4 files changed, 36 insertions, 2 deletions

diff --git a/llvm/lib/TableGen/Record.cpp b/llvm/lib/TableGen/Record.cpp
index 57d2703b82b..c17aea99f8e 100644
--- a/llvm/lib/TableGen/Record.cpp
+++ b/llvm/lib/TableGen/Record.cpp
@@ -918,6 +918,18 @@ Init *BinOpInit::Fold(Record *CurRec, MultiClass *CurMultiClass) const {
     }
     break;
   }
+  case LISTCONCAT: {
+    ListInit *LHSs = dyn_cast<ListInit>(LHS);
+    ListInit *RHSs = dyn_cast<ListInit>(RHS);
+    if (LHSs && RHSs) {
+      std::vector<Init *> Args;
+      Args.insert(Args.end(), LHSs->begin(), LHSs->end());
+      Args.insert(Args.end(), RHSs->begin(), RHSs->end());
+      return ListInit::get(
+          Args, static_cast<ListRecTy *>(LHSs->getType())->getElementType());
+    }
+    break;
+  }
   case STRCONCAT: {
     StringInit *LHSs = dyn_cast<StringInit>(LHS);
     StringInit *RHSs = dyn_cast<StringInit>(RHS);
@@ -987,6 +999,7 @@ std::string BinOpInit::getAsString() const {
   case SRA: Result = "!sra"; break;
   case SRL: Result = "!srl"; break;
   case EQ: Result = "!eq"; break;
+  case LISTCONCAT: Result = "!listconcat"; break;
   case STRCONCAT: Result = "!strconcat"; break;
   }
   return Result + "(" + LHS->getAsString() + ", " + RHS->getAsString() + ")";
diff --git a/llvm/lib/TableGen/TGLexer.cpp b/llvm/lib/TableGen/TGLexer.cpp
index 57f603183ba..1ec2eea67d9 100644
--- a/llvm/lib/TableGen/TGLexer.cpp
+++ b/llvm/lib/TableGen/TGLexer.cpp
@@ -478,6 +478,7 @@ tgtok::TokKind TGLexer::LexExclaim() {
     .Case("empty", tgtok::XEmpty)
     .Case("subst", tgtok::XSubst)
     .Case("foreach", tgtok::XForEach)
+    .Case("listconcat", tgtok::XListConcat)
     .Case("strconcat", tgtok::XStrConcat)
     .Default(tgtok::Error);
 
diff --git a/llvm/lib/TableGen/TGLexer.h b/llvm/lib/TableGen/TGLexer.h
index d1bd70d2eca..1e599f84b06 100644
--- a/llvm/lib/TableGen/TGLexer.h
+++ b/llvm/lib/TableGen/TGLexer.h
@@ -47,7 +47,7 @@ namespace tgtok {
     MultiClass, String,
     
     // !keywords.
-    XConcat, XADD, XSRA, XSRL, XSHL, XStrConcat, XCast, XSubst,
+    XConcat, XADD, XSRA, XSRL, XSHL, XListConcat, XStrConcat, XCast, XSubst,
     XForEach, XHead, XTail, XEmpty, XIf, XEq,
 
     // Integer value.
diff --git a/llvm/lib/TableGen/TGParser.cpp b/llvm/lib/TableGen/TGParser.cpp
index dd3a0967d14..038e0180fbb 100644
--- a/llvm/lib/TableGen/TGParser.cpp
+++ b/llvm/lib/TableGen/TGParser.cpp
@@ -903,6 +903,7 @@ Init *TGParser::ParseOperation(Record *CurRec) {
   case tgtok::XSRL:
   case tgtok::XSHL:
   case tgtok::XEq:
+  case tgtok::XListConcat:
   case tgtok::XStrConcat: {  // Value ::= !binop '(' Value ',' Value ')'
     tgtok::TokKind OpTok = Lex.getCode();
     SMLoc OpLoc = Lex.getLoc();
@@ -919,6 +920,10 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     case tgtok::XSRL:    Code = BinOpInit::SRL;   Type = IntRecTy::get(); break;
     case tgtok::XSHL:    Code = BinOpInit::SHL;   Type = IntRecTy::get(); break;
     case tgtok::XEq:     Code = BinOpInit::EQ;    Type = BitRecTy::get(); break;
+    case tgtok::XListConcat:
+      Code = BinOpInit::LISTCONCAT;
+      // We don't know the list type until we parse the first argument
+      break;
     case tgtok::XStrConcat:
       Code = BinOpInit::STRCONCAT;
       Type = StringRecTy::get();
@@ -949,9 +954,22 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     }
     Lex.Lex();  // eat the ')'
 
+    // If we are doing !listconcat, we should know the type by now
+    if (OpTok == tgtok::XListConcat) {
+      if (VarInit *Arg0 = dyn_cast<VarInit>(InitList[0]))
+        Type = Arg0->getType();
+      else if (ListInit *Arg0 = dyn_cast<ListInit>(InitList[0]))
+        Type = Arg0->getType();
+      else {
+        InitList[0]->dump();
+        Error(OpLoc, "expected a list");
+        return nullptr;
+      }
+    }
+
     // We allow multiple operands to associative operators like !strconcat as
     // shorthand for nesting them.
-    if (Code == BinOpInit::STRCONCAT) {
+    if (Code == BinOpInit::STRCONCAT || Code == BinOpInit::LISTCONCAT) {
       while (InitList.size() > 2) {
         Init *RHS = InitList.pop_back_val();
         RHS = (BinOpInit::get(Code, InitList.back(), RHS, Type))
@@ -1134,6 +1152,7 @@ RecTy *TGParser::ParseOperatorType() {
 ///   SimpleValue ::= SHLTOK '(' Value ',' Value ')'
 ///   SimpleValue ::= SRATOK '(' Value ',' Value ')'
 ///   SimpleValue ::= SRLTOK '(' Value ',' Value ')'
+///   SimpleValue ::= LISTCONCATTOK '(' Value ',' Value ')'
 ///   SimpleValue ::= STRCONCATTOK '(' Value ',' Value ')'
 ///
 Init *TGParser::ParseSimpleValue(Record *CurRec, RecTy *ItemType,
@@ -1417,6 +1436,7 @@ Init *TGParser::ParseSimpleValue(Record *CurRec, RecTy *ItemType,
   case tgtok::XSRL:
   case tgtok::XSHL:
   case tgtok::XEq:
+  case tgtok::XListConcat:
   case tgtok::XStrConcat:   // Value ::= !binop '(' Value ',' Value ')'
   case tgtok::XIf:
   case tgtok::XForEach: