Hi,
by making speculative indirect call machinery to be used by ipa-devirt I put it
on
wild on firefox converting about 30% of all polymorphic calls in the progrma
(30000).
This has provoked some issues I missed previously this patch fixes:
1) dumping - we no longer do only indirect calls from other units.
2) Adds sanity check to cgraph_speculative_call_info with explanation comment
since it already confused Maritn (Liska). I also noticed that
direct/indirect
names are swapped that is very confusing
3) I noticed that when we resolve speculation in a way so direct edge wins
and the edge is already inline, its frequency increases that ought to rescale
all callees of the node. I want to do this as part of edge scaling in
ipa-inline-transform, but droped a FIXME.
4) cgraph_redirect_edge_call_stmt_to_callee ICEd when especulation was
wrong and dumping was enabled.
5) ipa-inline needs to reset caches more carefuly because of the effect
described above: resolving a speculation in the middle of function has
cascading effect that eventually lead to sanity check failure.
Bootstrapped/regtested x86_64-linux, will commit it shortly.
* cgraph.c (cgraph_turn_edge_to_speculative): Fix debug output.
(cgraph_speculative_call_info): Fix parameter order and formating;
add sanity check.
(cgraph_resolve_speculation): Add FIXME about scaling profiles.
(cgraph_redirect_edge_call_stmt_to_callee): Fix ICE in debug dump.
* ipa-inline.c (heap_edge_removal_hook): Reset node growth cache.
(resolve_noninline_speculation): Update callee keys, too.
Index: cgraph.c
===================================================================
--- cgraph.c (revision 201966)
+++ cgraph.c (working copy)
@@ -1076,8 +1076,8 @@ cgraph_turn_edge_to_speculative (struct
if (dump_file)
{
- fprintf (dump_file, "Indirect call -> direct call from"
- " other module %s/%i => %s/%i\n",
+ fprintf (dump_file, "Indirect call -> speculative call"
+ " %s/%i => %s/%i\n",
xstrdup (cgraph_node_name (n)), n->symbol.order,
xstrdup (cgraph_node_name (n2)), n2->symbol.order);
}
@@ -1113,8 +1113,8 @@ cgraph_turn_edge_to_speculative (struct
void
cgraph_speculative_call_info (struct cgraph_edge *e,
- struct cgraph_edge *&indirect,
struct cgraph_edge *&direct,
+ struct cgraph_edge *&indirect,
struct ipa_ref *&reference)
{
struct ipa_ref *ref;
@@ -1137,16 +1137,18 @@ cgraph_speculative_call_info (struct cgr
}
else
for (e = e->caller->callees;
- e2->call_stmt != e->call_stmt || e2->lto_stmt_uid !=
e->lto_stmt_uid;
+ e2->call_stmt != e->call_stmt
+ || e2->lto_stmt_uid != e->lto_stmt_uid;
e = e->next_callee)
;
}
gcc_assert (e->speculative && e2->speculative);
- indirect = e;
- direct = e2;
+ direct = e;
+ indirect = e2;
reference = NULL;
- for (i = 0; ipa_ref_list_reference_iterate (&e->caller->symbol.ref_list, i,
ref); i++)
+ for (i = 0; ipa_ref_list_reference_iterate (&e->caller->symbol.ref_list,
+ i, ref); i++)
if (ref->speculative
&& ((ref->stmt && ref->stmt == e->call_stmt)
|| (ref->lto_stmt_uid == e->lto_stmt_uid)))
@@ -1154,6 +1156,11 @@ cgraph_speculative_call_info (struct cgr
reference = ref;
break;
}
+
+ /* Speculative edge always consist of all three components - direct edge,
+ indirect and reference. */
+
+ gcc_assert (e && e2 && ref);
}
/* Redirect callee of E to N. The function does not update underlying
@@ -1209,6 +1216,8 @@ cgraph_resolve_speculation (struct cgrap
fprintf (dump_file, "Speculative call turned into direct call.\n");
edge = e2;
e2 = tmp;
+ /* FIXME: If EDGE is inlined, we should scale up the frequencies and
counts
+ in the functions inlined through it. */
}
edge->count += e2->count;
edge->frequency += e2->frequency;
@@ -1305,12 +1314,12 @@ cgraph_redirect_edge_call_stmt_to_callee
else if (!gimple_check_call_matching_types (e->call_stmt,
e->callee->symbol.decl,
true))
{
- e = cgraph_resolve_speculation (e, NULL);
if (dump_file)
fprintf (dump_file, "Not expanding speculative call of %s/%i ->
%s/%i\n"
"Type mismatch.\n",
xstrdup (cgraph_node_name (e->caller)),
e->caller->symbol.order,
xstrdup (cgraph_node_name (e->callee)),
e->callee->symbol.order);
+ e = cgraph_resolve_speculation (e, NULL);
}
/* Expand speculation into GIMPLE code. */
else
Index: ipa-inline.c
===================================================================
--- ipa-inline.c (revision 201966)
+++ ipa-inline.c (working copy)
@@ -1397,6 +1397,8 @@ add_new_edges_to_heap (fibheap_t heap, v
static void
heap_edge_removal_hook (struct cgraph_edge *e, void *data)
{
+ if (e->callee)
+ reset_node_growth_cache (e->callee);
if (e->aux)
{
fibheap_delete_node ((fibheap_t)data, (fibnode_t)e->aux);
@@ -1467,12 +1469,12 @@ resolve_noninline_speculation (fibheap_t
bitmap updated_nodes = BITMAP_ALLOC (NULL);
cgraph_resolve_speculation (edge, NULL);
- reset_node_growth_cache (where);
reset_edge_caches (where);
inline_update_overall_summary (where);
update_caller_keys (edge_heap, where,
updated_nodes, NULL);
- reset_node_growth_cache (where);
+ update_callee_keys (edge_heap, where,
+ updated_nodes);
BITMAP_FREE (updated_nodes);
}
}
