Re: Natural alignment used on NetBSD/m68k

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

Hello Izumi,

On Sat, 2025-02-15 at 13:04 +0900, Izumi Tsutsui wrote:
> > Having been a Mac developer way back when, I know a lot of older
> > 68K platforms used two-byte alignment; it doesn't surprise me
> > that NetBSD a.out would use it too. I suspect the same is true
> > of SunOS; unfortunately I'm not in a position to power up my
> > Sun-3/60C at the moment to check what SunOS 4.1.1_U1 uses.
> > If someone has SunOS running in TME then it should be
> > straightforward to get this information though.
> 
> https://gist.github.com/tsutsui/60e8f10a0153d834393640cb52c9f521
> 
> (typed from the above screenshot)
> 
> ---
> # dmesg | head -8
> 
> Feb 15 12:38
> SunOS Release 4.1.1 (GENERIC) #1: Sat Oct 13 06:05:48 PDT 1990
> Copyright (c) 1983-1990, Sun Microsystems, Inc.
> mem = 24576K (0x18000000)
> avail mem = 23486464
> Ethernet address = 8:0:20:0:0:3
> si at vme24d16 0x200000 vec 0x40
> # uname -a
> SunOS ferrari 4.1.1 1 sun3
> # cat test.c
> #include <stdio.h>
> #include <sys/stdtypes.h>
> 
> #define offsetof(type, member) ((size_t)(unsigned long)(&((type *)0)->member))
> 
> struct test { char x; int y; };
> 
> int main()
> {
>     printf("struct test { char x; int y; };\n");
>     printf("sizeof(sturct test) = %d\n", sizeof(struct test));
>     printf("offsetof(struct test, y) = %d\n", offsetof(struct test, y));
> }
> # cc test.c
> # file a.out
> a.out:		mc68020 demand paged dynamically linked executable not stripped
> # ./a.out
> struct test { char x; int y; };
> sizeof(struct test) = 6
> offsetof(struct test, y) = 2
> # 

Thanks a lot for the test, also for testing with NetBSD 1.5.3.

Would you performing the same exact test on a current version of NetBSD?

I would like to collect the results on a wiki page.

Thanks,
Adrian

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