Solaris core dump with McMillan Installer

Martin von Loewis loewis at
Thu Oct 25 17:28:59 CEST 2001

> > So does anyone know what the worst case alignment rule is for
> > structs?

If you are talking about C structs, you should be aware that the
layout varies from system to system; in particular, the internal
padding may change.

So if you have a single worst-case alignment, the structure fields may
still end up on the wrong positions on some systems.

"Thomas Heller" <thomas.heller at> writes:
> Isn't this specified in the C-standard ?
> (That's what I heard, not that I would have one...)

The C standard doesn't explicitly mandate alignment for a structure;
it just mandates that all fields are aligned. In turn, that normally
means that a structure must be aligned in the same way as the field
with the largest alignment. That means that the worst-case alignment
for a structure is the same as the worst alignment for any type.

On most systems requiring primitive types to be aligned, the alignment
is 8 if they support a "double" type. On Ultra-SPARC, the worst-case
alignment is 16, for the "long double" type.


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