Reduce size of some tables in tablegen register info output.

Primarily done by using SequenceToOffsetTable to reduce the register pressure set tables and then sizing the indices into the tables appropriately. Size a few other table entries based on content as well. Reduces X86RegisterInfo.o by ~9k.

llvm-svn: 222621

llvm/utils/TableGen/RegisterInfoEmitter.cpp

@@ -156,6 +156,19 @@ void RegisterInfoEmitter::runEnums(raw_ostream &OS,
   OS << "#endif // GET_REGINFO_ENUM\n\n";
 }
 
+static void printInt(raw_ostream &OS, int Val) {
+  OS << Val;
+}
+
+static const char *getMinimalTypeForRange(uint64_t Range) {
+  assert(Range < 0xFFFFFFFFULL && "Enum too large");
+  if (Range > 0xFFFF)
+    return "uint32_t";
+  if (Range > 0xFF)
+    return "uint16_t";
+  return "uint8_t";
+}
+
 void RegisterInfoEmitter::
 EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
                     const std::string &ClassName) {
@@ -179,7 +192,7 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
     }
     OS << "},  \t// " << RC.getName() << "\n";
   }
-  OS << "    {0, 0} };\n"
+  OS << "  };\n"
      << "  return RCWeightTable[RC->getID()];\n"
      << "}\n\n";
 
@@ -204,7 +217,7 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
       assert(RU.Weight < 256 && "RegUnit too heavy");
       OS << RU.Weight << ", ";
     }
-    OS << "0 };\n"
+    OS << "};\n"
        << "  return RUWeightTable[RegUnit];\n";
   }
   else {
@@ -222,8 +235,11 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
      << "const char *" << ClassName << "::\n"
      << "getRegPressureSetName(unsigned Idx) const {\n"
      << "  static const char *PressureNameTable[] = {\n";
+  unsigned MaxRegUnitWeight = 0;
   for (unsigned i = 0; i < NumSets; ++i ) {
-    OS << "    \"" << RegBank.getRegSetAt(i).Name << "\",\n";
+    const RegUnitSet &RegUnits = RegBank.getRegSetAt(i);
+    MaxRegUnitWeight = std::max(MaxRegUnitWeight, RegUnits.Weight);
+    OS << "    \"" << RegUnits.Name << "\",\n";
   }
   OS << "    nullptr };\n"
      << "  return PressureNameTable[Idx];\n"
@@ -233,63 +249,54 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
      << "// This limit must be adjusted dynamically for reserved registers.\n"
      << "unsigned " << ClassName << "::\n"
      << "getRegPressureSetLimit(unsigned Idx) const {\n"
-     << "  static const unsigned PressureLimitTable[] = {\n";
+     << "  static const " << getMinimalTypeForRange(MaxRegUnitWeight)
+     << " PressureLimitTable[] = {\n";
   for (unsigned i = 0; i < NumSets; ++i ) {
     const RegUnitSet &RegUnits = RegBank.getRegSetAt(i);
     OS << "    " << RegUnits.Weight << ",  \t// " << i << ": "
        << RegUnits.Name << "\n";
   }
-  OS << "    0 };\n"
+  OS << "  };\n"
      << "  return PressureLimitTable[Idx];\n"
      << "}\n\n";
 
+  SequenceToOffsetTable<std::vector<int>> PSetsSeqs;
+
   // This table may be larger than NumRCs if some register units needed a list
   // of unit sets that did not correspond to a register class.
   unsigned NumRCUnitSets = RegBank.getNumRegClassPressureSetLists();
-  OS << "/// Table of pressure sets per register class or unit.\n"
+  std::vector<std::vector<int>> PSets(NumRCUnitSets);
-     << "static const int RCSetsTable[] = {\n    ";
+
-  std::vector<unsigned> RCSetStarts(NumRCUnitSets);
+  for (unsigned i = 0, e = NumRCUnitSets; i != e; ++i) {
-  for (unsigned i = 0, StartIdx = 0, e = NumRCUnitSets; i != e; ++i) {
-    RCSetStarts[i] = StartIdx;
     ArrayRef<unsigned> PSetIDs = RegBank.getRCPressureSetIDs(i);
-    std::vector<unsigned> PSets;
+    PSets[i].reserve(PSetIDs.size());
-    PSets.reserve(PSetIDs.size());
     for (ArrayRef<unsigned>::iterator PSetI = PSetIDs.begin(),
            PSetE = PSetIDs.end(); PSetI != PSetE; ++PSetI) {
-      PSets.push_back(RegBank.getRegPressureSet(*PSetI).Order);
+      PSets[i].push_back(RegBank.getRegPressureSet(*PSetI).Order);
     }
-    std::sort(PSets.begin(), PSets.end());
+    std::sort(PSets[i].begin(), PSets[i].end());
-    for (unsigned j = 0, e = PSets.size(); j < e; ++j) {
+    PSetsSeqs.add(PSets[i]);
-      OS << PSets[j] << ",  ";
-      ++StartIdx;
-    }
-    OS << "-1,  \t// #" << RCSetStarts[i] << " ";
-    if (i < NumRCs)
-      OS << RegBank.getRegClasses()[i]->getName();
-    else {
-      OS << "inferred";
-      for (ArrayRef<unsigned>::iterator PSetI = PSetIDs.begin(),
-             PSetE = PSetIDs.end(); PSetI != PSetE; ++PSetI) {
-        OS << "~" << RegBank.getRegSetAt(*PSetI).Name;
-      }
-    }
-    OS << "\n    ";
-    ++StartIdx;
   }
-  OS << "-1 };\n\n";
+
+  PSetsSeqs.layout();
+
+  OS << "/// Table of pressure sets per register class or unit.\n"
+     << "static const int RCSetsTable[] = {\n";
+  PSetsSeqs.emit(OS, printInt, "-1");
+  OS << "};\n\n";
 
