08 Feb 2008 08:51:45 -0800, Ian Lance Taylor <iant@xxxxxxxxxx>:
> "robert song" <robertsong.linux@xxxxxxxxx> writes:
>
> > without -fdata-sections:
> >
> > 00010d20 <h_nerr>:
> > 10d20: 00000005 00000000 00000000 00000000 ................
> >
> > 00010d30 <h_errlist>:
> > 10d30: 00000c24 00000c40 00000c50 00000c6c ...$...@...P...l
> > 10d40: 00000c84 00000000 00000000 00000000 ................
> >
> > with -fdata-sections:
> >
> > 00010d30 <h_errlist>:
> > 10d30: 00000c30 00000c4c 00000c5c 00000c78 ...0...L...\...x
> > 10d40: 00000c90 ....
> >
> > 00010d44 <h_nerr>:
> > 10d44: 00000005 00000000 00000000 ............
>
> I'm just guessing, but it looks like an alignment issue. It looks
> like the compiler is aligning h_errlist at a 16-byte boundary. That
> is causing an extra 4 zero bytes to be inserted in the "without
> -fdata-sections" case.
>
> Ian
>
lan,
thank you very much for your reply.
I found that in binutils/gas/config/tc-mips.c there are some codes as bellows:
/* On a native system other than VxWorks, sections must be aligned
to 16 byte boundaries. When configured for an embedded ELF
target, we don't bother. */
if (strcmp (TARGET_OS, "elf") != 0
&& strcmp (TARGET_OS, "vxworks") != 0)
{
(void) bfd_set_section_alignment (stdoutput, text_section, 4);
(void) bfd_set_section_alignment (stdoutput, data_section, 4);
(void) bfd_set_section_alignment (stdoutput, bss_section, 4);
}
I don't kow why the sections before must be set to 16 byte boundaries,
but not 4 bytes?
Will it cause problems in some target?
Thank you very much.
Robertsong
