This patch makes IPA-PTA work during the ltrans stage of LTO.
It basically makes sure to honor the accessed-from-other-ltrans-unit
flags for variables and functions where appropriate.
With this patch, IPA-PTA survives LTO bootstrap (with -fipa-pta
hard-wired to 1 in common.opt). Before the patch we miscompiled
the stage2 compiler (unsurprisingly).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
I hope to get to some of the remaining TODOs for IPA-PTA (basically
fixup nonlocal handling throughout the compiler ...) and then maybe
look at compile-time and memory usage issues.
Richard.
2011-06-29 Richard Guenther <rguent...@suse.de>
* opts.c (finish_options): Do not disable IPA-PTA during ltrans.
* tree-ssa-structalias.c (create_variable_info_for): Do not
add initial constraints for non-var-decls. Properly handle
globals in other ltrans partitions.
(intra_create_variable_infos): Manually create constraints for
the fake no-alias parameter.
(ipa_pta_execute): Dump the cgraph, handle ltrans partitions properly
and assert there are no clones.
Index: gcc/opts.c
===================================================================
*** gcc/opts.c.orig 2011-06-30 15:25:53.000000000 +0200
--- gcc/opts.c 2011-06-30 15:27:47.000000000 +0200
*************** finish_options (struct gcc_options *opts
*** 766,776 ****
maybe_set_param_value (PARAM_STACK_FRAME_GROWTH, 40,
opts->x_param_values, opts_set->x_param_values);
}
- if (opts->x_flag_wpa || opts->x_flag_ltrans)
- {
- /* These passes are not WHOPR compatible yet. */
- opts->x_flag_ipa_pta = 0;
- }
if (opts->x_flag_lto)
{
--- 766,771 ----
Index: gcc/tree-ssa-structalias.c
===================================================================
*** gcc/tree-ssa-structalias.c.orig 2011-06-30 15:26:07.000000000 +0200
--- gcc/tree-ssa-structalias.c 2011-06-30 15:55:02.000000000 +0200
*************** create_variable_info_for (tree decl, con
*** 5450,5455 ****
--- 5450,5458 ----
insert_vi_for_tree (decl, vi);
+ if (TREE_CODE (decl) != VAR_DECL)
+ return id;
+
/* Create initial constraints for globals. */
for (; vi; vi = vi->next)
{
*************** create_variable_info_for (tree decl, con
*** 5463,5499 ****
|| vi->only_restrict_pointers)
make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
! /* For escaped variables initialize them from nonlocal. */
if (!in_ipa_mode
! || DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
make_copy_constraint (vi, nonlocal_id);
! /* If this is a global variable with an initializer and we are in
! IPA mode generate constraints for it. In non-IPA mode
! the initializer from nonlocal is all we need. */
! if (in_ipa_mode
! && DECL_INITIAL (decl))
{
! VEC (ce_s, heap) *rhsc = NULL;
! struct constraint_expr lhs, *rhsp;
! unsigned i;
! get_constraint_for_rhs (DECL_INITIAL (decl), &rhsc);
! lhs.var = vi->id;
! lhs.offset = 0;
! lhs.type = SCALAR;
! FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
! process_constraint (new_constraint (lhs, *rhsp));
! /* If this is a variable that escapes from the unit
! the initializer escapes as well. */
! if (DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
{
! lhs.var = escaped_id;
lhs.offset = 0;
lhs.type = SCALAR;
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
}
- VEC_free (ce_s, heap, rhsc);
}
}
--- 5466,5509 ----
|| vi->only_restrict_pointers)
make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
! /* In non-IPA mode the initializer from nonlocal is all we need. */
if (!in_ipa_mode
! || DECL_HARD_REGISTER (decl))
make_copy_constraint (vi, nonlocal_id);
! else
{
! struct varpool_node *vnode = varpool_get_node (decl);
!
! /* For escaped variables initialize them from nonlocal. */
! if (!varpool_all_refs_explicit_p (vnode))
! make_copy_constraint (vi, nonlocal_id);
!
