[Bug target/46280] New: [4.6 regression] Several testcases FAIL with 16byte alignment ABI warning on Solaris 8/9 x86

["ro at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46280

           Summary: [4.6 regression] Several testcases FAIL with 16byte
                    alignment ABI warning on Solaris 8/9 x86
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ro@gcc.gnu.org
                CC: hjl@gcc.gnu.org
              Host: i386-pc-solaris2.[89]
            Target: i386-pc-solaris2.[89]
             Build: i386-pc-solaris2.[89]


Between 20101022 and 20101029, several testcases started to FAIL on Solaris 8
and 9/x86, e.g. 

+FAIL: g++.dg/eh/simd-2.C (test for excess errors)

Excess errors:
/vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/eh/simd-2.C:13:8: note: The
ABI of passing parameter with 16byte alignment has changed in GCC 4.6

This is almost certainly related to this patch

2010-10-26  H.J. Lu  <hongjiu.lu@intel.com>

    PR target/44948
    * config/i386/i386.c (ix86_old_function_arg_boundary): New.
    (ix86_function_arg_boundary): Always align parameters on stack
    in 64bit and align parameters with alignment >= 16byte on stack
    in 32bit.  Warn alignment change.

and the fact that those targets default to -march=pentiumpro instead of
-march=pentium4, since the tests pass with -march=pentium4.

Here's the list of affected testcases:

g++.dg/eh/simd-2.C
g++.dg/opt/combine.C
g++.dg/torture/pr36444.C
g++.dg/torture/pr36445.C
gcc.c-torture/compile/pr34856.c
gcc.c-torture/compile/pr39928-1.c
gcc.c-torture/compile/vector-1.c
gcc.c-torture/compile/vector-2.c
gcc.c-torture/execute/va-arg-25.c
gcc.c-torture/execute/vector-1.c
gcc.c-torture/execute/vector-2.c
gcc.dg/pr32912-1.c
gcc.dg/tree-ssa/forwprop-5.c
gcc.dg/tree-ssa/fre-vce-1.c
gcc.dg/tree-ssa/sra-4.c
gcc.dg/tree-ssa/vector-1.c
gcc.dg/tree-ssa/vector-2.c
gcc.target/i386/vect-args.c