From ecf2d9fc0d5ea162571b0e229f47b22e84c93eaa Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Fri, 30 Mar 2012 17:42:04 +0000
Subject: [PATCH] Compress SimpleValueType lists by sharing.

Many register classes have the same value types. Share the table space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153764 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/TableGen/RegisterInfoEmitter.cpp | 33 ++++++++++----------------
 utils/TableGen/SequenceToOffsetTable.h |  6 +++--
 2 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/utils/TableGen/RegisterInfoEmitter.cpp b/utils/TableGen/RegisterInfoEmitter.cpp
index f1719b8cac5..b43203d54f9 100644
--- a/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/utils/TableGen/RegisterInfoEmitter.cpp
@@ -264,6 +264,10 @@ static void printRegister(raw_ostream &OS, const CodeGenRegister *Reg) {
   OS << getQualifiedName(Reg->TheDef);
 }
 
+static void printSimpleValueType(raw_ostream &OS, MVT::SimpleValueType VT) {
+  OS << getEnumName(VT);
+}
+
 //
 // runMCDesc - Print out MC register descriptions.
 //
@@ -547,25 +551,14 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
       AllocatableRegs.insert(Order.begin(), Order.end());
   }
 
-  OS << "namespace {     // Register classes...\n";
-
-  // Emit the ValueType arrays 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.getName() + "VTs";
-
-    // Emit the register list now.
-    OS << "  // " << Name
-       << " Register Class Value Types...\n"
-       << "  const MVT::SimpleValueType " << Name
-       << "[] = {\n    ";
-    for (unsigned i = 0, e = RC.VTs.size(); i != e; ++i)
-      OS << getEnumName(RC.VTs[i]) << ", ";
-    OS << "MVT::Other\n  };\n\n";
-  }
-  OS << "}  // end anonymous namespace\n\n";
+  // Build a shared array of value types.
+  SequenceToOffsetTable<std::vector<MVT::SimpleValueType> > VTSeqs;
+  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc)
+    VTSeqs.add(RegisterClasses[rc]->VTs);
+  VTSeqs.layout();
+  OS << "\nstatic const MVT::SimpleValueType VTLists[] = {\n";
+  VTSeqs.emit(OS, printSimpleValueType, "MVT::Other");
+  OS << "};\n";
 
   // Now that all of the structs have been emitted, emit the instances.
   if (!RegisterClasses.empty()) {
@@ -692,7 +685,7 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
          << RegisterClasses[i]->getName() << "RegClass = {\n    "
          << '&' << Target.getName() << "MCRegisterClasses[" << RC.getName()
          << "RegClassID],\n    "
-         << RC.getName() << "VTs,\n    "
+         << "VTLists + " << VTSeqs.get(RC.VTs) << ",\n    "
          << RC.getName() << "SubclassMask,\n    ";
       if (RC.getSuperClasses().empty())
         OS << "NullRegClasses,\n    ";
diff --git a/utils/TableGen/SequenceToOffsetTable.h b/utils/TableGen/SequenceToOffsetTable.h
index 26e705841f2..09dccbb1084 100644
--- a/utils/TableGen/SequenceToOffsetTable.h
+++ b/utils/TableGen/SequenceToOffsetTable.h
@@ -103,7 +103,9 @@ public:
 
   /// emit - Print out the table as the body of an array initializer.
   /// Use the Print function to print elements.
-  void emit(raw_ostream &OS, void (*Print)(raw_ostream&, ElemT)) const {
+  void emit(raw_ostream &OS,
+            void (*Print)(raw_ostream&, ElemT),
+            const char *Term = "0") const {
     assert(Entries && "Call layout() before emit()");
     for (typename SeqMap::const_iterator I = Seqs.begin(), E = Seqs.end();
          I != E; ++I) {
@@ -113,7 +115,7 @@ public:
         Print(OS, *SI);
         OS << ", ";
       }
-      OS << "0,\n";
+      OS << Term << ",\n";
     }
   }
 };