[PATCH] D28491: [AArch64] Add new subtarget feature to fuse AES crypto operations

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

In https://reviews.llvm.org/D28491#643256, @evandro wrote:

> The `MacroFusion` pass is currently being added before the RA runs.  However, since the `AArch64ExpandPseudo` pass is run after the RA (in `AArch64PassConfig::addPreSched2()`), I wonder if it'd make more sense to run the `MISched` after the RA as well, and not before as it is now.  Thoughts?


There are a number benefits for running the scheduler before register allocation (reducing register pressure only makes sense before RA). We already have the PostMachineScheduler for scheduling again after regalloc (it's based on the same MISched framework but added considerably later in the pipeline; see also TargetSubtargetInfo::enablePostRAScheduler()).


Repository:
  rL LLVM

https://reviews.llvm.org/D28491