Re: [PR 79905] ICE with vector_type

[Bill Schmidt <wschmidt@linux.vnet.ibm.com>]

I'll try the POC patch in a bit (kind of ugly as we have to replicate this for a whole bunch of types, I guess).

Just FYI, I noticed this similar bug report came in today, not sure about the types:  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80309

-- Bill

Bill Schmidt, Ph.D.
GCC for Linux on Power
Linux on Power Toolchain
IBM Linux Technology Center
wschmidt@linux.vnet.ibm.com

> On Apr 4, 2017, at 8:49 AM, Nathan Sidwell <nathan@acm.org> wrote:
> 
> On 04/04/2017 09:00 AM, Richard Biener wrote:
> 
>> tree
>> add_builtin_type (const char *name, tree type)
>> {
>>  tree   id = get_identifier (name);
>>  tree decl = build_decl (BUILTINS_LOCATION, TYPE_DECL, id, type);
>>  return lang_hooks.decls.pushdecl (decl);
>> }
>> 
>> this seems to miss setting TYPE_NAME (type) = decl - oh, that may be
>> what set_underlying_type does via the langhook.
> 
> Correct, via the langhook.  I wonder if the smacking of the incoming-type's TYPE_NAME is so that the global tree node references the now-named builtin type.  If we were to make a clone here, (things like) VS4SI_type_node would remain an unnamed type.  And I guess debug would be unhappy?
> 
>> At this point I'd rather restrict fiddling in this fragile area in
>> rs6000.c only ;)
> 
> me too.
> 
>> Does removing the TYPE_NAME setting fix things?
> 
> no,  those TYPE_NAME assignments are redundant -- set_underlying_type has already initialized it.
> 
> The attached PoC fixes 79905 (no idea what ppc test it might break)
> 
> nathan
> 
> -- 
> Nathan Sidwell
> <79905-2.diff>