Jonathan Kinsey wrote:
This is a problem that I've seen in the archives and is marked as not
being a problem with gcc. I'm not sure what the solution is though, the
simple test below runs fine using the Microsoft compiler (on windows)
and fails using gcc (3.4.5) compiler. There is no pthreads or glib code
here.
The output shows that the second call to f(), in the thread, has a
misaligned s variable (which will crash in a SSE call).
Jon
#include <stdio.h>
#include <process.h>
#include <windows.h>
#include <xmmintrin.h>
void f(void *p)
{
__m128 s;
printf("%d\n", ((int)&s) % 16);
}
int main(int argc, char ** argv)
{
f(0);
_beginthread(f, 0, 0);
Sleep(2000);
return 0;
}
I don't remember what was said in the past, but any gcc function which
uses SSE parallel instructions must be called from a gcc function which
passes a 16-byte aligned stack. So you may be able to overcome it by
interposing a wrapper function at the thread entry point (which does not
use parallel SSE), with all gcc functions compiled with normal options
(not -Os, which sets a smaller value in -mpreferred-stack-alignment).
To speculate further, possibly your pthreads library was compiled with
options which don't pass 16-byte aligned stack.
