Index: llvm/trunk/docs/TableGen/LangIntro.rst
===================================================================
--- llvm/trunk/docs/TableGen/LangIntro.rst
+++ llvm/trunk/docs/TableGen/LangIntro.rst
@@ -165,6 +165,24 @@
     remaining elements in the list may be arbitrary other values, including
     nested ```dag``' values.
 
+``!con(a, b, ...)``
+    Concatenate two or more DAG nodes. Their operations must equal.
+
+    Example: !con((op a1:$name1, a2:$name2), (op b1:$name3)) results in
+    the DAG node (op a1:$name1, a2:$name2, b1:$name3).
+
+``!dag(op, children, names)``
+    Generate a DAG node programmatically. 'children' and 'names' must be lists
+    of equal length or unset ('?'). 'names' must be a 'list<string>'.
+
+    Due to limitations of the type system, 'children' must be a list of items
+    of a common type. In practice, this means that they should either have the
+    same type or be records with a common superclass. Mixing dag and non-dag
+    items is not possible.
+
+    Example: !dag(op, [a1, a2], ["name1", "name2"]) results in
+    (op a1:$name1, a2:$name2).
+
 ``!listconcat(a, b, ...)``
     A list value that is the result of concatenating the 'a' and 'b' lists.
     The lists must have the same element type.
Index: llvm/trunk/docs/TableGen/LangRef.rst
===================================================================
--- llvm/trunk/docs/TableGen/LangRef.rst
+++ llvm/trunk/docs/TableGen/LangRef.rst
@@ -99,7 +99,7 @@
                :!add    !shl     !sra     !srl       !and
                :!or     !empty   !subst   !foreach   !strconcat
                :!cast   !listconcat       !size      !foldl
-               :!isa
+               :!isa    !dag
 
 
 Syntax
Index: llvm/trunk/include/llvm/TableGen/Record.h
===================================================================
--- llvm/trunk/include/llvm/TableGen/Record.h
+++ llvm/trunk/include/llvm/TableGen/Record.h
@@ -856,7 +856,7 @@
 /// !op (X, Y, Z) - Combine two inits.
 class TernOpInit : public OpInit, public FoldingSetNode {
 public:
-  enum TernaryOp : uint8_t { SUBST, FOREACH, IF };
+  enum TernaryOp : uint8_t { SUBST, FOREACH, IF, DAG };
 
 private:
   Init *LHS, *MHS, *RHS;
Index: llvm/trunk/lib/TableGen/Record.cpp
===================================================================
--- llvm/trunk/lib/TableGen/Record.cpp
+++ llvm/trunk/lib/TableGen/Record.cpp
@@ -1114,6 +1114,30 @@
     }
     break;
   }
+
+  case DAG: {
+    ListInit *MHSl = dyn_cast<ListInit>(MHS);
+    ListInit *RHSl = dyn_cast<ListInit>(RHS);
+    bool MHSok = MHSl || isa<UnsetInit>(MHS);
+    bool RHSok = RHSl || isa<UnsetInit>(RHS);
+
+    if (isa<UnsetInit>(MHS) && isa<UnsetInit>(RHS))
+      break; // Typically prevented by the parser, but might happen with template args
+
+    if (MHSok && RHSok && (!MHSl || !RHSl || MHSl->size() == RHSl->size())) {
+      SmallVector<std::pair<Init *, StringInit *>, 8> Children;
+      unsigned Size = MHSl ? MHSl->size() : RHSl->size();
+      for (unsigned i = 0; i != Size; ++i) {
+        Init *Node = MHSl ? MHSl->getElement(i) : UnsetInit::get();
+        Init *Name = RHSl ? RHSl->getElement(i) : UnsetInit::get();
+        if (!isa<StringInit>(Name) && !isa<UnsetInit>(Name))
+          return const_cast<TernOpInit *>(this);
+        Children.emplace_back(Node, dyn_cast<StringInit>(Name));
+      }
+      return DagInit::get(LHS, nullptr, Children);
+    }
+    break;
+  }
   }
 
   return const_cast<TernOpInit *>(this);
@@ -1155,6 +1179,7 @@
   case SUBST: Result = "!subst"; break;
   case FOREACH: Result = "!foreach"; break;
   case IF: Result = "!if"; break;
+  case DAG: Result = "!dag"; break;
   }
   return Result + "(" + LHS->getAsString() + ", " + MHS->getAsString() + ", " +
          RHS->getAsString() + ")";
Index: llvm/trunk/lib/TableGen/TGLexer.h
===================================================================
--- llvm/trunk/lib/TableGen/TGLexer.h
+++ llvm/trunk/lib/TableGen/TGLexer.h
@@ -48,7 +48,7 @@
 
