[Bug c/12105] New: Local Variabels on "Out-of-phase" Alignment on x86

["dfoesch at cs dot nmsu dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12105

           Summary: Local Variabels on "Out-of-phase" Alignment on x86
           Product: gcc
           Version: 3.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dfoesch at cs dot nmsu dot edu
                CC: gcc-bugs at gcc dot gnu dot org

With the following code:

int main(void)
{
  int a __attribute__((mode(v4sf))) __attribute__((aligned(16)));

  printf("%i %p\n", __alignof__(a), &a);

  return 0;
}

I get the following information.  The address of a is supposed to be 16-byte
alligned (correct), but the actual address ends in a 4 (hex) which is surely not
16-byte aligned.

If I alter the potential position of the address with the following code:

int main(void)
{
  int i;
  int a __attribute__((mode(v4sf))) __attribute__((aligned(16)));

  printf("%i %p\n", __alignof__(i), &i);
  printf("%i %p\n", __alignof__(a), &a);

  return 0;
}

I still get that it is supposed to be 16-byte aligned, and I still get an
address which ends in a 4 (hex), just the next 16-byte alligned segment up.

If I compile the first to assembly, a is then stored in -24(%ebp), and changing
it to -28(%ebp) makes the code then work.

But I need a generic solution/workaround, which will compile without assistance,
that will make this work.