David Edelsohn via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> -fdata-sections places data symbols into their own, unique, named
> sections.
> -fsection-anchors create an anchor to access neighboring symbols
> within a section.
>
> When both are enabled, a separate section anchor is created for each
> symbol, which provides no benefit.
>
> This patch updates the common gating function use_blocks_for_decl_p() to
> return false if -fdata-sections is enabled. Constants still can
> be placed into
> object blocks because constants use a separate, different gating function.
>
> Bootstrapped on powerpc-ibm-aix7.2.3.0
>
> Okay?
Yes, thanks.
Richard
> Thanks, David
>
> gcc/ChangeLog:
>
> * varasm.c (use_blocks_for_decl_p): Don't use section anchors
> for VAR_DECLs if -fdata-sections enabled.
>
> diff --git a/gcc/varasm.c b/gcc/varasm.c
> index 3ecf9e039bb..ac256ef65e5 100644
> --- a/gcc/varasm.c
> +++ b/gcc/varasm.c
> @@ -1340,6 +1340,12 @@ use_blocks_for_decl_p (tree decl)
> {
> struct symtab_node *snode;
>
> + /* Don't create object blocks if each DECL is placed into a separate
> + section because that will uselessly create a section anchor for
> + each DECL. */
> + if (flag_data_sections)
> + return false;
> +
> /* Only data DECLs can be placed into object blocks. */
> if (!VAR_P (decl) && TREE_CODE (decl) != CONST_DECL)
> return false;
