From: Paul Koning <paulkoning@comcast.net>
To: jacob navia <jacob@jacob.remcomp.fr>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
jbeulich@suse.com, binutils@sourceware.org
Subject: Re: P.S. Follow up to my last post
Date: Fri, 25 Aug 2023 13:03:31 -0400 [thread overview]
Message-ID: <8C7981E4-01DE-4C70-92DB-6C711D95D710@comcast.net> (raw)
In-Reply-To: <502E2019-6C30-45ED-9EE4-A5ABAABBB750@jacob.remcomp.fr>
> On Aug 25, 2023, at 12:10 PM, jacob navia <jacob@jacob.remcomp.fr> wrote:
>
> OK.
> 1) We agree that the -march=rv64gc_zbb option is completely undocumented and impossible for the user to know.
> 2) We agree that « gnu gas » is an assembler whose duty is to assemble instructions. But « gas » will refuse to assemble those instructions.
> Why is that? It is the responsibility of the programmer or the compiler to write the instructions that are present in this or another machine.
> Why the assembler thinks it is necessary to forbid some instructions???
It's reasonable for the assembler to enforce ISA variations, based on what it's told in the -march switch. If so, then (a) gcc has to pass that switch, and (b) gcc can't add a variant that gas doesn't know about.
Is that the case here? Are you invoking the assembler manually or having it done for you by gcc? If the former, the -march switch is your responsibility; if the latter, then gcc is responsible for getting it right.
paul
next prev parent reply other threads:[~2023-08-25 17:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AEF14E89-14CF-4474-8822-B0139F3F740B@jacob.remcomp.fr>
2023-08-25 15:32 ` Palmer Dabbelt
2023-08-25 16:10 ` jacob navia
2023-08-25 17:03 ` Paul Koning [this message]
2023-08-25 19:44 ` jacob navia
2023-08-28 6:17 ` Jan Beulich
2023-08-28 7:04 ` jacob navia
2023-08-25 11:52 jacob navia
2023-08-25 12:00 ` Jan Beulich
2023-08-25 13:07 ` jacob navia
2023-08-25 13:30 ` Jan Beulich
2023-08-25 13:40 ` Paul Koning
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