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ipa-devirt TLC
- From: Jan Hubicka <hubicka at ucw dot cz>
- To: gcc-patches at gcc dot gnu dot org, mjambor at suse dot cz
- Date: Sat, 16 Aug 2014 11:15:10 +0200
- Subject: ipa-devirt TLC
- Authentication-results: sourceware.org; auth=none
Hi,
this patch wraps ipa_polymorphic_call_context into a C++ class. There are no functional changes.
I am heading to restructure the code in a way so call contextes can be used in forward propagation
and replace current ipa-cp BINFO walk. The goal is to split get_polymorphic_call_info in a way so it doesn't
need to know what call it is being used in.
Honza
* ipa-utils.h (ipa_polymorphic_call_context): Turn into class; add ctors.
(possible_polymorphic_call_targets, dump_possible_polymorphic_call_targets,
possible_polymorphic_call_target_p, possible_polymorphic_call_target_p): Simplify.
(get_dynamic_type): Remove.
* ipa-devirt.c (ipa_dummy_polymorphic_call_context): Remove.
(clear_speculation): Bring to ipa-deivrt.h
(get_class_context): Rename to ...
(ipa_polymorphic_call_context::restrict_to_inner_class): ... this one.
(contains_type_p): Update.
(get_dynamic_type): Rename to ...
ipa_polymorphic_call_context::get_dynamic_type(): ... this one.
(possible_polymorphic_call_targets): UPdate.
* tree-ssa-pre.c (eliminate_dom_walker::before_dom_children): Update.
* ipa-prop.c (ipa_analyze_call_uses): Update.
Index: ipa-utils.h
===================================================================
--- ipa-utils.h (revision 214041)
+++ ipa-utils.h (working copy)
@@ -36,7 +36,9 @@ struct ipa_dfs_info {
/* Context of polymorphic call. This is used by ipa-devirt walkers of the
type inheritance graph. */
-struct ipa_polymorphic_call_context {
+
+class ipa_polymorphic_call_context {
+public:
/* The called object appears in an object of type OUTER_TYPE
at offset OFFSET. When information is not 100% reliable, we
use SPECULATIVE_OUTER_TYPE and SPECULATIVE_OFFSET. */
@@ -51,10 +53,58 @@ struct ipa_polymorphic_call_context {
/* True if speculative outer object may be of derived type. We always
speculate that construction does not happen. */
bool speculative_maybe_derived_type;
+
+ /* Build empty "I know nothing" context. */
+ ipa_polymorphic_call_context ();
+
+ /* Build polymorphic call context for indirect call E. */
+ ipa_polymorphic_call_context (cgraph_edge *e);
+
+ /* Make context non-speculative. */
+ void clear_speculation ();
+
+ /* Walk container types and modify context to point to actual class
+ containing EXPECTED_TYPE as base class. */
+ bool restrict_to_inner_class (tree expected_type);
+
+ /* Look for vtable stores or constructor calls to work out dynamic type
+ of memory location. */
+ bool get_dynamic_type (tree, tree, tree, gimple);
};
-/* Context representing "I know nothing". */
-extern const ipa_polymorphic_call_context ipa_dummy_polymorphic_call_context;
+/* Build polymorphic call context for indirect call E. */
+
+inline
+ipa_polymorphic_call_context::ipa_polymorphic_call_context (cgraph_edge *e)
+{
+ offset = e->indirect_info->offset;
+ speculative_offset = e->indirect_info->speculative_offset;
+ outer_type = e->indirect_info->outer_type;
+ speculative_outer_type = e->indirect_info->speculative_outer_type;
+ maybe_in_construction = e->indirect_info->maybe_in_construction;
+ maybe_derived_type = e->indirect_info->maybe_derived_type;
+ speculative_maybe_derived_type = e->indirect_info->speculative_maybe_derived_type;
+}
+
+/* Build empty "I know nothing" context. */
+
+inline
+ipa_polymorphic_call_context::ipa_polymorphic_call_context ()
+ : offset(0), speculative_offset(0), outer_type(NULL),
+ speculative_outer_type(NULL), maybe_in_construction(false),
+ maybe_derived_type(false), speculative_maybe_derived_type(false)
+{
+}
+
+/* Make context non-speculative. */
+
+inline void
+ipa_polymorphic_call_context::clear_speculation ()
+{
+ speculative_outer_type = NULL;
+ speculative_offset = 0;
+ speculative_maybe_derived_type = false;
+}
