[PATCH] D122558: [2/3] TLS loads optimization (hoist)

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm added a comment.

> If the option is going to be on and never turned off

It is not supposed to be "never turned off".
Generally speaking, hoisting the common TLS address call operation will big probably have performance gains.
But this will also lengthen register interval, possible cause more spills.
especially in case

                     BB1
                   /      \
                 BB2    BB3 (with 1 tls call or more tls calls but BB is cold)
  (with 1 tls call)  

And this patch only add about 15 lines to support the driver options. (Others are refining the llvm option and test)


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  https://reviews.llvm.org/D122558/new/

https://reviews.llvm.org/D122558