PATCH: PR target/35657: TDmode isn't aligned at 128bit when passing to a function

[Kreitzer, David L]

Yes, I plan to write up a more formal ABI update by the end of the week, but the basic idea is that all three 8-byte scalar types should be treated the same for alignment purposes.  This means that long long, double, and _Decimal64 are aligned to 4 bytes within structures and in the outgoing parameter block.

Thanks,
David Kreitzer
IA-32/Intel(R) 64 Code Generation
Intel Compiler Lab

-----Original Message-----
From: H.J. Lu [mailto:hjl.tools@gmail.com]
Sent: Tuesday, April 29, 2008 2:27 PM
To: Mark Mitchell
Cc: Uros Bizjak; Richard Guenther; Jan Hubicka; GCC Patches; Girkar, Milind; Jan Hubicka; Kreitzer, David L
Subject: Re: PATCH: PR target/35657: TDmode isn't aligned at 128bit when passing to a function

Hi,

We are investigating ia32 Linux ABI update for all the new H/W and S/W
features. We want consistent alignment for all 8 byte types. That is to
align them to 4 byte. David has an update for ia32 Linux psABI to address
this.

David, can you post a formal ia32 ABI update on alignment of 8 byte
types to ia32 psABI group?

Thanks.


H.J.
On Tue, Apr 29, 2008 at 9:19 AM, Mark Mitchell <mark@codesourcery.com> wrote:
> Uros Bizjak wrote:
>
>
> > Has the conclusion w.r.t. to TDmode alignment been reached? Looking
> > into the thread at [1], I don't think that we have authoritative
> > answer on this issue. I think that to avoid possible ABI
> > incompatibilities with future gcc versions, this should be finalized
> > before 4.3.1 is released.
> >
>
>  I agree.  If we don't already have a P1 issue, please open one.  We can
> always decide to downgrade it, but we shoudn't forget.
>
>  Thanks,
>
>
>
>  --
>  Mark Mitchell
>  CodeSourcery
>  mark@codesourcery.com
>  (650) 331-3385 x713
>
>