Add an "implies" field to features. This indicates that, if the current

feature is set, then the features in the implied list should be set also.
The opposite is also enforced: if a feature in the implied list isn't set,
then the feature that owns that implies list shouldn't be set either.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36756 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 46 deletions

diff --git a/utils/TableGen/SubtargetEmitter.cpp b/utils/TableGen/SubtargetEmitter.cpp
index f6c7a44f34..fc913e69e1 100644
--- a/utils/TableGen/SubtargetEmitter.cpp
+++ b/utils/TableGen/SubtargetEmitter.cpp
@@ -56,8 +56,7 @@ void SubtargetEmitter::Enumeration(std::ostream &OS,
     Record *Def = DefList[i];
     
     // Get and emit name
-    std::string Name = Def->getName();
-    OS << "  " << Name;
+    OS << "  " << Def->getName();
     
     // If bit flags then emit expression (1 << i)
     if (isBits)  OS << " = " << " 1 << " << i;
@@ -73,8 +72,8 @@ void SubtargetEmitter::Enumeration(std::ostream &OS,
 }
 
 //
-// FeatureKeyValues - Emit data of all the subtarget features.  Used by command
-// line.
+// FeatureKeyValues - Emit data of all the subtarget features.  Used by the
+// command line.
 //
 void SubtargetEmitter::FeatureKeyValues(std::ostream &OS) {
   // Gather and sort all the features
@@ -91,18 +90,31 @@ void SubtargetEmitter::FeatureKeyValues(std::ostream &OS) {
     // Next feature
     Record *Feature = FeatureList[i];
 
-    std::string Name = Feature->getName();
-    std::string CommandLineName = Feature->getValueAsString("Name");
-    std::string Desc = Feature->getValueAsString("Desc");
+    const std::string &Name = Feature->getName();
+    const std::string &CommandLineName = Feature->getValueAsString("Name");
+    const std::string &Desc = Feature->getValueAsString("Desc");
     
     if (CommandLineName.empty()) continue;
     
-    // Emit as { "feature", "decription", feactureEnum }
+    // Emit as { "feature", "decription", feactureEnum, i1 | i2 | ... | in }
     OS << "  { "
        << "\"" << CommandLineName << "\", "
        << "\"" << Desc << "\", "
-       << Name
-       << " }";
+       << Name << ", ";
+
+    const std::vector<Record*> &ImpliesList = 
+      Feature->getValueAsListOfDefs("Implies");
+    
+    if (ImpliesList.empty()) {
+      OS << "0";
+    } else {
+      for (unsigned j = 0, M = ImpliesList.size(); j < M;) {
+        OS << ImpliesList[j]->getName();
+        if (++j < M) OS << " | ";
+      }
+    }
+
+    OS << " }";
     
     // Depending on 'if more in the list' emit comma
     if ((i + 1) < N) OS << ",";
@@ -138,8 +150,8 @@ void SubtargetEmitter::CPUKeyValues(std::ostream &OS) {
     // Next processor
     Record *Processor = ProcessorList[i];
 
-    std::string Name = Processor->getValueAsString("Name");
-    std::vector<Record*> FeatureList = 
+    const std::string &Name = Processor->getValueAsString("Name");
+    const std::vector<Record*> &FeatureList = 
       Processor->getValueAsListOfDefs("Features");
     
     // Emit as { "cpu", "description", f1 | f2 | ... fn },
@@ -151,14 +163,13 @@ void SubtargetEmitter::CPUKeyValues(std::ostream &OS) {
       OS << "0";
     } else {
       for (unsigned j = 0, M = FeatureList.size(); j < M;) {
-        Record *Feature = FeatureList[j];
-        std::string Name = Feature->getName();
-        OS << Name;
+        OS << FeatureList[j]->getName();
         if (++j < M) OS << " | ";
       }
     }
     
-    OS << " }";
+    // The "0" is for the "implies" section of this data structure.
+    OS << ", 0 }";
     
     // Depending on 'if more in the list' emit comma
     if (++i < N) OS << ",";
@@ -190,11 +201,10 @@ unsigned SubtargetEmitter::CollectAllItinClasses(std::ostream &OS,
   unsigned N = ItinClassList.size();
   for (unsigned i = 0; i < N; i++) {
     // Next itinerary class
-    Record *ItinClass = ItinClassList[i];
+    const Record *ItinClass = ItinClassList[i];
     // Get name of itinerary class
-    std::string Name = ItinClass->getName();
     // Assign itinerary class a unique number
-    ItinClassesMap[Name] = i;
+    ItinClassesMap[ItinClass->getName()] = i;
   }
   
   // Emit size of table
@@ -214,28 +224,26 @@ void SubtargetEmitter::FormItineraryString(Record *ItinData,
                                            std::string &ItinString,
                                            unsigned &NStages) {
   // Get states list
-  std::vector<Record*> StageList = ItinData->getValueAsListOfDefs("Stages");
+  const std::vector<Record*> &StageList =
+    ItinData->getValueAsListOfDefs("Stages");
 
