diff --git a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -2907,14 +2907,13 @@
   else if (FBS[AArch64::HasV8_6aOps])
     Str += "ARMv8.6a";
   else {
-    auto ext = std::find_if(std::begin(ExtensionMap),
-      std::end(ExtensionMap),
-      [&](const Extension& e)
+    SmallVector<std::string, 2> ExtMatches;
+    for (const auto& Ext : ExtensionMap) {
       // Use & in case multiple features are enabled
-      { return (FBS & e.Features) != FeatureBitset(); }
-    );
-
-    Str += ext != std::end(ExtensionMap) ? ext->Name : "(unknown)";
+      if ((FBS & Ext.Features) != FeatureBitset())
+        ExtMatches.push_back(Ext.Name);
+    }
+    Str += !ExtMatches.empty() ? llvm::join(ExtMatches, ", ") : "(unknown)";
   }
 }
 
@@ -2959,7 +2958,7 @@
     if (!IC)
       return TokError("invalid operand for IC instruction");
     else if (!IC->haveFeatures(getSTI().getFeatureBits())) {
-      std::string Str("IC " + std::string(IC->Name) + " requires ");
+      std::string Str("IC " + std::string(IC->Name) + " requires: ");
       setRequiredFeatureString(IC->getRequiredFeatures(), Str);
       return TokError(Str.c_str());
     }
@@ -2969,7 +2968,7 @@
     if (!DC)
       return TokError("invalid operand for DC instruction");
     else if (!DC->haveFeatures(getSTI().getFeatureBits())) {
-      std::string Str("DC " + std::string(DC->Name) + " requires ");
+      std::string Str("DC " + std::string(DC->Name) + " requires: ");
       setRequiredFeatureString(DC->getRequiredFeatures(), Str);
       return TokError(Str.c_str());
     }
@@ -2979,7 +2978,7 @@
     if (!AT)
       return TokError("invalid operand for AT instruction");
     else if (!AT->haveFeatures(getSTI().getFeatureBits())) {
-      std::string Str("AT " + std::string(AT->Name) + " requires ");
+      std::string Str("AT " + std::string(AT->Name) + " requires: ");
       setRequiredFeatureString(AT->getRequiredFeatures(), Str);
       return TokError(Str.c_str());
     }
@@ -2989,7 +2988,7 @@
     if (!TLBI)
       return TokError("invalid operand for TLBI instruction");
     else if (!TLBI->haveFeatures(getSTI().getFeatureBits())) {
-      std::string Str("TLBI " + std::string(TLBI->Name) + " requires ");
+      std::string Str("TLBI " + std::string(TLBI->Name) + " requires: ");
       setRequiredFeatureString(TLBI->getRequiredFeatures(), Str);
       return TokError(Str.c_str());
     }
@@ -3000,7 +2999,7 @@
       return TokError("invalid operand for prediction restriction instruction");
     else if (!PRCTX->haveFeatures(getSTI().getFeatureBits())) {
       std::string Str(
-          Mnemonic.upper() + std::string(PRCTX->Name) + " requires ");
+          Mnemonic.upper() + std::string(PRCTX->Name) + " requires: ");
       setRequiredFeatureString(PRCTX->getRequiredFeatures(), Str);
       return TokError(Str.c_str());
     }
diff --git a/llvm/test/MC/AArch64/armv8.2a-at.s b/llvm/test/MC/AArch64/armv8.2a-at.s
--- a/llvm/test/MC/AArch64/armv8.2a-at.s
+++ b/llvm/test/MC/AArch64/armv8.2a-at.s
@@ -7,5 +7,5 @@
   at s1e1wp, x2
 // CHECK: at      s1e1rp, x1              // encoding: [0x01,0x79,0x08,0xd5]
 // CHECK: at      s1e1wp, x2              // encoding: [0x22,0x79,0x08,0xd5]
-// ERROR: error: AT S1E1RP requires pan-rwv
-// ERROR: error: AT S1E1WP requires pan-rwv
+// ERROR: error: AT S1E1RP requires: pan-rwv
+// ERROR: error: AT S1E1WP requires: pan-rwv
diff --git a/llvm/test/MC/AArch64/armv8.2a-persistent-memory.s b/llvm/test/MC/AArch64/armv8.2a-persistent-memory.s
--- a/llvm/test/MC/AArch64/armv8.2a-persistent-memory.s
+++ b/llvm/test/MC/AArch64/armv8.2a-persistent-memory.s
@@ -4,4 +4,4 @@
 
   dc cvap, x7
 // CHECK: dc cvap, x7   // encoding: [0x27,0x7c,0x0b,0xd5]
-// ERROR: error: DC CVAP requires ccpp
+// ERROR: error: DC CVAP requires: ccpp
diff --git a/llvm/test/MC/AArch64/armv8.4a-tlb.s b/llvm/test/MC/AArch64/armv8.4a-tlb.s
--- a/llvm/test/MC/AArch64/armv8.4a-tlb.s
+++ b/llvm/test/MC/AArch64/armv8.4a-tlb.s
@@ -48,55 +48,55 @@
 //CHECK-ERROR-NEXT: tlbi vae1os, sp
 //CHECK-ERROR-NEXT:              ^
 