   OS << "/// Get the dimensions of register pressure impacted by this "
      << "register class.\n"
      << "/// Returns a -1 terminated array of pressure set IDs\n"
      << "const int* " << ClassName << "::\n"
      << "getRegClassPressureSets(const TargetRegisterClass *RC) const {\n";
-  OS << "  static const unsigned RCSetStartTable[] = {\n    ";
+  OS << "  static const " << getMinimalTypeForRange(PSetsSeqs.size()-1)
+     << " RCSetStartTable[] = {\n    ";
   for (unsigned i = 0, e = NumRCs; i != e; ++i) {
-    OS << RCSetStarts[i] << ",";
+    OS << PSetsSeqs.get(PSets[i]) << ",";
   }
-  OS << "0 };\n"
+  OS << "};\n"
-     << "  unsigned SetListStart = RCSetStartTable[RC->getID()];\n"
+     << "  return &RCSetsTable[RCSetStartTable[RC->getID()]];\n"
-     << "  return &RCSetsTable[SetListStart];\n"
      << "}\n\n";
 
   OS << "/// Get the dimensions of register pressure impacted by this "
@@ -299,14 +306,15 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
      << "getRegUnitPressureSets(unsigned RegUnit) const {\n"
      << "  assert(RegUnit < " << RegBank.getNumNativeRegUnits()
      << " && \"invalid register unit\");\n";
-  OS << "  static const unsigned RUSetStartTable[] = {\n    ";
+  OS << "  static const " << getMinimalTypeForRange(PSetsSeqs.size()-1)
+     << " RUSetStartTable[] = {\n    ";
   for (unsigned UnitIdx = 0, UnitEnd = RegBank.getNumNativeRegUnits();
        UnitIdx < UnitEnd; ++UnitIdx) {
-    OS << RCSetStarts[RegBank.getRegUnit(UnitIdx).RegClassUnitSetsIdx] << ",";
+    OS << PSetsSeqs.get(PSets[RegBank.getRegUnit(UnitIdx).RegClassUnitSetsIdx])
+       << ",";
   }
-  OS << "0 };\n"
+  OS << "};\n"
-     << "  unsigned SetListStart = RUSetStartTable[RegUnit];\n"
+     << "  return &RCSetsTable[RUSetStartTable[RegUnit]];\n"
-     << "  return &RCSetsTable[SetListStart];\n"
      << "}\n\n";
 }
 
@@ -616,15 +624,6 @@ static bool combine(const CodeGenSubRegIndex *Idx,
   return true;
 }
 
-static const char *getMinimalTypeForRange(uint64_t Range) {
-  assert(Range < 0xFFFFFFFFULL && "Enum too large");
-  if (Range > 0xFFFF)
-    return "uint32_t";
-  if (Range > 0xFF)
-    return "uint16_t";
-  return "uint8_t";
-}
-
 void
 RegisterInfoEmitter::emitComposeSubRegIndices(raw_ostream &OS,
                                               CodeGenRegBank &RegBank,

llvm/utils/TableGen/SequenceToOffsetTable.h

@@ -84,6 +84,11 @@ public:
 
   bool empty() const { return Seqs.empty(); }
 
+  unsigned size() const {
+    assert(Entries && "Call layout() before size()");
+    return Entries;
+  }
+
   /// layout - Computes the final table layout.
   void layout() {
     assert(Entries == 0 && "Can only call layout() once");