Re: [PATCH v2 2/3] x86/cpu/intel: Simplify F00F bug notice using pr_notice_once()

From: David Laight

Date: Mon Jun 01 2026 - 17:45:44 EST


On Mon, 01 Jun 2026 07:43:32 -0700
"H. Peter Anvin" <hpa@xxxxxxxxx> wrote:

> On May 27, 2026 9:14:10 AM PDT, "Maciej W. Rozycki" <macro@xxxxxxxxxxx> wrote:
> >On Wed, 27 May 2026, H. Peter Anvin wrote:
> >
> >> >> If full precision is enabled there are a whole lot of horrid corner cases.
> >> >> Mostly due to correctly generating the FP signals when the 80bit return
> >> >> value from a function is written to a 64bit 'double'.
> >> >
> >> > No IEEE quad for `long double' still, not even on 64-bit hw? Weird.
> >>
> >> The ABI was designed in 2003 or so...
> >
> > Hmm, usually it's hardware that gets features first with software to
> >follow. For instance by now the POWER port has gained three `long double'
> >formats in their psABI, all of which can coexist in a single system (I got
> >that covered in the course of the glibc test improvement effort too).
> >
> > Maciej
>
> The x87 psABI does have a __float128 type IIRC.
>

Isn't that the 16bit exponent, 64bit mantissa of the x87 fpu?
It has to aligned so there are 48bits unused.

-- David