[Bug target/79404] h8300: ICE at gcc/ira.c:5541 whilst building libgcc

["dhowells at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79404

--- Comment #3 from dhowells at redhat dot com <dhowells at redhat dot com> ---
Program received signal SIGSEGV, Segmentation fault.
0x00000000007e13fb in allocno_copy_cost_saving (
    allocno=allocno@entry=0x149f340, hard_regno=2)
    at ../../gcc-7.0.1-20170204/gcc/ira-color.c:2764
2764          cost += cp->freq *
ira_register_move_cost[allocno_mode][rclass][rclass];

(gdb) p cp
$1 = (ira_copy_t) 0x14cee38
(gdb) p cp->freq
$2 = 194

   0x00000000007e13f0 <+176>:   mov    %r9,%rdx
   0x00000000007e13f3 <+179>:   add    0x12a4860(,%r10,8),%rdx
=> 0x00000000007e13fb <+187>:   movzwl (%rdx,%r11,1),%edx

r9             0x8      8
r10            0x21b    539
r11            0x38     56
rdx            0x8      8

$3 = (target_ira_int *) 0x12a4860 <default_target_ira_int>
(gdb) p &((struct target_ira_int*)0)->x_ira_register_move_cost
$4 = (move_table *(*)[39]) 0x10a0
(gdb) p 0x10a0/8
$5 = 532

So r10 is the offset of x_ira_register_move_cost/8 + 7 where allocno_mode is 7
(DImode).

But:

(gdb) p default_target_ira_int.x_ira_register_move_cost[7]
$8 = (move_table *) 0x0

(gdb) p default_target_ira_int.x_ira_register_move_cost 
$2 = {0x12f7170, 0x12f7170, 0x13e8f80, 0x0, 0x14876f0, 0x1487450, 0x14875a0, 
  0x0 <repeats 32 times>}