[PATCH] D26991: Hoist redundant load

[Sebastian Pop via Phabricator via cfe-commits]

sebpop added a comment.

In https://reviews.llvm.org/D26991#606764, @mclow.lists wrote:

> /me wonders what the perf difference when `_LIBCPP_UNROLL_LOOPS` is defined or  not.
>
> I think this (`_LIBCPP_UNROLL_LOOPS`) falls squarely into Chandler's request that we complain to him when the compiler generates sub-optimal code, instead of doing things like manually unrolling loops.


I think we should remove all the code in the ifdef: it looks to me like this code was left in from a previous "experiment", as it never gets executed unless one compiles the code with -D_LIBCPP_UNROLL_LOOPS, which seems wrong.  Let's push this cleanup in a separate commit.


https://reviews.llvm.org/D26991