diff --git a/llvm/include/llvm/Support/RISCVISAInfo.h b/llvm/include/llvm/Support/RISCVISAInfo.h
--- a/llvm/include/llvm/Support/RISCVISAInfo.h
+++ b/llvm/include/llvm/Support/RISCVISAInfo.h
@@ -85,10 +85,12 @@
 
   static bool isSupportedExtensionFeature(StringRef Ext);
   static bool isSupportedExtension(StringRef Ext);
+  static bool isSupportedExtensionWithVersion(StringRef Ext);
   static bool isSupportedExtension(StringRef Ext, unsigned MajorVersion,
                                    unsigned MinorVersion);
   static llvm::Expected<std::unique_ptr<RISCVISAInfo>>
   postProcessAndChecking(std::unique_ptr<RISCVISAInfo> &&ISAInfo);
+  static std::string getTargetFeatureFromOneExt(StringRef Ext);
 
 private:
   RISCVISAInfo(unsigned XLen)
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -1192,3 +1192,34 @@
   }
   llvm_unreachable("Invalid XLEN");
 }
+
+bool RISCVISAInfo::isSupportedExtensionWithVersion(StringRef Ext) {
+  if (Ext.empty())
+    return false;
+
+  auto Pos = findFirstNonVersionCharacter(Ext) + 1;
+  StringRef Name(Ext.substr(0, Pos));
+  StringRef Vers(Ext.substr(Pos));
+  if (Vers.empty())
+    return false;
+
+  unsigned Major, Minor, ConsumeLength;
+  if (auto E = getExtensionVersion(Name, Vers, Major, Minor, ConsumeLength,
+                                   true, true)) {
+    consumeError(std::move(E));
+    return false;
+  }
+
+  return true;
+}
+
+std::string RISCVISAInfo::getTargetFeatureFromOneExt(StringRef Ext) {
+  auto Pos = findFirstNonVersionCharacter(Ext) + 1;
+  StringRef Name(Ext.substr(0, Pos));
+
+  if (!isSupportedExtension(Name))
+    return std::string();
+
+  return isExperimentalExtension(Name) ? "experimental-" + Name.str()
+                                       : Name.str();
+}