On Fri, Dec 28, 2012 at 6:35 PM, Steven Bosscher <stevenb....@gmail.com> wrote:
> On Tue, Mar 27, 2012 at 10:59 AM, Richard Guenther wrote:
>> On Tue, Mar 27, 2012 at 10:32 AM, Steven Bosscher wrote:
>>> On Tue, Mar 27, 2012 at 9:17 AM, Richard Guenther wrote:
>>>> It would be nice to finally move
>>>> the call to cgraph_finalize_compilation_unit to the middle-end ...
>>>> (warning, if you try that you run into an issue with the Java frontend ...
>>>> :/)
>>>
>>> Do you remember what issues that causes? I'm running into a great
>>> number of issues there already with some varasm fixes (basically just
>>> cleanups for the tree-ssa and unit-at-a-time era we're supposed to
>>> live in - except Java).
>>
>> I think it was the
>>
>> /* Generate hidden aliases for Java. */
>> if (candidates)
>> {
>> build_java_method_aliases (candidates);
>> pointer_set_destroy (candidates);
>> }
>>
>> hunk in cp_write_global_declarations that does not work when run
>> before cgraph_finalize_compilation_unit
>> (I simply tried to move that call out of, and after calling the
>> langhook). So the problem materialized when
>> building libjava I think.
>
> Hello,
>
> Coming back to this issue... Attached patch is an attempt to resolve
> this part of the finalize_compilation_unit problem. Instead of
> emitting aliases with assemble_alias after finalize_compilation_unit,
> this patch uses cgraph_same_body_alias before it.
>
> Bootstrapped&tested on powerpc64-unknown-linux-gnu.
> Richi, Honza, does this make sense?
Looks sensible to me. In theory it should even allow more optimizations
this way ...
Of course it looks like stage1 material.
Thanks,
Richard.
> Ciao!
> Steven
>
> cp/
> * decl2.c (collect_candidates_for_java_method_aliases): Remove.
> (build_java_method_aliases): Rewrite to emit the aliases via the
> cgraphunit machinery.
> (cp_write_global_declarations): Adjust for abovementioned changes.
>
> Index: cp/decl2.c
> ===================================================================
> --- cp/decl2.c (revision 194725)
> +++ cp/decl2.c (working copy)
> stevenb@stevenb-laptop:~$ cat devel/java_method_aliases.diff
> cp/
> * decl2.c (collect_candidates_for_java_method_aliases): Remove.
> (build_java_method_aliases): Rewrite to emit the aliases via the
> cgraphunit machinery.
> (cp_write_global_declarations): Adjust for abovementioned changes.
>
> Index: cp/decl2.c
> ===================================================================
> --- cp/decl2.c (revision 194725)
> +++ cp/decl2.c (working copy)
> @@ -3615,79 +3615,53 @@ generate_ctor_and_dtor_functions_for_priority (spl
>
> /* Java requires that we be able to reference a local address for a
> method, and not be confused by PLT entries. If hidden aliases are
> - supported, collect and return all the functions for which we should
> + supported, emit one for each java function that we've emitted.
> emit a hidden alias. */
>
> -static struct pointer_set_t *
> -collect_candidates_for_java_method_aliases (void)
> +static void
> +build_java_method_aliases (void)
> {
> +#ifdef HAVE_GAS_HIDDEN
> struct cgraph_node *node;
> - struct pointer_set_t *candidates = NULL;
> + tree fndecl;
> + vec<tree> candidates = vNULL;
> + unsigned int ix;
>
> -#ifndef HAVE_GAS_HIDDEN
> - return candidates;
> -#endif
> -
> + /* First collect all candidates. We cannot create the aliases
> + in place, it confuses the FOR_EACH_FUNCTION iterator. */
> FOR_EACH_FUNCTION (node)
> {
> - tree fndecl = node->symbol.decl;
> -
> + fndecl = node->symbol.decl;
> if (DECL_CONTEXT (fndecl)
> && TYPE_P (DECL_CONTEXT (fndecl))
> && TYPE_FOR_JAVA (DECL_CONTEXT (fndecl))
> && TARGET_USE_LOCAL_THUNK_ALIAS_P (fndecl))
> - {
> - if (candidates == NULL)
> - candidates = pointer_set_create ();
> - pointer_set_insert (candidates, fndecl);
> - }
> + candidates.safe_push (fndecl);
> }
>
> - return candidates;
> -}
> -
> -
> -/* Java requires that we be able to reference a local address for a
> - method, and not be confused by PLT entries. If hidden aliases are
> - supported, emit one for each java function that we've emitted.
