Merge (x & y) == 0 pattern to emit a single test instruction.

runtime/vm/assembler_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
@@ skipping 1440 matching lines @@
     } else {
       EmitRegisterREX(reg, REX_W);
       EmitUint8(0xF7);
       EmitUint8(0xC0 | (reg & 7));
     }
     EmitImmediate(imm);
   }
 }
 
 
+void Assembler::TestImmediate(Register dst, const Immediate& imm, Register pp) {
+  if (CanLoadImmediateFromPool(imm, pp)) {
+    ASSERT(dst != TMP);
+    LoadImmediate(TMP, imm, pp);
+    testq(dst, TMP);
+  } else {
+    testq(dst, imm);
+  }
+}
+
+
 void Assembler::andl(Register dst, Register src) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   Operand operand(src);
   EmitOperandREX(dst, operand, REX_NONE);
   EmitUint8(0x23);
   EmitOperand(dst & 7, operand);
 }
 
 
 void Assembler::andl(Register dst, const Immediate& imm) {
@@ skipping 1614 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64