BeagleV – An affordable RISC-V computer designed to run Linux

Re:BeagleV – An affordable RISC-V computer designed to run L... by IshKebab on Wednesday January 13, 2021 @02:52PM (#25767119)

Yeah if you're willing to do something completely non-standard of course you can do whatever you want.

> Note that there are also vast differences in performance between different hardware implementations of multiply and divide, with 32-64 cycle latencies not unheard of.

Yes that is exactly the problem.

[ Parent | on HN ]

Re:BeagleV – An affordable RISC-V computer designed to run L... by brucehoult on Thursday January 14, 2021 @06:57PM (#25784890)

This problem exists even among different CPUs that all implement the M extension in hardware -- or different CPUs in ISAs where multiply and divide are not optional, such as x86 or aarch64.

The worst (but conforming) hardware implementations are barely better than the best software emulations -- and maybe worse if the software emulation is running on a wide OoO CPU.

[ Parent | on HN ]