[Bug c/49927] New: ice in spill_failure, at reload1.c:2120

[regehr at cs dot utah.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49927

           Summary: ice in spill_failure, at reload1.c:2120
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: reg...@cs.utah.edu


regehr@home:~/volatile/bugs/tmp040$ current-gcc -c -O0 small.c

small.c: In function ‘func_7’:
small.c:8:1: error: unable to find a register to spill in class ‘Q_REGS’
small.c:8:1: error: this is the insn:
(insn 9 8 10 2 (set (mem/s/j:QI (plus:SI (plus:SI (subreg:SI (reg:DI 60 [
g_91.1 ]) 0)
                    (subreg:SI (reg:DI 59 [ g_91.0 ]) 0))
                (symbol_ref:SI ("g_73") <var_decl 0xb72f9720 g_73>)) [0 g_73 S1
A8])
        (reg:QI 4 si [orig:62 D.1999 ] [62])) small.c:6 52 {*movqi_internal}
     (expr_list:REG_DEAD (reg:QI 4 si [orig:62 D.1999 ] [62])
        (expr_list:REG_DEAD (reg:DI 60 [ g_91.1 ])
            (expr_list:REG_DEAD (reg:DI 59 [ g_91.0 ])
                (nil)))))
small.c:8:1: internal compiler error: in spill_failure, at reload1.c:2120
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

regehr@home:~/volatile/bugs/tmp040$ current-gcc -v

Using built-in specs.
COLLECT_GCC=current-gcc
COLLECT_LTO_WRAPPER=/mnt/z/z/compiler-install/gcc-r176994-install/libexec/gcc/i686-pc-linux-gnu/4.7.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ../configure --with-libelf=/usr/local --enable-lto
--prefix=/mnt/z/z/compiler-install/gcc-r176994-install
--program-prefix=r176994- --enable-languages=c,c++
Thread model: posix
gcc version 4.7.0 20110801 (experimental) (GCC) 

regehr@home:~/volatile/bugs/tmp040$ cat small.c

char g_73[1][1];
long long g_91;
int *
func_7 (int p_11, int p_12)
{
  --g_73[g_91][g_91];
  return 0;
}