[PATCH] D60295: [SelectionDAG] Change the jump table size unit from entry to target

[Hans Wennborg via Phabricator via llvm-commits]

hans added a comment.

> This patch changes the semantics of the options min-jump-table-entries and max-jump-table-size to use the number of different targets instead of the number of entries in a jump table. Thus, the are now renamed to min-jump-table-cases and max-jump-table-cases, respectively.

Hmm, I'll have to think about this one.

I'm not sure it makes sense to change -min-jump-table-entries. I think that one is really supposed to decide when a jump table is better than separate branches, and I'm not sure it should change because of this.

-max-jump-table-size was introduced exactly for this purpose (limiting the load on the branch predictor), so making that based on the number of targets sounds reasonable (I'd suggest calling it max-jump-table-targets instead of -cases though).

I also don't see exactly how the semantics of max-jump-table-size are changed with this patch? What am I missing? Can you upload it again with more context maybe?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D60295/new/

https://reviews.llvm.org/D60295