At least in these benchmarks that phoronix run time-to-time, (so they at least can be compared to their older self) LLVM, in its Clang incarnation, is finally getting some parity in execution times with GCC

https://www.phoronix.com/scan.php?page=article&item=gcc-clan...

Of course, benchmarks, yada yada, but at least is some sort of comparison axis where the improvement over the years is clear.