From: Mark Rutland > Sent: 31 July 2020 19:32 ... > > It requires PC-relative data references. I have not worked on all architectures. > > So, I need to study this. But do all ISAs support PC-relative data references? > > Not all do, but pretty much any recent ISA will as it's a practical > necessity for fast position-independent code. i386 has neither PC-relative addressing nor moves from %pc. The cpu architecture knows that the sequence: call 1f 1: pop %reg is used to get the %pc value so is treated specially so that it doesn't 'trash' the return stack. So PIC code isn't too bad, but you have to use the correct sequence. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
