change Target.getInstructionsByEnumValue to return a reference
to a vector that CGT stores instead of synthesizing it on every 
call.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98910 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index 82b064e..e5c068b 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -845,8 +845,8 @@
   // singleton register classes.
   std::set<std::string> SingletonRegisterNames;
   
-  std::vector<const CodeGenInstruction*> InstrList;
-  Target.getInstructionsByEnumValue(InstrList);
+  const std::vector<const CodeGenInstruction*> &InstrList =
+    Target.getInstructionsByEnumValue();
   
   for (unsigned i = 0, e = InstrList.size(); i != e; ++i) {
     const CodeGenInstruction &CGI = *InstrList[i];
diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index 3a38dd4..9378343 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -263,7 +263,7 @@
                       AsmWriter->getValueAsInt("OperandSpacing")));
 
   // Get the instruction numbering.
-  Target.getInstructionsByEnumValue(NumberedInstructions);
+  NumberedInstructions = Target.getInstructionsByEnumValue();
   
   // Compute the CodeGenInstruction -> AsmWriterInst mapping.  Note that not
   // all machine instructions are necessarily being printed, so there may be
@@ -499,8 +499,8 @@
   Record *AsmWriter = Target.getAsmWriter();
   std::string ClassName = AsmWriter->getValueAsString("AsmWriterClassName");
 
-  std::vector<const CodeGenInstruction*> NumberedInstructions;
-  Target.getInstructionsByEnumValue(NumberedInstructions);
+  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
+    Target.getInstructionsByEnumValue();
   
   StringToOffsetTable StringTable;
   O <<
diff --git a/utils/TableGen/CodeEmitterGen.cpp b/utils/TableGen/CodeEmitterGen.cpp
index a057dec..641c224 100644
--- a/utils/TableGen/CodeEmitterGen.cpp
+++ b/utils/TableGen/CodeEmitterGen.cpp
@@ -86,8 +86,8 @@
   EmitSourceFileHeader("Machine Code Emitter", o);
   std::string Namespace = Insts[0]->getValueAsString("Namespace") + "::";
   
-  std::vector<const CodeGenInstruction*> NumberedInstructions;
-  Target.getInstructionsByEnumValue(NumberedInstructions);
+  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
+    Target.getInstructionsByEnumValue();
 
   // Emit function declaration
   o << "unsigned " << Target.getName() << "CodeEmitter::"
@@ -95,7 +95,7 @@
 
   // Emit instruction base values
   o << "  static const unsigned InstBits[] = {\n";
-  for (std::vector<const CodeGenInstruction*>::iterator
+  for (std::vector<const CodeGenInstruction*>::const_iterator
           IN = NumberedInstructions.begin(),
           EN = NumberedInstructions.end();
        IN != EN; ++IN) {
diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index 8c07c4a..bf4a719 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -2362,8 +2362,8 @@
 
 
 void CodeGenDAGPatterns::InferInstructionFlags() {
-  std::vector<const CodeGenInstruction*> Instructions;
-  Target.getInstructionsByEnumValue(Instructions);
+  const std::vector<const CodeGenInstruction*> &Instructions =
+    Target.getInstructionsByEnumValue();
   for (unsigned i = 0, e = Instructions.size(); i != e; ++i) {
     CodeGenInstruction &InstInfo =
       const_cast<CodeGenInstruction &>(*Instructions[i]);
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index ea0746f..36a9d1e 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -300,11 +300,8 @@
 
 /// getInstructionsByEnumValue - Return all of the instructions defined by the
 /// target, ordered by their enum value.
-void CodeGenTarget::
-getInstructionsByEnumValue(std::vector<const CodeGenInstruction*>
-                                                 &NumberedInstructions) {
+void CodeGenTarget::ComputeInstrsByEnum() {
   const std::map<std::string, CodeGenInstruction> &Insts = getInstructions();
-  
   const CodeGenInstruction *PHI = GetInstByName("PHI", Insts);
   const CodeGenInstruction *INLINEASM = GetInstByName("INLINEASM", Insts);
   const CodeGenInstruction *DBG_LABEL = GetInstByName("DBG_LABEL", Insts);
@@ -323,18 +320,18 @@
   const CodeGenInstruction *DBG_VALUE = GetInstByName("DBG_VALUE", Insts);
 
