Re: ipa-visibility TLC 2/n

[David Edelsohn <dje.gcc@gmail.com>]

Honza,

I finally was able to bootstrap GCC on AIX yesterday. The bootstrap
works, but the testsuite results are in extremely bad shape: 250
failures in G++ testsuite and 470 failures in libstdc++ testsuite.

G++ previously had about 65 failures, mainly TLS and init. libstdc++
previously hovered around 12-14 failure.

This is unacceptable breakage and fallout from the recent changes.

- David

On Fri, May 30, 2014 at 3:20 AM, Richard Sandiford
<rdsandiford@googlemail.com> wrote:
> Jan Hubicka <hubicka@ucw.cz> writes:
>>> Jan Hubicka <hubicka@ucw.cz> writes:
>>> >> Richard Sandiford wrote the original section anchors implementation,
>>> >> so he would be a good person to comment about the interaction between
>>> >> aliases and section anchors.
>>> >
>>> > Thanks! Richard, does this patch seem sane?
>>>
>>> Looks good to me in principle, but with:
>>>
>>> > +      struct symtab_node *snode;
>>> >        decl = SYMBOL_REF_DECL (symbol);
>>> > +
>>> > +      snode = symtab_node (decl);
>>> > +      if (snode->alias)
>>> > +       {
>>> > + rtx target = DECL_RTL (symtab_alias_ultimate_target
>>> > (snode)->decl);
>>> > + SYMBOL_REF_BLOCK_OFFSET (symbol) = SYMBOL_REF_BLOCK_OFFSET
>>> > (target);
>>> > +         return;
>>> > +       }
>>>
>>> is SYMBOL_REF_BLOCK_OFFSET (target) guaranteed to be valid at this point?
>>> It looked at face value like you'd need a recursive call to place_block_symbol
>>> on the target before the copy.
>>
>> My reading was that SYMBOL_REF_BLOCK_OFFSET is computed at DECL_RTL
>> calculation time. But you are right - it is done by validize_mem that
>> is not done by DECL_RTL.  Shall I just call it on target first?
>
> Yeah, sounds like calling place_block_symbol would be safer.
>
> IIRC, the reason I didn't do it at SET_DECL_RTL time is that some frontends
> tended to create placeholder decls that for whatever reason ended up with
> an initial DECL_RTL, then changed the properties of the decl later once
> more information was known.  (This was all many years ago.)
>
> Thanks,
> Richard