Implement bitLength intrinsic on x64.

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"  // NOLINT
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
@@ skipping 2379 matching lines @@
 }
 
 
 void Assembler::notq(Register reg) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitRegisterREX(reg, REX_W);
   EmitUint8(0xF7);
   EmitUint8(0xD0 | (reg & 7));
 }
 
+
+void Assembler::bsrq(Register dst, Register src) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  Operand operand(src);
+  EmitOperandREX(dst, operand, REX_W);
+  EmitUint8(0x0F);
+  EmitUint8(0xBD);
+  EmitOperand(dst & 7, operand);
+}
+
+
 void Assembler::btq(Register base, Register offset) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   Operand operand(base);
   EmitOperandREX(offset, operand, REX_W);
   EmitUint8(0x0F);
   EmitUint8(0xA3);
   EmitOperand(offset & 7, operand);
 }
 
 
@@ skipping 1536 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