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
@@ -181,7 +181,7 @@
 // NOTE: This function is NOT able to take empty strings or strings that only
 // have version numbers and no extension name. It assumes the extension name
 // will be at least more than one character.
-static size_t findFirstNonVersionCharacter(StringRef Ext) {
+static size_t findLastNonVersionCharacter(StringRef Ext) {
   assert(!Ext.empty() &&
          "Already guarded by if-statement in ::parseArchString");
 
@@ -789,7 +789,7 @@
 
       StringRef Type = getExtensionType(Ext);
       StringRef Desc = getExtensionTypeDesc(Ext);
-      auto Pos = findFirstNonVersionCharacter(Ext) + 1;
+      auto Pos = findLastNonVersionCharacter(Ext) + 1;
       StringRef Name(Ext.substr(0, Pos));
       StringRef Vers(Ext.substr(Pos));
 
@@ -1192,3 +1192,41 @@
   }
   llvm_unreachable("Invalid XLEN");
 }
+
+bool RISCVISAInfo::isSupportedExtensionWithVersion(StringRef Ext) {
+  if (Ext.empty())
+    return false;
+
+  auto Pos = findLastNonVersionCharacter(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) {
+  if (Ext.empty())
+    return std::string();
+
+  auto Pos = findLastNonVersionCharacter(Ext) + 1;
+  StringRef Name = Ext.substr(0, Pos);
+  StringRef Vers = Ext.substr(Pos);
+
+  if (!Vers.empty() && !isSupportedExtensionWithVersion(Ext))
+    return std::string();
+
+  if (!isSupportedExtension(Name))
+    return std::string();
+
+  return isExperimentalExtension(Name) ? "experimental-" + Name.str()
+                                       : Name.str();
+}
diff --git a/llvm/unittests/Support/RISCVISAInfoTest.cpp b/llvm/unittests/Support/RISCVISAInfoTest.cpp
--- a/llvm/unittests/Support/RISCVISAInfoTest.cpp
+++ b/llvm/unittests/Support/RISCVISAInfoTest.cpp
@@ -485,3 +485,24 @@
               ElementsAre("i", "m", "l", "c", "y", "zicsr", "zmfoo", "zfinx",
                            "zzfoo", "sbar", "sfoo", "xbar", "xfoo"));
 }
+
+TEST(isSupportedExtensionWithVersion, AcceptsSingleExtensionWithVersion) {
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion("zbb1p0"), true);
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion("zbb"), false);
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion("zfoo1p0"), false);
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion("zfoo"), false);
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion(""), false);
+  EXPECT_EQ(RISCVISAInfo::isSupportedExtensionWithVersion("c2p0zbb1p0"), false);
+}
+
+TEST(getTargetFeatureFromOneExt, RetrieveTargetFeatureFromOneExt) {
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zbb"), "zbb");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zihintntl0p2"),
+            "experimental-zihintntl");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zihintntl"),
+            "experimental-zihintntl");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zihintntl1234p4321"), "");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zfoo"), "");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt(""), "");
+  EXPECT_EQ(RISCVISAInfo::getTargetFeatureFromOneExt("zbbzihintntl"), "");
+}