Illuminating the processor core with LLVM-mca(abseil.io)
64 points by ckennelly 1 day ago | 5 comments
- KeplerBoy 1 day agoAlso nicely demonstrated in godbolt's currently ongoing Advent of compiler optimizations series.
- fweimer 1 day agoWouldn't LLVM adjust the models if it is beneficial to its code generation, even if the result less accurately reflects the processor? (I think GCC does that.)
- alain94040 1 day agoThis is interesting if quite incomplete (as noted in the end conclusion). CPU re-order buffers turn what you think as mostly sequential execution into a massively parallel engine. Data memory access, perfecting, speculative execution, etc. But if you are running a micro-bencmark with a tight loop of millions of iterations, then understanding the pipeline dependencies and dispatching can provide good insights.[-]
- drob518 1 day agoYep. Cache is always the wildcard.
- esbranson 1 day agoToo bad they don't support LC-3 or DLX. More my level lol. So begins another deep dive side quest with the chatbot into a tool I didn't even know existed.