1 files changed, 16 insertions, 1 deletions
diff --git a/utils/TableGen/CodeGenRegisters.h b/utils/TableGen/CodeGenRegisters.h
index 1fcba8a135d18..d0f96a035ea19 100644
--- a/utils/TableGen/CodeGenRegisters.h
+++ b/utils/TableGen/CodeGenRegisters.h
@@ -329,6 +329,9 @@ namespace llvm {
     const std::string &getName() const { return Name; }
     std::string getQualifiedName() const;
     ArrayRef<MVT::SimpleValueType> getValueTypes() const {return VTs;}
+    bool hasValueType(MVT::SimpleValueType VT) const {
+      return std::find(VTs.begin(), VTs.end(), VT) != VTs.end();
+    }
     unsigned getNumValueTypes() const { return VTs.size(); }
 
     MVT::SimpleValueType getValueTypeNum(unsigned VTNum) const {
@@ -360,6 +363,18 @@ namespace llvm {
       return SubClassWithSubReg.lookup(SubIdx);
     }
 
+    /// Find largest subclass where all registers have SubIdx subregisters in
+    /// SubRegClass and the largest subregister class that contains those
+    /// subregisters without (as far as possible) also containing additional registers.
+    ///
+    /// This can be used to find a suitable pair of classes for subregister copies.
+    /// \return std::pair<SubClass, SubRegClass> where SubClass is a SubClass is
+    /// a class where every register has SubIdx and SubRegClass is a class where
+    /// every register is covered by the SubIdx subregister of SubClass.
+    Optional<std::pair<CodeGenRegisterClass *, CodeGenRegisterClass *>>
+    getMatchingSubClassWithSubRegs(CodeGenRegBank &RegBank,
+                                   const CodeGenSubRegIndex *SubIdx) const;
+
     void setSubClassWithSubReg(const CodeGenSubRegIndex *SubIdx,
                                CodeGenRegisterClass *SubRC) {
       SubClassWithSubReg[SubIdx] = SubRC;
@@ -370,7 +385,7 @@ namespace llvm {
     void getSuperRegClasses(const CodeGenSubRegIndex *SubIdx,
                             BitVector &Out) const;
 
-    // addSuperRegClass - Add a class containing only SudIdx super-registers.
+    // addSuperRegClass - Add a class containing only SubIdx super-registers.
     void addSuperRegClass(CodeGenSubRegIndex *SubIdx,
                           CodeGenRegisterClass *SuperRC) {
       SuperRegClasses[SubIdx].insert(SuperRC);