[Bug tree-optimization/71866] New: gcc locks up after fix for PR70159

[anton at samba dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71866

            Bug ID: 71866
           Summary: gcc locks up after fix for PR70159
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anton at samba dot org
  Target Milestone: ---

Created attachment 38891
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38891&action=edit
Test case

The attached testcase is locking up on ppc64le when run with -O2.

#0  0x0000000010733df8 in iterative_hash_hashval_t (val=2902752560,
val2=2655680748) at ../../gcc/gcc/inchash.h:156
#1  0x0000000010ac2004 in phi_trans_add (pred=0x3fffb57d8818, e=0x11b553c0,
entry=0x3fffffffe3f8)
    at ../../gcc/gcc/tree-ssa-pre.c:620
#2  phi_translate (expr=0x11b553c0, set1=0x11b369a8, set2=0x0,
pred=0x3fffb57d8818, phiblock=0x3fffb57d6f50)
    at ../../gcc/gcc/tree-ssa-pre.c:1815
#3  0x0000000010ac4744 in do_pre_regular_insertion (dom=0x3fffb57d6e80,
block=0x3fffb57d6f50)
    at ../../gcc/gcc/tree-ssa-pre.c:3266
#4  insert_aux (block=0x3fffb57d6f50, do_pre=true, do_hoist=true) at
../../gcc/gcc/tree-ssa-pre.c:3679
#5  0x0000000010ac43e0 in insert_aux (block=0x3fffb57d6e80, do_pre=true,
do_hoist=true)
    at ../../gcc/gcc/tree-ssa-pre.c:3693
#6  0x0000000010ac43e0 in insert_aux (block=0x3fffb57d6db0, do_pre=<optimised
out>, do_hoist=<optimised out>)
    at ../../gcc/gcc/tree-ssa-pre.c:3693
#7  0x0000000010ac74b4 in insert () at ../../gcc/gcc/tree-ssa-pre.c:3717
#8  (anonymous namespace)::pass_pre::execute (this=<optimised out>,
fun=0x3fffb5848b20)
    at ../../gcc/gcc/tree-ssa-pre.c:5082
#9  0x00000000107b9fe4 in execute_one_pass (pass=0x11950c30) at
../../gcc/gcc/passes.c:2344
#10 0x00000000107ba6d8 in execute_pass_list_1 (pass=0x11950c30) at
../../gcc/gcc/passes.c:2428
#11 0x00000000107ba6f0 in execute_pass_list_1 (pass=0x1194fbb0) at
../../gcc/gcc/passes.c:2429
#12 0x00000000107ba798 in execute_pass_list (fn=<optimised out>,
pass=<optimised out>)
    at ../../gcc/gcc/passes.c:2439
#13 0x00000000103bea34 in cgraph_node::expand (this=0x3fffb5861870) at
../../gcc/gcc/cgraphunit.c:1983
#14 0x00000000103c0b6c in expand_all_functions () at
../../gcc/gcc/cgraphunit.c:2119
#15 symbol_table::compile (this=0x3fffb5630000) at
../../gcc/gcc/cgraphunit.c:2475
#16 0x00000000103c3914 in symbol_table::compile (this=0x3fffb5630000) at
../../gcc/gcc/cgraphunit.c:2380
#17 symbol_table::finalize_compilation_unit (this=0x3fffb5630000) at
../../gcc/gcc/cgraphunit.c:2565
#18 0x00000000108c4a1c in compile_file () at ../../gcc/gcc/toplev.c:490
#19 0x00000000101b12fc in do_compile () at ../../gcc/gcc/toplev.c:1998
#20 toplev::main (this=0x3ffffffff0d6, argc=3, argv=0x3ffffffff4f8) at
../../gcc/gcc/toplev.c:2132
#21 0x00000000101b3344 in main (argc=<optimised out>, argv=0x3ffffffff4f8) at
../../gcc/gcc/main.c:39