DAG: Add helper for testing constant values

There are helpers for testing for constant or constant build_vector,
and for splat ConstantFP vectors, but not for a constantfp or
non-splat ConstantFP vector.

llvm-svn: 290317

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -1370,6 +1370,16 @@ public:
   /// Test whether the given value is a constant int or similar node.
   SDNode *isConstantIntBuildVectorOrConstantInt(SDValue N);
 
+  /// Test whether the given value is a constant FP or similar node.
+  SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N);
+
+  /// \returns true if \p N is any kind of constant or build_vector of
+  /// constants, int or float. If a vector, it may not necessarily be a splat.
+  inline bool isConstantValueOfAnyType(SDValue N) {
+    return isConstantIntBuildVectorOrConstantInt(N) ||
+           isConstantFPBuildVectorOrConstantFP(N);
+  }
+
 private:
   void InsertNode(SDNode *N);
   bool RemoveNodeFromCSEMaps(SDNode *N);

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -7517,6 +7517,16 @@ SDNode *SelectionDAG::isConstantIntBuildVectorOrConstantInt(SDValue N) {
   return nullptr;
 }
 
+SDNode *SelectionDAG::isConstantFPBuildVectorOrConstantFP(SDValue N) {
+  if (isa<ConstantFPSDNode>(N))
+    return N.getNode();
+
+  if (ISD::isBuildVectorOfConstantFPSDNodes(N.getNode()))
+    return N.getNode();
+
+  return nullptr;
+}
+
 #ifndef NDEBUG
 static void checkForCyclesHelper(const SDNode *N,
                                  SmallPtrSetImpl<const SDNode*> &Visited,