Re: [PATCH] RISC-V: Update multilib-generator to handle V

[Kito Cheng <kito.cheng@gmail.com>]

Wait, take second round review:

> * All extensions were being prefixed with an underscore, which leads to
>   some odd combinations like "rv32gc_v", this just adds underscores to
>   the multi-letter extensions.
> * The input base ISAs were being canonicalized, which resulted in some
>   odd multilib default search paths.  I'm not sure if anything breaks
>   due to this, but it seems safer to just leave them alone.

>* All extensions were being prefixed with an underscore, which leads to
>  some odd combinations like "rv32gc_v", this just adds underscores to
>  the multi-letter extensions.

I think that weirdness can be removed arch-canonicalize I think?

And currently all -march will be canonicalized before query multi lib

> @@ -163,14 +168,13 @@ for cmodel in cmodels:
>      if cmodel == "compact" and arch.startswith("rv32"):
>        continue
>
> -    arch = arch_canonicalize (arch, args.misa_spec)
>      arches[arch] = 1
>      abis[abi] = 1
>      extra = list(filter(None, extra.split(',')))
>      ext_combs = expand_combination(ext)
>      alts = sum([[x] + [x + y for y in ext_combs] for x in [arch] + extra], [])
>      alts = filter(lambda x: len(x) != 0, alts)
> -    alts = list(map(lambda a : arch_canonicalize(a, args.misa_spec), alts))
> +    alts = alts + list(map(lambda a : arch_canonicalize(a, args.misa_spec), alts))

So we don't really need to append non-canonical one to the list?