Changeset 223715 in webkit for trunk/Source/JavaScriptCore/runtime/JSObject.h

Timestamp:

Oct 19, 2017, 3:23:58 PM (8 years ago)

Author:

[email protected]

Message:

We should hard code the poly proto offset
​https://bugs.webkit.org/show_bug.cgi?id=178531

Reviewed by Filip Pizlo.

This patch embraces that the poly proto offset is always zero. It's already
the case that we would always get the inline offset zero for poly proto just
by construction. This just hardcodes this assumption throughout the codebase.
This appears to be a 1% speedometer progression in my testing.

The downside of this patch is that it may require changing how we do
things when we implement poly proto when inheriting from builtin
types. I think we can face this problem when we decide to implement
that.

• bytecode/AccessCase.cpp:

(JSC::AccessCase::generateWithGuard):

• dfg/DFGOperations.cpp:
• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileInstanceOfForObject):
(JSC::DFG::SpeculativeJIT::compileGetPrototypeOf):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::compileGetPrototypeOf):
(JSC::FTL::DFG::LowerDFGToB3::compileInstanceOf):

• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_instanceof):

• jit/JITOpcodes32_64.cpp:

(JSC::JIT::emit_op_instanceof):

• runtime/CommonSlowPaths.cpp:

(JSC::SLOW_PATH_DECL):

• runtime/JSObject.cpp:

(JSC::JSObject::setPrototypeDirect):

• runtime/JSObject.h:

(JSC::JSObject::locationForOffset const):
(JSC::JSObject::locationForOffset):
(JSC::JSObject::getDirect const):

• runtime/PropertyOffset.h:
• runtime/Structure.cpp:

(JSC::Structure::create):
(JSC::Structure::dump const):

• runtime/Structure.h:
• runtime/StructureInlines.h:

(JSC::Structure::storedPrototype const):
(JSC::Structure::storedPrototypeObject const):

File:

• trunk/Source/JavaScriptCore/runtime/JSObject.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/runtime/JSObject.h

@@ -676 +676 @@
     PropertyStorage outOfLineStorage() { return m_butterfly->propertyStorage(); }
 
-    const WriteBarrierBase<Unknown>* locationForOffset(PropertyOffset offset) const
+    ALWAYS_INLINE const WriteBarrierBase<Unknown>* locationForOffset(PropertyOffset offset) const
     {
         if (isInlineOffset(offset))
@@ -683 +683 @@
     }
 
-    WriteBarrierBase<Unknown>* locationForOffset(PropertyOffset offset)
+    ALWAYS_INLINE WriteBarrierBase<Unknown>* locationForOffset(PropertyOffset offset)
     {
         if (isInlineOffset(offset))
@@ -705 +705 @@
 
     // Fast access to known property offsets.
-    JSValue getDirect(PropertyOffset offset) const { return locationForOffset(offset)->get(); }
+    ALWAYS_INLINE JSValue getDirect(PropertyOffset offset) const { return locationForOffset(offset)->get(); }
     void putDirect(VM& vm, PropertyOffset offset, JSValue value) { locationForOffset(offset)->set(vm, this, value); }
     void putDirectWithoutBarrier(PropertyOffset offset, JSValue value) { locationForOffset(offset)->setWithoutWriteBarrier(value); }