[PATCH] D95136: [X86] Fix tile config register spill issue.

Sat Jan 30 01:02:12 PST 2021

xiangzhangllvm added inline comments.

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Comment at: llvm/lib/Target/X86/X86PreTileConfig.cpp:229
+
+struct ReloadTileConfig {
+  enum SuccStatus { NoAMXAtAll = 0, HasAfterCallAMX, HasBeforeCallAMX };
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pengfei wrote:
> xiangzhangllvm wrote:
> > pengfei wrote:
> > > xiangzhangllvm wrote:
> > > > LGTM for the logic.
> > > Thanks for the review.
> > Not try to replace this patch, I update the O(N) algorithm in https://reviews.llvm.org/D95508 just for interest.
> > In Non-loop case, it cost O(N), in loop case, it cost O(2N)
> So it is related on the number of loops? But in the worst case, a graph may have O(N!) loops? The worst complexity is terrible.
So it is not related on the number of loops, in loop case the max cost is O(2N), (we see O(2N) == O(N) in program)

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95136/new/

https://reviews.llvm.org/D95136