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
@@ -5535,43 +5535,43 @@
   switch (Kind) {
   default:
     return Match_InvalidOperand;
-  case MCK__35_0:
+  case MCK__HASH_0:
     ExpectedVal = 0;
     break;
-  case MCK__35_1:
+  case MCK__HASH_1:
     ExpectedVal = 1;
     break;
-  case MCK__35_12:
+  case MCK__HASH_12:
     ExpectedVal = 12;
     break;
-  case MCK__35_16:
+  case MCK__HASH_16:
     ExpectedVal = 16;
     break;
-  case MCK__35_2:
+  case MCK__HASH_2:
     ExpectedVal = 2;
     break;
-  case MCK__35_24:
+  case MCK__HASH_24:
     ExpectedVal = 24;
     break;
-  case MCK__35_3:
+  case MCK__HASH_3:
     ExpectedVal = 3;
     break;
-  case MCK__35_32:
+  case MCK__HASH_32:
     ExpectedVal = 32;
     break;
-  case MCK__35_4:
+  case MCK__HASH_4:
     ExpectedVal = 4;
     break;
-  case MCK__35_48:
+  case MCK__HASH_48:
     ExpectedVal = 48;
     break;
-  case MCK__35_6:
+  case MCK__HASH_6:
     ExpectedVal = 6;
     break;
-  case MCK__35_64:
+  case MCK__HASH_64:
     ExpectedVal = 64;
     break;
-  case MCK__35_8:
+  case MCK__HASH_8:
     ExpectedVal = 8;
     break;
   }
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -11806,19 +11806,19 @@
   // immediate in the syntax.
   switch (Kind) {
   default: break;
-  case MCK__35_0:
+  case MCK__HASH_0:
     if (Op.isImm())
       if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Op.getImm()))
         if (CE->getValue() == 0)
           return Match_Success;
     break;
-  case MCK__35_8:
+  case MCK__HASH_8:
     if (Op.isImm())
       if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Op.getImm()))
         if (CE->getValue() == 8)
           return Match_Success;
     break;
-  case MCK__35_16:
+  case MCK__HASH_16:
     if (Op.isImm())
       if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Op.getImm()))
         if (CE->getValue() == 16)
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -1111,6 +1111,7 @@
     case '<': Res += "_LT_"; break;
     case '>': Res += "_GT_"; break;
     case '-': Res += "_MINUS_"; break;
+    case '#': Res += "_HASH_"; break;
     default:
       if ((*it >= 'A' && *it <= 'Z') ||
           (*it >= 'a' && *it <= 'z') ||