From ff54f31c67f1425abcb15a7858210e55c38c6776 Mon Sep 17 00:00:00 2001
From: Jan de Mooij <jdemooij@mozilla.com>
Date: Tue, 13 Dec 2022 16:57:16 +0000
Subject: [PATCH] Bug 1805430 part 2 - Optimize generateNewDictionaryShape a
bit. r=jonco
Adds a constructor that takes the object for which we want to create a new shape,
so that we can get rid of some roots.
Differential Revision: https://phabricator.services.mozilla.com/D164572
---
js/src/vm/Shape.cpp | 20 +++++++++++++-------
js/src/vm/Shape.h | 6 ++++--
2 files changed, 17 insertions(+), 9 deletions(-)
diff --git a/js/src/vm/Shape.cpp b/js/src/vm/Shape.cpp
index ac2a1e04f43f1..357dd8a75d65e 100644
--- a/js/src/vm/Shape.cpp
+++ b/js/src/vm/Shape.cpp
@@ -986,13 +986,7 @@ bool NativeObject::generateNewDictionaryShape(JSContext* cx,
MOZ_ASSERT(obj->inDictionaryMode());
- Rooted<BaseShape*> base(cx, obj->shape()->base());
- Rooted<DictionaryPropMap*> map(cx, obj->dictionaryShape()->propMap());
- uint32_t mapLength = obj->shape()->propMapLength();
-
- Shape* shape =
- DictionaryShape::new_(cx, base, obj->shape()->objectFlags(),
- obj->shape()->numFixedSlots(), map, mapLength);
+ Shape* shape = DictionaryShape::new_(cx, obj);
if (!shape) {
return false;
}
@@ -1128,6 +1122,18 @@ DictionaryShape* DictionaryShape::new_(JSContext* cx, Handle<BaseShape*> base,
mapLength);
}
+DictionaryShape::DictionaryShape(NativeObject* nobj)
+ : DictionaryShape(nobj->shape()->base(), nobj->shape()->objectFlags(),
+ nobj->shape()->numFixedSlots(),
+ nobj->dictionaryShape()->propMap(),
+ nobj->shape()->propMapLength()) {}
+
+// static
+DictionaryShape* DictionaryShape::new_(JSContext* cx,
+ Handle<NativeObject*> obj) {
+ return cx->newCell<DictionaryShape>(obj);
+}
+
// static
ProxyShape* ProxyShape::new_(JSContext* cx, Handle<BaseShape*> base,
ObjectFlags objectFlags) {
diff --git a/js/src/vm/Shape.h b/js/src/vm/Shape.h
index 9af9df3041917..9492135d0f0a7 100644
--- a/js/src/vm/Shape.h
+++ b/js/src/vm/Shape.h
@@ -511,7 +511,7 @@ class NativeShape : public Shape {
class SharedShape : public NativeShape {
friend class js::gc::CellAllocator;
SharedShape(BaseShape* base, ObjectFlags objectFlags, uint32_t nfixed,
- PropMap* map, uint32_t mapLength)
+ SharedPropMap* map, uint32_t mapLength)
: NativeShape(Kind::Shared, base, objectFlags, nfixed, map, mapLength) {
initSmallSlotSpan();
}
@@ -622,11 +622,12 @@ class DictionaryShape : public NativeShape {
friend class NativeObject;
DictionaryShape(BaseShape* base, ObjectFlags objectFlags, uint32_t nfixed,
- PropMap* map, uint32_t mapLength)
+ DictionaryPropMap* map, uint32_t mapLength)
: NativeShape(Kind::Dictionary, base, objectFlags, nfixed, map,
mapLength) {
MOZ_ASSERT(map);
}
+ explicit DictionaryShape(NativeObject* nobj);
// Methods to set fields of a new dictionary shape. Must not be used for
// shapes that might have been exposed to script.
@@ -648,6 +649,7 @@ class DictionaryShape : public NativeShape {
ObjectFlags objectFlags, uint32_t nfixed,
Handle<DictionaryPropMap*> map,
uint32_t mapLength);
+ static DictionaryShape* new_(JSContext* cx, Handle<NativeObject*> obj);
DictionaryPropMap* propMap() const {
MOZ_ASSERT(isDictionary());
--
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