[Bug target/71389] [7 Regression] ICE on trunk gcc on ivybridge target (df_refs_verify)

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71389

--- Comment #2 from UroÅ Bizjak <ubizjak at gmail dot com> ---
The compiler chokes in

(gdb) bt
#0  internal_error (gmsgid=0x2384c05 "in %s, at %s:%d") at
../../git/gcc/gcc/diagnostic.c:1254
#1  0x0000000001bb19c5 in fancy_abort (file=0x1cc90c0
"../../git/gcc/gcc/df-scan.c", line=4033, 
    function=0x1cc9c23 <df_refs_verify(vec<df_ref_d*, va_heap, vl_ptr> const*,
df_ref_d*, bool)::__FUNCTION__> "df_refs_verify") at
../../git/gcc/gcc/diagnostic.c:1327
#2  0x0000000000b72162 in df_refs_verify (new_rec=0x7fffffffd180,
old_rec=0x2b48020, abort_if_fail=true)
    at ../../git/gcc/gcc/df-scan.c:4033
#3  0x0000000000b75aed in df_insn_refs_verify (collection_rec=0x7fffffffcd70,
bb=0x2aaaafb608f0, 
    insn=0x2aaaafb7edc0, abort_if_fail=true) at
../../git/gcc/gcc/df-scan.c:4115
#4  0x0000000000b76e37 in df_bb_verify (bb=0x2aaaafb608f0) at
../../git/gcc/gcc/df-scan.c:4142
#5  0x0000000000b77178 in df_scan_verify () at ../../git/gcc/gcc/df-scan.c:4274
#6  0x0000000000b651b7 in df_verify () at ../../git/gcc/gcc/df-core.c:1831
#7  0x0000000000b66573 in df_analyze_1 () at ../../git/gcc/gcc/df-core.c:1217
#8  0x0000000000b668e3 in df_analyze () at ../../git/gcc/gcc/df-core.c:1294
#9  0x0000000000df1a75 in ira (f=0x0) at ../../git/gcc/gcc/ira.c:5137
#10 0x0000000000df1fec in (anonymous namespace)::pass_ira::execute
(this=0x29b03a0) at ../../git/gcc/gcc/ira.c:5525
#11 0x0000000000f1126e in execute_one_pass (pass=0x29b03a0) at
../../git/gcc/gcc/passes.c:2344
#12 0x0000000000f11580 in execute_pass_list_1 (pass=0x29b03a0) at
../../git/gcc/gcc/passes.c:2428
#13 0x0000000000f115b3 in execute_pass_list_1 (pass=0x29af380) at
../../git/gcc/gcc/passes.c:2429
#14 0x0000000000f11606 in execute_pass_list (fn=0x2aaaaf9535e8, pass=0x29abcc0)
at ../../git/gcc/gcc/passes.c:2439
#15 0x0000000000b36618 in cgraph_node::expand (this=0x2aaaaf920450) at
../../git/gcc/gcc/cgraphunit.c:1983
#16 0x0000000000b392fc in expand_all_functions () at
../../git/gcc/gcc/cgraphunit.c:2119
#17 0x0000000000b395d5 in symbol_table::compile (this=0x2aaaae7ad0a8) at
../../git/gcc/gcc/cgraphunit.c:2475
#18 0x0000000000b397d1 in symbol_table::finalize_compilation_unit
(this=0x2aaaae7ad0a8)
    at ../../git/gcc/gcc/cgraphunit.c:2565
#19 0x00000000010304ac in compile_file () at ../../git/gcc/gcc/toplev.c:488
#20 0x0000000001032351 in do_compile () at ../../git/gcc/gcc/toplev.c:1987
#21 0x00000000010324b8 in toplev::main (this=0x7fffffffd880, argc=7,
argv=0x7fffffffd988)
    at ../../git/gcc/gcc/toplev.c:2095
#22 0x0000000001b98cef in main (argc=7, argv=0x7fffffffd988) at
../../git/gcc/gcc/main.c:39
(gdb) f 4
#4  0x0000000000b76e37 in df_bb_verify (bb=0x2aaaafb608f0) at
../../git/gcc/gcc/df-scan.c:4142
4142          df_insn_refs_verify (&collection_rec, bb, insn, true);
(gdb) list
4137      /* Scan the block, one insn at a time, from beginning to end.  */
4138      FOR_BB_INSNS_REVERSE (bb, insn)
4139        {
4140          if (!INSN_P (insn))
4141            continue;
4142          df_insn_refs_verify (&collection_rec, bb, insn, true);
4143          df_free_collection_rec (&collection_rec);
4144        }
4145
4146      /* Do the artificial defs and uses.  */

with:

(gdb) p debug_rtx (insn)
(insn 198 206 199 11 (set (mem/c:V16QI (plus:DI (reg/f:DI 20 frame)
                (const_int -664 [0xfffffffffffffd68])) [7 MEM[(value_type
&)&v13 + 344]+16 S16 A64])
        (vec_select:V16QI (subreg:V32QI (reg:V8SI 175) 0)
            (parallel [
                    (const_int 16 [0x10])
                    (const_int 17 [0x11])
                    (const_int 18 [0x12])
                    (const_int 19 [0x13])
                    (const_int 20 [0x14])
                    (const_int 21 [0x15])
                    (const_int 22 [0x16])
                    (const_int 23 [0x17])
                    (const_int 24 [0x18])
                    (const_int 25 [0x19])
                    (const_int 26 [0x1a])
                    (const_int 27 [0x1b])
                    (const_int 28 [0x1c])
                    (const_int 29 [0x1d])
                    (const_int 30 [0x1e])
                    (const_int 31 [0x1f])
                ]))) -1
     (expr_list:REG_DEAD (reg:V8SI 175)
        (nil)))