diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 097713f..84e1612 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8840,7 +8840,37 @@
     // FIXME: not handling fp-stack yet!
     switch (Constraint[0]) {      // GCC X86 Constraint Letters
     default: break;  // Unknown constraint letter
-    case 'q':   // Q_REGS (GENERAL_REGS in 64-bit mode)
+    case 'q':   // GENERAL_REGS in 64-bit mode, Q_REGS in 32-bit mode.
+      if (Subtarget->is64Bit()) {
+        if (VT == MVT::i32)
+          return make_vector<unsigned>(X86::EAX, X86::EDX, X86::ECX, X86::EBX,
+                                       X86::ESI, X86::EDI, X86::R8D, X86::R9D,
+                                       X86::R10D,X86::R11D,X86::R12D,
+                                       X86::R13D,X86::R14D,X86::R15D,
+                                       X86::EBP, X86::ESP, 0);
+        else if (VT == MVT::i16)
+          return make_vector<unsigned>(X86::AX,  X86::DX,  X86::CX, X86::BX,
+                                       X86::SI,  X86::DI,  X86::R8W,X86::R9W,
+                                       X86::R10W,X86::R11W,X86::R12W,
+                                       X86::R13W,X86::R14W,X86::R15W,
+                                       X86::BP,  X86::SP, 0);
+        else if (VT == MVT::i8)
+          return make_vector<unsigned>(X86::AL,  X86::DL,  X86::CL, X86::BL,
+                                       X86::SIL, X86::DIL, X86::R8B,X86::R9B,
+                                       X86::R10B,X86::R11B,X86::R12B,
+                                       X86::R13B,X86::R14B,X86::R15B,
+                                       X86::BPL, X86::SPL, 0);
+
+        else if (VT == MVT::i64)
+          return make_vector<unsigned>(X86::RAX, X86::RDX, X86::RCX, X86::RBX,
+                                       X86::RSI, X86::RDI, X86::R8,  X86::R9,
+                                       X86::R10, X86::R11, X86::R12,
+                                       X86::R13, X86::R14, X86::R15,
+                                       X86::RBP, X86::RSP, 0);
+
+        break;
+      }
+      // 32-bit fallthrough 
     case 'Q':   // Q_REGS
       if (VT == MVT::i32)
         return make_vector<unsigned>(X86::EAX, X86::EDX, X86::ECX, X86::EBX, 0);
diff --git a/test/CodeGen/X86/inline-asm-q-regs.ll b/test/CodeGen/X86/inline-asm-q-regs.ll
new file mode 100644
index 0000000..19df81b
--- /dev/null
+++ b/test/CodeGen/X86/inline-asm-q-regs.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | llc -march=x86-64
+; rdar://7066579
+
+	type { i64, i64, i64, i64, i64 }		; type %0
+
+define void @t() nounwind {
+entry:
+	%asmtmp = call %0 asm sideeffect "mov    %cr0, $0       \0Amov    %cr2, $1       \0Amov    %cr3, $2       \0Amov    %cr4, $3       \0Amov    %cr8, $0       \0A", "=q,=q,=q,=q,=q,~{dirflag},~{fpsr},~{flags}"() nounwind		; <%0> [#uses=0]
+	ret void
+}