[PATCH] D30728: CodeGen: Placement: Apply triangle heuristic more aggressively at O3.

Wed Mar 15 15:58:07 PDT 2017

echristo added a comment.

In https://reviews.llvm.org/D30728#702250, @iteratee wrote:

> In https://reviews.llvm.org/D30728#701847, @davidxl wrote:
>
> > Should the mips problem be fixed? I don't see a fundamental reason this needs to be opt level specific.
>
>
> We looked into the mips issue. It is only a problem on mips2 and mips3, which are now 25 years old. The lowering for those targets could be better, but I'll file a bug and let it be.
>
> The issue also goes away with branch coalescing if the mips branch targets are correctly marked as not clobbering the AT register.

Agreed, I'd very much like to file a bug and punt here. I don't think it's worth the yak shave of fixing the mips port to avoid treating all conditional branches as macro instructions and the branch coalescing patch will be turned on by default soon.

Repository:
  rL LLVM

https://reviews.llvm.org/D30728