Changeset 176079 in webkit for trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

Timestamp:

Nov 13, 2014, 11:18:43 AM (11 years ago)

Author:

[email protected]

Message:

Generate put_by_id for bracket assignment with constant string subscript.
<​https://webkit.org/b/138702>

Reviewed by Geoffrey Garen.

Transform of=x to o.f=x when generating bytecode. This allows our JIT
to inline-cache those accesses instead of always dropping out to C++.

Just like the get_by_id transformations, this gets a bunch of use on
real-web content (and Speedometer) but little/none on raw JS benchmarks.

• bytecompiler/NodesCodegen.cpp:

(JSC::AssignBracketNode::emitBytecode):

File:

• trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

@@ -1645 +1645 @@
     generator.emitExpressionInfo(divot(), divotStart(), divotEnd());
     RegisterID* forwardResult = (dst == generator.ignoredResult()) ? result : generator.moveToDestinationIfNeeded(generator.tempDestination(result), result);
-    generator.emitPutByVal(base.get(), property.get(), forwardResult);
+
+    if (m_subscript->isString())
+        generator.emitPutById(base.get(), static_cast<StringNode*>(m_subscript)->value(), forwardResult);
+    else
+        generator.emitPutByVal(base.get(), property.get(), forwardResult);
+
     if (generator.vm()->typeProfiler()) {
         generator.emitProfileType(forwardResult, ProfileTypeBytecodeDoesNotHaveGlobalID, nullptr);