Changeset 142377 in webkit for trunk/Source/JavaScriptCore/dfg/DFGDriver.cpp

Timestamp:

Feb 9, 2013, 11:33:00 AM (13 years ago)

Author:

[email protected]

Message:

DFG should allow phases to break Phi's and then have one phase to rebuild them
​https://bugs.webkit.org/show_bug.cgi?id=108414

Reviewed by Mark Hahnenberg.

Introduces two new DFG forms: LoadStore and ThreadedCPS. These are described in
detail in DFGCommon.h.

Consequently, DFG phases no longer have to worry about preserving data flow
links between basic blocks. It is generally always safe to request that the
graph be dethreaded (Graph::dethread), which brings it into LoadStore form, where
the data flow is implicit. In this form, only liveness-at-head needs to be
preserved.

All of the machinery for "threading" the graph to introduce data flow between
blocks is now moved out of the bytecode parser and into the CPSRethreadingPhase.
All phases that previously did this maintenance themselves now just rely on
being able to dethread the graph. The one exception is the structure check
hoising phase, which operates over a threaded graph and preserves it, for the
sake of performance.

Also moved two other things into their own phases: unification (previously found
in the parser) and prediction injection (previously found in various places).

• CMakeLists.txt:
• GNUmakefile.list.am:
• JavaScriptCore.xcodeproj/project.pbxproj:
• Target.pri:
• bytecode/Operands.h:

(Operands):
(JSC::Operands::sizeFor):
(JSC::Operands::atFor):

• dfg/DFGAbstractState.cpp:

(JSC::DFG::AbstractState::execute):
(JSC::DFG::AbstractState::mergeStateAtTail):

• dfg/DFGAllocator.h:

(JSC::DFG::::allocateSlow):

• dfg/DFGArgumentsSimplificationPhase.cpp:

(JSC::DFG::ArgumentsSimplificationPhase::run):

• dfg/DFGBasicBlockInlines.h:

(DFG):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::getLocal):
(JSC::DFG::ByteCodeParser::getArgument):
(JSC::DFG::ByteCodeParser::flushDirect):
(JSC::DFG::ByteCodeParser::parseBlock):
(DFG):
(JSC::DFG::ByteCodeParser::parse):

• dfg/DFGCFGSimplificationPhase.cpp:

(JSC::DFG::CFGSimplificationPhase::run):
(JSC::DFG::CFGSimplificationPhase::killUnreachable):
(JSC::DFG::CFGSimplificationPhase::keepOperandAlive):
(CFGSimplificationPhase):
(JSC::DFG::CFGSimplificationPhase::fixJettisonedPredecessors):
(JSC::DFG::CFGSimplificationPhase::mergeBlocks):

• dfg/DFGCPSRethreadingPhase.cpp: Added.

(DFG):
(CPSRethreadingPhase):
(JSC::DFG::CPSRethreadingPhase::CPSRethreadingPhase):
(JSC::DFG::CPSRethreadingPhase::run):
(JSC::DFG::CPSRethreadingPhase::freeUnnecessaryNodes):
(JSC::DFG::CPSRethreadingPhase::clearVariablesAtHeadAndTail):
(JSC::DFG::CPSRethreadingPhase::addPhiSilently):
(JSC::DFG::CPSRethreadingPhase::addPhi):
(JSC::DFG::CPSRethreadingPhase::canonicalizeGetLocalFor):
(JSC::DFG::CPSRethreadingPhase::canonicalizeGetLocal):
(JSC::DFG::CPSRethreadingPhase::canonicalizeSetLocal):
(JSC::DFG::CPSRethreadingPhase::canonicalizeFlushOrPhantomLocalFor):
(JSC::DFG::CPSRethreadingPhase::canonicalizeFlushOrPhantomLocal):
(JSC::DFG::CPSRethreadingPhase::canonicalizeSetArgument):
(JSC::DFG::CPSRethreadingPhase::canonicalizeLocalsInBlock):
(JSC::DFG::CPSRethreadingPhase::canonicalizeLocalsInBlocks):
(JSC::DFG::CPSRethreadingPhase::propagatePhis):
(JSC::DFG::CPSRethreadingPhase::PhiStackEntry::PhiStackEntry):
(PhiStackEntry):
(JSC::DFG::CPSRethreadingPhase::phiStackFor):
(JSC::DFG::performCPSRethreading):

• dfg/DFGCPSRethreadingPhase.h: Added.

