[Bug target/22229] New: Segfault due to unaligned movaps access

[uros at kss-loka dot si]

This testcase segfaults due to unaligned movaps access when compiled with 'gcc -
O2 -msse':

--cut here--
#include <xmmintrin.h>

__m128 bar (__m128 x1, __m128 y1, __m128 x2, __m128 y2)
{
  return x1;
}

__m128 foo (__m128 x)
{
  return bar (x, x, x, x);
}

int main()
{
  __m128 a = {1.0, 2.0, 3.0, 4.0};

  union {
    __m128 _xmm;
    float x[4];
  } temp;

  temp._xmm = foo (a);

  printf("%f\n", temp.x[2]);
  return 0;
}
--cut here--

The problem is, that 4th parameter to bar is now passed on stack (this is 
specified by x86 ABI). Unfortunatelly, stack is not aligned correctly and 
testcase segfaults in foo():

foo:
        subss   %xmm1, %xmm0
        pushl   %ebp
        movl    %esp, %ebp
        subl    $16, %esp
        movaps  %xmm0, (%esp)         <<<< here
        movaps  %xmm0, %xmm2
        movaps  %xmm0, %xmm1
        call    bar
        leave
        ret

Value of %esp is 0xbffff958 at the point of segfault.

-- 
           Summary: Segfault due to unaligned movaps access
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: ssemmx
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: uros at kss-loka dot si
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22229