     // !keywords.
     XConcat, XADD, XAND, XOR, XSRA, XSRL, XSHL, XListConcat, XStrConcat, XCast,
-    XSubst, XForEach, XFoldl, XHead, XTail, XSize, XEmpty, XIf, XEq, XIsA,
+    XSubst, XForEach, XFoldl, XHead, XTail, XSize, XEmpty, XIf, XEq, XIsA, XDag,
 
     // Integer value.
     IntVal,
Index: llvm/trunk/lib/TableGen/TGLexer.cpp
===================================================================
--- llvm/trunk/lib/TableGen/TGLexer.cpp
+++ llvm/trunk/lib/TableGen/TGLexer.cpp
@@ -473,6 +473,7 @@
     .Case("tail", tgtok::XTail)
     .Case("size", tgtok::XSize)
     .Case("con", tgtok::XConcat)
+    .Case("dag", tgtok::XDag)
     .Case("add", tgtok::XADD)
     .Case("and", tgtok::XAND)
     .Case("or", tgtok::XOR)
Index: llvm/trunk/lib/TableGen/TGParser.cpp
===================================================================
--- llvm/trunk/lib/TableGen/TGParser.cpp
+++ llvm/trunk/lib/TableGen/TGParser.cpp
@@ -1159,6 +1159,7 @@
                ->Fold(CurRec, CurMultiClass);
   }
 
+  case tgtok::XDag:
   case tgtok::XIf:
   case tgtok::XSubst: {  // Value ::= !ternop '(' Value ',' Value ',' Value ')'
     TernOpInit::TernaryOp Code;
@@ -1168,6 +1169,11 @@
     Lex.Lex();  // eat the operation
     switch (LexCode) {
     default: llvm_unreachable("Unhandled code!");
+    case tgtok::XDag:
+      Code = TernOpInit::DAG;
+      Type = DagRecTy::get();
+      ItemType = nullptr;
+      break;
     case tgtok::XIf:
       Code = TernOpInit::IF;
       break;
@@ -1190,6 +1196,7 @@
     }
     Lex.Lex();  // eat the ','
 
+    SMLoc MHSLoc = Lex.getLoc();
     Init *MHS = ParseValue(CurRec, ItemType);
     if (!MHS)
       return nullptr;
@@ -1200,6 +1207,7 @@
     }
     Lex.Lex();  // eat the ','
 
+    SMLoc RHSLoc = Lex.getLoc();
     Init *RHS = ParseValue(CurRec, ItemType);
     if (!RHS)
       return nullptr;
@@ -1212,6 +1220,36 @@
 