(DFG):

• dfg/DFGCSEPhase.cpp:

(CSEPhase):
(JSC::DFG::CSEPhase::performNodeCSE):

• dfg/DFGCommon.cpp:

(WTF):
(WTF::printInternal):

• dfg/DFGCommon.h:

(JSC::DFG::logCompilationChanges):
(DFG):
(WTF):

• dfg/DFGConstantFoldingPhase.cpp:

(JSC::DFG::ConstantFoldingPhase::foldConstants):

• dfg/DFGDriver.cpp:

(JSC::DFG::compile):

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::Graph):
(JSC::DFG::Graph::dump):
(JSC::DFG::Graph::dethread):
(JSC::DFG::Graph::collectGarbage):

• dfg/DFGGraph.h:

(JSC::DFG::Graph::performSubstitution):
(Graph):
(JSC::DFG::Graph::performSubstitutionForEdge):
(JSC::DFG::Graph::convertToConstant):

• dfg/DFGNode.h:

(JSC::DFG::Node::convertToPhantomLocal):
(Node):
(JSC::DFG::Node::convertToGetLocal):
(JSC::DFG::Node::hasVariableAccessData):

• dfg/DFGNodeType.h:

(DFG):

• dfg/DFGPhase.cpp:

(JSC::DFG::Phase::beginPhase):

• dfg/DFGPhase.h:

(JSC::DFG::runAndLog):

• dfg/DFGPredictionInjectionPhase.cpp: Added.

(DFG):
(PredictionInjectionPhase):
(JSC::DFG::PredictionInjectionPhase::PredictionInjectionPhase):
(JSC::DFG::PredictionInjectionPhase::run):
(JSC::DFG::performPredictionInjection):

• dfg/DFGPredictionInjectionPhase.h: Added.

(DFG):

• dfg/DFGPredictionPropagationPhase.cpp:

(JSC::DFG::PredictionPropagationPhase::run):
(JSC::DFG::PredictionPropagationPhase::propagate):

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGStructureCheckHoistingPhase.cpp:

(JSC::DFG::StructureCheckHoistingPhase::run):

• dfg/DFGUnificationPhase.cpp: Added.

(DFG):
(UnificationPhase):
(JSC::DFG::UnificationPhase::UnificationPhase):
(JSC::DFG::UnificationPhase::run):
(JSC::DFG::performUnification):

• dfg/DFGUnificationPhase.h: Added.

(DFG):

• dfg/DFGValidate.cpp:

(JSC::DFG::Validate::validate):
(JSC::DFG::Validate::dumpGraphIfAppropriate):

• dfg/DFGVirtualRegisterAllocationPhase.cpp:

(JSC::DFG::VirtualRegisterAllocationPhase::run):

• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::setUpCall):

• runtime/JSCJSValue.cpp:

(JSC::JSValue::dump):

• runtime/JSString.h:

(JSString):

• runtime/Options.h:

(JSC):

File:

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

trunk/Source/JavaScriptCore/dfg/DFGDriver.cpp

@@ -37 +37 @@
 #include "DFGCFAPhase.h"
 #include "DFGCFGSimplificationPhase.h"
+#include "DFGCPSRethreadingPhase.h"
 #include "DFGCSEPhase.h"
 #include "DFGConstantFoldingPhase.h"
 #include "DFGFixupPhase.h"
 #include "DFGJITCompiler.h"
+#include "DFGPredictionInjectionPhase.h"
 #include "DFGPredictionPropagationPhase.h"
 #include "DFGStructureCheckHoistingPhase.h"
+#include "DFGUnificationPhase.h"
 #include "DFGValidate.h"
 #include "DFGVirtualRegisterAllocationPhase.h"
@@ -73 +76 @@
         return false;
     
-    if (verboseCompilationEnabled())
+    if (logCompilationChanges())
         dataLog("DFG compiling ", *codeBlock, ", number of instructions = ", codeBlock->instructionCount(), "\n");
     
@@ -103 +106 @@
         return false;
     
-    if (compileMode == CompileFunction)
-        dfg.predictArgumentTypes();
-    
     // By this point the DFG bytecode parser will have potentially mutated various tables
     // in the CodeBlock. This is a good time to perform an early shrink, which is more
@@ -114 +114 @@
     if (validationEnabled())
         validate(dfg);
+    
+    performCPSRethreading(dfg);
+    performUnification(dfg);
+    performPredictionInjection(dfg);
+    
+    if (validationEnabled())
+        validate(dfg);
+    
     performPredictionPropagation(dfg);
     performFixup(dfg);
     performStructureCheckHoisting(dfg);
+    
     unsigned cnt = 1;
     dfg.m_fixpointState = FixpointNotConverged;
     for (;; ++cnt) {
-        if (verboseCompilationEnabled())
+        if (logCompilationChanges())
             dataLogF("DFG beginning optimization fixpoint iteration #%u.\n", cnt);
         bool changed = false;
+        
+        if (validationEnabled())
+            validate(dfg);
+        
         performCFA(dfg);
         changed |= performConstantFolding(dfg);
@@ -128 +141 @@
         changed |= performCFGSimplification(dfg);
         changed |= performCSE(dfg);
+        
         if (!changed)
             break;
+        
         dfg.resetExitStates();
         performFixup(dfg);
+        performCPSRethreading(dfg);
     }
+    
     dfg.m_fixpointState = FixpointConverged;
     performCSE(dfg);
-    if (verboseCompilationEnabled())
+    performCPSRethreading(dfg); // This should usually be a no-op since CSE rarely dethreads the graph.
+    if (logCompilationChanges())
         dataLogF("DFG optimization fixpoint converged in %u iterations.\n", cnt);
     performVirtualRegisterAllocation(dfg);