Re: Fixing MIPS delay slot emulation weakness?

From: Rich Felker
Date: Sun Dec 16 2018 - 13:11:53 EST

On Sat, Dec 15, 2018 at 09:26:45PM +0000, Paul Burton wrote:
> > The really nice but less compatible fix would be to let processes or
> > even the whole system opt out by promising not to put anything in FPU
> > branch delay slots, of course.
> The ultimate fix comes with a switch to the nanoMIPS ISA which has no
> delay slots :)

I don't understand the MIPS position that introducing new ISAs
(including silently-new like r6) and not supporting or deprecating
support for the old one is a solution to anything. If one doesn't care
about the ability to run existing binaries for your platform, one
might as well switch to RISC-V or ARM or whatever. The whole advantage
of an ISA as a "platform" is the ability to run existing software and
use existing tooling (not just compilers; think also JITs, FFI
frameworks, etc), not any particular design advantage the ISA has.