[PATCH] D154579: [InstCombine] Only perform one iteration

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added a comment.

re:

> All instructions are initially pushed to the worklist. The initial order is (roughly) in program order / RPO.
> All newly inserted instructions get added to the worklist.
> When an instruction is folded, its users get added back to the worklist.
> When the use-count of an instruction decreases, it gets added back to the worklist.
> ...plus a bunch of other heuristics on when we should revisit instructions.

What does it look like if instead of decreasing iteration count, we change re-insertion
logic based on iteration?
I.e:
iteration 1 -> do everything
iteration 2+ -> only re-add newly created insn or insn that are now single-use.


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https://reviews.llvm.org/D154579