Re: Question on BIGGEST_ALIGNMENT in GCC on NetBSD/m68k

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

On Sat, 2025-06-07 at 17:20 +0200, Andreas Schwab wrote:
> On Jun 07 2025, John Paul Adrian Glaubitz wrote:
> 
> > On Sat, 2025-06-07 at 17:03 +0200, Andreas Schwab wrote:
> > > On Jun 07 2025, John Paul Adrian Glaubitz wrote:
> > > 
> > > > you cannot change the ABI because that would change the ABI.
> > > 
> > > That's the fundamental property of an ABI.
> > 
> > Not if the ABI was made-up by yourself ;-).
> 
> No, I didn't.

»When I implemented ELF support for m68k-linux I wanted to follow the SVR4
 ABI (which has 32-bit alignment), but there were too many UAPI structures
 (esp. struct stat) that would have become incompatible (it would have made
 it impossible to run ELF binaries on an a.out kernel or vice-versa), so I
 had to keep the historical mistake.«

Source: https://lore.kernel.org/all/87y3i442w1.fsf@linux-m68k.org/

It was very obviously your decision to use 2 byte alignment even though it
was against the official SVR4 ABI ;-).

Adrian

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