diff --git a/clang/include/clang/Basic/BuiltinsRISCV.def b/clang/include/clang/Basic/BuiltinsRISCV.def
--- a/clang/include/clang/Basic/BuiltinsRISCV.def
+++ b/clang/include/clang/Basic/BuiltinsRISCV.def
@@ -19,7 +19,7 @@
 
 // Zbb extension
 TARGET_BUILTIN(__builtin_riscv_orc_b_32, "ZiZi", "nc", "experimental-zbb")
-TARGET_BUILTIN(__builtin_riscv_orc_b_64, "WiWi", "nc", "experimental-zbb")
+TARGET_BUILTIN(__builtin_riscv_orc_b_64, "WiWi", "nc", "experimental-zbb,64bit")
 
 // Zbc extension
 TARGET_BUILTIN(__builtin_riscv_clmul, "LiLiLi", "nc", "experimental-zbc")
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -99,6 +99,11 @@
 
   std::string convertConstraint(const char *&Constraint) const override;
 
+  bool
+  initFeatureMap(llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags,
+                 StringRef CPU,
+                 const std::vector<std::string> &FeaturesVec) const override;
+
   bool hasFeature(StringRef Feature) const override;
 
   bool handleTargetFeatures(std::vector<std::string> &Features,
diff --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -239,6 +239,16 @@
                                              Builtin::FirstTSBuiltin);
 }
 
+bool RISCVTargetInfo::initFeatureMap(
+    llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
+    const std::vector<std::string> &FeaturesVec) const {
+
+  if (getTriple().getArch() == llvm::Triple::riscv64)
+    Features["64bit"] = true;
+
+  return TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec);
+}
+
 /// Return true if has this feature, need to sync with handleTargetFeatures.
 bool RISCVTargetInfo::hasFeature(StringRef Feature) const {
   bool Is64Bit = getTriple().getArch() == llvm::Triple::riscv64;
@@ -246,6 +256,7 @@
       .Case("riscv", true)
       .Case("riscv32", !Is64Bit)
       .Case("riscv64", Is64Bit)
+      .Case("64bit", Is64Bit)
       .Case("m", HasM)
       .Case("a", HasA)
       .Case("f", HasF)
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3422,12 +3422,18 @@
   Features.split(ReqFeatures, ',');
 
   // Check if each required feature is included
-  for (auto &I : ReqFeatures) {
-    if (TI.hasFeature(I))
+  for (StringRef F : ReqFeatures) {
+    if (TI.hasFeature(F))
       continue;
+
+    // If the feature is 64bit, alter the string so it will print better in
+    // the diagnostic.
+    if (F == "64bit")
+      F = "RV64";
+
     // Convert features like "zbr" and "experimental-zbr" to "Zbr".
-    I.consume_front("experimental-");
-    std::string FeatureStr = I.str();
+    F.consume_front("experimental-");
+    std::string FeatureStr = F.str();
     FeatureStr[0] = std::toupper(FeatureStr[0]);
 
     // Error message
diff --git a/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c
@@ -0,0 +1,6 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple riscv32 -target-feature +experimental-zbb -verify %s -o -
+
+int orc_b_64(int a) {
+  return __builtin_riscv_orc_b_64(a); // expected-error {{builtin requires 'RV64' extension support to be enabled}}
+}