[Bug tree-optimization/68809] [6 Regression] ICE: verify_gimple failed (error: type mismatch in binary expression) w/ -O2 (-O3, -Ofast) -floop-nest-optimize

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68809

--- Comment #3 from vries at gcc dot gnu.org ---
Hmm, apparently char 0 and int 0 are equal as far as operand_equal_p is
concerned:
...
(gdb) p gimple_phi_arg_def (p1, 0)
$3 = (tree_node *) 0x7ffff61463a8
(gdb) p gimple_phi_arg_def (p2, 0)
$4 = (tree_node *) 0x7ffff604f048
(gdb) call debug_tree ($3)
 <integer_cst 0x7ffff61463a8 type <integer_type 0x7ffff60365e8 char> constant
0>
(gdb) call debug_tree ($4)
 <integer_cst 0x7ffff604f048 type <integer_type 0x7ffff60367e0 int> constant 0>
(gdb) p operand_equal_p (gimple_phi_arg_def (p1, 0), gimple_phi_arg_def (p2,
0), 0)
$5 = 1
...