Add support to tablegen for specifying subregister classes on a per register class basis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37572 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 50 insertions, 0 deletions

diff --git a/utils/TableGen/CodeGenRegisters.h b/utils/TableGen/CodeGenRegisters.h
index 8e9008c..83c85b8 100644
--- a/utils/TableGen/CodeGenRegisters.h
+++ b/utils/TableGen/CodeGenRegisters.h
@@ -38,6 +38,7 @@ namespace llvm {
     std::vector<MVT::ValueType> VTs;
     unsigned SpillSize;
     unsigned SpillAlignment;
+    std::vector<Record*> SubRegClasses;
     std::string MethodProtos, MethodBodies;
 
     const std::string &getName() const;
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index 17cea6f..c3c1ac22 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -199,6 +199,16 @@ CodeGenRegisterClass::CodeGenRegisterClass(Record *R) : TheDef(R) {
     Elements.push_back(Reg);
   }
   
+  std::vector<Record*> SubRegClassList = 
+                        R->getValueAsListOfDefs("SubRegClassList");
+  for (unsigned i = 0, e = SubRegClassList.size(); i != e; ++i) {
+    Record *SubRegClass = SubRegClassList[i];
+    if (!SubRegClass->isSubClassOf("RegisterClass"))
+      throw "Register Class member '" + SubRegClass->getName() +
+            "' does not derive from the RegisterClass class!";
+    SubRegClasses.push_back(SubRegClass);
+  }  
+  
   // Allow targets to override the size in bits of the RegisterClass.
   unsigned Size = R->getValueAsInt("Size");
 
diff --git a/utils/TableGen/RegisterInfoEmitter.cpp b/utils/TableGen/RegisterInfoEmitter.cpp
index 5fbd013..a2269a8 100644
--- a/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/utils/TableGen/RegisterInfoEmitter.cpp
@@ -224,6 +224,44 @@ void RegisterInfoEmitter::run(std::ostream &OS) {
          
     std::map<unsigned, std::set<unsigned> > SuperClassMap;
     OS << "\n";
+    
+    
+    // Emit the sub-register classes for each RegisterClass
+    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
+      const CodeGenRegisterClass &RC = RegisterClasses[rc];
+
+      // Give the register class a legal C name if it's anonymous.
+      std::string Name = RC.TheDef->getName();
+
+      OS << "  // " << Name 
+         << " Sub-register Classess...\n"
+         << "  static const TargetRegisterClass* const "
+         << Name << "SubRegClasses [] = {\n    ";
+
+      bool Empty = true;
+      
+      for (unsigned subrc = 0, e2 = RC.SubRegClasses.size();
+            subrc != e2; ++subrc) {
+        unsigned rc2 = 0, e2 = RegisterClasses.size();
+        for (; rc2 != e2; ++rc2) {
+          const CodeGenRegisterClass &RC2 =  RegisterClasses[rc2];
+          if (RC.SubRegClasses[subrc]->getName() == RC2.getName()) {
+            if (!Empty) OS << ", ";
+              OS << "&" << getQualifiedName(RC2.TheDef) << "RegClass";
+            Empty = false;
+            break;
+          }
+        }
+        if (rc2 == e2)
+          throw "Register Class member '" + 
+            RC.SubRegClasses[subrc]->getName() + 
+            "' is not a valid RegisterClass!";
+      }
+
+      OS << (!Empty ? ", " : "") << "NULL";
+      OS << "\n  };\n\n";
+    }
+    
     // Emit the sub-classes array for each RegisterClass
     for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
       const CodeGenRegisterClass &RC = RegisterClasses[rc];
@@ -304,6 +342,7 @@ void RegisterInfoEmitter::run(std::ostream &OS) {
          << RC.getName() + "VTs" << ", "
          << RC.getName() + "Subclasses" << ", "
          << RC.getName() + "Superclasses" << ", "
+         << RC.getName() + "SubRegClasses" << ", "
          << RC.SpillSize/8 << ", "
          << RC.SpillAlignment/8 << ", " << RC.getName() << ", "
          << RC.getName() << " + " << RC.Elements.size() << ") {}\n";