[Bug middle-end/52097] ICE: in get_bit_range, at expr.c:4535 with -O -flto -fexceptions -fnon-call-exceptions --param allow-store-data-races=0

["aldyh at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52097

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |rguenth at gcc dot gnu.org

--- Comment #2 from Aldy Hernandez <aldyh at gcc dot gnu.org> 2012-02-14 01:10:43 UTC ---
In get_bit_range() we get the following COMPONENT_REF:

(gdb) call debug_generic_stmt(exp)
MEM[(struct io *)0B].e0;

Then we extract the field so we can search for it in the original
record/structure:

  field = TREE_OPERAND (exp, 1);
  record_type = DECL_FIELD_CONTEXT (field);

But when we iterate through TYPE_FIELDS(record_type), "field" is not found
because the COMPONENT_REF's field "e0" has a different pointer than the "e0" in
the record itself:

(gdb) call debug_generic_stmt (fld)
e0

(gdb) call debug_generic_stmt (field)
e0

(gdb) p fld == field
$12 = 0

I'm not very LTO savvy.  Is this supposed to happen?  Should we have been
comparing something else than pointer equality here, or is there something else
broken?