4 ms·
Thank you very much. He does say he's reporting the minimum latency; I was thinking that no case would be faster than reading from L1 cache, but it makes sense
by mjw1007 9y ago
Thank you very much.
He does say he's reporting the minimum latency; I was thinking that no case would be faster than reading from L1 cache, but it makes sense that store-forwarding can be faster.
- BeeOnRope 9y agoRight, but store forwarding is definitely not 2 cycles. 4 and 5 cycles is common for store forwarding although other values are possible. So I think Agner measured 4 cycles and divided it as 2 for the load and 2 for the store. For pure loads the latency is easy to measure and often widely reported and it's 4 cycles minimum for Intel.