Revision: 7094
Author: [email protected]
Date: Tue Mar 8 07:08:36 2011
Log: Avoid allocation of temporary zone lists when inserting representation
changes.
Instead of allocating fresh temporary lists for every instruction, reuse
the same instance and reset it between instructions.
This reduces the amount of zone memory used for inserting the HChange
instructions roughly by half.
Review URL: http://codereview.chromium.org/6628079
http://code.google.com/p/v8/source/detail?r=7094
Modified:
/branches/bleeding_edge/src/hydrogen.cc
/branches/bleeding_edge/src/hydrogen.h
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Tue Mar 8 02:04:23 2011
+++ /branches/bleeding_edge/src/hydrogen.cc Tue Mar 8 07:08:36 2011
@@ -1775,15 +1775,18 @@
}
-void HGraph::InsertRepresentationChanges(HValue* current) {
+void HGraph::InsertRepresentationChangesForValue(
+ HValue* current,
+ ZoneList<HValue*>* to_convert,
+ ZoneList<Representation>* to_convert_reps) {
Representation r = current->representation();
if (r.IsNone()) return;
if (current->uses()->length() == 0) return;
// Collect the representation changes in a sorted list. This allows
// us to avoid duplicate changes without searching the list.
- ZoneList<HValue*> to_convert(2);
- ZoneList<Representation> to_convert_reps(2);
+ ASSERT(to_convert->is_empty());
+ ASSERT(to_convert_reps->is_empty());
for (int i = 0; i < current->uses()->length(); ++i) {
HValue* use = current->uses()->at(i);
// The occurrences index means the index within the operand array
of "use"
@@ -1803,10 +1806,10 @@
Representation req = use->RequiredInputRepresentation(operand_index);
if (req.IsNone() || req.Equals(r)) continue;
int index = 0;
- while (to_convert.length() > index &&
- CompareConversionUses(to_convert[index],
+ while (index < to_convert->length() &&
+ CompareConversionUses(to_convert->at(index),
use,
- to_convert_reps[index],
+ to_convert_reps->at(index),
req) < 0) {
++index;
}
@@ -1816,13 +1819,13 @@
current->id(),
use->id());
}
- to_convert.InsertAt(index, use);
- to_convert_reps.InsertAt(index, req);
+ to_convert->InsertAt(index, use);
+ to_convert_reps->InsertAt(index, req);
}
- for (int i = 0; i < to_convert.length(); ++i) {
- HValue* use = to_convert[i];
- Representation r_to = to_convert_reps[i];
+ for (int i = 0; i < to_convert->length(); ++i) {
+ HValue* use = to_convert->at(i);
+ Representation r_to = to_convert_reps->at(i);
InsertRepresentationChangeForUse(current, use, r_to);
}
@@ -1830,6 +1833,8 @@
ASSERT(current->IsConstant());
current->Delete();
}
+ to_convert->Rewind(0);
+ to_convert_reps->Rewind(0);
}
@@ -1865,17 +1870,19 @@
}
}
+ ZoneList<HValue*> value_list(4);
+ ZoneList<Representation> rep_list(4);
for (int i = 0; i < blocks_.length(); ++i) {
// Process phi instructions first.
for (int j = 0; j < blocks_[i]->phis()->length(); j++) {
HPhi* phi = blocks_[i]->phis()->at(j);
- InsertRepresentationChanges(phi);
+ InsertRepresentationChangesForValue(phi, &value_list, &rep_list);
}
// Process normal instructions.
HInstruction* current = blocks_[i]->first();
while (current != NULL) {
- InsertRepresentationChanges(current);
+ InsertRepresentationChangesForValue(current, &value_list, &rep_list);
current = current->next();
}
}
=======================================
--- /branches/bleeding_edge/src/hydrogen.h Tue Mar 8 02:04:23 2011
+++ /branches/bleeding_edge/src/hydrogen.h Tue Mar 8 07:08:36 2011
@@ -296,7 +296,9 @@
void InsertRepresentationChangeForUse(HValue* value,
HValue* use,
Representation to);
- void InsertRepresentationChanges(HValue* current);
+ void InsertRepresentationChangesForValue(HValue* current,
+ ZoneList<HValue*>* value_list,
+ ZoneList<Representation>*
rep_list);
void InferTypes(ZoneList<HValue*>* worklist);
void InitializeInferredTypes(int from_inclusive, int to_inclusive);
void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
--
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