Index: llvm/trunk/include/llvm/Target/Target.td
===================================================================
--- llvm/trunk/include/llvm/Target/Target.td
+++ llvm/trunk/include/llvm/Target/Target.td
@@ -488,6 +488,12 @@
   /// constraint. For example, "$Rn = $Rd".
   string TwoOperandAliasConstraint = "";
 
+  /// Assembler variant name to use for this instruction. If specified then
+  /// instruction will be presented only in MatchTable for this variant. If
+  /// not specified then assembler variants will be determined based on
+  /// AsmString
+  string AsmVariantName = "";
+
   ///@}
 
   /// UseNamedOperandTable - If set, the operand indices of this instruction
@@ -1134,6 +1140,10 @@
   // defined AsmMatchConverter and instead use the function generated by the
   // dag Result.
   bit UseInstAsmMatchConverter = 1;
+
+  // Assembler variant name to use for this alias. If not specified then
+  // assembler variants will be determined based on AsmString
+  string AsmVariantName = "";
 }
 
 //===----------------------------------------------------------------------===//
Index: llvm/trunk/test/TableGen/AsmVariant.td
===================================================================
--- llvm/trunk/test/TableGen/AsmVariant.td
+++ llvm/trunk/test/TableGen/AsmVariant.td
@@ -0,0 +1,46 @@
+// RUN: llvm-tblgen -gen-asm-matcher -I %p/../../include %s | FileCheck %s
+
+// Check that cpecifying AsmVariant works correctly
+
+include "llvm/Target/Target.td"
+
+def ArchInstrInfo : InstrInfo { }
+
+def FooAsmParserVariant : AsmParserVariant {
+  let Variant = 0;
+  let Name = "Foo";
+}
+
+def BarAsmParserVariant : AsmParserVariant {
+  let Variant = 1;
+  let Name = "Bar";
+}
+
+def Arch : Target {
+  let InstructionSet = ArchInstrInfo;
+  let AssemblyParserVariants = [FooAsmParserVariant, BarAsmParserVariant];
+}
+
+def Reg : Register<"reg">;
+
+def RegClass : RegisterClass<"foo", [i32], 0, (add Reg)>;
+
+def foo : Instruction {
+  let Size = 2;
+  let OutOperandList = (outs);
+  let InOperandList = (ins);
+  let AsmString = "foo";
+  let AsmVariantName = "Foo";
+}
+
+def BarAlias : InstAlias<"bar", (foo)> {
+  string AsmVariantName = "Bar";
+}
+
+// CHECK: static const MatchEntry MatchTable0[] = {
+// CHECK-NEXT: /* foo */, Arch::foo
+// CHECK-NEXT: };
+
+// CHECK: static const MatchEntry MatchTable1[] = {
+// CHECK-NEXT: /* bar */, Arch::foo
+// CHECK-NEXT: };
Index: llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
===================================================================
--- llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
+++ llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
@@ -353,6 +353,7 @@
   std::string TokenizingCharacters;
   std::string SeparatorCharacters;
   std::string BreakCharacters;
+  std::string Name;
   int AsmVariantNo;
 };
 
@@ -1468,6 +1469,7 @@
         AsmVariant->getValueAsString("SeparatorCharacters");
     Variant.BreakCharacters =
         AsmVariant->getValueAsString("BreakCharacters");
+    Variant.Name = AsmVariant->getValueAsString("Name");
     Variant.AsmVariantNo = AsmVariant->getValueAsInt("Variant");
 
     for (const CodeGenInstruction *CGI : Target.getInstructionsByEnumValue()) {
@@ -1481,6 +1483,11 @@
       if (CGI->TheDef->getValueAsBit("isCodeGenOnly"))
         continue;
 
+      // Ignore instructions for different instructions
+      const std::string V = CGI->TheDef->getValueAsString("AsmVariantName");
+      if (!V.empty() && V != Variant.Name)
+        continue;
+
       auto II = llvm::make_unique<MatchableInfo>(*CGI);
 
       II->initialize(*this, SingletonRegisters, Variant, HasMnemonicFirst);
@@ -1509,6 +1516,10 @@
             .startswith( MatchPrefix))
         continue;
 
+      const std::string V = Alias->TheDef->getValueAsString("AsmVariantName");
+      if (!V.empty() && V != Variant.Name)
+        continue;
+
       auto II = llvm::make_unique<MatchableInfo>(std::move(Alias));
 
       II->initialize(*this, SingletonRegisters, Variant, HasMnemonicFirst);