Move the composite map into CodeGenSubRegIndex.

Each SubRegIndex keeps track of how it composes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149423 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 51 insertions, 30 deletions

diff --git a/utils/TableGen/CodeGenRegisters.cpp b/utils/TableGen/CodeGenRegisters.cpp
index 3b15d06790..7c6661742a 100644
--- a/utils/TableGen/CodeGenRegisters.cpp
+++ b/utils/TableGen/CodeGenRegisters.cpp
@@ -49,6 +49,16 @@ std::string CodeGenSubRegIndex::getQualifiedName() const {
   return N;
 }
 
+void CodeGenSubRegIndex::cleanComposites() {
+  // Clean out redundant mappings of the form this+X -> X.
+  for (CompMap::iterator i = Composed.begin(), e = Composed.end(); i != e;) {
+    CompMap::iterator j = i;
+    ++i;
+    if (j->first == j->second)
+      Composed.erase(j);
+  }
+}
+
 //===----------------------------------------------------------------------===//
 //                              CodeGenRegister
 //===----------------------------------------------------------------------===//
@@ -168,7 +178,7 @@ CodeGenRegister::getSubRegs(CodeGenRegBank &RegBank) {
     Orphan &O = Orphans[i];
     if (!O.SubReg)
       continue;
-    SubRegs[RegBank.getCompositeSubRegIndex(O.First, O.Second, true)] =
+    SubRegs[RegBank.getCompositeSubRegIndex(O.First, O.Second)] =
       O.SubReg;
   }
   return SubRegs;
@@ -679,16 +689,16 @@ CodeGenRegisterClass *CodeGenRegBank::getRegClass(Record *Def) {
 
 CodeGenSubRegIndex*
 CodeGenRegBank::getCompositeSubRegIndex(CodeGenSubRegIndex *A,
-                                        CodeGenSubRegIndex *B,
-                                        bool create) {
+                                        CodeGenSubRegIndex *B) {
   // Look for an existing entry.
-  CodeGenSubRegIndex *&Comp = Composite[std::make_pair(A, B)];
-  if (Comp || !create)
+  CodeGenSubRegIndex *Comp = A->compose(B);
+  if (Comp)
     return Comp;
 
   // None exists, synthesize one.
   std::string Name = A->getName() + "_then_" + B->getName();
   Comp = getSubRegIdx(new Record(Name, SMLoc(), Records));
+  A->addComposite(B, Comp);
   return Comp;
 }
 
@@ -707,8 +717,7 @@ void CodeGenRegBank::computeComposites() {
       // Try composing Idx1 with another SubRegIndex.
       for (CodeGenRegister::SubRegMap::const_iterator i2 = SRM2.begin(),
            e2 = SRM2.end(); i2 != e2; ++i2) {
-        std::pair<CodeGenSubRegIndex*, CodeGenSubRegIndex*>
-          IdxPair(Idx1, i2->first);
+      CodeGenSubRegIndex *Idx2 = i2->first;
         CodeGenRegister *Reg3 = i2->second;
         // Ignore identity compositions.
         if (Reg2 == Reg3)
@@ -717,16 +726,13 @@ void CodeGenRegBank::computeComposites() {
         for (CodeGenRegister::SubRegMap::const_iterator i1d = SRM1.begin(),
              e1d = SRM1.end(); i1d != e1d; ++i1d) {
           if (i1d->second == Reg3) {
-            std::pair<CompositeMap::iterator, bool> Ins =
-              Composite.insert(std::make_pair(IdxPair, i1d->first));
             // Conflicting composition? Emit a warning but allow it.
-            if (!Ins.second && Ins.first->second != i1d->first) {
+            if (CodeGenSubRegIndex *Prev = Idx1->addComposite(Idx2, i1d->first))
               errs() << "Warning: SubRegIndex " << Idx1->getQualifiedName()
-                     << " and " << IdxPair.second->getQualifiedName()
+                     << " and " << Idx2->getQualifiedName()
                      << " compose ambiguously as "
-                     << Ins.first->second->getQualifiedName() << " or "
+                     << Prev->getQualifiedName() << " or "
                      << i1d->first->getQualifiedName() << "\n";
-            }
           }
         }
       }
@@ -735,13 +741,8 @@ void CodeGenRegBank::computeComposites() {
 
