Re: VAX: Another small GAS bug?

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

Hi,

On 2024/04/07 1:16, Jan-Benedict Glaw wrote:
> What the heck?! The original output (full unimpl_emul.S) was
> different, but the critical excerpt is no longer? That'll be "fun" to
> debug. Unfortunately, paid work is demanding right now, that might
> take a while for me to really work on...

Yeah, I assembled unimpl_emul.S on NetBSD/amd64 and aarch64{,eb}
hosts, and obtained different values in immediate fields of the
instructions.

There should be bugs in gas logic handling floating-point immediates.

Note also:

- MALLOC_CONF="junk:true" (for NetBSD jemalloc) does not affect
  the results.

- This is not a recent regression; objdump for GENERIC kernel of
  NetBSD/vax 5.0 has the same bit pattern as NetBSD 10.0 in the insns.

It would be nice if we can fix gas, but cannot we replace $0f0.0 with
$0x0 for now? According to "Vax Architecture Handbook", a floating-
point number is recognized as 0.0 if sign and exponent fields are zero,
and CPU always generates 0x0 for 0.0.

Thanks,
rin