diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index d01581555fe..8d6db9d7917 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -591,9 +591,10 @@ class MnemonicAlias<string From, string To> {
 /// InstAlias - This defines an alternate assembly syntax that is allowed to
 /// match an instruction that has a different (more canonical) assembly
 /// representation.
-class InstAlias<string Asm, dag Result> {
+class InstAlias<string Asm, dag Result, bit Emit = 0b1> {
   string AsmString = Asm;      // The .s format to match the instruction with.
   dag ResultInst = Result;     // The MCInst to generate.
+  bit EmitAlias = Emit;        // Emit the alias instead of what's aliased.
 
   // Predicates - Predicates that must be true for this to match.
   list<Predicate> Predicates = [];
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index f832a7c85a8..251b2fa1704 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -1534,8 +1534,10 @@ def : InstAlias<"mov $seg, $mem", (MOV32ms i32mem:$mem, SEGMENT_REG:$seg)>;
 def : InstAlias<"movq $imm, $reg", (MOV64ri GR64:$reg, i64imm:$imm)>;
 
 // Match 'movq GR64, MMX' as an alias for movd.
-def : InstAlias<"movq $src, $dst", (MMX_MOVD64to64rr VR64:$dst, GR64:$src)>;
-def : InstAlias<"movq $src, $dst", (MMX_MOVD64from64rr GR64:$dst, VR64:$src)>;
+def : InstAlias<"movq $src, $dst",
+                (MMX_MOVD64to64rr VR64:$dst, GR64:$src), 0b0>;
+def : InstAlias<"movq $src, $dst",
+                (MMX_MOVD64from64rr GR64:$dst, VR64:$src), 0b0>;
 
 // movsd with no operands (as opposed to the SSE scalar move of a double) is an
 // alias for movsl. (as in rep; movsd)
diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index 05bc113c374..f9686fd9b5a 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -840,6 +840,8 @@ void AsmWriterEmitter::EmitPrintAliasInstruction(raw_ostream &O) {
          I = AllInstAliases.begin(), E = AllInstAliases.end(); I != E; ++I) {
     CodeGenInstAlias *Alias = new CodeGenInstAlias(*I, Target);
     const Record *R = *I;
+    if (!R->getValueAsBit("EmitAlias"))
+      continue; // We were told not to emit the alias, but to emit the aliasee.
     const DagInit *DI = R->getValueAsDag("ResultInst");
     const DefInit *Op = dynamic_cast<const DefInit*>(DI->getOperator());
     AliasMap[getQualifiedName(Op->getDef())].push_back(Alias);