3 ms·

Though... RISC-V support in gnu c and clang have evolved significantly over the last 5 years. Did you re-run any of the tests with more recent compilers? When

Though... RISC-V support in gnu c and clang have evolved significantly over the last 5 years. Did you re-run any of the tests with more recent compilers? When we were doing benchmarking 5 years ago, it seemed we got slightly better performance every month as Palmer integrated improvements into the gnu toolchain. There were at least a couple months there where we REALLY didn't want to publish benchmarks because we were expecting the numbers to be noticeably better in n days.

brucehoult 3y ago
This is very straightforward code (which I wrote in 2016 before I'd even heard of RISC-V) that maps very cleanly and obviously to instructions and any gcc from the last 20 years will make essentially the same code. A large part of my goal when I wrote it was to make it far more impervious to compiler "improvements" and gaming that Dhrystone and Coremark -- and I think I succeeded very well. The RISC-V B extension's `sh2add` and friends make a small difference -- that's basically the 2.7% gap between the VisionFive 2 and the HiFive Unmatched. If I disable Zba on the VF2 then the times are just about identical.