[llvm] [AArch64] Change the cost of fma and fmuladd to match fmul. (PR #152963)

[Sjoerd Meijer via llvm-commits]

https://github.com/sjoerdmeijer approved this pull request.

> this is mostly to try and help out https://github.com/llvm/llvm-project/pull/149102 to make sure it doesn't make silly decisions because the default cost of a fma/fmuladd is lower than a fmul.

Okay, thanks. Yes, I was wondering about the motivation for this, but makes sense. I assume you've checked for potential fall out for this and ran some performance numbers, so LGTM.

https://github.com/llvm/llvm-project/pull/152963