[Bug tree-optimization/16001] New: unable to find a register to spill in class `AREG' (-O2 -funroll-loops)

["rguenth at tat dot physik dot uni-tuebingen dot de" <gcc-bugzilla at gcc dot gnu dot org>]

g++ (GCC) 3.5-tree-ssa-lno 20040615 (merged 20040612)

rguenth@alwazn tmp $ ~/ix86/gccssa-lno/bin/g++ -O2 -funroll-loops -o
 tramp3d-v3.lno.lo tramp3d-v3.cpp -static -Dleafify=fooblah
tramp3d-v3.cpp:15627: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:15636: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:27426: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:31114: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:31390: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:40288: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:40296: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:41213: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp:41399: warning: `fooblah' attribute directive ignored
tramp3d-v3.cpp: In member function `void
RefBlockController<T>::reallocateStorage(size_t, bool) [with T = Vector<3,
double, Full>]':
tramp3d-v3.cpp:10547: error: unable to find a register to spill in class
`AREG'
tramp3d-v3.cpp:10547: error: this is the insn:
(insn:HI 38 37 39 2 (parallel [
            (set (reg:SI 1 dx [93])
                (truncate:SI (lshiftrt:DI (mult:DI (zero_extend:DI (reg:SI
3 bx [91]))
                            (zero_extend:DI (reg:SI 1 dx [94])))
                        (const_int 32 [0x20]))))
            (clobber (scratch:SI))
            (clobber (reg:CC 17 flags))
        ]) 182 {*umulsi3_highpart_insn} (insn_list 37 (nil))
    (expr_list:REG_UNUSED (reg:CC 17 flags)
        (expr_list:REG_UNUSED (scratch:SI)
            (expr_list:REG_DEAD (reg:SI 3 bx [91])
                (expr_list:REG_DEAD (reg:SI 1 dx [94])
                    (expr_list:REG_UNUSED (reg:CC 17 flags)
                        (expr_list:REG_UNUSED (scratch:SI)
                            (expr_list:REG_EQUAL (truncate:SI (lshiftrt:DI
(mult:DI (zero_extend:DI (reg:SI 3 bx [91]))
                                            (const_double -1431655765
[0xaaaaaaab] 0 [0x0] 0 [0x0] 0 [0x0] 0 [0x0] 0 [0x0]))
                                        (const_int 32 [0x20])))
                                (nil)))))))))
tramp3d-v3.cpp:10547: confused by earlier errors, bailing out


Using -fpeel-loops instead of -funroll-loops makes the failure go away.

You can fetch tramp3d-v3.cpp from
http://www.tat.physik.uni-tuebingen.de/~rguenth/gcc/tramp3d-v3.cpp.gz

-- 
           Summary: unable to find a register to spill in class `AREG' (-O2
                    -funroll-loops)
           Product: gcc
           Version: lno
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at tat dot physik dot uni-tuebingen dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16001