[Bug rtl-optimization/24497] New: internal compiler error: in apply_opt_in_copies, at loop-unroll.c:2122

[pbrook at gcc dot gnu dot org]

long long foo(void)
{
  long long unsigned s=0;
  long long unsigned b;
  for (b = 0; b++, s == 0; )
    {
      s = b;
    }
  return s;
}

Compiled with -O2 -funroll-all-loops gives

internal compiler error: in apply_opt_in_copies, at loop-unroll.c:2122

The problematic line is:

gcc_assert (rtx_equal_p (PATTERN (insn), PATTERN (orig_insn)));

And PATTERN(insn) is

(parallel [
        (set (reg/v:DI 32 [ b ])
            (plus:DI (reg/v:DI 32 [ b ])
                (const_int 1 [0x1])))
        (clobber (scratch:SI))
    ])

This fails because rtx_equal_p thinks the two (scratch:SI) are different
scratch registers, and returns 0.


-- 
           Summary: internal compiler error: in apply_opt_in_copies, at
                    loop-unroll.c:2122
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: ice-checking
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pbrook at gcc dot gnu dot org
GCC target triplet: m68k-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24497