Reviewers: Yang,
Description:
Fasterify ICSlotCache
Use a hash map instead of a list for faster lookups.
BUG=chromium:517406
LOG=n
[email protected]
Please review this at https://codereview.chromium.org/1279763006/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+27, -24 lines):
M src/ast.h
M src/ast.cc
M src/ast-numbering.cc
M src/hashmap.h
Index: src/ast-numbering.cc
diff --git a/src/ast-numbering.cc b/src/ast-numbering.cc
index
8676eeb995e064ffd5bb77c7097903459286de83..1f3268ca29fd89c92ef7c3930e5a955cde47d543
100644
--- a/src/ast-numbering.cc
+++ b/src/ast-numbering.cc
@@ -15,7 +15,7 @@ class AstNumberingVisitor final : public AstVisitor {
: AstVisitor(),
next_id_(BailoutId::FirstUsable().ToInt()),
properties_(zone),
- ic_slot_cache_(4),
+ ic_slot_cache_(zone),
dont_optimize_reason_(kNoReason) {
InitializeAstVisitor(isolate, zone);
}
Index: src/ast.cc
diff --git a/src/ast.cc b/src/ast.cc
index
9dd825a6f96b96065806e9b8f489dd96364776a5..624d462323a9574c278af3e01a240976509239ac
100644
--- a/src/ast.cc
+++ b/src/ast.cc
@@ -102,7 +102,7 @@ void
VariableProxy::SetFirstFeedbackICSlot(FeedbackVectorICSlot slot,
ICSlotCache* cache) {
variable_feedback_slot_ = slot;
if (var()->IsUnallocated()) {
- cache->Add(VariableICSlotPair(var(), slot));
+ cache->Put(var(), slot);
}
}
@@ -113,12 +113,11 @@ FeedbackVectorRequirements
VariableProxy::ComputeFeedbackRequirements(
// VariableProxies that point to the same Variable within a function
can
// make their loads from the same IC slot.
if (var()->IsUnallocated()) {
- for (int i = 0; i < cache->length(); i++) {
- VariableICSlotPair& pair = cache->at(i);
- if (pair.variable() == var()) {
- variable_feedback_slot_ = pair.slot();
- return FeedbackVectorRequirements(0, 0);
- }
+ ZoneHashMap::Entry* entry = cache->Get(var());
+ if (entry != NULL) {
+ variable_feedback_slot_ = FeedbackVectorICSlot(
+ static_cast<int>(reinterpret_cast<intptr_t>(entry->value)));
+ return FeedbackVectorRequirements(0, 0);
}
}
return FeedbackVectorRequirements(0, 1);
Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index
f9d7af1e0d70d624d2f88372b75facba3e6f27ee..b9e79270da1a895d4fc20dc90acd83c3fd1a1f80
100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -152,25 +152,29 @@ class FeedbackVectorRequirements {
};
-class VariableICSlotPair final {
+class ICSlotCache {
public:
- VariableICSlotPair(Variable* variable, FeedbackVectorICSlot slot)
- : variable_(variable), slot_(slot) {}
- VariableICSlotPair()
- : variable_(NULL), slot_(FeedbackVectorICSlot::Invalid()) {}
+ explicit ICSlotCache(Zone* zone)
+ : zone_(zone),
+ hash_map_(HashMap::PointersMatch,
ZoneHashMap::kDefaultHashMapCapacity,
+ ZoneAllocationPolicy(zone)) {}
- Variable* variable() const { return variable_; }
- FeedbackVectorICSlot slot() const { return slot_; }
+ void Put(Variable* variable, FeedbackVectorICSlot slot) {
+ ZoneHashMap::Entry* entry = hash_map_.LookupOrInsert(
+ variable, ComputePointerHash(variable),
ZoneAllocationPolicy(zone_));
+ entry->value = reinterpret_cast<void*>(slot.ToInt());
+ }
+
+ ZoneHashMap::Entry* Get(Variable* variable) const {
+ return hash_map_.Lookup(variable, ComputePointerHash(variable));
+ }
private:
- Variable* variable_;
- FeedbackVectorICSlot slot_;
+ Zone* zone_;
+ ZoneHashMap hash_map_;
};
-typedef List<VariableICSlotPair> ICSlotCache;
-
-
class AstProperties final BASE_EMBEDDED {
public:
enum Flag {
Index: src/hashmap.h
diff --git a/src/hashmap.h b/src/hashmap.h
index
688fc2cf369ad3c5d100d06f54655e2b5e267da4..ee3797fe5940b82abc78af2de4ab2f6da7c2541e
100644
--- a/src/hashmap.h
+++ b/src/hashmap.h
@@ -43,7 +43,7 @@ class TemplateHashMapImpl {
// If an entry with matching key is found, returns that entry.
// Otherwise, NULL is returned.
- Entry* Lookup(void* key, uint32_t hash);
+ Entry* Lookup(void* key, uint32_t hash) const;
// If an entry with matching key is found, returns that entry.
// If no matching entry is found, a new entry is inserted with
@@ -90,7 +90,7 @@ class TemplateHashMapImpl {
uint32_t occupancy_;
Entry* map_end() const { return map_ + capacity_; }
- Entry* Probe(void* key, uint32_t hash);
+ Entry* Probe(void* key, uint32_t hash) const;
void Initialize(uint32_t capacity, AllocationPolicy allocator);
void Resize(AllocationPolicy allocator);
};
@@ -113,7 +113,7 @@
TemplateHashMapImpl<AllocationPolicy>::~TemplateHashMapImpl() {
template <class AllocationPolicy>
typename TemplateHashMapImpl<AllocationPolicy>::Entry*
-TemplateHashMapImpl<AllocationPolicy>::Lookup(void* key, uint32_t hash) {
+TemplateHashMapImpl<AllocationPolicy>::Lookup(void* key, uint32_t hash)
const {
Entry* p = Probe(key, hash);
return p->key != NULL ? p : NULL;
}
@@ -242,7 +242,7 @@ typename TemplateHashMapImpl<AllocationPolicy>::Entry*
template <class AllocationPolicy>
typename TemplateHashMapImpl<AllocationPolicy>::Entry*
-TemplateHashMapImpl<AllocationPolicy>::Probe(void* key, uint32_t hash) {
+TemplateHashMapImpl<AllocationPolicy>::Probe(void* key, uint32_t hash)
const {
DCHECK(key != NULL);
DCHECK(base::bits::IsPowerOfTwo32(capacity_));
--
--
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