Changeset 239013 in webkit for trunk/Source/JavaScriptCore/runtime/PutPropertySlot.h

Timestamp:

Dec 8, 2018, 3:53:29 PM (7 years ago)

Author:

[email protected]

Message:

Reduce size of PropertySlot and PutPropertySlot.
​https://bugs.webkit.org/show_bug.cgi?id=192526

Reviewed by Keith Miller.

With some minor adjustments, we can reduce the size of PropertySlot from 80 bytes
(19 padding bytes) to 64 bytes (3 padding bytes), and PutPropertySlot from 40
bytes (4 padding bytes) to 32 bytes (0 padding bytes but with 6 unused bits).
These measurements are for a 64-bit build.

• runtime/PropertySlot.h:
• runtime/PutPropertySlot.h:

(JSC::PutPropertySlot::PutPropertySlot):

File:

• trunk/Source/JavaScriptCore/runtime/PutPropertySlot.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/runtime/PutPropertySlot.h

@@ -37 +37 @@
 class PutPropertySlot {
 public:
-    enum Type { Uncachable, ExistingProperty, NewProperty, SetterProperty, CustomValue, CustomAccessor };
+    enum Type : uint8_t { Uncachable, ExistingProperty, NewProperty, SetterProperty, CustomValue, CustomAccessor };
     enum Context { UnknownContext, PutById, PutByIdEval };
     typedef bool (*PutValueFunc)(ExecState*, EncodedJSValue thisObject, EncodedJSValue value);
 
     PutPropertySlot(JSValue thisValue, bool isStrictMode = false, Context context = UnknownContext, bool isInitialization = false)
-        : m_type(Uncachable)
-        , m_base(0)
+        : m_base(0)
         , m_thisValue(thisValue)
         , m_offset(invalidOffset)
         , m_isStrictMode(isStrictMode)
         , m_isInitialization(isInitialization)
+        , m_type(Uncachable)
         , m_context(context)
         , m_cacheability(CachingAllowed)
@@ -130 +130 @@
     bool isCacheable() const { return m_cacheability == CachingAllowed; }
 
-    Type m_type;
     JSObject* m_base;
     JSValue m_thisValue;
     PropertyOffset m_offset;
-    bool m_isStrictMode;
-    bool m_isInitialization;
+    bool m_isStrictMode : 1;
+    bool m_isInitialization : 1;
+    Type m_type;
     uint8_t m_context;
     CacheabilityType m_cacheability;