Changeset 153248 in webkit for trunk/Source/JavaScriptCore/dfg/DFGLazyJSValue.cpp

Timestamp:

Jul 24, 2013, 9:03:51 PM (12 years ago)

Author:

[email protected]

Message:

fourthTier: DFG should support switch_string
​https://bugs.webkit.org/show_bug.cgi?id=117967

Source/JavaScriptCore:

Reviewed by Sam Weinig.

Add a reusable binary switch creator.

Implement switch on string using three modes:

• Binary switch on StringImpl* in the case of identifiers.

• Trie of binary switches on characters in the case of a not-too-big switch over not-too-big 8-bit strings.

• Hash lookup if all else fails.

Anywhere from a 2x to 3x speed-up on microbenchmarks that stress
string switches. 25-35% speed-up on HashMap tests. 4% speed-up on
pdfjs.

• JavaScriptCore.xcodeproj/project.pbxproj:
• bytecode/JumpTable.h:

(StringJumpTable):
(JSC::StringJumpTable::clear):

• dfg/DFGBackwardsPropagationPhase.cpp:

(JSC::DFG::BackwardsPropagationPhase::propagate):

• dfg/DFGBinarySwitch.cpp: Added.

(DFG):
(JSC::DFG::BinarySwitch::BinarySwitch):
(JSC::DFG::BinarySwitch::advance):
(JSC::DFG::BinarySwitch::build):

• dfg/DFGBinarySwitch.h: Added.

(DFG):
(BinarySwitch):
(JSC::DFG::BinarySwitch::caseIndex):
(JSC::DFG::BinarySwitch::caseValue):
(JSC::DFG::BinarySwitch::fallThrough):
(JSC::DFG::BinarySwitch::Case::Case):
(Case):
(JSC::DFG::BinarySwitch::Case::operator<):
(JSC::DFG::BinarySwitch::BranchCode::BranchCode):
(BranchCode):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGCapabilities.cpp:

(JSC::DFG::capabilityLevel):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::link):

• dfg/DFGLazyJSValue.cpp:

(JSC::DFG::LazyJSValue::getValue):
(JSC::DFG::equalToStringImpl):
(DFG):
(JSC::DFG::LazyJSValue::strictEqual):
(JSC::DFG::LazyJSValue::dump):

• dfg/DFGLazyJSValue.h:

(JSC::DFG::LazyJSValue::knownStringImpl):
(LazyJSValue):
(JSC::DFG::LazyJSValue::stringImpl):
(JSC::DFG::LazyJSValue::switchLookupValue):

• dfg/DFGNode.cpp:

(WTF::printInternal):

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

(JSC::DFG::SpeculativeJIT::emitSwitchChar):
(JSC::DFG::SpeculativeJIT::StringSwitchCase::operator<):
(DFG):
(JSC::DFG::SpeculativeJIT::emitBinarySwitchStringRecurse):
(JSC::DFG::SpeculativeJIT::emitSwitchStringOnString):
(JSC::DFG::SpeculativeJIT::emitSwitchString):
(JSC::DFG::SpeculativeJIT::emitSwitch):
(JSC::DFG::SpeculativeJIT::addBranch):

• dfg/DFGSpeculativeJIT.h:

(JSC::DFG::SpeculativeJIT::callOperation):
(JSC::DFG::SpeculativeJIT::branch8):
(SpeculativeJIT):
(JSC::DFG::SpeculativeJIT::StringSwitchCase::StringSwitchCase):
(StringSwitchCase):

• ftl/FTLLowerDFGToLLVM.cpp:

(JSC::FTL::LowerDFGToLLVM::compileSwitch):

• runtime/Options.h:

(JSC):

Source/WTF:

Reviewed by Sam Weinig.

Make it possible to compare a RefPtr<StringImpl> and a StringImpl* without
having to ref the StringImpl.

• wtf/text/StringHash.h:

(WTF::StringHash::equal):

LayoutTests:

Reviewed by Sam Weinig.

