[Bug rtl-optimization/57422] [4.9 Regression] ICE: SIGSEGV in dominated_by_p with custom flags

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57422

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-10-30
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
BLOCK_FOR_INSN is NULL for FENCE_INSN

#1  0x0000000000b6dadb in remove_insns_that_need_bookkeeping (fence=0x1e86ae8, 
    av_ptr=0x7fffffffd900)
    at /space/rguenther/src/svn/trunk/gcc/sel-sched.c:4906
4906                                      BLOCK_FOR_INSN (FENCE_INSN
(fence)))))
(gdb) l
4901              && (!bookkeeping_p || VINSN_UNIQUE_P (EXPR_VINSN (expr)))
4902              && (EXPR_SPEC (expr)
4903                  || !EXPR_ORIG_BB_INDEX (expr)
4904                  || !dominated_by_p (CDI_DOMINATORS,
4905                                      BASIC_BLOCK (EXPR_ORIG_BB_INDEX
(expr)),
4906                                      BLOCK_FOR_INSN (FENCE_INSN
(fence)))))

(gdb) call debug_rtx (fence->insn)
(insn/v 81 0 0 (set (reg:DI 0 ax [165])
        (mem/c:DI (plus:DI (reg/f:DI 38 r9 [118])
                (const_int 32 [0x20])) [0 MEM[(void *)&srcb]+32 S8 A128]))
t.c:15 85 {*movdi_internal}
     (expr_list:REG_EQUIV (mem/c:DI (plus:DI (reg/f:DI 37 r8 [117])
                (const_int 32 [0x20])) [0 MEM[(void *)&dstb]+32 S8 A128])
        (nil)))