   // Print out the rest of the instructions now.
-  NumberedInstructions.push_back(PHI);
-  NumberedInstructions.push_back(INLINEASM);
-  NumberedInstructions.push_back(DBG_LABEL);
-  NumberedInstructions.push_back(EH_LABEL);
-  NumberedInstructions.push_back(GC_LABEL);
-  NumberedInstructions.push_back(KILL);
-  NumberedInstructions.push_back(EXTRACT_SUBREG);
-  NumberedInstructions.push_back(INSERT_SUBREG);
-  NumberedInstructions.push_back(IMPLICIT_DEF);
-  NumberedInstructions.push_back(SUBREG_TO_REG);
-  NumberedInstructions.push_back(COPY_TO_REGCLASS);
-  NumberedInstructions.push_back(DBG_VALUE);
+  InstrsByEnum.push_back(PHI);
+  InstrsByEnum.push_back(INLINEASM);
+  InstrsByEnum.push_back(DBG_LABEL);
+  InstrsByEnum.push_back(EH_LABEL);
+  InstrsByEnum.push_back(GC_LABEL);
+  InstrsByEnum.push_back(KILL);
+  InstrsByEnum.push_back(EXTRACT_SUBREG);
+  InstrsByEnum.push_back(INSERT_SUBREG);
+  InstrsByEnum.push_back(IMPLICIT_DEF);
+  InstrsByEnum.push_back(SUBREG_TO_REG);
+  InstrsByEnum.push_back(COPY_TO_REGCLASS);
+  InstrsByEnum.push_back(DBG_VALUE);
   for (inst_iterator II = inst_begin(), E = inst_end(); II != E; ++II)
     if (&II->second != PHI &&
         &II->second != INLINEASM &&
@@ -348,7 +345,7 @@
         &II->second != SUBREG_TO_REG &&
         &II->second != COPY_TO_REGCLASS &&
         &II->second != DBG_VALUE)
-      NumberedInstructions.push_back(&II->second);
+      InstrsByEnum.push_back(&II->second);
 }
 
 
diff --git a/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index d48e49a..ac6574d 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -70,6 +70,8 @@
   void ReadRegisterClasses() const;
   void ReadInstructions() const;
   void ReadLegalValueTypes() const;
+  
+  std::vector<const CodeGenInstruction*> InstrsByEnum;
 public:
   CodeGenTarget();
 
@@ -210,13 +212,18 @@
 
   /// getInstructionsByEnumValue - Return all of the instructions defined by the
   /// target, ordered by their enum value.
-  void getInstructionsByEnumValue(std::vector<const CodeGenInstruction*>
-                                                &NumberedInstructions);
+  const std::vector<const CodeGenInstruction*> &getInstructionsByEnumValue() {
+    if (InstrsByEnum.empty()) ComputeInstrsByEnum();
+    return InstrsByEnum;
+  }
 
 
   /// isLittleEndianEncoding - are instruction bit patterns defined as  [0..n]?
   ///
   bool isLittleEndianEncoding() const;
+  
+private:
+  void ComputeInstrsByEnum();
 };
 
 /// ComplexPattern - ComplexPattern info, corresponding to the ComplexPattern
diff --git a/utils/TableGen/DisassemblerEmitter.cpp b/utils/TableGen/DisassemblerEmitter.cpp
index 61b9b15..a195c0b 100644
--- a/utils/TableGen/DisassemblerEmitter.cpp
+++ b/utils/TableGen/DisassemblerEmitter.cpp
@@ -108,8 +108,8 @@
   if (Target.getName() == "X86") {
     DisassemblerTables Tables;
   
-    std::vector<const CodeGenInstruction*> numberedInstructions;
-    Target.getInstructionsByEnumValue(numberedInstructions);
+    const std::vector<const CodeGenInstruction*> &numberedInstructions =
+      Target.getInstructionsByEnumValue();
     
     for (unsigned i = 0, e = numberedInstructions.size(); i != e; ++i)
       RecognizableInstr::processInstr(Tables, *numberedInstructions[i], i);
diff --git a/utils/TableGen/EDEmitter.cpp b/utils/TableGen/EDEmitter.cpp
index 2149410..f83ab48 100644
--- a/utils/TableGen/EDEmitter.cpp
+++ b/utils/TableGen/EDEmitter.cpp
@@ -549,8 +549,8 @@
 /// @arg target     - The CodeGenTarget to use as a source of instructions
 static void populateInstInfo(CompoundConstantEmitter &infoArray,
                              CodeGenTarget &target) {
-  std::vector<const CodeGenInstruction*> numberedInstructions;
-  target.getInstructionsByEnumValue(numberedInstructions);
+  const std::vector<const CodeGenInstruction*> &numberedInstructions =
+    target.getInstructionsByEnumValue();
   
   unsigned int index;
   unsigned int numInstructions = numberedInstructions.size();
diff --git a/utils/TableGen/InstrEnumEmitter.cpp b/utils/TableGen/InstrEnumEmitter.cpp
index d1e7f3d..4162107 100644
--- a/utils/TableGen/InstrEnumEmitter.cpp
+++ b/utils/TableGen/InstrEnumEmitter.cpp
@@ -40,8 +40,8 @@
     exit(1);
   }
 
-  std::vector<const CodeGenInstruction*> NumberedInstructions;
-  Target.getInstructionsByEnumValue(NumberedInstructions);
+  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
+    Target.getInstructionsByEnumValue();
 
   OS << "namespace " << Namespace << " {\n";
   OS << "  enum {\n";
diff --git a/utils/TableGen/InstrInfoEmitter.cpp b/utils/TableGen/InstrInfoEmitter.cpp
index 898c92a..83602bb 100644
--- a/utils/TableGen/InstrInfoEmitter.cpp
+++ b/utils/TableGen/InstrInfoEmitter.cpp
@@ -244,8 +244,8 @@
   //
   OS << "\nstatic const TargetInstrDesc " << TargetName
      << "Insts[] = {\n";
-  std::vector<const CodeGenInstruction*> NumberedInstructions;
-  Target.getInstructionsByEnumValue(NumberedInstructions);
+  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
+    Target.getInstructionsByEnumValue();
 
   for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i)
     emitRecord(*NumberedInstructions[i], i, InstrInfo, EmittedLists,