[Bug tree-optimization/15731] New: Invalid operand to binary operator ICE when __builtin_va_arg is used

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

The following testcase

void
Perl_sv_vcatpvfn (__builtin_va_list * args)
{
  if (args)
    {
      __builtin_va_arg (*args, char *);
    }
  return;
}

fails with

./cc1 -O1 sv.i
 Perl_sv_vcatpvfn

sv.i: In function `Perl_sv_vcatpvfn':
sv.i:3: error: Invalid operand to binary operator
args<D1099>

sv.i:3: internal compiler error: verify_stmts failed.

This seems to be a gimplification problem -- args is marked
volatile, but it is still used in the if (args) statement.

-- 
           Summary: Invalid operand to binary operator ICE when
                    __builtin_va_arg is used
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rakdver at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15731