/* In ipa-utils.c */
void ipa_print_order (FILE*, const char *, struct cgraph_node**, int);
@@ -95,7 +145,6 @@ tree get_polymorphic_call_info (tree, tr
HOST_WIDE_INT *,
ipa_polymorphic_call_context *,
gimple call = NULL);
-bool get_dynamic_type (tree, ipa_polymorphic_call_context *, tree, tree, gimple);
bool get_polymorphic_call_info_from_invariant (ipa_polymorphic_call_context *,
tree, tree, HOST_WIDE_INT);
bool decl_maybe_in_construction_p (tree, tree, gimple, tree);
@@ -121,13 +170,7 @@ possible_polymorphic_call_targets (struc
int *nonconstruction_targets = NULL)
{
gcc_checking_assert (e->indirect_info->polymorphic);
- ipa_polymorphic_call_context context = {e->indirect_info->offset,
- e->indirect_info->speculative_offset,
- e->indirect_info->outer_type,
- e->indirect_info->speculative_outer_type,
- e->indirect_info->maybe_in_construction,
- e->indirect_info->maybe_derived_type,
- e->indirect_info->speculative_maybe_derived_type};
+ ipa_polymorphic_call_context context(e);
return possible_polymorphic_call_targets (e->indirect_info->otr_type,
e->indirect_info->otr_token,
context,
@@ -163,13 +206,7 @@ inline void
dump_possible_polymorphic_call_targets (FILE *f, struct cgraph_edge *e)
{
gcc_checking_assert (e->indirect_info->polymorphic);
- ipa_polymorphic_call_context context = {e->indirect_info->offset,
- e->indirect_info->speculative_offset,
- e->indirect_info->outer_type,
- e->indirect_info->speculative_outer_type,
- e->indirect_info->maybe_in_construction,
- e->indirect_info->maybe_derived_type,
- e->indirect_info->speculative_maybe_derived_type};
+ ipa_polymorphic_call_context context(e);
dump_possible_polymorphic_call_targets (f, e->indirect_info->otr_type,
e->indirect_info->otr_token,
context);
@@ -182,11 +219,7 @@ inline bool
possible_polymorphic_call_target_p (struct cgraph_edge *e,
struct cgraph_node *n)
{
- ipa_polymorphic_call_context context = {e->indirect_info->offset, 0,
- e->indirect_info->outer_type, NULL,
- e->indirect_info->maybe_in_construction,
- e->indirect_info->maybe_derived_type,
- false};
+ ipa_polymorphic_call_context context(e);
return possible_polymorphic_call_target_p (e->indirect_info->otr_type,
e->indirect_info->otr_token,
context, n);
@@ -199,10 +232,11 @@ inline bool
possible_polymorphic_call_target_p (tree call,
struct cgraph_node *n)
{
+ ipa_polymorphic_call_context context;
return possible_polymorphic_call_target_p (obj_type_ref_class (call),
tree_to_uhwi
(OBJ_TYPE_REF_TOKEN (call)),
- ipa_dummy_polymorphic_call_context,
+ context,
n);
}
#endif /* GCC_IPA_UTILS_H */
Index: ipa-devirt.c
===================================================================
--- ipa-devirt.c (revision 214041)
+++ ipa-devirt.c (working copy)
@@ -141,10 +141,6 @@ static bool odr_types_equivalent_p (tree
static bool odr_violation_reported = false;
-/* Dummy polymorphic call context. */
-
-const ipa_polymorphic_call_context ipa_dummy_polymorphic_call_context
- = {0, 0, NULL, NULL, false, true, true};
/* Pointer set of all call targets appearing in the cache. */
static hash_set<cgraph_node *> *cached_polymorphic_call_targets;
@@ -1853,23 +1849,13 @@ contains_polymorphic_type_p (const_tree
return false;
}
-/* Clear speculative info from CONTEXT. */
-
-static void
-clear_speculation (ipa_polymorphic_call_context *context)
-{
- context->speculative_outer_type = NULL;
- context->speculative_offset = 0;
- context->speculative_maybe_derived_type = false;
-}
-
-/* CONTEXT->OUTER_TYPE is a type of memory object where object of EXPECTED_TYPE
- is contained at CONTEXT->OFFSET. Walk the memory representation of
- CONTEXT->OUTER_TYPE and find the outermost class type that match
- EXPECTED_TYPE or contain EXPECTED_TYPE as a base. Update CONTEXT
+/* THIS->OUTER_TYPE is a type of memory object where object of EXPECTED_TYPE
+ is contained at THIS->OFFSET. Walk the memory representation of
+ THIS->OUTER_TYPE and find the outermost class type that match
+ EXPECTED_TYPE or contain EXPECTED_TYPE as a base. Update THIS
to represent it.