! /* If this is a global variable with an initializer and we are in
! IPA mode generate constraints for it. */
! if (DECL_INITIAL (decl))
{
! VEC (ce_s, heap) *rhsc = NULL;
! struct constraint_expr lhs, *rhsp;
! unsigned i;
! get_constraint_for_rhs (DECL_INITIAL (decl), &rhsc);
! lhs.var = vi->id;
lhs.offset = 0;
lhs.type = SCALAR;
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
+ /* If this is a variable that escapes from the unit
+ the initializer escapes as well. */
+ if (!varpool_all_refs_explicit_p (vnode))
+ {
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ lhs.type = SCALAR;
+ FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
+ process_constraint (new_constraint (lhs, *rhsp));
+ }
+ VEC_free (ce_s, heap, rhsc);
}
}
}
*************** intra_create_variable_infos (void)
*** 5557,5563 ****
varinfo_t vi;
tree heapvar = build_fake_var_decl (TREE_TYPE (TREE_TYPE (t)));
DECL_EXTERNAL (heapvar) = 1;
! vi = get_varinfo (create_variable_info_for (heapvar, "PARM_NOALIAS"));
lhsc.var = get_vi_for_tree (t)->id;
lhsc.type = SCALAR;
lhsc.offset = 0;
--- 5567,5574 ----
varinfo_t vi;
tree heapvar = build_fake_var_decl (TREE_TYPE (TREE_TYPE (t)));
DECL_EXTERNAL (heapvar) = 1;
! vi = create_variable_info_for_1 (heapvar, "PARM_NOALIAS");
! insert_vi_for_tree (heapvar, vi);
lhsc.var = get_vi_for_tree (t)->id;
lhsc.type = SCALAR;
lhsc.offset = 0;
*************** intra_create_variable_infos (void)
*** 5566,5571 ****
--- 5577,5589 ----
rhsc.offset = 0;
process_constraint (new_constraint (lhsc, rhsc));
vi->is_restrict_var = 1;
+ for (; vi; vi = vi->next)
+ if (vi->may_have_pointers)
+ {
+ if (vi->only_restrict_pointers)
+ make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
+ make_copy_constraint (vi, nonlocal_id);
+ }
continue;
}
*************** ipa_pta_execute (void)
*** 6744,6749 ****
--- 6762,6773 ----
init_alias_vars ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ dump_cgraph (dump_file);
+ fprintf (dump_file, "\n");
+ }
+
/* Build the constraints. */
for (node = cgraph_nodes; node; node = node->next)
{
*************** ipa_pta_execute (void)
*** 6751,6760 ****
/* Nodes without a body are not interesting. Especially do not
visit clones at this point for now - we get duplicate decls
there for inline clones at least. */
! if (!cgraph_function_with_gimple_body_p (node)
! || node->clone_of)
continue;
vi = create_function_info_for (node->decl,
alias_get_name (node->decl));
cgraph_for_node_and_aliases (node, associate_varinfo_to_alias, vi,
true);
--- 6775,6785 ----
/* Nodes without a body are not interesting. Especially do not
visit clones at this point for now - we get duplicate decls
there for inline clones at least. */
! if (!cgraph_function_with_gimple_body_p (node))
continue;
+ gcc_assert (!node->clone_of);
+
vi = create_function_info_for (node->decl,
alias_get_name (node->decl));
cgraph_for_node_and_aliases (node, associate_varinfo_to_alias, vi,
true);
*************** ipa_pta_execute (void)
*** 6785,6792 ****
tree old_func_decl;
/* Nodes without a body are not interesting. */
! if (!cgraph_function_with_gimple_body_p (node)
! || node->clone_of)
continue;
if (dump_file)
--- 6810,6816 ----
tree old_func_decl;
/* Nodes without a body are not interesting. */
! if (!cgraph_function_with_gimple_body_p (node))
continue;
if (dump_file)
*************** ipa_pta_execute (void)
*** 6804,6814 ****
push_cfun (func);
current_function_decl = node->decl;
! if (node->local.externally_visible)
{
- /* For externally visible functions use local constraints for
- their arguments. For local functions we see all callers
- and thus do not need initial constraints for parameters. */
intra_create_variable_infos ();
/* We also need to make function return values escape. Nothing
--- 6828,6841 ----
push_cfun (func);
current_function_decl = node->decl;
! /* For externally visible or attribute used annotated functions use
! local constraints for their arguments.
! For local functions we see all callers and thus do not need initial
! constraints for parameters. */
! if (node->reachable_from_other_partition
! || node->local.externally_visible
! || node->needed)
{
intra_create_variable_infos ();
/* We also need to make function return values escape. Nothing
*************** ipa_pta_execute (void)
*** 6894,6901 ****
struct cgraph_edge *e;
/* Nodes without a body are not interesting. */
! if (!cgraph_function_with_gimple_body_p (node)
! || node->clone_of)
continue;
fn = DECL_STRUCT_FUNCTION (node->decl);
--- 6921,6927 ----
struct cgraph_edge *e;
/* Nodes without a body are not interesting. */
! if (!cgraph_function_with_gimple_body_p (node))
continue;
fn = DECL_STRUCT_FUNCTION (node->decl);
