diff --git a/llvm/include/llvm/TargetParser/AArch64TargetParser.h b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
--- a/llvm/include/llvm/TargetParser/AArch64TargetParser.h
+++ b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
@@ -156,7 +156,8 @@
   AEK_RASv2 =         55, // FEAT_RASv2
   AEK_ITE =           56, // FEAT_ITE
   AEK_GCS =           57, // FEAT_GCS
-  AEK_NUM_EXTENSIONS =  AEK_GCS + 1
+  AEK_FPAC =          58, // FEAT_FPAC
+  AEK_NUM_EXTENSIONS =  AEK_FPAC + 1
 };
 using ExtensionBitset = Bitset<AEK_NUM_EXTENSIONS>;
 // clang-format on
@@ -264,6 +265,7 @@
     {"tme", AArch64::AEK_TME, "+tme", "-tme", FEAT_MAX, "", 0},
     {"wfxt", AArch64::AEK_NONE, {}, {}, FEAT_WFXT, "+wfxt", 550},
     {"gcs", AArch64::AEK_GCS, "+gcs", "-gcs", FEAT_MAX, "", 0},
+    {"fpac", AArch64::AEK_FPAC, "+fpac", "-fpac", FEAT_MAX, "", 0},
     // Special cases
     {"none", AArch64::AEK_NONE, {}, {}, FEAT_MAX, "", ExtensionInfo::MaxFMVPriority},
 };
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
@@ -314,6 +314,10 @@
     "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)",
diff --git a/llvm/unittests/TargetParser/TargetParserTest.cpp b/llvm/unittests/TargetParser/TargetParserTest.cpp
--- a/llvm/unittests/TargetParser/TargetParserTest.cpp
+++ b/llvm/unittests/TargetParser/TargetParserTest.cpp
@@ -1731,7 +1731,7 @@
       AArch64::AEK_B16B16,  AArch64::AEK_SMEF16F16, AArch64::AEK_CSSC,
       AArch64::AEK_RCPC3,   AArch64::AEK_THE,       AArch64::AEK_D128,
       AArch64::AEK_LSE128,  AArch64::AEK_SPECRES2,  AArch64::AEK_RASv2,
-      AArch64::AEK_ITE,     AArch64::AEK_GCS,
+      AArch64::AEK_ITE,     AArch64::AEK_GCS,       AArch64::AEK_FPAC,
   };
 
   std::vector<StringRef> Features;
@@ -1804,6 +1804,7 @@
   EXPECT_TRUE(llvm::is_contained(Features, "+specres2"));
   EXPECT_TRUE(llvm::is_contained(Features, "+ite"));
   EXPECT_TRUE(llvm::is_contained(Features, "+gcs"));
+  EXPECT_TRUE(llvm::is_contained(Features, "+fpac"));
 
   // Assuming we listed every extension above, this should produce the same
   // result. (note that AEK_NONE doesn't have a name so it won't be in the
@@ -1927,6 +1928,7 @@
       {"predres2", "nopredres2", "+specres2", "-specres2"},
       {"rasv2", "norasv2", "+rasv2", "-rasv2"},
       {"gcs", "nogcs", "+gcs", "-gcs"},
+      {"fpac", "nofpac", "+fpac", "-fpac"},
   };
 
   for (unsigned i = 0; i < std::size(ArchExt); i++) {