[PATCH] D81924: [PowerPC] Allow constrained FP intrinsics in mightUseCTR

[Qing Shan Zhang via Phabricator via llvm-commits]

steven.zhang added a comment.

In D81924#2225652 <https://reviews.llvm.org/D81924#2225652>, @qiucf wrote:

> In D81924#2189996 <https://reviews.llvm.org/D81924#2189996>, @steven.zhang wrote:
>
>> Can you add checker for the bdnz ?
>
> We don't think any loop containing calls is profitable to transform:

I think the comments is out of date. This is the full context and we will check if we are using CTR for some calls as what you did now.

  // We don't want to spill/restore the counter register, and so we don't
  // want to use the counter register if the loop contains calls.
  SmallPtrSet<const Value *, 4> Visited;
  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
       I != IE; ++I)
    if (mightUseCTR(*I, LibInfo, Visited))
      return false;

>   // We don't want to spill/restore the counter register, and so we don't
>   // want to use the counter register if the loop contains calls.
>
> And it seems PPC won't set hardware loops info properly if it's not profitable. So when forcing it to use hardware loops, it would crash.




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