• fast/js/regress/script-tests/switch-string-basic-big-var.js: Added.

(foo):
(make):

• fast/js/regress/script-tests/switch-string-basic-big.js: Added.

(foo):
(make):

• fast/js/regress/script-tests/switch-string-basic-var.js: Added.

(foo):
(make):

• fast/js/regress/script-tests/switch-string-basic.js: Added.

(foo):

• fast/js/regress/script-tests/switch-string-big-length-tower-var.js: Added.

(foo):

• fast/js/regress/script-tests/switch-string-length-tower-var.js: Added.

(foo):

• fast/js/regress/script-tests/switch-string-length-tower.js: Added.

(foo):

• fast/js/regress/script-tests/switch-string-short.js: Added.

(foo):

• fast/js/regress/switch-string-basic-big-expected.txt: Added.
• fast/js/regress/switch-string-basic-big-var-expected.txt: Added.
• fast/js/regress/switch-string-basic-big-var.html: Added.
• fast/js/regress/switch-string-basic-big.html: Added.
• fast/js/regress/switch-string-basic-expected.txt: Added.
• fast/js/regress/switch-string-basic-var-expected.txt: Added.
• fast/js/regress/switch-string-basic-var.html: Added.
• fast/js/regress/switch-string-basic.html: Added.
• fast/js/regress/switch-string-big-length-tower-var-expected.txt: Added.
• fast/js/regress/switch-string-big-length-tower-var.html: Added.
• fast/js/regress/switch-string-length-tower-expected.txt: Added.
• fast/js/regress/switch-string-length-tower-var-expected.txt: Added.
• fast/js/regress/switch-string-length-tower-var.html: Added.
• fast/js/regress/switch-string-length-tower.html: Added.
• fast/js/regress/switch-string-short-expected.txt: Added.
• fast/js/regress/switch-string-short.html: Added.

Conflicts:

Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj

File:

• trunk/Source/JavaScriptCore/dfg/DFGLazyJSValue.cpp (modified) (5 diffs)

trunk/Source/JavaScriptCore/dfg/DFGLazyJSValue.cpp

@@ -40 +40 @@
     case SingleCharacterString:
         return jsSingleCharacterString(&vm, u.character);
+    case KnownStringImpl:
+        return jsString(&vm, u.stringImpl);
     }
     RELEASE_ASSERT_NOT_REACHED();
@@ -60 +62 @@
 }
 
+static TriState equalToStringImpl(JSValue value, StringImpl* stringImpl)
+{
+    if (!value.isString())
+        return FalseTriState;
+    
+    JSString* jsString = asString(value);
+    const StringImpl* string = jsString->tryGetValueImpl();
+    if (!string)
+        return MixedTriState;
+    
+    return triState(WTF::equal(stringImpl, string));
+}
+
 TriState LazyJSValue::strictEqual(const LazyJSValue& other) const
 {
@@ -69 +84 @@
         case SingleCharacterString:
             return equalToSingleCharacter(value(), other.character());
+        case KnownStringImpl:
+            return equalToStringImpl(value(), other.stringImpl());
         }
         break;
@@ -75 +92 @@
         case SingleCharacterString:
             return triState(character() == other.character());
+        case KnownStringImpl:
+            if (other.stringImpl()->length() != 1)
+                return FalseTriState;
+            return triState(other.stringImpl()->at(0) == character());
+        default:
+            return other.strictEqual(*this);
+        }
+        break;
+    case KnownStringImpl:
+        switch (other.m_kind) {
+        case KnownStringImpl:
+            return triState(WTF::equal(stringImpl(), other.stringImpl()));
         default:
             return other.strictEqual(*this);
@@ -94 +123 @@
         out.print(" / ", StringImpl::utf8ForCharacters(&u.character, 1), ")");
         return;
+    case KnownStringImpl:
+        out.print("Lazy:String(", stringImpl(), ")");
+        return;
     }
     RELEASE_ASSERT_NOT_REACHED();