3 ms·
> Not just different, inferior. Because they're not going to spend time working out by trial and error (it's possible based on timing and evaluating code) how
by berkut 13y ago
> Not just different, inferior.
Because they're not going to spend time working out by trial and error (it's possible based on timing and evaluating code) how many float ops / cycle each AMD chip can do. For their own chips they know the numbers themselves.
So they make an assumption for non Intel chips. Maybe they assume 2 when some AMD chips can do 4.
> ICC exists to sell Intel processors
And strangely enough, if you use ICC you'll generally be getting better code out the other end regardless of what chip you run it on compared to the other two major compilers.
- aidenn0 13y agoI don't know the current state of ICC, but previously it would ignore the instruction set the CPU claimed to support and not use a large fraction of SSE instructions on non Intel CPUs that supported it. Centaur did a study where they changed their CPU ID to pretend claim to be an Intel part and they got a significant performance boost when running code compiled with ICC.