- For example when CONTEXT represents type
+ For example when THIS represents type
class A
{
int a;
@@ -1880,32 +1866,31 @@ clear_speculation (ipa_polymorphic_call_
sizeof(int).
If we can not find corresponding class, give up by setting
- CONTEXT->OUTER_TYPE to EXPECTED_TYPE and CONTEXT->OFFSET to NULL.
+ THIS->OUTER_TYPE to EXPECTED_TYPE and THIS->OFFSET to NULL.
Return true when lookup was sucesful. */
-static bool
-get_class_context (ipa_polymorphic_call_context *context,
- tree expected_type)
+bool
+ipa_polymorphic_call_context::restrict_to_inner_class (tree expected_type)
{
- tree type = context->outer_type;
- HOST_WIDE_INT offset = context->offset;
+ tree type = outer_type;
+ HOST_WIDE_INT cur_offset = offset;
bool speculative = false;
bool speculation_valid = false;
bool valid = false;
- if (!context->outer_type)
+ if (!outer_type)
{
- type = context->outer_type = expected_type;
- context->offset = offset = 0;
+ type = outer_type = expected_type;
+ offset = cur_offset = 0;
}
- if (context->speculative_outer_type == context->outer_type
- && (!context->maybe_derived_type
- || context->speculative_maybe_derived_type))
+ if (speculative_outer_type == outer_type
+ && (!maybe_derived_type
+ || speculative_maybe_derived_type))
{
- context->speculative_outer_type = NULL;
- context->speculative_offset = 0;
- context->speculative_maybe_derived_type = false;
+ speculative_outer_type = NULL;
+ speculative_offset = 0;
+ speculative_maybe_derived_type = false;
}
/* See if speculative type seem to be derrived from outer_type.
@@ -1917,14 +1902,14 @@ get_class_context (ipa_polymorphic_call_
MAYBE_DERIVED_TYPE is false and we have full non-speculative information or
the loop bellow will correctly update SPECULATIVE_OUTER_TYPE
and SPECULATIVE_MAYBE_DERIVED_TYPE. */
- if (context->speculative_outer_type
- && context->speculative_offset >= context->offset
- && contains_type_p (context->speculative_outer_type,
- context->offset - context->speculative_offset,
- context->outer_type))
- speculation_valid = context->maybe_derived_type;
+ if (speculative_outer_type
+ && speculative_offset >= offset
+ && contains_type_p (speculative_outer_type,
+ offset - speculative_offset,
+ outer_type))
+ speculation_valid = maybe_derived_type;
else
- clear_speculation (context);
+ clear_speculation ();
/* Find the sub-object the constant actually refers to and mark whether it is
an artificial one (as opposed to a user-defined one).
