"Zuxy Meng" <zuxy.meng@gmail.com> ååæææé: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'.