> LLVM is also slow in general. Agreed. But so is GCC. And I guess many of the 'zero cost' abstractions require some advanced optimizing compiler like LLVM to

> LLVM is also slow in general. Agreed. But so is GCC. And I guess many of the 'zero cost' abstractions require some advanced optimizing compiler like LLVM to be zero cost (or move that complexity to compiler end). They specifically mentioned the technical debt and poor LLVM IR Generation issue though. I wonder if it has yet gotten attention or fixed. Maybe @pcwalton knows.