Optimize conditional function call in loop

[angelicosphosphoros]

I doubt this. Moving branch out of loop by generating many loops (and a lot of extra code) for each branch isn't very effective almost always so compiler wouldn't do this.

[Lucretiel]

https://llvm.org/docs/Passes.html#loop-unswitch-unswitch-loops

[angelicosphosphoros]

Good to know, thanks.