AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

Drop obsolete HCheckMaps::HandleSideEffectsDominator().

Browse Source 
In HCheckMaps::HandleSideEffectsDominator() we try to remove
redundant HCheckMaps instructions that are dominated by an
HStoreNamedField instruction with a transition. This is just
a special case of the check elimination and therefore obsolete
(it also gives some nice speedup since GVN just got cheaper).

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/261003002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21108 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
bmeurer@chromium.org 2014-05-02 05:59:07 +00:00
parent 30e5a737b3
commit b7148380cc
2 changed files with 1 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/hydrogen-instructions.cc
View File

@ -1669,25 +1669,6 @@ void HCheckInstanceType::GetCheckMaskAndTag(uint8_t* mask, uint8_t* tag) {
}
bool HCheckMaps::HandleSideEffectDominator(GVNFlag side_effect,
HValue* dominator) {
ASSERT(side_effect == kMaps);
// TODO(mstarzinger): For now we specialize on HStoreNamedField, but once
// type information is rich enough we should generalize this to any HType
// for which the map is known.
if (HasNoUses() && dominator->IsStoreNamedField()) {
HStoreNamedField* store = HStoreNamedField::cast(dominator);
if (!store->has_transition() || store->object() != value()) return false;
HConstant* transition = HConstant::cast(store->transition());
if (map_set_.Contains(Unique<Map>::cast(transition->GetUnique()))) {
DeleteAndReplaceWith(NULL);
return true;
}
}
return false;
}
void HCheckMaps::PrintDataTo(StringStream* stream) {
value()->PrintNameTo(stream);
stream->Add(" [%p", *map_set_.at(0).handle());

5
src/hydrogen-instructions.h
View File

@ -161,7 +161,6 @@ class LChunkBuilder;
V(WrapReceiver)
#define GVN_TRACKED_FLAG_LIST(V) \
V(Maps) \
V(NewSpacePromotion)
#define GVN_UNTRACKED_FLAG_LIST(V) \
@ -177,6 +176,7 @@ class LChunkBuilder;
V(ElementsPointer) \
V(GlobalVars) \
V(InobjectFields) \
V(Maps) \
V(OsrEntries) \
V(ExternalMemory) \
V(StringChars) \
@ -2762,8 +2762,6 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
return Representation::Tagged();
}
virtual bool HandleSideEffectDominator(GVNFlag side_effect,
HValue* dominator) V8_OVERRIDE;
virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
HValue* value() { return OperandAt(0); }
@ -2813,7 +2811,6 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
SetOperandAt(1, typecheck != NULL ? typecheck : value);
set_representation(Representation::Tagged());
SetFlag(kUseGVN);
SetFlag(kTrackSideEffectDominators);
}
bool omit_;