diff --git a/lib/Target/R600/SIRegisterInfo.cpp b/lib/Target/R600/SIRegisterInfo.cpp
index f5307f88038..3715e6a6cf8 100644
--- a/lib/Target/R600/SIRegisterInfo.cpp
+++ b/lib/Target/R600/SIRegisterInfo.cpp
@@ -288,13 +288,6 @@ const TargetRegisterClass *SIRegisterInfo::getPhysRegClass(unsigned Reg) const {
   return nullptr;
 }
 
-bool SIRegisterInfo::isSGPRClass(const TargetRegisterClass *RC) const {
-  if (!RC) {
-    return false;
-  }
-  return !hasVGPRs(RC);
-}
-
 bool SIRegisterInfo::hasVGPRs(const TargetRegisterClass *RC) const {
   return getCommonSubClass(&AMDGPU::VReg_32RegClass, RC) ||
          getCommonSubClass(&AMDGPU::VReg_64RegClass, RC) ||
diff --git a/lib/Target/R600/SIRegisterInfo.h b/lib/Target/R600/SIRegisterInfo.h
index 0ac9f368d95..c7e54dbf0ec 100644
--- a/lib/Target/R600/SIRegisterInfo.h
+++ b/lib/Target/R600/SIRegisterInfo.h
@@ -46,7 +46,20 @@ struct SIRegisterInfo : public AMDGPURegisterInfo {
   const TargetRegisterClass *getPhysRegClass(unsigned Reg) const;
 
   /// \returns true if this class contains only SGPR registers
-  bool isSGPRClass(const TargetRegisterClass *RC) const;
+  bool isSGPRClass(const TargetRegisterClass *RC) const {
+    if (!RC)
+      return false;
+
+    return !hasVGPRs(RC);
+  }
+
+  /// \returns true if this class ID contains only SGPR registers
+  bool isSGPRClassID(unsigned RCID) const {
+    if (static_cast<int>(RCID) == -1)
+      return false;
+
+    return isSGPRClass(getRegClass(RCID));
+  }
 
   /// \returns true if this class contains VGPR registers.
   bool hasVGPRs(const TargetRegisterClass *RC) const;