Index: utils/TableGen/AsmWriterEmitter.cpp
===================================================================
--- utils/TableGen/AsmWriterEmitter.cpp
+++ utils/TableGen/AsmWriterEmitter.cpp
@@ -1011,15 +1011,17 @@
   O.indent(2) << "}\n\n";
 
   // Code that prints the alias, replacing the operands with the ones from the
-  // MCInst.
+  // MCInst. Follows the format given by the instruction AsmString field,
+  // slightly complicated by opcodes with optional suffixes
+  // '<opcode>('${'<operand>'}')*<separator><operands>'.
   O << "  unsigned I = 0;\n";
   O << "  while (AsmString[I] != ' ' && AsmString[I] != '\t' &&\n";
-  O << "         AsmString[I] != '\\0')\n";
+  O << "         AsmString[I] != '\\0' && AsmString[I] != '$')\n";
   O << "    ++I;\n";
   O << "  OS << '\\t' << StringRef(AsmString, I);\n";
 
   O << "  if (AsmString[I] != '\\0') {\n";
-  O << "    OS << '\\t';\n";
+  O << "    bool NeedOpcodeSep = true;\n";
   O << "    do {\n";
   O << "      if (AsmString[I] == '$') {\n";
   O << "        ++I;\n";
@@ -1030,9 +1032,13 @@
   O << "          printCustomAliasOperand(MI, OpIdx, PrintMethodIdx, OS);\n";
   O << "        } else\n";
   O << "          printOperand(MI, unsigned(AsmString[I++]) - 1, OS);\n";
-  O << "      } else {\n";
+  O << "      } else if (NeedOpcodeSep &&\n";
+  O << "                 (AsmString[I] == ' ' || AsmString[I] == '\t')) {\n";
+  O << "          NeedOpcodeSep = false;\n";
+  O << "          OS << '\\t';\n";
+  O << "          ++I;\n";
+  O << "      } else\n";
   O << "        OS << AsmString[I++];\n";
-  O << "      }\n";
   O << "    } while (AsmString[I] != '\\0');\n";
   O << "  }\n\n";