@@ -1950,19 +1935,19 @@ get_class_context (ipa_polymorphic_call_
gcc_assert (valid);
/* If we did not match the offset, just give up on speculation. */
- if (offset != 0
- || (types_same_for_odr (context->speculative_outer_type,
- context->outer_type)
- && (context->maybe_derived_type
- == context->speculative_maybe_derived_type)))
- clear_speculation (context);
+ if (cur_offset != 0
+ || (types_same_for_odr (speculative_outer_type,
+ outer_type)
+ && (maybe_derived_type
+ == speculative_maybe_derived_type)))
+ clear_speculation ();
return true;
}
else
{
/* Type can not contain itself on an non-zero offset. In that case
just give up. */
- if (offset != 0)
+ if (cur_offset != 0)
{
valid = false;
goto give_up;
@@ -1971,17 +1956,17 @@ get_class_context (ipa_polymorphic_call_
/* If speculation is not valid or we determined type precisely,
we are done. */
if (!speculation_valid
- || !context->maybe_derived_type)
+ || !maybe_derived_type)
{
- clear_speculation (context);
+ clear_speculation ();
return true;
}
/* Otherwise look into speculation now. */
else
{
speculative = true;
- type = context->speculative_outer_type;
- offset = context->speculative_offset;
+ type = speculative_outer_type;
+ cur_offset = speculative_offset;
continue;
}
}
@@ -1997,7 +1982,7 @@ get_class_context (ipa_polymorphic_call_
pos = int_bit_position (fld);
size = tree_to_uhwi (DECL_SIZE (fld));
- if (pos <= offset && (pos + size) > offset)
+ if (pos <= cur_offset && (pos + size) > cur_offset)
break;
}
@@ -2005,23 +1990,23 @@ get_class_context (ipa_polymorphic_call_
goto give_up;
type = TYPE_MAIN_VARIANT (TREE_TYPE (fld));
- offset -= pos;
+ cur_offset -= pos;
/* DECL_ARTIFICIAL represents a basetype. */
if (!DECL_ARTIFICIAL (fld))
{
if (!speculative)
{
- context->outer_type = type;
- context->offset = offset;
+ outer_type = type;
+ offset = cur_offset;
/* As soon as we se an field containing the type,
we know we are not looking for derivations. */
- context->maybe_derived_type = false;
+ maybe_derived_type = false;
}
else
{
- context->speculative_outer_type = type;
- context->speculative_offset = offset;
- context->speculative_maybe_derived_type = false;
+ speculative_outer_type = type;
+ speculative_offset = cur_offset;
+ speculative_maybe_derived_type = false;
}
}
}
@@ -2033,19 +2018,19 @@ get_class_context (ipa_polymorphic_call_
if (!tree_fits_shwi_p (TYPE_SIZE (subtype))
|| !tree_to_shwi (TYPE_SIZE (subtype)) <= 0)
goto give_up;
- offset = offset % tree_to_shwi (TYPE_SIZE (subtype));
+ cur_offset = cur_offset % tree_to_shwi (TYPE_SIZE (subtype));
type = subtype;
if (!speculative)
{
- context->outer_type = type;
- context->offset = offset;
- context->maybe_derived_type = false;
+ outer_type = type;
+ offset = cur_offset;
+ maybe_derived_type = false;
}
else
{
- context->speculative_outer_type = type;
- context->speculative_offset = offset;
- context->speculative_maybe_derived_type = false;
+ speculative_outer_type = type;
+ speculative_offset = cur_offset;
+ speculative_maybe_derived_type = false;
}
}
/* Give up on anything else. */
@@ -2056,13 +2041,13 @@ get_class_context (ipa_polymorphic_call_
/* If we failed to find subtype we look for, give up and fall back to the
most generic query. */
give_up:
- clear_speculation (context);
+ clear_speculation ();
if (valid)
return true;
- context->outer_type = expected_type;
- context->offset = 0;
- context->maybe_derived_type = true;
- context->maybe_in_construction = true;
+ outer_type = expected_type;
+ offset = 0;
+ maybe_derived_type = true;
+ maybe_in_construction = true;
/* POD can be changed to an instance of a polymorphic type by
placement new. Here we play safe and assume that any
non-polymorphic type is POD. */
@@ -2071,7 +2056,7 @@ give_up:
|| !polymorphic_type_binfo_p (TYPE_BINFO (type)))
&& (!TYPE_SIZE (type)
|| TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
- || (offset + tree_to_uhwi (TYPE_SIZE (expected_type)) <=
+ || (cur_offset + tree_to_uhwi (TYPE_SIZE (expected_type)) <=
tree_to_uhwi (TYPE_SIZE (type)))))
return true;
return false;
@@ -2083,10 +2068,10 @@ static bool
contains_type_p (tree outer_type, HOST_WIDE_INT offset,
tree otr_type)
{
- ipa_polymorphic_call_context context = {offset, 0,
- TYPE_MAIN_VARIANT (outer_type),
- NULL, false, true, false};
- return get_class_context (&context, otr_type);
+ ipa_polymorphic_call_context context;
+ context.offset = offset;
+ context.outer_type = TYPE_MAIN_VARIANT (outer_type);
+ return context.restrict_to_inner_class (otr_type);
}
/* Lookup base of BINFO that has virtual table VTABLE with OFFSET. */
@@ -2834,7 +2819,7 @@ check_stmt_for_type_change (ao_ref *ao A
return false;
}
-/* CONTEXT is polymorphic call context obtained from get_polymorphic_context.
