Misaligned .bss section for PE?

[Zuxy Meng]

"Zuxy Meng" <zuxy.meng@gmail.com> 写å
¥æ¶ˆæ¯æ–°é—»:g15ap1$2he$1@ger.gmane.org...
> "Zuxy Meng" <zuxy.meng@gmail.com> 写å
¥æ¶ˆæ¯æ–°é—»:g13f6l$t70$1@ger.gmane.org...
>> Hi there,
>>
>> Recently I met a crash on MinGW32 caused by misaligned access of SSE 
>> instructions. The root cause was that a static var wasn't aligned to a 
>> 16-byte boundary. However, in gcc source this var had already been marked 
>> with "__attribute__((aligned(16)))".
>>
>> I then checked the output of "gcc -S" and it turned out that with PE you 
>> couldn't specify a symbol's alignment. Rather, the alignment was ensured 
>> by explicit padding. But gcc seemed to do it right, at least within a 
>> compilation unit. Unfortunately, after hundreds of objects got linked 
>> together, some symbols' alignment was broken.
>>
>> I'm just wondering if I should report it as a GCC bug or a binutils one. 
>> Any help? Thanks!
>
>
> I guess I've figured it out; the object compiled with an older version of 
> "as" has an alignment of 2**4, while with the new "as" has 2**2. The 
> source if simple (just one line of "float var[512] 
> __attribute__((aligned(16)));" The new version is
>
> C:\MSYS\source>as --version
> GNU assembler (GNU Binutils) 2.18.50.20080109
> Copyright 2007 Free Software Foundation, Inc.
> This program is free software; you may redistribute it under the terms of
> the GNU General Public License version 3 or later.
> This program has absolutely no warranty.
> This assembler was configured for a target of `i686-pc-mingw32'.

Unfortunately I can't get a minimized set that can reproduce the problem. 
But can anybody tell me if the alignment shown by "objdump -h" is 
problematic?

-- 
Zuxy