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Re: What's the meaning of "Algn" in "objdump -h"?


On Wed, Jun 25, 2008 at 3:33 PM, Zuxy Meng <zuxy.meng@gmail.com> wrote:
> Hi,
>
> Under MinGW32 I got the following results:
>
> C:\MSYS\home\jimeng>type x.c
> short b __attribute__((aligned(16)));
>
>
> C:\MSYS\home\jimeng>objdump -h x.o
>
> x.o:     file format pe-i386
>
> Sections:
> Idx Name          Size      VMA       LMA       File off  Algn
>  0 .text         00000000  00000000  00000000  00000000  2**2
>                 ALLOC, LOAD, READONLY, CODE
>  1 .data         00000000  00000000  00000000  00000000  2**2
>                 ALLOC, LOAD, DATA
>  2 .bss          00000000  00000000  00000000  00000000  2**2
>                 ALLOC
>
> Shouldn't .data be aligned to "2**4" or the "Algn" of an object doesn't mean
> too much?


PE-COFF doesn't support aligned common

Compile with -fno-common and you should see .bss aligned correctly

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         00000000  00000000  00000000  00000000  2**2
                  ALLOC, LOAD, READONLY, CODE
  1 .data         00000000  00000000  00000000  00000000  2**2
                  ALLOC, LOAD, DATA
  2 .bss          00000010  00000000  00000000  00000000  2**4
                  ALLOC

Danny


> --
> Zuxy
>
>


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