Skip the liveness lint dataflow when there is nothing to check [-0.05% avg] - #104
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Skip the liveness lint dataflow when there is nothing to check [-0.05% avg]#104xmakro wants to merge 1 commit into
xmakro wants to merge 1 commit into
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Bodies with no user-declared variables and no captures (compiler generated and trivial bodies) can never produce an unused-assignment lint, yet still paid for the full backward dataflow and a postorder scan.
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Bodies with no user-declared variables and no captures, which covers compiler generated and trivial bodies, can never produce an unused-assignment lint, yet still paid for the full backward dataflow and a postorder scan.
Measured alone at head 969b803 (clean from-scratch ThinLTO plus jemalloc stage2 build per side, instructions:u, Check/Debug/Opt across Full/IncrFull/IncrUnchanged/IncrPatched, 551 cells): -0.05% mean, 23 cells improved by at least 0.25%, none regressed. The win concentrates where such bodies dominate: tuple-stress -1.3% to -1.6% across all profiles.