Reviewers: Toon Verwaest,
Message:
PTAL
Description:
Unify monomorphic and polymorphic cases in IC::PatchCache.
BUG=
Please review this at https://codereview.chromium.org/171683007/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+18, -24 lines):
M src/ic.cc
Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index
bd06cb6f9617d5bcf435673cbf507ae91eeedc97..2c0c59031c508d86c8e5d8af3aa5f9b52910af96
100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -605,27 +605,34 @@ bool IC::UpdatePolymorphicIC(Handle<HeapType> type,
Handle<String> name,
Handle<Code> code) {
if (!code->is_handler()) return false;
- int number_of_valid_types;
- int handler_to_overwrite = -1;
int number_of_types = types()->length();
- number_of_valid_types = number_of_types;
+
+ int deprecated_types = 0;
+ int handler_to_overwrite = -1;
for (int i = 0; i < number_of_types; i++) {
Handle<HeapType> current_type = types()->at(i);
- // Filter out deprecated maps to ensure their instances get migrated.
if (current_type->IsClass() &&
current_type->AsClass()->is_deprecated()) {
- number_of_valid_types--;
- // If the receiver type is already in the polymorphic IC, this
indicates
- // there was a prototoype chain failure. In that case, just overwrite
the
- // handler.
+ // Filter out deprecated maps to ensure their instances get migrated.
+ ++deprecated_types;
} else if (type->IsCurrently(current_type)) {
- ASSERT(handler_to_overwrite == -1);
- number_of_valid_types--;
+ // If the receiver type is already in the polymorphic IC, this
indicates
+ // there was a prototoype chain failure. In that case, just
overwrite the
+ // handler.
+ handler_to_overwrite = i;
+ } else if (handler_to_overwrite == -1 &&
+ current_type->IsClass() &&
+ type->IsClass() &&
+ IsTransitionOfMonomorphicTarget(*current_type->AsClass(),
+ *type->AsClass())) {
handler_to_overwrite = i;
}
}
+ int number_of_valid_types =
+ number_of_types - deprecated_types - (handler_to_overwrite != -1);
+
if (number_of_valid_types >= 4) return false;
if (number_of_types == 0) return false;
if (handlers()->length() < types()->length()) return false;
@@ -727,20 +734,7 @@ void IC::PatchCache(Handle<HeapType> type,
case MONOMORPHIC_PROTOTYPE_FAILURE:
UpdateMonomorphicIC(type, code, name);
break;
- case MONOMORPHIC: {
- // For now, call stubs are allowed to rewrite to the same stub. This
- // happens e.g., when the field does not contain a function.
- ASSERT(!target().is_identical_to(code));
- Map* old_map = first_map();
- Code* old_handler = first_handler();
- Map* map = type->IsClass() ? *type->AsClass() : NULL;
- if (old_handler == *code &&
- IsTransitionOfMonomorphicTarget(old_map, map)) {
- UpdateMonomorphicIC(type, code, name);
- break;
- }
- // Fall through.
- }
+ case MONOMORPHIC: // Fall through.
case POLYMORPHIC:
if (!target()->is_keyed_stub()) {
if (UpdatePolymorphicIC(type, name, code)) break;
--
--
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