   // For each stage
   unsigned N = NStages = StageList.size();
   for (unsigned i = 0; i < N;) {
     // Next stage
-    Record *Stage = StageList[i];
+    const Record *Stage = StageList[i];
   
     // Form string as ,{ cycles, u1 | u2 | ... | un }
     int Cycles = Stage->getValueAsInt("Cycles");
     ItinString += "  { " + itostr(Cycles) + ", ";
     
     // Get unit list
-    std::vector<Record*> UnitList = Stage->getValueAsListOfDefs("Units");
+    const std::vector<Record*> &UnitList = Stage->getValueAsListOfDefs("Units");
     
     // For each unit
     for (unsigned j = 0, M = UnitList.size(); j < M;) {
-      // Next unit
-      Record *Unit = UnitList[j];
-      
       // Add name and bitwise or
-      ItinString += Unit->getName();
+      ItinString += UnitList[j]->getName();
       if (++j < M) ItinString += " | ";
     }
     
@@ -271,7 +279,7 @@ void SubtargetEmitter::EmitStageData(std::ostream &OS,
     Record *Proc = ProcItinList[i];
     
     // Get processor itinerary name
-    std::string Name = Proc->getName();
+    const std::string &Name = Proc->getName();
     
     // Skip default
     if (Name == "NoItineraries") continue;
@@ -308,7 +316,7 @@ void SubtargetEmitter::EmitStageData(std::ostream &OS,
       InstrItinerary Intinerary = { Find, Find + NStages };
 
       // Locate where to inject into processor itinerary table
-      std::string Name = ItinData->getValueAsDef("TheClass")->getName();
+      const std::string &Name = ItinData->getValueAsDef("TheClass")->getName();
       Find = ItinClassesMap[Name];
       
       // Inject - empty slots will be 0, 0
@@ -347,7 +355,7 @@ void SubtargetEmitter::EmitProcessorData(std::ostream &OS,
     Record *Itin = Itins[i];
 
     // Get processor itinerary name
-    std::string Name = Itin->getName();
+    const std::string &Name = Itin->getName();
     
     // Skip default
     if (Name == "NoItineraries") continue;
@@ -398,8 +406,9 @@ void SubtargetEmitter::EmitProcessorLookup(std::ostream &OS) {
     // Next processor
     Record *Processor = ProcessorList[i];
 
-    std::string Name = Processor->getValueAsString("Name");
-    std::string ProcItin = Processor->getValueAsDef("ProcItin")->getName();
+    const std::string &Name = Processor->getValueAsString("Name");
+    const std::string &ProcItin =
+      Processor->getValueAsDef("ProcItin")->getName();
     
     // Emit as { "cpu", procinit },
     OS << "  { "
@@ -456,33 +465,32 @@ void SubtargetEmitter::ParseFeaturesFunction(std::ostream &OS) {
   std::sort(Features.begin(), Features.end(), LessRecord());
 
   OS << "// ParseSubtargetFeatures - Parses features string setting specified\n" 
-        "// subtarget options.\n" 
-        "void llvm::";
+     << "// subtarget options.\n" 
+     << "void llvm::";
   OS << Target;
   OS << "Subtarget::ParseSubtargetFeatures(const std::string &FS,\n"
-        "                                  const std::string &CPU) {\n"
-        "  SubtargetFeatures Features(FS);\n"
-        "  Features.setCPUIfNone(CPU);\n"
-        "  uint32_t Bits =  Features.getBits(SubTypeKV, SubTypeKVSize,\n"
-        "                                    FeatureKV, FeatureKVSize);\n";
-        
+     << "                                  const std::string &CPU) {\n"
+     << "  SubtargetFeatures Features(FS);\n"
+     << "  Features.setCPUIfNone(CPU);\n"
+     << "  uint32_t Bits =  Features.getBits(SubTypeKV, SubTypeKVSize,\n"
+     << "                                    FeatureKV, FeatureKVSize);\n";
+
   for (unsigned i = 0; i < Features.size(); i++) {
     // Next record
     Record *R = Features[i];
-    std::string Instance = R->getName();
-    std::string Name = R->getValueAsString("Name");
-    std::string Value = R->getValueAsString("Value");
-    std::string Attribute = R->getValueAsString("Attribute");
+    const std::string &Instance = R->getName();
+    const std::string &Value = R->getValueAsString("Value");
+    const std::string &Attribute = R->getValueAsString("Attribute");
 
     OS << "  if ((Bits & " << Instance << ") != 0) "
        << Attribute << " = " << Value << ";\n";
   }
-  
+
   if (HasItineraries) {
     OS << "\n"
        << "  InstrItinerary *Itinerary = (InstrItinerary *)"
-                        "Features.getInfo(ProcItinKV, ProcItinKVSize);\n"
-          "  InstrItins = InstrItineraryData(Stages, Itinerary);\n";
+       <<              "Features.getInfo(ProcItinKV, ProcItinKVSize);\n"
+       << "  InstrItins = InstrItineraryData(Stages, Itinerary);\n";
   }
   
   OS << "}\n";