Revision: 19322
Author: [email protected]
Date: Wed Feb 12 12:34:14 2014 UTC
Log: Improve computation of effects for load elimination.
[email protected]
Review URL: https://codereview.chromium.org/152953004
http://code.google.com/p/v8/source/detail?r=19322
Modified:
/branches/bleeding_edge/src/hydrogen-load-elimination.cc
=======================================
--- /branches/bleeding_edge/src/hydrogen-load-elimination.cc Tue Feb 11
19:18:06 2014 UTC
+++ /branches/bleeding_edge/src/hydrogen-load-elimination.cc Wed Feb 12
12:34:14 2014 UTC
@@ -453,11 +453,7 @@
class HLoadEliminationEffects : public ZoneObject {
public:
explicit HLoadEliminationEffects(Zone* zone)
- : zone_(zone),
- maps_stored_(false),
- fields_stored_(false),
- elements_stored_(false),
- stores_(5, zone) { }
+ : zone_(zone), stores_(5, zone) { }
inline bool Disabled() {
return false; // Effects are _not_ disabled.
@@ -465,37 +461,25 @@
// Process a possibly side-effecting instruction.
void Process(HInstruction* instr, Zone* zone) {
- switch (instr->opcode()) {
- case HValue::kStoreNamedField: {
- stores_.Add(HStoreNamedField::cast(instr), zone_);
- break;
- }
- case HValue::kOsrEntry: {
- // Kill everything. Loads must not be hoisted past the OSR entry.
- maps_stored_ = true;
- fields_stored_ = true;
- elements_stored_ = true;
- }
- default: {
- fields_stored_ |= instr->CheckChangesFlag(kInobjectFields);
- maps_stored_ |= instr->CheckChangesFlag(kMaps);
- maps_stored_ |= instr->CheckChangesFlag(kElementsKind);
- elements_stored_ |= instr->CheckChangesFlag(kElementsKind);
- elements_stored_ |= instr->CheckChangesFlag(kElementsPointer);
- }
+ if (instr->IsStoreNamedField()) {
+ stores_.Add(HStoreNamedField::cast(instr), zone_);
+ } else {
+ flags_.Add(instr->ChangesFlags());
}
}
// Apply these effects to the given load elimination table.
void Apply(HLoadEliminationTable* table) {
- if (fields_stored_) {
+ // Loads must not be hoisted past the OSR entry, therefore we kill
+ // everything if we see an OSR entry.
+ if (flags_.Contains(kInobjectFields) || flags_.Contains(kOsrEntries)) {
table->Kill();
return;
}
- if (maps_stored_) {
+ if (flags_.Contains(kElementsKind) || flags_.Contains(kMaps)) {
table->KillOffset(JSObject::kMapOffset);
}
- if (elements_stored_) {
+ if (flags_.Contains(kElementsKind) ||
flags_.Contains(kElementsPointer)) {
table->KillOffset(JSObject::kElementsOffset);
}
@@ -507,9 +491,7 @@
// Union these effects with the other effects.
void Union(HLoadEliminationEffects* that, Zone* zone) {
- maps_stored_ |= that->maps_stored_;
- fields_stored_ |= that->fields_stored_;
- elements_stored_ |= that->elements_stored_;
+ flags_.Add(that->flags_);
for (int i = 0; i < that->stores_.length(); i++) {
stores_.Add(that->stores_[i], zone);
}
@@ -517,9 +499,7 @@
private:
Zone* zone_;
- bool maps_stored_ : 1;
- bool fields_stored_ : 1;
- bool elements_stored_ : 1;
+ GVNFlagSet flags_;
ZoneList<HStoreNamedField*> stores_;
};
--
--
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