-//CHECK-NO-V84:      error: TLBI VMALLE1OS requires tlb-rmi
+//CHECK-NO-V84:      error: TLBI VMALLE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vmalle1os
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vae1os, xzr
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vae1os, x0
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI ASIDE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI ASIDE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi aside1os, x1
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAAE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAAE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vaae1os, x2
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VALE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VALE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vale1os, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAALE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAALE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vaale1os, x4
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI IPAS2E1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI IPAS2E1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ipas2e1os, x5
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI IPAS2LE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI IPAS2LE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ipas2le1os, x6
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAE2OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAE2OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vae2os, x7
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VALE2OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VALE2OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vale2os, x8
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VMALLS12E1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VMALLS12E1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vmalls12e1os
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VAE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VAE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vae3os, x9
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI VALE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI VALE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi vale3os, x10
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI ALLE2OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI ALLE2OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi alle2os
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI ALLE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI ALLE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi alle1os
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI ALLE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI ALLE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi alle3os
 //CHECK-NO-V84-NEXT:      ^
 
@@ -171,96 +171,96 @@
 //CHECK-ERROR-NEXT: tlbi rvae1, sp
 //CHECK-ERROR-NEXT:             ^
 
-//CHECK-NO-V84:      error: TLBI RVAE1 requires tlb-rmi
+//CHECK-NO-V84:      error: TLBI RVAE1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae1, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAAE1 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAAE1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaae1, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE1 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale1, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAALE1 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAALE1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaale1, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT:  error: TLBI RVAE1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT:  error: TLBI RVAE1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAAE1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAAE1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaae1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAALE1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAALE1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaale1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae1os, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAAE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAAE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaae1os, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale1os, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAALE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAALE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvaale1os, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2e1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2le1is, x3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2e1, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2le1, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2E1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2e1os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RIPAS2LE1OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi ripas2le1os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE2 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE2 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae2, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE2 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE2 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale2, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE2IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE2IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae2is, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE2IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE2IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale2is, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE2OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE2OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae2os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE2OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE2OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale2os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE3 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE3 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae3, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE3 requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE3 requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale3, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE3IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE3IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae3is, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE3IS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE3IS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale3is, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVAE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVAE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvae3os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale3os, X3
 //CHECK-NO-V84-NEXT:      ^
-//CHECK-NO-V84-NEXT: error: TLBI RVALE3OS requires tlb-rmi
+//CHECK-NO-V84-NEXT: error: TLBI RVALE3OS requires: tlb-rmi
 //CHECK-NO-V84-NEXT: tlbi rvale3os, XZR
 //CHECK-NO-V84-NEXT:      ^
diff --git a/llvm/test/MC/AArch64/armv8.5a-mte.s b/llvm/test/MC/AArch64/armv8.5a-mte.s
--- a/llvm/test/MC/AArch64/armv8.5a-mte.s
+++ b/llvm/test/MC/AArch64/armv8.5a-mte.s
@@ -441,24 +441,24 @@
 // CHECK: dc cigdvac, x16       // encoding: [0xb0,0x7e,0x0b,0xd5]
 // CHECK: dc gzva, x17          // encoding: [0x91,0x74,0x0b,0xd5]
 
