diff --git a/compiler/compiled_method.cc b/compiler/compiled_method.cc
index d884bc0..17c2e94 100644
--- a/compiler/compiled_method.cc
+++ b/compiler/compiled_method.cc
@@ -88,7 +88,8 @@
       return RoundUp(offset, kArmAlignment);
     case kMips:
       return RoundUp(offset, kMipsAlignment);
-    case kX86:
+    case kX86:  // Fall-through.
+    case kX86_64:
       return RoundUp(offset, kX86Alignment);
     default:
       LOG(FATAL) << "Unknown InstructionSet: " << instruction_set;
diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index 4b823ef..a6daa5d 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -377,6 +377,11 @@
       elf_header.e_flags = 0;
       break;
     }
+    case kX86_64: {
+      elf_header.e_machine = EM_X86_64;
+      elf_header.e_flags = 0;
+      break;
+    }
     case kMips: {
       elf_header.e_machine = EM_MIPS;
       elf_header.e_flags = (EF_MIPS_NOREORDER |
diff --git a/compiler/trampolines/trampoline_compiler.cc b/compiler/trampolines/trampoline_compiler.cc
index 32ae558..3e13e44 100644
--- a/compiler/trampolines/trampoline_compiler.cc
+++ b/compiler/trampolines/trampoline_compiler.cc
@@ -100,6 +100,23 @@
 }
 }  // namespace x86
 
+namespace x86_64 {
+static const std::vector<uint8_t>* CreateTrampoline(ThreadOffset offset) {
+  UniquePtr<x86::X86Assembler> assembler(static_cast<x86::X86Assembler*>(Assembler::Create(kX86_64)));
+
+  // All x86 trampolines call via the Thread* held in gs.
+  __ gs()->jmp(x86::Address::Absolute(offset, true));
+  __ int3();
+
+  size_t cs = assembler->CodeSize();
+  UniquePtr<std::vector<uint8_t> > entry_stub(new std::vector<uint8_t>(cs));
+  MemoryRegion code(&(*entry_stub)[0], entry_stub->size());
+  assembler->FinalizeInstructions(code);
+
+  return entry_stub.release();
+}
+}  // namespace x86_64
+
 const std::vector<uint8_t>* CreateTrampoline(InstructionSet isa, EntryPointCallingConvention abi,
                                              ThreadOffset offset) {
   switch (isa) {
@@ -110,6 +127,8 @@
       return mips::CreateTrampoline(abi, offset);
     case kX86:
       return x86::CreateTrampoline(offset);
+    case kX86_64:
+      return x86_64::CreateTrampoline(offset);
     default:
       LOG(FATAL) << "Unknown InstructionSet: " << isa;
       return NULL;
diff --git a/compiler/utils/assembler.cc b/compiler/utils/assembler.cc
index 6732476..a7cb278 100644
--- a/compiler/utils/assembler.cc
+++ b/compiler/utils/assembler.cc
@@ -111,7 +111,8 @@
       return new arm64::Arm64Assembler();
     case kMips:
       return new mips::MipsAssembler();
-    case kX86:
+    case kX86:  // Fall-through.
+    case kX86_64:
       return new x86::X86Assembler();
     default:
       LOG(FATAL) << "Unknown InstructionSet: " << instruction_set;
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 136d248..26300e0 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -1210,6 +1210,13 @@
   return this;
 }
 
+X86Assembler* X86Assembler::gs() {
+  // TODO: fs is a prefix and not an instruction
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x65);
+  return this;
+}
+
 void X86Assembler::AddImmediate(Register reg, const Immediate& imm) {
   int value = imm.value();
   if (value > 0) {
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 0fa8e00..e284d8c 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -192,15 +192,21 @@
     }
   }
 
-  static Address Absolute(uword addr) {
+  static Address Absolute(uword addr, bool has_rip = false) {
     Address result;
-    result.SetModRM(0, EBP);
-    result.SetDisp32(addr);
+    if (has_rip) {
+      result.SetModRM(0, ESP);
+      result.SetSIB(TIMES_1, ESP, EBP);
+      result.SetDisp32(addr);
+    } else {
+      result.SetModRM(0, EBP);
+      result.SetDisp32(addr);
+    }
     return result;
   }
 
-  static Address Absolute(ThreadOffset addr) {
-    return Absolute(addr.Int32Value());
+  static Address Absolute(ThreadOffset addr, bool has_rip = false) {
+    return Absolute(addr.Int32Value(), has_rip);
   }
 
  private:
@@ -210,9 +216,9 @@
 };
 
 
-class X86Assembler : public Assembler {
+class X86Assembler FINAL : public Assembler {
  public:
-  X86Assembler() {}
+  explicit X86Assembler() {}
   virtual ~X86Assembler() {}
 
   /*
@@ -427,6 +433,7 @@
   void mfence();
 
   X86Assembler* fs();
+  X86Assembler* gs();
 
   //
   // Macros for High-level operations.