Put instruction names into an indexed string table on the side, removing a pointer from MCInstrDesc.

Make them accessible through MCInstrInfo. They are only used for debugging purposes so this doesn't
have an impact on performance. X86MCTargetDesc.o goes from 630K to 461K on x86_64.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150245 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCInstrDesc.h

@@ -142,7 +142,6 @@ public:
   const unsigned *ImplicitUses;  // Registers implicitly read by this instr
   const unsigned *ImplicitDefs;  // Registers implicitly defined by this instr
   const MCOperandInfo *OpInfo;   // 'NumOperands' entries about operands
-  const char     *Name;          // Name of the instruction record in td file
 
   /// getOperandConstraint - Returns the value of the specific constraint if
   /// it is set. Returns -1 if it is not set.
@@ -161,12 +160,6 @@ public:
     return Opcode;
   }
 
-  /// getName - Return the name of the record in the .td file for this
-  /// instruction, for example "ADD8ri".
-  const char *getName() const {
-    return Name;
-  }
-
   /// getNumOperands - Return the number of declared MachineOperands for this
   /// MachineInstruction.  Note that variadic (isVariadic() returns true)
   /// instructions may have additional operands at the end of the list, and note

include/llvm/MC/MCInstrInfo.h

@@ -24,14 +24,19 @@ namespace llvm {
 /// MCInstrInfo - Interface to description of machine instruction set
 ///
 class MCInstrInfo {
-  const MCInstrDesc *Desc;  // Raw array to allow static init'n
-  unsigned NumOpcodes;      // Number of entries in the desc array
+  const MCInstrDesc *Desc;          // Raw array to allow static init'n
+  const unsigned *InstrNameIndices; // Array for name indices in InstrNameData
+  const char *InstrNameData;        // Instruction name string pool
+  unsigned NumOpcodes;              // Number of entries in the desc array
 
 public:
   /// InitMCInstrInfo - Initialize MCInstrInfo, called by TableGen
   /// auto-generated routines. *DO NOT USE*.
-  void InitMCInstrInfo(const MCInstrDesc *D, unsigned NO) {
+  void InitMCInstrInfo(const MCInstrDesc *D, const unsigned *NI, const char *ND,
+                       unsigned NO) {
     Desc = D;
+    InstrNameIndices = NI;
+    InstrNameData = ND;
     NumOpcodes = NO;
   }
 
@@ -44,6 +49,12 @@ public:
     assert(Opcode < NumOpcodes && "Invalid opcode!");
     return Desc[Opcode];
   }
+
+  /// getName - Returns the name for the instructions with the given opcode.
+  const char *getName(unsigned Opcode) const {
+    assert(Opcode < NumOpcodes && "Invalid opcode!");
+    return &InstrNameData[InstrNameIndices[Opcode]];
+  }
 };
 
 } // End llvm namespace

lib/CodeGen/MachineInstr.cpp

@@ -1484,7 +1484,10 @@ void MachineInstr::print(raw_ostream &OS, const TargetMachine *TM) const {
     OS << " = ";
 
   // Print the opcode name.
-  OS << getDesc().getName();
+  if (TM && TM->getInstrInfo())
+    OS << TM->getInstrInfo()->getName(getOpcode());
+  else
+    OS << "UNKNOWN";
 
   // Print the rest of the operands.
   bool OmittedAnyCallClobbers = false;

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -5910,7 +5910,7 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
       if (G)
         if (const TargetInstrInfo *TII = G->getTarget().getInstrInfo())
           if (getMachineOpcode() < TII->getNumOpcodes())
-            return TII->get(getMachineOpcode()).getName();
+            return TII->getName(getMachineOpcode());
       return "<<Unknown Machine Node #" + utostr(getOpcode()) + ">>";
     }
     if (G) {

utils/TableGen/InstrInfoEmitter.cpp

@@ -14,6 +14,7 @@
 
 #include "InstrInfoEmitter.h"
 #include "CodeGenTarget.h"
+#include "StringToOffsetTable.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/ADT/StringExtras.h"
 #include <algorithm>
@@ -212,10 +213,26 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
                OperandInfoIDs, OS);
   OS << "};\n\n";
 
+  OS << "extern const unsigned " << TargetName <<"InstrNameIndices[] = {\n    ";
+  StringToOffsetTable StringTable;
+  for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
+    const CodeGenInstruction *Instr = NumberedInstructions[i];
+    OS << StringTable.GetOrAddStringOffset(Instr->TheDef->getName()) << "U, ";
+    if (i % 8 == 0)
+      OS << "\n    ";
+  }
+
+  OS << "\n};\n\n";
+
+  OS << "const char *" << TargetName << "InstrNameData =\n";
+  StringTable.EmitString(OS);
+  OS << ";\n\n";
+
   // MCInstrInfo initialization routine.
   OS << "static inline void Init" << TargetName
      << "MCInstrInfo(MCInstrInfo *II) {\n";
   OS << "  II->InitMCInstrInfo(" << TargetName << "Insts, "
+     << TargetName << "InstrNameIndices, " << TargetName << "InstrNameData, "
      << NumberedInstructions.size() << ");\n}\n\n";
 
   OS << "} // End llvm namespace \n";
@@ -240,9 +257,12 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
 
   OS << "namespace llvm {\n";
   OS << "extern const MCInstrDesc " << TargetName << "Insts[];\n";
+  OS << "extern const unsigned " << TargetName << "InstrNameIndices[];\n";
+  OS << "extern const char *" << TargetName << "InstrNameData;\n";
   OS << ClassName << "::" << ClassName << "(int SO, int DO)\n"
      << "  : TargetInstrInfoImpl(SO, DO) {\n"
      << "  InitMCInstrInfo(" << TargetName << "Insts, "
+     << TargetName << "InstrNameIndices, " << TargetName << "InstrNameData, "
      << NumberedInstructions.size() << ");\n}\n";
   OS << "} // End llvm namespace \n";
 
@@ -329,8 +349,6 @@ void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
   else
     OS << "OperandInfo" << OpInfo.find(OperandInfo)->second;
 
-  OS << ", \"" << Inst.TheDef->getName() << '"';
-
   OS << " },  // Inst #" << Num << " = " << Inst.TheDef->getName() << "\n";
 }