[flang-commits] [flang] [flang] Set low probability for array repacking code. (PR #144830)

[Slava Zakharin via flang-commits]

vzakhari wrote:

> Code changes look good. Have you seen improvements in benchmarks from this?
> 
> Do we need tests to guard that the attribute makes it to the branch after conversion through cf to llvm dialect?

I did not measure it yet, and I do not expect much.  This change is mostly for more convenient comparison of the perf profiles with and w/o repacking.  I will measure perf after merging this and will present a summary on one of the Flang meetings.

I guess such an end-to-end test is worhwile.  We only have individual steps being tested, e.g. in `test/Fir/cfg-conversion-if.fir` and tests like https://github.com/llvm/llvm-project/pull/144822

I will add a test before merging this.

https://github.com/llvm/llvm-project/pull/144830