     switch (LexCode) {
     default: llvm_unreachable("Unhandled code!");
+    case tgtok::XDag: {
+      TypedInit *MHSt = dyn_cast<TypedInit>(MHS);
+      if (!MHSt && !isa<UnsetInit>(MHS)) {
+        Error(MHSLoc, "could not determine type of the child list in !dag");
+        return nullptr;
+      }
+      if (MHSt && !isa<ListRecTy>(MHSt->getType())) {
+        Error(MHSLoc, Twine("expected list of children, got type '") +
+                          MHSt->getType()->getAsString() + "'");
+        return nullptr;
+      }
+
+      TypedInit *RHSt = dyn_cast<TypedInit>(RHS);
+      if (!RHSt && !isa<UnsetInit>(RHS)) {
+        Error(RHSLoc, "could not determine type of the name list in !dag");
+        return nullptr;
+      }
+      if (RHSt && StringRecTy::get()->getListTy() != RHSt->getType()) {
+        Error(RHSLoc, Twine("expected list<string>, got type '") +
+                          RHSt->getType()->getAsString() + "'");
+        return nullptr;
+      }
+
+      if (!MHSt && !RHSt) {
+        Error(MHSLoc,
+              "cannot have both unset children and unset names in !dag");
+        return nullptr;
+      }
+      break;
+    }
     case tgtok::XIf: {
       RecTy *MHSTy = nullptr;
       RecTy *RHSTy = nullptr;
@@ -1728,6 +1766,7 @@
   case tgtok::XCast:  // Value ::= !unop '(' Value ')'
   case tgtok::XIsA:
   case tgtok::XConcat:
+  case tgtok::XDag:
   case tgtok::XADD:
   case tgtok::XAND:
   case tgtok::XOR:
Index: llvm/trunk/test/TableGen/dag-functional.td
===================================================================
--- llvm/trunk/test/TableGen/dag-functional.td
+++ llvm/trunk/test/TableGen/dag-functional.td
@@ -0,0 +1,95 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+// XFAIL: vg_leak
+
+// CHECK: --- Defs ---
+
+// CHECK: def A0 {
+// CHECK:   dag ret = (ops);
+// CHECK: }
+
+// CHECK: def A1 {
+// CHECK:   dag ret = (ops 1:$a, 2:$b);
+// CHECK: }
+
+// CHECK: def A2 {
+// CHECK:   dag ret = (ops (ops ?:$name):$a, (ops 1):$b, (ops "foo"):$c);
+// CHECK: }
+
+// CHECK: def A3 {
+// CHECK:   dag ret = (ops NodeA0:$a, NodeB0:$b);
+// CHECK: }
+
+// CHECK: def A4 {
+// CHECK:   dag ret = (ops NodeA0, NodeB0);
+// CHECK: }
+
+// CHECK: def B0 {
+// CHECK:   dag ret = (ops);
+// CHECK: }
+
+// CHECK: def B1 {
+// CHECK:   dag ret = (ops 1:$a, 2:$b);
+// CHECK: }
+
+// CHECK: def C0 {
+// CHECK:   dag ret1 = (ops ?:$a, ?:$b);
+// CHECK:   dag ret2 = (ops 1, 2);
+// CHECK: }
+
+def ops;
+
+class Node<int val, string name> {
+  int Val = val;
+  string Name = name;
+}
+
+class Aint<list<int> nodes, list<string> names> {
+  dag ret = !dag(ops, nodes, names);
+}
+
+class Adag<list<dag> nodes, list<string> names> {
+  dag ret = !dag(ops, nodes, names);
+}
+
+class NodeBase;
+
+class NodeA<int val> : NodeBase {
+  int x = val;
+}
+
+class NodeB<int val> : NodeBase {
+  int y = val;
+}
+
+class Anode<list<NodeBase> nodes, list<string> names> {
+  dag ret = !dag(ops, nodes, names);
+}
+
+class B<list<Node> nodes> {
+  dag ret = !foldl((ops), nodes, lhs, rhs, !con(lhs, !dag(ops, [rhs.Val], [rhs.Name])));
+}
+
+def A0 : Aint<[], []>;
+def A1 : Aint<[1, 2], ["a", "b"]>;
+
+def A2 : Adag<[(ops $name), (ops 1), (ops "foo")], ["a", "b", "c"]>;
+
+def NodeA0 : NodeA<0>;
+def NodeB0 : NodeB<0>;
+
+def A3 : Anode<[NodeA0, NodeB0], ["a", "b"]>;
+
+def A4 {
+  // Like A3, but with a literal list directly in the !dag.
+  dag ret = !dag(ops, [NodeA0, NodeB0], ?);
+}
+
+def B0 : B<[]>;
+def B1 : B<[Node<1, "a">, Node<2, "b">]>;
+
+class C<list<int> nodes, list<string> names> {
+  dag ret1 = !dag(ops, ?, names);
+  dag ret2 = !dag(ops, nodes, ?);
+}
+
+def C0 : C<[1, 2], ["a", "b"]>;