My source is that Google spent a bunch of engineer time to write, test, and tweak complicated outlining passes for LLVM to get broad 1% performance gains in C++ software, and everybody hailed it as a masterstroke when it shipped. Was that performance art? 1% of C++ developers drowning out the apparent 99% of ones that didn’t (or shouldn’t) care?

I never said there was no place for taking a 2x performance hit for C or C++ code. I think Fil-C is a really interesting direction and definitely well executed. I just don’t see how you can claim that C++ code that can’t take a 2x performance hit is some bizarre, 1% edge case for C++.