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

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

> Since there aren't that many jump tables, the increase in code size is negligible.

For a point of reference on the codesize tests I ran, the increases from this patch are larger than the decreases from D59936 <https://reviews.llvm.org/D59936> (which was the last decent codesize change I saw). Codesize changes might seem small at times, but they often come small change at a time. Plus it depends how you measure them.

Also, many cpus don't really work the way you claim. Some don't even have branch predictors, or the time would not be dominated by the branch mispredict. With those it's more about the difference between jump table setup code and the equivalent series of branches.


Repository:
  rL LLVM

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

https://reviews.llvm.org/D60295