alt Hacker NewsBecause SIMT is not a general programming framework like CPUs are. It’s a technique for a dedicated accelerator for a specific kind of problem. SIMD on the other hand lets you get meaningful speed up inline with traditional code.
Because SIMT is not a general programming framework like CPUs are. It’s a technique for a dedicated accelerator for a specific kind of problem. SIMD on the other hand lets you get meaningful speed up inline with traditional code.
No no no! The programming model "meets you where you are" in exactly the way that an auto-vectorizer does. You write unconstrained single-threaded code, the compiler tries to make it parallel, and if it fails your code still works, just slowly. The difference is a few abstractions and social contract tweaks to make the auto-vectorizer reliable and easy to think about. These tweaks "smell like" hacks, but CPU folks have spent 20 years trying to do better and their auto-vectorizers are still failing at the basics so it's past time to copy what works and move on.