[PATCH] D34458: [TTI] Refine the cost of EXT in getUserCost()

[Haicheng Wu via Phabricator via llvm-commits]

haicheng added a comment.

In https://reviews.llvm.org/D34458#818835, @delena wrote:

> I dug into the performance degradation and found that isExtLoad() reduces cost of a loop, as a result the loop is being unrolled. Unrolling this loop causes performance degradation.
>  But the load + zext cost is correct and it is 1 Op. I'll work more with our architects in order to understand what parameter is incorrect on X86.


Thank you very much for clearing things up.  Please let me know if you want anything from me.

Haicheng


Repository:
  rL LLVM

https://reviews.llvm.org/D34458