but loop inversion/cloning/etc. stand to benefit from it, this is a natural checkpoint for running synthesis.)