Rearrange handling of jump tables. Highlights:

1. MachineJumpTableInfo is now created lazily for a function the first time
   it actually makes a jump table instead of for every function.
2. The encoding of jump table entries is now described by the
   MachineJumpTableInfo::JTEntryKind enum.  This enum is determined by the
   TLI::getJumpTableEncoding() hook, instead of by lots of code scattered
   throughout the compiler that "knows" that jump table entries are always
   32-bits in pic mode (for example).
3. The size and alignment of jump table entries is now calculated based on
   their kind, instead of at machinefunction creation time.

Future work includes using the EntryKind in more places in the compiler,
eliminating other logic that "knows" the layout of jump tables in various
situations.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94470 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 154 insertions, 82 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 024a252d95..19cb41de72 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -498,8 +498,9 @@ void AsmPrinter::EmitJumpTableInfo(MachineFunction &MF) {
     OutStreamer.SwitchSection(ReadOnlySection);
     JTInDiffSection = true;
   }
-  
-  EmitAlignment(Log2_32(MJTI->getAlignment()));
+
+  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
+  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
   
   for (unsigned i = 0, e = JT.size(); i != e; ++i) {
     const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
@@ -528,7 +529,6 @@ void AsmPrinter::EmitJumpTableInfo(MachineFunction &MF) {
     if (!IsPic) {
       // In non-pic mode, the entries in the jump table are direct references
       // to the basic blocks.
-      unsigned EntrySize = MJTI->getEntrySize();
       for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
         MCSymbol *MBBSym = GetMBBSymbol(JTBBs[ii]->getNumber());
         OutStreamer.EmitValue(MCSymbolRefExpr::Create(MBBSym, OutContext),
@@ -566,7 +566,8 @@ void AsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
     Val = MCBinaryExpr::CreateSub(Val, JTI, OutContext);
   }
   
-  OutStreamer.EmitValue(Val, MJTI->getEntrySize(), /*addrspace*/0);
+  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
+  OutStreamer.EmitValue(Val, EntrySize, /*addrspace*/0);
 }
 
 
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 92849d31e5..4f76aac279 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -206,53 +206,56 @@ bool BranchFolder::OptimizeFunction(MachineFunction &MF,
   // See if any jump tables have become mergable or dead as the code generator
   // did its thing.
   MachineJumpTableInfo *JTI = MF.getJumpTableInfo();
+  if (JTI == 0) {
+    delete RS;
+    return MadeChange;
+  }
+  
   const std::vector<MachineJumpTableEntry> &JTs = JTI->getJumpTables();
-  if (!JTs.empty()) {
-    // Figure out how these jump tables should be merged.
-    std::vector<unsigned> JTMapping;
-    JTMapping.reserve(JTs.size());
-
-    // We always keep the 0th jump table.
-    JTMapping.push_back(0);
-
-    // Scan the jump tables, seeing if there are any duplicates.  Note that this
-    // is N^2, which should be fixed someday.
-    for (unsigned i = 1, e = JTs.size(); i != e; ++i) {
-      if (JTs[i].MBBs.empty())
-        JTMapping.push_back(i);
-      else
-        JTMapping.push_back(JTI->getJumpTableIndex(JTs[i].MBBs));
-    }
-
-    // If a jump table was merge with another one, walk the function rewriting
-    // references to jump tables to reference the new JT ID's.  Keep track of
-    // whether we see a jump table idx, if not, we can delete the JT.
-    BitVector JTIsLive(JTs.size());
-    for (MachineFunction::iterator BB = MF.begin(), E = MF.end();
-         BB != E; ++BB) {
-      for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
-           I != E; ++I)
-        for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) {
-          MachineOperand &Op = I->getOperand(op);
-          if (!Op.isJTI()) continue;
-          unsigned NewIdx = JTMapping[Op.getIndex()];
-          Op.setIndex(NewIdx);
-
-          // Remember that this JT is live.
-          JTIsLive.set(NewIdx);
-        }
-    }
+  // Figure out how these jump tables should be merged.
+  std::vector<unsigned> JTMapping;
+  JTMapping.reserve(JTs.size());
+
+  // We always keep the 0th jump table.
+  JTMapping.push_back(0);
+
+  // Scan the jump tables, seeing if there are any duplicates.  Note that this
+  // is N^2, which should be fixed someday.
+  for (unsigned i = 1, e = JTs.size(); i != e; ++i) {
+    if (JTs[i].MBBs.empty())
+      JTMapping.push_back(i);
+    else
+      JTMapping.push_back(JTI->getJumpTableIndex(JTs[i].MBBs));
+  }
 
