fourthTier: DFG should have switch_char
https://bugs.webkit.org/show_bug.cgi?id=117710
Source/JavaScriptCore:
Reviewed by Michael Saboff.
Add op_switch_char. Most of this is fairly simple, except for the whole
LazyJSValue thing.
It's long been the case that anytime you wanted the DFG to speak of a string
that didn't appear in the constant pool, you would have a hard time since
the DFG isn't allowed to allocate in the GC heap. For example, if you know
that you want to speak of a single character string, you might find that
the one you wanted to speak of had been GC'd. Another example is if you
wanted to add constant folding for string concatenation - something we don't
have yet but will want eventually.
I solve this by finally adding the notion of LazyJSValue. In the future I
anticipate using this for a variety of string-related things. The idea here
is that the DFG can either say that it already knows what the value is, or
it can describe the value. For example, in this patch I needed to be able to
describe single-character strings.
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::dumpBytecode):
(JSC::CodeBlock::CodeBlock):
* bytecode/JumpTable.h:
* dfg/DFGBackwardsPropagationPhase.cpp:
(JSC::DFG::BackwardsPropagationPhase::propagate):
* dfg/DFGByteCodeParser.cpp:
(InlineStackEntry):
(JSC::DFG::ByteCodeParser::parseBlock):
(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
* dfg/DFGCFGSimplificationPhase.cpp:
(JSC::DFG::CFGSimplificationPhase::run):
* dfg/DFGCapabilities.cpp:
(JSC::DFG::capabilityLevel):
* dfg/DFGDriver.cpp:
(JSC::DFG::compile):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* dfg/DFGGPRInfo.h:
(JSC::DFG::JSValueRegs::payloadGPR):
* dfg/DFGJITCompiler.cpp:
(JSC::DFG::JITCompiler::jumpTable):
(DFG):
(JSC::DFG::JITCompiler::numberOfJumpTables):
(JSC::DFG::JITCompiler::linkSwitches):
(JSC::DFG::JITCompiler::link):
* dfg/DFGJITCompiler.h:
(JITCompiler):
* dfg/DFGLazyJSValue.cpp: Added.
(DFG):
(JSC::DFG::LazyJSValue::getValue):
(JSC::DFG::equalToSingleCharacter):
(JSC::DFG::LazyJSValue::strictEqual):
(JSC::DFG::LazyJSValue::dump):
* dfg/DFGLazyJSValue.h: Added.
(DFG):
(LazyJSValue):
(JSC::DFG::LazyJSValue::LazyJSValue):
(JSC::DFG::LazyJSValue::singleCharacterString):
(JSC::DFG::LazyJSValue::tryGetValue):
(JSC::DFG::LazyJSValue::value):
(JSC::DFG::LazyJSValue::character):
(JSC::DFG::LazyJSValue::switchLookupValue):
* dfg/DFGNode.h:
(JSC::DFG::SwitchCase::SwitchCase):
(SwitchCase):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::emitSwitchIntJump):
(JSC::DFG::SpeculativeJIT::emitSwitchImmIntJump):
(DFG):
(JSC::DFG::SpeculativeJIT::emitSwitchImm):
(JSC::DFG::SpeculativeJIT::emitSwitchCharStringJump):
(JSC::DFG::SpeculativeJIT::emitSwitchChar):
(JSC::DFG::SpeculativeJIT::emitSwitch):
* dfg/DFGSpeculativeJIT.h:
(SpeculativeJIT):
Source/WTF:
Reviewed by Michael Saboff.
I wanted to be able to say stringImpl->at(index), and now I can!
Also made it possible to convert a UChar to a utf8 CString without
allocating a StringImpl.
* wtf/text/StringImpl.cpp:
(WTF::StringImpl::utf8Impl):
(WTF):
(WTF::StringImpl::utf8ForCharacters):
(WTF::StringImpl::utf8ForRange):
* wtf/text/StringImpl.h:
(StringImpl):
(WTF::StringImpl::at):
(WTF::StringImpl::operator[]):
LayoutTests:
Rubber stamped by Mark Hahnenberg.
* fast/js/regress/script-tests/switch-char-constant.js: Added.
(foo):
(bar):
* fast/js/regress/script-tests/switch-char.js: Added.
(foo):
(bar):
* fast/js/regress/switch-char-constant-expected.txt: Added.
* fast/js/regress/switch-char-constant.html: Added.
* fast/js/regress/switch-char-expected.txt: Added.
* fast/js/regress/switch-char.html: Added.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153234 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
index 6af634f..e8b0b5b 100644
--- a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
@@ -585,6 +585,10 @@
if (node->child1()->shouldSpeculateInteger())
setUseKindAndUnboxIfProfitable<Int32Use>(node->child1());
break;
+ case SwitchChar:
+ if (node->child1()->shouldSpeculateString())
+ setUseKindAndUnboxIfProfitable<StringUse>(node->child1());
+ break;
}
break;
}