+/* THIS is polymorphic call context obtained from get_polymorphic_context.
OTR_OBJECT is pointer to the instance returned by OBJ_TYPE_REF_OBJECT.
INSTANCE is pointer to the outer instance as returned by
get_polymorphic_context. To avoid creation of temporary expressions,
@@ -2851,11 +2836,10 @@ check_stmt_for_type_change (ao_ref *ao A
So it is not suitable for use withing fold_stmt and similar uses. */
bool
-get_dynamic_type (tree instance,
- ipa_polymorphic_call_context *context,
- tree otr_object,
- tree otr_type,
- gimple call)
+ipa_polymorphic_call_context::get_dynamic_type (tree instance,
+ tree otr_object,
+ tree otr_type,
+ gimple call)
{
struct type_change_info tci;
ao_ref ao;
@@ -2863,7 +2847,7 @@ get_dynamic_type (tree instance,
tree instance_ref = NULL;
gimple stmt = call;
- if (!context->maybe_in_construction && !context->maybe_derived_type)
+ if (!maybe_in_construction && !maybe_derived_type)
return false;
/* We need to obtain refernce to virtual table pointer. It is better
@@ -2916,11 +2900,11 @@ get_dynamic_type (tree instance,
or from INSTANCE with offset OFFSET. */
if (base_ref
&& ((TREE_CODE (base_ref) == MEM_REF
- && ((offset2 == context->offset
+ && ((offset2 == offset
&& TREE_OPERAND (base_ref, 0) == instance)
|| (!offset2 && TREE_OPERAND (base_ref, 0) == otr_object)))
|| (DECL_P (instance) && base_ref == instance
- && offset2 == context->offset)))
+ && offset2 == offset)))
{
stmt = SSA_NAME_DEF_STMT (ref);
instance_ref = ref_exp;
@@ -2959,13 +2943,13 @@ get_dynamic_type (tree instance,
print_generic_expr (dump_file, otr_object, TDF_SLIM);
fprintf (dump_file, " Outer instance pointer: ");
print_generic_expr (dump_file, instance, TDF_SLIM);
- fprintf (dump_file, " offset: %i (bits)", (int)context->offset);
+ fprintf (dump_file, " offset: %i (bits)", (int)offset);
fprintf (dump_file, " vtbl reference: ");
print_generic_expr (dump_file, instance_ref, TDF_SLIM);
fprintf (dump_file, "\n");
}
- tci.offset = context->offset;
+ tci.offset = offset;
tci.instance = instance;
tci.vtbl_ptr_ref = instance_ref;
gcc_assert (TREE_CODE (instance) != MEM_REF);
@@ -3021,17 +3005,17 @@ get_dynamic_type (tree instance,
and we can stop, we will never see the calls into constructors of
sub-objects in this code.
