DFG should not have code that directly decodes the states of old JIT inline
cache data structures
https://bugs.webkit.org/show_bug.cgi?id=76768
Reviewed by Sam Weinig.
Introduced new classes (like GetByIdStatus) that encapsulate the set of things
that the DFG would like to know about property accesses and calls. Whereas it
previously got this information by directly decoding the data structures used
by the old JIT for inline caching, it now uses these classes, which do the work
for it. This should make it somewhat more straight forward to introduce new
ways of profiling the same information.
Also hoisted StructureSet into bytecode/ from dfg/, because it's now used by
code in bytecode/.
Making this work right involved carefully ensuring that the heuristics for
choosing how to handle property accesses was at least as good as what we had
before, since I completely restructured that code. Currently the performance
looks neutral. Since I rewrote the code I did change some things that I never
liked before, like previously if a put_bu_id had executed exactly once then
we'd compile it as if it had taken slow-path. Executing once is special because
then the inline cache is not baked in, so there is no information about how the
DFG should optimize the code. Now this is rationalized: if the put_by_id does
not offer enough information to be optimized (i.e. had executed 0 or 1 times)
then we turn it into a forced OSR exit (i.e. a patch point). However, get_by_id
still has the old behavior; I left it that way because I didn't want to make
too many changes at once.
* CMakeLists.txt:
* GNUmakefile.list.am:
* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.vcproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* Target.pri:
* bytecode/CallLinkStatus.cpp: Added.
(JSC::CallLinkStatus::computeFor):
* bytecode/CallLinkStatus.h: Added.
(JSC::CallLinkStatus::CallLinkStatus):
(JSC::CallLinkStatus::isSet):
(JSC::CallLinkStatus::operator!):
(JSC::CallLinkStatus::couldTakeSlowPath):
(JSC::CallLinkStatus::callTarget):
* bytecode/GetByIdStatus.cpp: Added.
(JSC::GetByIdStatus::computeFor):
* bytecode/GetByIdStatus.h: Added.
(JSC::GetByIdStatus::GetByIdStatus):
(JSC::GetByIdStatus::state):
(JSC::GetByIdStatus::isSet):
(JSC::GetByIdStatus::operator!):
(JSC::GetByIdStatus::isSimpleDirect):
(JSC::GetByIdStatus::takesSlowPath):
(JSC::GetByIdStatus::makesCalls):
(JSC::GetByIdStatus::structureSet):
(JSC::GetByIdStatus::offset):
* bytecode/MethodCallLinkStatus.cpp: Added.
(JSC::MethodCallLinkStatus::computeFor):
* bytecode/MethodCallLinkStatus.h: Added.
(JSC::MethodCallLinkStatus::MethodCallLinkStatus):
(JSC::MethodCallLinkStatus::isSet):
(JSC::MethodCallLinkStatus::operator!):
(JSC::MethodCallLinkStatus::needsPrototypeCheck):
(JSC::MethodCallLinkStatus::structure):
(JSC::MethodCallLinkStatus::prototypeStructure):
(JSC::MethodCallLinkStatus::function):
(JSC::MethodCallLinkStatus::prototype):
* bytecode/PutByIdStatus.cpp: Added.
(JSC::PutByIdStatus::computeFor):
* bytecode/PutByIdStatus.h: Added.
(JSC::PutByIdStatus::PutByIdStatus):
(JSC::PutByIdStatus::state):
(JSC::PutByIdStatus::isSet):
(JSC::PutByIdStatus::operator!):
(JSC::PutByIdStatus::isSimpleReplace):
(JSC::PutByIdStatus::isSimpleTransition):
(JSC::PutByIdStatus::takesSlowPath):
(JSC::PutByIdStatus::oldStructure):
(JSC::PutByIdStatus::newStructure):
(JSC::PutByIdStatus::structureChain):
(JSC::PutByIdStatus::offset):
* bytecode/StructureSet.h: Added.
(JSC::StructureSet::StructureSet):
(JSC::StructureSet::clear):
(JSC::StructureSet::add):
(JSC::StructureSet::addAll):
(JSC::StructureSet::remove):
(JSC::StructureSet::contains):
(JSC::StructureSet::isSubsetOf):
(JSC::StructureSet::isSupersetOf):
(JSC::StructureSet::size):
(JSC::StructureSet::at):
(JSC::StructureSet::operator[]):
(JSC::StructureSet::last):
(JSC::StructureSet::predictionFromStructures):
(JSC::StructureSet::operator==):
(JSC::StructureSet::dump):
* dfg/DFGAbstractValue.h:
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleCall):
(JSC::DFG::ByteCodeParser::parseBlock):
* dfg/DFGStructureSet.h: Removed.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105581 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp b/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
new file mode 100644
index 0000000..abedc84
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/CallLinkStatus.cpp
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "CallLinkStatus.h"
+
+#include "CodeBlock.h"
+
+namespace JSC {
+
+CallLinkStatus CallLinkStatus::computeFor(CodeBlock* profiledBlock, unsigned bytecodeIndex)
+{
+#if ENABLE(JIT)
+ return CallLinkStatus(
+ profiledBlock->getCallLinkInfo(bytecodeIndex).lastSeenCallee.get(),
+ profiledBlock->couldTakeSlowCase(bytecodeIndex));
+#else
+ return CallLinkStatus(0, false);
+#endif
+}
+
+} // namespace JSC
+
