[PATCH] D140100: [SLP]Integrate looking through shuffles logic into ShuffleInstructionBuilder.

Wed Jan 4 07:52:02 PST 2023

alexfh added a comment.

In D140100#4024152 <https://reviews.llvm.org/D140100#4024152>, @ABataev wrote:

> In D140100#4024147 <https://reviews.llvm.org/D140100#4024147>, @alexfh wrote:
>
>> In D140100#4018269 <https://reviews.llvm.org/D140100#4018269>, @asmok-g wrote:
>>
>>> Heads-up: This has caused a change in behavior when using `#pragma unroll` in some test using SIMD. In other words, using `#pragma unroll` results in a different output than without it. I'm preparing a reduced test case.
>>
>> I've got a reduced IR file for that case: F26088275: q.ll <https://reviews.llvm.org/F26088275>
>>
>>   $ old-clang -O2 q.ll && ./a.out
>>   0.0
>>   $ new-clang -O2 q.ll && ./a.out
>>   5.0
>>
>> Please fix or revert the patch, if there's no trivial fix.
>>
>> Thanks!
>
> Thanks for the reproducer, will investigate it.

Alexey, could you revert the commit in the meantime?

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140100/new/

https://reviews.llvm.org/D140100