-    // Finally, remove dead jump tables.  This happens either because the
-    // indirect jump was unreachable (and thus deleted) or because the jump
-    // table was merged with some other one.
-    for (unsigned i = 0, e = JTIsLive.size(); i != e; ++i)
-      if (!JTIsLive.test(i)) {
-        JTI->RemoveJumpTable(i);
-        MadeChange = true;
+  // If a jump table was merge with another one, walk the function rewriting
+  // references to jump tables to reference the new JT ID's.  Keep track of
+  // whether we see a jump table idx, if not, we can delete the JT.
+  BitVector JTIsLive(JTs.size());
+  for (MachineFunction::iterator BB = MF.begin(), E = MF.end();
+       BB != E; ++BB) {
+    for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
+         I != E; ++I)
+      for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) {
+        MachineOperand &Op = I->getOperand(op);
+        if (!Op.isJTI()) continue;
+        unsigned NewIdx = JTMapping[Op.getIndex()];
+        Op.setIndex(NewIdx);
+
+        // Remember that this JT is live.
+        JTIsLive.set(NewIdx);
       }
   }
 
+  // Finally, remove dead jump tables.  This happens either because the
+  // indirect jump was unreachable (and thus deleted) or because the jump
+  // table was merged with some other one.
+  for (unsigned i = 0, e = JTIsLive.size(); i != e; ++i)
+    if (!JTIsLive.test(i)) {
+      JTI->RemoveJumpTable(i);
+      MadeChange = true;
+    }
+
   delete RS;
   return MadeChange;
 }
@@ -957,7 +960,8 @@ ReoptimizeBlock:
       }
       // If MBB was the target of a jump table, update jump tables to go to the
       // fallthrough instead.
-      MF.getJumpTableInfo()->ReplaceMBBInJumpTables(MBB, FallThrough);
+      if (MachineJumpTableInfo *MJTI = MF.getJumpTableInfo())
+        MJTI->ReplaceMBBInJumpTables(MBB, FallThrough);
       MadeChange = true;
     }
     return MadeChange;
@@ -1191,7 +1195,8 @@ ReoptimizeBlock:
           }
 
           // Change any jumptables to go to the new MBB.
-          MF.getJumpTableInfo()->ReplaceMBBInJumpTables(MBB, CurTBB);
+          if (MachineJumpTableInfo *MJTI = MF.getJumpTableInfo())
+            MJTI->ReplaceMBBInJumpTables(MBB, CurTBB);
           if (DidChange) {
             ++NumBranchOpts;
             MadeChange = true;
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 1e3e3145a3..bea0445b15 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -96,15 +96,7 @@ MachineFunction::MachineFunction(Function *F,
                      MachineConstantPool(TM.getTargetData());
   Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
 
-  // Set up jump table.
-  const TargetData &TD = *TM.getTargetData();
-  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
-  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
-  unsigned TyAlignment = IsPic ?
-                       TD.getABITypeAlignment(Type::getInt32Ty(F->getContext()))
-                               : TD.getPointerABIAlignment();
-  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
-                      MachineJumpTableInfo(EntrySize, TyAlignment);
+  JumpTableInfo = 0;
 }
 
 MachineFunction::~MachineFunction() {
@@ -121,9 +113,23 @@ MachineFunction::~MachineFunction() {
   }
   FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
   ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
-  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
+  
+  if (JumpTableInfo) {
+    JumpTableInfo->~MachineJumpTableInfo();
+    Allocator.Deallocate(JumpTableInfo);
+  }
 }
 
+/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
+/// does already exist, allocate one.
+MachineJumpTableInfo *MachineFunction::
+getOrCreateJumpTableInfo(unsigned EntryKind) {
+  if (JumpTableInfo) return JumpTableInfo;
+  
+  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
+    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
+  return JumpTableInfo;
+}
 
 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
 /// recomputes them.  This guarantees that the MBB numbers are sequential,
@@ -311,7 +317,8 @@ void MachineFunction::print(raw_ostream &OS) const {
   FrameInfo->print(*this, OS);
   
   // Print JumpTable Information
-  JumpTableInfo->print(OS);
+  if (JumpTableInfo)
+    JumpTableInfo->print(OS);
 