   // We don't care about the difference between (Idx1, Idx2) -> Idx2 and invalid
   // compositions, so remove any mappings of that form.
-  for (CompositeMap::iterator i = Composite.begin(), e = Composite.end();
-       i != e;) {
-    CompositeMap::iterator j = i;
-    ++i;
-    if (j->first.second == j->second)
-      Composite.erase(j);
-  }
+  for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i)
+    SubRegIndices[i]->cleanComposites();
 }
 
 // Compute sets of overlapping registers.
diff --git a/utils/TableGen/CodeGenRegisters.h b/utils/TableGen/CodeGenRegisters.h
index 7b96bd599e..b83ad6e785 100644
--- a/utils/TableGen/CodeGenRegisters.h
+++ b/utils/TableGen/CodeGenRegisters.h
@@ -51,6 +51,34 @@ namespace llvm {
         return A->EnumValue < B->EnumValue;
       }
     };
+
+    // Map of composite subreg indices.
+    typedef std::map<CodeGenSubRegIndex*, CodeGenSubRegIndex*, Less> CompMap;
+
+    // Returns the subreg index that results from composing this with Idx.
+    // Returns NULL if this and Idx don't compose.
+    CodeGenSubRegIndex *compose(CodeGenSubRegIndex *Idx) const {
+      CompMap::const_iterator I = Composed.find(Idx);
+      return I == Composed.end() ? 0 : I->second;
+    }
+
+    // Add a composite subreg index: this+A = B.
+    // Return a conflicting composite, or NULL
+    CodeGenSubRegIndex *addComposite(CodeGenSubRegIndex *A,
+                                     CodeGenSubRegIndex *B) {
+      std::pair<CompMap::iterator, bool> Ins =
+        Composed.insert(std::make_pair(A, B));
+      return (Ins.second || Ins.first->second == B) ? 0 : Ins.first->second;
+    }
+
+    // Clean out redundant composite mappings.
+    void cleanComposites();
+
+    // Return the map of composites.
+    const CompMap &getComposites() const { return Composed; }
+
+  private:
+    CompMap Composed;
   };
 
   /// CodeGenRegister - Represents a register definition.
@@ -298,12 +326,6 @@ namespace llvm {
     void inferMatchingSuperRegClass(CodeGenRegisterClass *RC,
                                     unsigned FirstSubRegRC = 0);
 
-    // Composite SubRegIndex instances.
-    // Map (SubRegIndex, SubRegIndex) -> SubRegIndex.
-    typedef DenseMap<std::pair<CodeGenSubRegIndex*, CodeGenSubRegIndex*>,
-                     CodeGenSubRegIndex*> CompositeMap;
-    CompositeMap Composite;
-
     // Populate the Composite map from sub-register relationships.
     void computeComposites();
 
@@ -323,8 +345,7 @@ namespace llvm {
 
     // Find or create a sub-register index representing the A+B composition.
     CodeGenSubRegIndex *getCompositeSubRegIndex(CodeGenSubRegIndex *A,
-                                                CodeGenSubRegIndex *B,
-                                                bool create = false);
+                                                CodeGenSubRegIndex *B);
 
     const std::vector<CodeGenRegister*> &getRegisters() { return Registers; }
 
diff --git a/utils/TableGen/RegisterInfoEmitter.cpp b/utils/TableGen/RegisterInfoEmitter.cpp
index 2734896461..fb950d0607 100644
--- a/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/utils/TableGen/RegisterInfoEmitter.cpp
@@ -766,8 +766,7 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
     bool Open = false;
     for (unsigned j = 0; j != e; ++j) {
       if (CodeGenSubRegIndex *Comp =
-            RegBank.getCompositeSubRegIndex(SubRegIndices[i],
-                                            SubRegIndices[j])) {
+            SubRegIndices[i]->compose(SubRegIndices[j])) {
         if (!Open) {
           OS << "  case " << SubRegIndices[i]->getQualifiedName()
              << ": switch(IdxB) {\n    default: return IdxB;\n";