------- 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!" -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38496