> On 05/27/14 23:20, Jan Hubicka wrote:
> >>
> >>here we have decl and its local alias:
> >>(gdb) p debug_tree (sect->named.decl)
> >> <var_decl 70f7d060 _ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si
> >> type<array_type 70dd8840
> >> type<pointer_type 700f5840 __vtbl_ptr_type type<function_type
> >> 700f57e0>
> >> unsigned SI
> >> size<integer_cst 70006498 constant 32>
> >> unit size<integer_cst 700064b0 constant 4>
> >> align 32 symtab 45 alias set 3 canonical type 700f5840
> >> pointer_to_this<pointer_type 700f5900>>
> >> BLK
> >> size<integer_cst 708002d0 constant 320>
> >> unit size<integer_cst 708000d8 constant 40>
> >> align 32 symtab 0 alias set 3 canonical type 70dd8840
> >> domain<integer_type 701a78a0 type<integer_type 7001d000 sizetype>
> >> type_6 SI size<integer_cst 70006498 32> unit size<integer_cst
> >> 700064b0 4>
> >> align 32 symtab 0 alias set -1 canonical type 701a78a0
> >> precision 32 min<integer_cst 700064c8 0> max<integer_cst 701a5b88 9>>
> >> pointer_to_this<pointer_type 71272d80>>
> >> readonly addressable used public static tree_1 tree_5 tree_6 ignored
> >> weak in_system_header virtual decl_5 SI file
> >> /home/jh/trunk/c/powerpc-ibm-aix7.1.0.0/libstdc++-v3/include/fstream line
> >> 444 col 11 size<integer_cst 708002d0 320> unit size<integer_cst 708000d8
> >> 40>
> >> user align 32 context<record_type 701eb000 basic_ifstream>
> >> initial<constructor 70f63680>
> >>
> >> (mem/u/c:SI (symbol_ref/i:SI
> >> ("_ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si") [flags 0x82]<var_decl
> >> 70f7d060 _ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si>) [3
> >> _ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si+0 S40 A32])>
> >>$6 = 10
> >>(gdb) p debug_tree (decl)
> >> <var_decl 714174e0
> >> _ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si.localalias.69
> >> type<array_type 70dd8840
> >> type<pointer_type 700f5840 __vtbl_ptr_type type<function_type
> >> 700f57e0>
> >> unsigned SI
> >> size<integer_cst 70006498 constant 32>
> >> unit size<integer_cst 700064b0 constant 4>
> >> align 32 symtab 45 alias set 3 canonical type 700f5840
> >> pointer_to_this<pointer_type 700f5900>>
> >> BLK
> >> size<integer_cst 708002d0 constant 320>
> >> unit size<integer_cst 708000d8 constant 40>
> >> align 32 symtab 0 alias set 3 canonical type 70dd8840
> >> domain<integer_type 701a78a0 type<integer_type 7001d000 sizetype>
> >> type_6 SI size<integer_cst 70006498 32> unit size<integer_cst
> >> 700064b0 4>
> >> align 32 symtab 0 alias set -1 canonical type 701a78a0
> >> precision 32 min<integer_cst 700064c8 0> max<integer_cst 701a5b88 9>>
> >> pointer_to_this<pointer_type 71272d80>>
> >> readonly addressable used static tree_1 tree_5 tree_6 ignored
> >> in_system_header decl_5 SI file
> >> /home/jh/trunk/c/powerpc-ibm-aix7.1.0.0/libstdc++-v3/include/fstream line
> >> 444 col 11 size<integer_cst 708002d0 320> unit size<integer_cst 708000d8
> >> 40>
> >> user align 32 context<record_type 701eb000 basic_ifstream>
> >> >
> >>$7 = 10
> >>
> >>
> >>Perhaps get_vairable_section should look for alias target, since that is the
> >>decl really deciding on the section? Richard?
> >
> >This is patch that makes get_variable_section to look through the aliases
> >
> >Index: varasm.c
> >===================================================================
> >--- varasm.c (revision 210914)
> >+++ varasm.c (working copy)
> >@@ -1083,6 +1083,9 @@
> > {
> > addr_space_t as = ADDR_SPACE_GENERIC;
> > int reloc;
> >+ symtab_node *snode = symtab_get_node (decl);
> >+ if (snode)
> >+ decl = symtab_alias_ultimate_target (snode)->decl;
> >
> > if (TREE_TYPE (decl) != error_mark_node)
> > as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
> >
> >For AIX it makes the bug go away and I eventually get:
> >
> >/tmp//ccyAATFr.s: line 30042: 1252-001
> >_ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si.localalias.69 is defined
> >already.
> >/tmp//ccyAATFr.s: line 30125: 1252-001
> >_ZTCSt14basic_ofstreamIcSt11char_traitsIcEE0_So.localalias.71 is defined
> >already.
> >/tmp//ccyAATFr.s: line 30164: 1252-001
> >_ZTCSt13basic_fstreamIcSt11char_traitsIcEE8_So.localalias.75 is defined
> >already.
> >/tmp//ccyAATFr.s: line 30223: 1252-001
> >_ZTCSt13basic_fstreamIcSt11char_traitsIcEE0_Si.localalias.74 is defined
> >already.
> >/tmp//ccyAATFr.s: line 30263: 1252-001
> >_ZTCSt14basic_ofstreamIwSt11char_traitsIwEE0_St13basic_ostreamIwS1_E.localalias.80
> > is defined already.
> >/tmp//ccyAATFr.s: line 30323: 1252-001
> >_ZTCSt13basic_fstreamIwSt11char_traitsIwEE8_St13basic_ostreamIwS1_E.localalias.84
> > is defined already.
> >/tmp//ccyAATFr.s: line 30388: 1252-001
> >_ZTCSt14basic_ifstreamIwSt11char_traitsIwEE0_St13basic_istreamIwS1_E.localalias.78
> > is defined already.
> >/tmp//ccyAATFr.s: line 30436: 1252-001
> >_ZTCSt13basic_fstreamIwSt11char_traitsIwEE0_St13basic_istreamIwS1_E.localalias.83
> > is defined already.
> >
> >David, this looks like a bug in the AIX target output macros. I get:
> > .set
> > _ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si.localalias.69,_ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si
> >
> >(this is correct since localalias is really an alias)
> >
> >_ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si.localalias.69:
> > .space 40
> >_ZTCSt14basic_ifstreamIcSt11char_traitsIcEE0_Si:
> >...
> >
> >This is wrong, since we should not try to out the variable at least if I
> >read AIX assembly correctly.
> >
> >varpool has explicit test to not output any aliases, so perhaps this is a
> >bug in wrapup_globals
> >and AIX output macros. I will try to track more after my teaching tonight.
>
> Any update?
>
> I've managed to generate a simple test case from
> libstdc++-v3/src/c++98/strstream.cc which reproduces the issue on
> ARM that Ramana has reported previously:
Thanks, that is very useful! I will look into it today - I am teaching at
evening, so first I need
to prepare my class and will do it next.
Honza
