[Bug bootstrap/49964] Bootstrap failed with AVX turned on

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49964
--- Comment #4 from Richard Henderson <rth at gcc dot gnu.org> 2011-08-03 
19:11:48 UTC ---
It's a bug in the i386 backend:

(call_insn 28 27 136 2 (parallel [
            (parallel [
                    (call (mem:QI (mem/f:SI (plus:SI (reg/f:SI 73 [
__ec$_M_cat_2->_vptr.error_category ])
                                    (const_int 12 [0xc])) [3 MEM[(int
(*__vtbl_ptr_type) () *)D.126512_12 + 12B]+0 S4 A32]) [0
*OBJ_TYPE_REF(D.126513_13;__ec$_M_cat_2->3) S1 A8])
                        (const_int 12 [0xc]))
                    (set (reg/f:SI 7 sp)
                        (plus:SI (reg/f:SI 7 sp)
                            (const_int 4 [0x4])))
                ])
            (unspec [
                    (const_int 2 [0x2])
                ] UNSPEC_CALL_NEEDS_VZEROUPPER)
        ])
/home/rth/work/gcc/bld/i686-linux/libstdc++-v3/include/system_error:158 480
{*call_pop_vzeroupper}

Note the nested PARALLEL.