- Therefore if the static outer type was found (context->outer_type)
+ Therefore if the static outer type was found (outer_type)
we can safely ignore tci.speculative that is set on calls and give up
only if there was dyanmic type store that may affect given variable
(seen_unanalyzed_store) */
if (!tci.type_maybe_changed)
{
- if (!context->outer_type || tci.seen_unanalyzed_store)
+ if (!outer_type || tci.seen_unanalyzed_store)
return false;
- if (context->maybe_in_construction)
- context->maybe_in_construction = false;
+ if (maybe_in_construction)
+ maybe_in_construction = false;
if (dump_file)
fprintf (dump_file, " No dynamic type change found.\n");
return true;
@@ -3044,25 +3028,25 @@ get_dynamic_type (tree instance,
if (!tci.speculative
/* Again in instances located in static storage we are interested only
in constructor stores. */
- || (context->outer_type
+ || (outer_type
&& !tci.seen_unanalyzed_store
- && context->offset == tci.offset
+ && offset == tci.offset
&& types_same_for_odr (tci.known_current_type,
- context->outer_type)))
+ outer_type)))
{
- context->outer_type = tci.known_current_type;
- context->offset = tci.known_current_offset;
- context->maybe_in_construction = false;
- context->maybe_derived_type = false;
+ outer_type = tci.known_current_type;
+ offset = tci.known_current_offset;
+ maybe_in_construction = false;
+ maybe_derived_type = false;
if (dump_file)
fprintf (dump_file, " Determined dynamic type.\n");
}
- else if (!context->speculative_outer_type
- || context->speculative_maybe_derived_type)
+ else if (!speculative_outer_type
+ || speculative_maybe_derived_type)
{
- context->speculative_outer_type = tci.known_current_type;
- context->speculative_offset = tci.known_current_offset;
- context->speculative_maybe_derived_type = false;
+ speculative_outer_type = tci.known_current_type;
+ speculative_offset = tci.known_current_offset;
+ speculative_maybe_derived_type = false;
if (dump_file)
fprintf (dump_file, " Determined speculative dynamic type.\n");
}
@@ -3253,7 +3237,7 @@ possible_polymorphic_call_targets (tree
/* Do not bother to compute speculative info when user do not asks for it. */
if (!speculative_targetsp || !context.speculative_outer_type)
- clear_speculation (&context);
+ context.clear_speculation ();
type = get_odr_type (otr_type, true);
@@ -3263,7 +3247,7 @@ possible_polymorphic_call_targets (tree
/* Lookup the outer class type we want to walk. */
if ((context.outer_type || context.speculative_outer_type)
- && !get_class_context (&context, otr_type))
+ && !context.restrict_to_inner_class (otr_type))
{
if (completep)
*completep = false;
@@ -3274,7 +3258,7 @@ possible_polymorphic_call_targets (tree
return nodes;
}
- /* Check that get_class_context kept the main variant. */
+ /* Check that restrict_to_inner_class kept the main variant. */
gcc_assert (!context.outer_type
|| TYPE_MAIN_VARIANT (context.outer_type) == context.outer_type);
Index: tree-ssa-pre.c
===================================================================
--- tree-ssa-pre.c (revision 214041)
+++ tree-ssa-pre.c (working copy)
@@ -4374,8 +4374,7 @@ eliminate_dom_walker::before_dom_childre
fn,
&otr_type, &otr_token, &context, stmt);
- get_dynamic_type (instance, &context,
- OBJ_TYPE_REF_OBJECT (fn), otr_type, stmt);
+ context.get_dynamic_type (instance, OBJ_TYPE_REF_OBJECT (fn), otr_type, stmt);
vec <cgraph_node *>targets
= possible_polymorphic_call_targets (obj_type_ref_class (fn),
Index: ipa-prop.c
===================================================================
--- ipa-prop.c (revision 214041)
+++ ipa-prop.c (working copy)
@@ -2356,9 +2356,9 @@ ipa_analyze_call_uses (struct func_body_
&otr_type, &otr_token,
&context, call);
- if (get_dynamic_type (instance, &context,
- OBJ_TYPE_REF_OBJECT (target),
- otr_type, call))
+ if (context.get_dynamic_type (instance,
+ OBJ_TYPE_REF_OBJECT (target),
+ otr_type, call))
{
gcc_assert (TREE_CODE (otr_type) == RECORD_TYPE);
cs->indirect_info->polymorphic = true;