Created attachment 13432 [details]
testcase

Slightly more reduced:

class QString
{
public:QString ();
  QString & operator+= (const QString & str);
};
class Qt
{
};
template < class T > class QValueListIterator
{
};
template < class T > class QValueList
{
public:typedef QValueListIterator < T > iterator;
  const T & operator[] (long unsigned int i) const
  {
  }
};
class QNumberSection
{
public: QNumberSection (bool separat):
  sep (separat)
  {
  }
  bool separator ()
  {
    return sep;
  }
private:
  int act:7;
  bool sep:1;
};
class ExtDateTimeEditorPrivate
{
public:
  QString separator ()
  {
  }
  QNumberSection section (int idx)
  {
    return sections[idx];
  }
private:
  QValueList < QNumberSection > sections;
};
void
ExtDateTimeEditor()
{
  ExtDateTimeEditorPrivate *d;
  QString txt;
  for (unsigned int i = 0; i < 10; ++i)
    {
          if (d->section (i).separator ())
            txt += d->separator ();
    }
}

Janis, can you please do a regression hunt on this?

It appears to be related to bitfields.

Here's a better, C based testcase:

tbm@coconut0:~$ /usr/lib/gcc-snapshot/bin/gcc -c -O anthy-wordlist.c
anthy-wordlist.c: In function 'anthy_make_word_list_all':
anthy-wordlist.c:33: internal compiler error: internal consistency failure
Please submit a full bug report, [...]
tbm@coconut0:~$ /usr/lib/gcc-snapshot/bin/gcc -c anthy-wordlist.c
tbm@coconut0:~$

Testcase:

struct wtype
{
  unsigned int pos:5;
  unsigned int cos:4;
};
typedef struct wtype wtype_t;
struct word_list
{
  wtype_t wt;
};
extern wtype_t anthy_wtype_num_noun;
static void
make_pre_words (wtype_t x)
{
  wtype_t core_wt = x;
  anthy_wtype_include (anthy_wtype_num_noun, core_wt);
}
static void
make_word_list (int len)
{
  struct word_list tmpl;
  if (len == 1)
  {
      make_pre_words (tmpl.wt);
      make_suc_words (&tmpl);
  }
}
anthy_make_word_list_all ()
{
  int i;
  for (i = 0; i < 3; i++)
      make_word_list (i);
}

A regression hunt on powerpc-linux with an ia64-linux cross compiler using the C test case from comment #5 identified the following patch:

    http://gcc.gnu.org/viewcvs?view=rev&rev=123524

    r123524 | aoliva | 2007-04-05 18:50:34 +0000 (Thu, 05 Apr 2007)

Alexandre, can you investigate this issue?

Sorry about the delay.  The patch that introduced this problem was reverted, and the revised version thereof, still awaiting review, does not trigger the problem any more.