[PATCH] D25291: [AArch64] Optionally use the reciprocal estimation machinery

Evandro Menezes via llvm-commits llvm-commits at lists.llvm.org
Fri Oct 7 08:26:19 PDT 2016


evandro added a comment.

In https://reviews.llvm.org/D25291#564529, @evandro wrote:

> In https://reviews.llvm.org/D25291#564496, @jmolloy wrote:
>
> > If you want to just enable reciprocal selection and test it, then a cl::opt flag seems most appropriate because that's how we enable experimental stuff broad-brush for testing. A CPU feature really isn't right as it ignores the important context that should go into deciding whether to use these instructions (on ARM/AArch64).
>
>
> Adding an option is a good idea to provide a means for users to tap into this feature.


Of course, one can always use `-mattr=+use-reciprocal-square-root`.

Thank you.


Repository:
  rL LLVM

https://reviews.llvm.org/D25291





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