Support REG_SEQUENCE in tablegen.

The problem is mostly that variadic output instruction
aren't handled, so it is rejected for having an inconsistent
number of operands, and then the right number of operands
isn't emitted.

llvm-svn: 221117

1 files changed, 39 insertions, 2 deletions

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index d195ba823b5..165f8e4c33d 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -1387,7 +1387,7 @@ static EEVT::TypeSet getImplicitType(Record *R, unsigned ResNo,
 
   if (R->isSubClassOf("SubRegIndex")) {
     assert(ResNo == 0 && "SubRegisterIndices only produce one result!");
-    return EEVT::TypeSet();
+    return EEVT::TypeSet(MVT::i32, TP);
   }
 
   if (R->isSubClassOf("ValueType")) {
@@ -1529,7 +1529,16 @@ TreePatternNode::isCommutativeIntrinsic(const CodeGenDAGPatterns &CDP) const {
   return false;
 }
 
+static bool isOperandClass(const TreePatternNode *N, StringRef Class) {
+  if (!N->isLeaf())
+    return N->getOperator()->isSubClassOf(Class);
 
+  DefInit *DI = dyn_cast<DefInit>(N->getLeafValue());
+  if (DI && DI->getDef()->isSubClassOf(Class))
+    return true;
+
+  return false;
+}
 /// ApplyTypeConstraints - Apply all of the type constraints relevant to
 /// this node and its children in the tree.  This returns true if it makes a
 /// change, false otherwise.  If a type contradiction is found, flag an error.
@@ -1689,6 +1698,34 @@ bool TreePatternNode::ApplyTypeConstraints(TreePattern &TP, bool NotRegisters) {
       assert(getChild(0)->getNumTypes() == 1 && "FIXME: Unhandled");
       MadeChange |= UpdateNodeType(0, getChild(0)->getExtType(0), TP);
       MadeChange |= getChild(0)->UpdateNodeType(0, getExtType(0), TP);
+    } else if (getOperator()->getName() == "REG_SEQUENCE") {
+      // We need to do extra, custom typechecking for REG_SEQUENCE since it is
+      // variadic.
+
+      unsigned NChild = getNumChildren();
+      if (NChild < 3) {
+        TP.error("REG_SEQUENCE requires at least 3 operands!");
+        return false;
+      }
+
+      if (NChild % 2 == 0) {
+        TP.error("REG_SEQUENCE requires an odd number of operands!");
+        return false;
+      }
+
+      if (!isOperandClass(getChild(0), "RegisterClass")) {
+        TP.error("REG_SEQUENCE requires a RegisterClass for first operand!");
+        return false;
+      }
+
+      for (unsigned I = 1; I < NChild; I += 2) {
+        TreePatternNode *SubIdxChild = getChild(I + 1);
+        if (!isOperandClass(SubIdxChild, "SubRegIndex")) {
+          TP.error("REG_SEQUENCE requires a SubRegIndex for operand " +
+                   itostr(I + 1) + "!");
+          return false;
+        }
+      }
     }
 
     unsigned ChildNo = 0;
@@ -1749,7 +1786,7 @@ bool TreePatternNode::ApplyTypeConstraints(TreePattern &TP, bool NotRegisters) {
       MadeChange |= Child->UpdateNodeTypeFromInst(ChildResNo, OperandNode, TP);
     }
 
-    if (ChildNo != getNumChildren()) {
+    if (!InstInfo.Operands.isVariadic && ChildNo != getNumChildren()) {
       TP.error("Instruction '" + getOperator()->getName() +
                "' was provided too many operands!");
       return false;