   // Print Constant Pool
   ConstantPool->print(OS);
@@ -528,6 +535,37 @@ void MachineFrameInfo::dump(const MachineFunction &MF) const {
 //  MachineJumpTableInfo implementation
 //===----------------------------------------------------------------------===//
 
+/// getEntrySize - Return the size of each entry in the jump table.
+unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
+  // The size of a jump table entry is 4 bytes unless the entry is just the
+  // address of a block, in which case it is the pointer size.
+  switch (getEntryKind()) {
+  case MachineJumpTableInfo::EK_BlockAddress:
+    return TD.getPointerSize();
+  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
+  case MachineJumpTableInfo::EK_LabelDifference32:
+    return 4;
+  }
+  assert(0 && "Unknown jump table encoding!");
+  return ~0;
+}
+
+/// getEntryAlignment - Return the alignment of each entry in the jump table.
+unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
+  // The alignment of a jump table entry is the alignment of int32 unless the
+  // entry is just the address of a block, in which case it is the pointer
+  // alignment.
+  switch (getEntryKind()) {
+  case MachineJumpTableInfo::EK_BlockAddress:
+    return TD.getPointerABIAlignment();
+  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
+  case MachineJumpTableInfo::EK_LabelDifference32:
+    return TD.getABIIntegerTypeAlignment(32);
+  }
+  assert(0 && "Unknown jump table encoding!");
+  return ~0;
+}
+
 /// getJumpTableIndex - Create a new jump table entry in the jump table info
 /// or return an existing one.
 ///
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 1c83869d77..12a4b31e5b 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2816,9 +2816,12 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node,
     SDValue Index = Node->getOperand(2);
 
     EVT PTy = TLI.getPointerTy();
-    MachineFunction &MF = DAG.getMachineFunction();
-    unsigned EntrySize = MF.getJumpTableInfo()->getEntrySize();
-    Index= DAG.getNode(ISD::MUL, dl, PTy,
+
+    const TargetData &TD = *TLI.getTargetData();
+    unsigned EntrySize =
+      DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
+    
+    Index = DAG.getNode(ISD::MUL, dl, PTy,
                         Index, DAG.getConstant(EntrySize, PTy));
     SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
 
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 23c7059a9b..dddf385163 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1733,8 +1733,8 @@ bool SelectionDAGBuilder::handleJTSwitchCase(CaseRec& CR,
   std::vector<MachineBasicBlock*> DestBBs;
   APInt TEI = First;
   for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++TEI) {
-    const APInt& Low = cast<ConstantInt>(I->Low)->getValue();
-    const APInt& High = cast<ConstantInt>(I->High)->getValue();
+    const APInt &Low = cast<ConstantInt>(I->Low)->getValue();
+    const APInt &High = cast<ConstantInt>(I->High)->getValue();
 
     if (Low.sle(TEI) && TEI.sle(High)) {
       DestBBs.push_back(I->BB);
@@ -1757,7 +1757,9 @@ bool SelectionDAGBuilder::handleJTSwitchCase(CaseRec& CR,
 
   // Create a jump table index for this jump table, or return an existing
   // one.
-  unsigned JTI = CurMF->getJumpTableInfo()->getJumpTableIndex(DestBBs);
+  unsigned JTEncoding = TLI.getJumpTableEncoding();
+  unsigned JTI = CurMF->getOrCreateJumpTableInfo(JTEncoding)
+                       ->getJumpTableIndex(DestBBs);
 
   // Set the jump table information so that we can codegen it as a second
   // MachineBasicBlock
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 5b00adb52a..966c817ad9 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -21,6 +21,7 @@
 #include "llvm/GlobalVariable.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -793,6 +794,22 @@ unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const {
   return TD->getCallFrameTypeAlignment(Ty);
 }
 
+/// getJumpTableEncoding - Return the entry encoding for a jump table in the
+/// current function.  The returned value is a member of the
+/// MachineJumpTableInfo::JTEntryKind enum.
+unsigned TargetLowering::getJumpTableEncoding() const {
+  // In non-pic modes, just use the address of a block.
+  if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
+    return MachineJumpTableInfo::EK_BlockAddress;
+  
+  // In PIC mode, if the target supports a GPRel32 directive, use it.
+  if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != 0)
+    return MachineJumpTableInfo::EK_GPRel32BlockAddress;
+  
+  // Otherwise, use a label difference.
+  return MachineJumpTableInfo::EK_LabelDifference32;
+}
+
 SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
                                                  SelectionDAG &DAG) const {
   if (usesGlobalOffsetTable())
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index 4dc119dddb..080a88cc56 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -847,9 +847,7 @@ static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
   for (unsigned i = 0, e = JT.size(); i != e; ++i)
     NumEntries += JT[i].MBBs.size();
 
