[PATCH] D39976: [AArch64] Consider the cost model when folding loads and stores

[Sirish Pande via Phabricator via llvm-commits]

SirishP added a comment.

In https://reviews.llvm.org/D39976#924618, @mcrosier wrote:

> The load/store opt pass is already pretty expensive in terms of compile-time.  Did you see any compile-time regressions in your testing?  Also, what performance results have you collected?


Cost model check is done at the very end when we are merging instructions, after most of the other checks are already done. Having said that, yes compile time regression test is a good idea. As for the performance, A72 and A57 both have higher latency with decoder bubble on load with pre-post update. That is definitely going to benefit where we look at cost model and decide not to create LD update. If we were to leave LD/ADD in epilogue and this pass not create LD update instruction, that's benefit as well.


Repository:
  rL LLVM

https://reviews.llvm.org/D39976