[Bug debug/45865] [4.6 regression] Failed to build 403.gcc in SPEC CPU 2006

["hjl.tools at gmail dot com" <gcc-bugzilla-noreply@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45865

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2010-10-06 01:11:30 UTC ---
A simple testcase:

[hjl@gnu-32 rrs]$ cat pr45865.c
typedef struct rtx_def *rtx;
enum machine_mode {
  VOIDmode,
  CCFPmode,
  CCFPUmode,
  MAX_MACHINE_MODE
};
enum mode_class {
  MODE_CC,
  MODE_FLOAT,
  MODE_COMPLEX_FLOAT,
  MODE_VECTOR_FLOAT
};
extern const enum mode_class mode_class[(int) MAX_MACHINE_MODE];
enum rtx_code {
  UNKNOWN,
  GEU,
  ORDERED,
  CONST_INT
};
struct rtx_def {
  unsigned int code: 16;
  unsigned int mode : 8;
};
extern enum rtx_code reverse_condition (enum rtx_code);
enum rtx_code
reversed_comparison_code_parts (enum rtx_code code, rtx insn, rtx arg0,
                rtx arg1)
{
  enum machine_mode mode;
  mode = (enum machine_mode) (arg0)->mode;
  if (mode == VOIDmode)
    mode = (enum machine_mode) (arg1)->mode;
  if ((mode_class[(int) (mode)]) == MODE_CC)
    return (mode != CCFPmode && mode != CCFPUmode
        ? reverse_condition (code)
        : reverse_condition_maybe_unordered (code));
  switch (code) 
    {
    case GEU:
      return reverse_condition (code);
    case ORDERED:
      return UNKNOWN;
    }
  if (((enum rtx_code) (arg0)->code) == CONST_INT
      || (((enum machine_mode) (arg0)->mode) != VOIDmode
      && ! ((mode_class[(int) (mode)]) == MODE_FLOAT
        || (mode_class[(int) (mode)]) == MODE_COMPLEX_FLOAT
        || (mode_class[(int) (mode)]) == MODE_VECTOR_FLOAT)))
    return reverse_condition (code);
  return UNKNOWN;
}
[hjl@gnu-32 rrs]$ /export/gnu/import/rrs/164914/usr/bin/gcc -O2 -S -m32
pr45865.c
pr45865.c: In function \u2018reversed_comparison_code_parts\u2019:
pr45865.c:52:1: internal compiler error: in dwarf2out_cfi_begin_epilogue, at
dwarf2out.c:2930
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
[hjl@gnu-32 rrs]$