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RE: Gnu assembler question for ARM
- From: "Dave Korn" <dave dot korn at artimi dot com>
- To: "'Ciaccia'" <ciacciax at yahoo dot com>, "'Ian Lance Taylor'" <iant at google dot com>
- Cc: <binutils at sourceware dot org>
- Date: Sun, 6 May 2007 23:56:56 +0100
- Subject: RE: Gnu assembler question for ARM
- References: <226262.60838.qm@web31013.mail.mud.yahoo.com>
On 06 May 2007 23:51, Ciaccia wrote:
> Could you please give me some examples on how to use the .struct
> expression? Online there is not much information, the only useful file I
> could find was the "struct.s" fine in the gas testsuite.
>
> I tried to convert this C-struct
>
> struct test {
> int x;
> char y;
> int z;
> };
>
> to assember with the following:
>
> .struct 0
> x: .int 0
> y: .byte 0
> z: .int 0
>
> But the offset for the z field is 5 instead of the expected 8. How to fix
> that?
> I would really be happy to see an example of struct in action...
The compiler alway aligns the members of structs, so you would really need
to precede each member with alignment directive:
.struct 0
.balign 4
x: .int 0
.balign 1
y: .byte 0
.balign 4
z: .int 0
except if the struct has __attribute__ ((packed)), then there is no padding.
cheers,
DaveK
--
Can't think of a witty .sigline today....