From: Nelson Chu <nelson@rivosinc.com>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Jan Beulich <jbeulich@suse.com>,
Binutils <binutils@sourceware.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Andrew Waterman <andrew@sifive.com>,
Jim Wilson <jim.wilson.gcc@gmail.com>,
Kito Cheng <kito.cheng@sifive.com>
Subject: Re: [PATCH] RISC-V: don't disassemble unrecognized insns as .byte
Date: Tue, 31 Jan 2023 09:51:04 +0800 [thread overview]
Message-ID: <CAPpQWtB=MvYLUJpx34XUfPzFqD6dPJ-pFs_TuiLDFGEj0Fgmog@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.21.2301300314540.55843@angie.orcam.me.uk>
On Mon, Jan 30, 2023 at 11:33 AM Maciej W. Rozycki <macro@orcam.me.uk> wrote:
>
> Hi Nelson,
>
> > 0000000000000000 <.text>:
> > 0: 0001 .short 0x0001
> > 2: 0001 .2byte 0x1
> > 4: 0001 .short 0x0001
> > ...
> >
> > The .<N>byte in assembly will also be treated as data to dump, so
> > ideally, dump these unrecognized instructions as .insn is probably
> > more reasonable and won't be confused.
>
> I wasn't aware about the RISC-V `.insn' pseudo-op. I think it will make
> a lot of sense to use it here then, so I'd be happier with either:
>
> 2: 0001 .insn 0x0001
>
> or:
>
> 2: 0001 .insn 0x2, 0x1
>
> and analogously for unrecognised instructions comprised of a higher number
> of parcels according to the opcode allocation, e.g.:
>
> Disassembly of section .text:
> 0000000000000000 <foo> .insn 0x00000000001f
>
> or:
>
> Disassembly of section .text:
> 0000000000000000 <foo> .insn 0x6, 0x1f
>
> (here in the `--prefix-addresses' format). The single-argument format may
> by clearer to the casual eye at the cost of extra leading zeros with some
> encodings.
Yeah, dump these unrecognized instructions into the .insn directives
with the <bytes> field looks better. Thanks for pointing this out :-)
Nelson
next prev parent reply other threads:[~2023-01-31 1:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 13:14 Jan Beulich
2023-01-30 1:40 ` Nelson Chu
2023-01-30 1:51 ` Maciej W. Rozycki
2023-01-30 3:03 ` Nelson Chu
2023-01-30 3:33 ` Maciej W. Rozycki
2023-01-31 1:51 ` Nelson Chu [this message]
2023-01-30 2:07 ` Kito Cheng
2023-01-30 7:51 ` Jan Beulich
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