Wonderful talk. Summarising four main ideas on how hardware design impacts higher level languages - 1/ Branch misprediction 2/ Cache misses 3/ Slowness in denormal floating point ops 4/ False sharing among threads.
In the context of the optimistic branch predictions featured in 18:17, wouldn't the second set of prediction hits be a result of "7 > 6?" and not "7 < 6?"
4 роки тому
Sorry for the confusion, the X < Y simply states what is actually executed, not what is predicted. Since the condition is if(x < 6), it is 1 < 6, 2 < 6, 6 < 6, 7 < 6 etc. The next prediction is visualized at the bottom and the results (success/fail) of predictions are visualized using green/red color. I know, it's probably confusing, but I didn't think of a better way of how to visualize it :-)
I don't have a problem with the dark theme. What is wrong with it?
4 роки тому+3
I didn't know beforehand what will the lightning conditions look like and I think that the organizers recommended a dark background, but I may be wrong. It's hard to predict if light/dark background will be the better choice :-) Thanks.
Wonderful talk.
Summarising four main ideas on how hardware design impacts higher level languages -
1/ Branch misprediction
2/ Cache misses
3/ Slowness in denormal floating point ops
4/ False sharing among threads.
And this is why having some knowledge of Assembly is still relevant today regardless of the higher-level language one is accustomed to working with!!!
Great talk! I really liked that rusty crab sneaking around the corner xD
Really good talk with lots of tips on measuring CPU events.
Wow! I knew that data cache misses heavily affects performance, but did't expected that branch misses can affect performance so much :o
very informative and high quality talk. Thanks
Nice talk, learnt a lot.
13:34 vtune is free now!
Great talk for "software people" like me.
Are we sure that the branches in the sorting algorithme are well predicted?
In the context of the optimistic branch predictions featured in 18:17, wouldn't the second set of prediction hits be a result of "7 > 6?" and not "7 < 6?"
Sorry for the confusion, the X < Y simply states what is actually executed, not what is predicted. Since the condition is if(x < 6), it is 1 < 6, 2 < 6, 6 < 6, 7 < 6 etc. The next prediction is visualized at the bottom and the results (success/fail) of predictions are visualized using green/red color. I know, it's probably confusing, but I didn't think of a better way of how to visualize it :-)
9:00 Google Benchmark
Please use light UI theme for demonstrations! Wonderful presentation! Learnt tons.
I don't have a problem with the dark theme. What is wrong with it?
I didn't know beforehand what will the lightning conditions look like and I think that the organizers recommended a dark background, but I may be wrong. It's hard to predict if light/dark background will be the better choice :-) Thanks.