Re: [PATCH 1/2] gdb: introduce command "info architecture"

Maciej W. Rozycki
2025-11-08T02:26:23Z

On Fri, 7 Nov 2025, Guinevere Larsen wrote:

> > Thanks. The documentation parts are okay (with one nit, see below),
> > but I'm struggling to understand what you mean by "CPU
> > microarchitectures". And without examples, I cannot even guess.
> > Would it be possible to expand on that in the manual, or at least
> > provide a could of examples of what the output will look like?
>
> A CPU architecture is something like "arm" or "x86". The microarchitecture is
> changes within that architecture, like "armv3", "armv4", "armv3m" and so on.

I don't think it's correct, not at least it's the definition I've been
taught. In my dictionary microarchitecture is a particular implementation
of a given architecture with all its properties, such as instruction
latencies, the execution units and pipeline stages, the existence or the
lack of specific pipeline dependencies, and so on and so on.

I can't comment on ARM particulars as I'm not very familiar with them,
but offhand "armv3" or "armv4" seem to me to be architecture revisions
rather than microarchitectures.

In MIPS terms MIPS is the target architecture, MIPS32r2 is a particular
architecture revision ("mips:isa32r2" in terms of `set architecture') and
24Kf or 74Kf are microarchitectures, both implementing the MIPS32r2
architecture.

Cf. <https://en.wikipedia.org/wiki/Microarchitecture> for an overview.

I think the GDB manual has been pretty correct in its "architecture" term
usage.

Maciej