-  unsigned EntrySize = MJTI->getEntrySize();
-
-  return NumEntries * EntrySize;
+  return NumEntries * MJTI->getEntrySize(*TheJIT->getTargetData());
 }
 
 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
@@ -1017,7 +1015,6 @@ void JITEmitter::startFunction(MachineFunction &F) {
   if (MemMgr->NeedsExactSize()) {
     DEBUG(dbgs() << "JIT: ExactSize\n");
     const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
-    MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
     MachineConstantPool *MCP = F.getConstantPool();
 
     // Ensure the constant pool/jump table info is at least 4-byte aligned.
@@ -1029,11 +1026,14 @@ void JITEmitter::startFunction(MachineFunction &F) {
     // Add the constant pool size
     ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
 
-    // Add the aligment of the jump table info
-    ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
+    if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) {
+      // Add the aligment of the jump table info
+      ActualSize = RoundUpToAlign(ActualSize,
+                             MJTI->getEntryAlignment(*TheJIT->getTargetData()));
 
-    // Add the jump table size
-    ActualSize += GetJumpTableSizeInBytes(MJTI);
+      // Add the jump table size
+      ActualSize += GetJumpTableSizeInBytes(MJTI);
+    }
 
     // Add the alignment for the function
     ActualSize = RoundUpToAlign(ActualSize,
@@ -1062,7 +1062,8 @@ void JITEmitter::startFunction(MachineFunction &F) {
   emitAlignment(16);
 
   emitConstantPool(F.getConstantPool());
-  initJumpTableInfo(F.getJumpTableInfo());
+  if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
+    initJumpTableInfo(MJTI);
 
   // About to start emitting the machine code for the function.
   emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
@@ -1084,7 +1085,8 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
     return true;
   }
 
-  emitJumpTableInfo(F.getJumpTableInfo());
+  if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
+    emitJumpTableInfo(MJTI);
 
   // FnStart is the start of the text, not the start of the constant pool and
   // other per-function data.
@@ -1404,13 +1406,14 @@ void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
   for (unsigned i = 0, e = JT.size(); i != e; ++i)
     NumEntries += JT[i].MBBs.size();
 
-  unsigned EntrySize = MJTI->getEntrySize();
+  unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
 
   // Just allocate space for all the jump tables now.  We will fix up the actual
   // MBB entries in the tables after we emit the code for each block, since then
   // we will know the final locations of the MBBs in memory.
   JumpTable = MJTI;
-  JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
+  JumpTableBase = allocateSpace(NumEntries * EntrySize,
+                             MJTI->getEntryAlignment(*TheJIT->getTargetData()));
 }
 
 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
@@ -1420,8 +1423,10 @@ void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
   if (JT.empty() || JumpTableBase == 0) return;
 
+  // FIXME: This should use MachineJumpTableInfo::getEntryKind() instead of
+  // checking for PIC etc.
   if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
-    assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
+    assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
     // For each jump table, place the offset from the beginning of the table
     // to the target address.
     int *SlotPtr = (int*)JumpTableBase;
@@ -1437,7 +1442,8 @@ void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
       }
     }
   } else {
-    assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
+    assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
+           "Cross JIT'ing?");
 
     // For each jump table, map each target in the jump table to the address of
     // an emitted MachineBasicBlock.
@@ -1505,9 +1511,9 @@ uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
   const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
   assert(Index < JT.size() && "Invalid jump table index!");
 
-  unsigned Offset = 0;
-  unsigned EntrySize = JumpTable->getEntrySize();
+  unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
 
+  unsigned Offset = 0;
   for (unsigned i = 0; i < Index; ++i)
     Offset += JT[i].MBBs.size();
 
diff --git a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
index b79d19a850..c13040ab71 100644
--- a/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
+++ b/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
@@ -488,7 +488,7 @@ void X86AsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
 void X86AsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
                                            const MachineBasicBlock *MBB,
                                            unsigned uid) const {
-  const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
+  const char *JTEntryDirective = MJTI->getEntrySize(*TM.getTargetData()) == 4 ?
     MAI->getData32bitsDirective() : MAI->getData64bitsDirective();
 
   O << JTEntryDirective << ' ';