-// NOMTE: DC IGVAC requires mte
-// NOMTE: DC IGSW requires mte
-// NOMTE: DC CGSW requires mte
-// NOMTE: DC CIGSW requires mte
-// NOMTE: DC CGVAC requires mte
-// NOMTE: DC CGVAP requires mte
-// NOMTE: DC CGVADP requires mte
-// NOMTE: DC CIGVAC requires mte
-// NOMTE: DC GVA requires mte
-// NOMTE: DC IGDVAC requires mte
-// NOMTE: DC IGDSW requires mte
-// NOMTE: DC CGDSW requires mte
-// NOMTE: DC CIGDSW requires mte
-// NOMTE: DC CGDVAC requires mte
-// NOMTE: DC CGDVAP requires mte
-// NOMTE: DC CGDVADP requires mte
-// NOMTE: DC CIGDVAC requires mte
-// NOMTE: DC GZVA requires mte
+// NOMTE: DC IGVAC requires: mte
+// NOMTE: DC IGSW requires: mte
+// NOMTE: DC CGSW requires: mte
+// NOMTE: DC CIGSW requires: mte
+// NOMTE: DC CGVAC requires: mte
+// NOMTE: DC CGVAP requires: mte
+// NOMTE: DC CGVADP requires: mte
+// NOMTE: DC CIGVAC requires: mte
+// NOMTE: DC GVA requires: mte
+// NOMTE: DC IGDVAC requires: mte
+// NOMTE: DC IGDSW requires: mte
+// NOMTE: DC CGDSW requires: mte
+// NOMTE: DC CIGDSW requires: mte
+// NOMTE: DC CGDVAC requires: mte
+// NOMTE: DC CGDVAP requires: mte
+// NOMTE: DC CGDVADP requires: mte
+// NOMTE: DC CIGDVAC requires: mte
+// NOMTE: DC GZVA requires: mte
 
 mrs x0, tco
 mrs x1, gcr_el1
diff --git a/llvm/test/MC/AArch64/armv8.5a-persistent-memory.s b/llvm/test/MC/AArch64/armv8.5a-persistent-memory.s
--- a/llvm/test/MC/AArch64/armv8.5a-persistent-memory.s
+++ b/llvm/test/MC/AArch64/armv8.5a-persistent-memory.s
@@ -4,4 +4,4 @@
 
 dc cvadp, x7
 // CHECK:  dc cvadp, x7   // encoding: [0x27,0x7d,0x0b,0xd5]
-// NOCCDP: error: DC CVADP requires ccdp
+// NOCCDP: error: DC CVADP requires: ccdp
diff --git a/llvm/test/MC/AArch64/armv8.5a-predres.s b/llvm/test/MC/AArch64/armv8.5a-predres.s
--- a/llvm/test/MC/AArch64/armv8.5a-predres.s
+++ b/llvm/test/MC/AArch64/armv8.5a-predres.s
@@ -10,9 +10,9 @@
 // CHECK: dvp rctx, x1      // encoding: [0xa1,0x73,0x0b,0xd5]
 // CHECK: cpp rctx, x2      // encoding: [0xe2,0x73,0x0b,0xd5]
 
-// NOPREDCTRL: CFPRCTX requires predres
+// NOPREDCTRL: CFPRCTX requires: predres
 // NOPREDCTRL-NEXT: cfp
-// NOPREDCTRL: DVPRCTX requires predres
+// NOPREDCTRL: DVPRCTX requires: predres
 // NOPREDCTRL-NEXT: dvp
-// NOPREDCTRL: CPPRCTX requires predres
+// NOPREDCTRL: CPPRCTX requires: predres
 // NOPREDCTRL-NEXT: cpp
diff --git a/llvm/test/MC/AArch64/directive-arch_extension-negative.s b/llvm/test/MC/AArch64/directive-arch_extension-negative.s
--- a/llvm/test/MC/AArch64/directive-arch_extension-negative.s
+++ b/llvm/test/MC/AArch64/directive-arch_extension-negative.s
@@ -51,12 +51,12 @@
 
 .arch_extension nopredres
 cfp rctx, x0
-// CHECK: error: CFPRCTX requires predres
+// CHECK: error: CFPRCTX requires: predres
 // CHECK-NEXT: cfp rctx, x0
 
 .arch_extension noccdp
 dc cvadp, x7
-// CHECK: error: DC CVADP requires ccdp
+// CHECK: error: DC CVADP requires: ccdp
 // CHECK-NEXT: dc cvadp, x7
 
 .arch_extension nomte
@@ -66,17 +66,17 @@
 
 .arch_extension notlb-rmi
 tlbi vmalle1os
-// CHECK: error: TLBI VMALLE1OS requires tlb-rmi
+// CHECK: error: TLBI VMALLE1OS requires: tlb-rmi
 // CHECK-NEXT: tlbi vmalle1os
 
 .arch_extension nopan-rwv
 at s1e1wp, x2
-// CHECK: error: AT S1E1WP requires pan-rwv
+// CHECK: error: AT S1E1WP requires: pan-rwv
 // CHECK-NEXT: at s1e1wp, x2
 
 .arch_extension noccpp
 dc cvap, x7
-// CHECK: error: DC CVAP requires ccpp
+// CHECK: error: DC CVAP requires: ccpp
 // CHECK-NEXT: dc cvap, x7
 
 .arch_extension norcpc