[PATCH] D24451: [LoopUnroller] Replace UnrollingPreferences::Force with ForceMaxCount + SystemZ getUnrollingPreferences().

[Evgeny Stupachenko via llvm-commits]

evstupac added a comment.

> Having worked with this patch for a while, it has become clear that the *exact number of iterations* produced needs to be controlled. The resulting loop should have no more than 12 stores, and it seems bad to have more than 3 exit branches w/ forced unrolling.


Is this true for other unroll candidates (Partial, Runtime)? I'm trying to understand what is so specific about Force unroll.
If You need to control number of stores/branches you can limit MaxCount for all kinds of unroll. Or even better - calculate specific count for your architecture based on number of stores/branches.


https://reviews.llvm.org/D24451