Three facts: 1: clang was significantly worse when Apple removed GCC support, 2: clang is still significantly worse than GCC, and 3: it's because of Google's investment, not Apple's, that we can think of clang as a "in the same stadium" competitor to GCC that makes Apple's removal of GCC surprising.
Any pair of these wouldn't be surprising. Apple is investing in an unproven technology, ok fine. But the congruence of these three facts is surprising. Apple is investing in a worse technology and also relies entirely on Google to improve that technology for them. Blows my mind.
The compile times are much longer and the generated code is usually slower except for autovectorized code.
I've spent a lot of time testing both clang and gcc, and right now the only part of clang I use regularly is the static analyzer in my continuous integration.
For C++ in particular, the compile times are 2-3 times as long. It's unbelievable how slow it is.
Anecdote from someone who's not the parent: I have had issues with C++ compile times in Mac OS X for a long time. GCC compiles many things in almost half the time.
Any pair of these wouldn't be surprising. Apple is investing in an unproven technology, ok fine. But the congruence of these three facts is surprising. Apple is investing in a worse technology and also relies entirely on Google to improve that technology for them. Blows my mind.