On 9 March 2015 at 00:37, Jan Hubicka <hubi...@ucw.cz> wrote:
>>
>> I unforutnately spot another problem. With presence of section anchors we
>> can not increase alignment of symbol that was already placed into the
>> section.
>> I think this is reason why we still have pass_increase_alignments that runs
>> only on target with anchors.
>>
>> I added the following check:
>>
>> + /* If target is already placed in an anchor, we can not touch its
>> + alignment. */
>> + if (DECL_RTL_SET_P (target->decl)
>> + && MEM_P (DECL_RTL (target->decl))
>> + && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (DECL_RTL (target->decl), 0)))
>> + return false;
>>
>> but found it breaks several vectorization testcases with LTO. This is
>> becuase notice_global_symbol computes DECL_RTL even before
>> node->increase_alignment is run and we are stuck.
>>
>> I decided to track this separately from this patch that snowballed quite a
>> bit
>> already. I do not see how to solve it short of making notice_global_symbol to
>> not compute DECL_RTL. It was never quite clear to me why
>> notice_global_symbol
>> is actually doing this at first place. Is it becuase of target mangling
>> happing only at RTL generation time?
>
> This is now PR65355
Your follow-up patch 88ada5e935d58223ae2d9ce6d0c1c71c372680a8 a.k.a r221269
added this to emit_local():
static bool
-emit_local (tree decl ATTRIBUTE_UNUSED,
+emit_local (tree decl,
const char *name ATTRIBUTE_UNUSED,
unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
{
+ int align = symtab_node::get (decl)->definition_alignment ();
#if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
- size, DECL_ALIGN (decl));
+ size, align);
return true;
#elif defined ASM_OUTPUT_ALIGNED_LOCAL
- ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
+ ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, align);
return true;
#else
ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
return false;
#endif
}
which gives
gcc/varasm.c:1936:7: error: unused variable ‘align’ [-Werror=unused-variable]
int align = symtab_node::get (decl)->definition_alignment ();
^
on
log/alpha64-dec-vms
log/alpha-dec-vms
log/i686-cygwinOPT-enable-threads=yes
log/i686-mingw32crt
log/i686-openbsd3.0
log/i686-pc-msdosdjgpp
log/m68k-openbsd
Maybe just flag it as used or copy-move it?
TIA,
