[Bug target/38496] Gcc misaligns arrays when stack is forced follow the x8632 ABI

mikulas at artax dot karlin dot mff dot cuni dot cz gcc-bugzilla@gcc.gnu.org
Fri Jul 31 01:18:00 GMT 2009

------- Comment #26 from mikulas at artax dot karlin dot mff dot cuni dot cz  2009-07-31 01:18 -------
Very unfortunatelly, gcc does assume stack alignment.

The problem is not technical (the code to realign the stack is already there,
it's easy to activate it), the problem is ideological, because some gcc
developers think that they can declare their own ABI and the world will be
changing according to them.

See comments in the bug #40838. I added that alignment test at the beginning of
every libc function, the result is that 75% programs in /bin misalign the stack
and are non-conforming to GCC-developer's ideas about their new ABI.

I also posted a simple example there that does floating point math in the
function that is called as a callback from glibc --- and crashes because of SSE
and unaligned stack.

I really say that they should align the stack in SSE functions instead of
closing this bug with WONTFIX and shouting "everyone's code is bad because we
declared it so!"



More information about the Gcc-bugs mailing list