“Feanor” adds a comment to Slava’s Mach-O ABI post: Case in point: the _msgSend routine of ObjC is in /usr/lib/libobjc so every message sent in any piece of ObjC code has that 11 cycle penalty tacked onto the beginning, and then it gets the 9 cycle PIC penalty once you actually get there… every object … Continue reading More Mach-O and GCC Slowness