diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -45,6 +45,7 @@
   bool HasMTE = false;
   bool HasTME = false;
   bool HasPAuth = false;
+  bool HasFPAC = false;
   bool HasLS64 = false;
   bool HasRandGen = false;
   bool HasMatMul = false;
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -909,6 +909,8 @@
       HasTME = true;
     if (Feature == "+pauth")
       HasPAuth = true;
+    if (Feature == "+fpac")
+      HasFPAC = true;
     if (Feature == "+i8mm")
       HasMatMul = true;
     if (Feature == "+bf16")
diff --git a/llvm/lib/Target/AArch64/AArch64.td b/llvm/lib/Target/AArch64/AArch64.td
--- a/llvm/lib/Target/AArch64/AArch64.td
+++ b/llvm/lib/Target/AArch64/AArch64.td
@@ -316,6 +316,10 @@
     "pauth", "HasPAuth", "true",
     "Enable v8.3-A Pointer Authentication extension (FEAT_PAuth)">;
 
+def FeatureFPAC : SubtargetFeature<
+    "fpac", "HasFPAC", "true",
+    "Assume AUT* instructions generate fault on invalid PAC (FEAT_FPAC)">;
+
 def FeatureJS : SubtargetFeature<
     "jsconv", "HasJS", "true",
     "Enable v8.3-A JavaScript FP conversion instructions (FEAT_JSCVT)",