> - CANDIDATES is the set of FUNCTION_DECLs that were gathered
> - by collect_candidates_for_java_method_aliases. */
> -
> -static void
> -build_java_method_aliases (struct pointer_set_t *candidates)
> -{
> - struct cgraph_node *node;
> -
> -#ifndef HAVE_GAS_HIDDEN
> - return;
> -#endif
> -
> - FOR_EACH_FUNCTION (node)
> + /* Now add the aliases for the candidates collected above.
> + Mangle the name in a predictable way; we need to reference
> + this from a java compiled object file. */
> + FOR_EACH_VEC_ELT (candidates, ix, fndecl)
> {
> - tree fndecl = node->symbol.decl;
> + tree oid, nid, alias;
> + const char *oname;
> + char *nname;
>
> - if (TREE_ASM_WRITTEN (fndecl)
> - && pointer_set_contains (candidates, fndecl))
> - {
> - /* Mangle the name in a predictable way; we need to reference
> - this from a java compiled object file. */
> - tree oid, nid, alias;
> - const char *oname;
> - char *nname;
> + oid = DECL_ASSEMBLER_NAME (fndecl);
> + oname = IDENTIFIER_POINTER (oid);
> + gcc_assert (oname[0] == '_' && oname[1] == 'Z');
> + nname = ACONCAT (("_ZGA", oname+2, NULL));
> + nid = get_identifier (nname);
>
> - oid = DECL_ASSEMBLER_NAME (fndecl);
> - oname = IDENTIFIER_POINTER (oid);
> - gcc_assert (oname[0] == '_' && oname[1] == 'Z');
> - nname = ACONCAT (("_ZGA", oname+2, NULL));
> - nid = get_identifier (nname);
> -
> - alias = make_alias_for (fndecl, nid);
> - TREE_PUBLIC (alias) = 1;
> - DECL_VISIBILITY (alias) = VISIBILITY_HIDDEN;
> -
> - assemble_alias (alias, oid);
> - }
> + alias = make_alias_for (fndecl, nid);
> + TREE_PUBLIC (alias) = 1;
> + DECL_VISIBILITY (alias) = VISIBILITY_HIDDEN;
> + node = cgraph_same_body_alias (NULL, alias, fndecl);
> + gcc_assert (node);
> }
> +#endif
> + return;
> }
>
> /* Return C++ property of T, based on given operation OP. */
> @@ -3933,7 +3907,6 @@ cp_write_global_declarations (void)
> unsigned ssdf_count = 0;
> int retries = 0;
> tree decl;
> - struct pointer_set_t *candidates;
>
> locus = input_location;
> at_eof = 1;
> @@ -4282,8 +4255,8 @@ cp_write_global_declarations (void)
> linkage now. */
> pop_lang_context ();
>
> - /* Collect candidates for Java hidden aliases. */
> - candidates = collect_candidates_for_java_method_aliases ();
> + /* Generate hidden aliases for Java. */
> + build_java_method_aliases ();
>
> timevar_stop (TV_PHASE_DEFERRED);
> timevar_start (TV_PHASE_OPT_GEN);
> @@ -4306,13 +4279,6 @@ cp_write_global_declarations (void)
>
> perform_deferred_noexcept_checks ();
>
> - /* Generate hidden aliases for Java. */
> - if (candidates)
> - {
> - build_java_method_aliases (candidates);
> - pointer_set_destroy (candidates);
> - }
> -
> finish_repo ();
>
> /* The entire file is now complete. If requested, dump everything
