Adds comparisons, labels, branches to arm64

runtime/vm/assembler_arm64.cc

 // Copyright (c) 2014, 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_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 56 matching lines @@
   "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31",
 };
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 
+// TODO(zra): Support for far branches. Requires loading large immediates.
+void Assembler::Bind(Label* label) {
+  ASSERT(!label->IsBound());
+  intptr_t bound_pc = buffer_.Size();
+
+  while (label->IsLinked()) {
+    const int64_t position = label->Position();
+    const int64_t dest = bound_pc - position;
+    const int32_t next = buffer_.Load<int32_t>(position);
+    const int32_t encoded = EncodeImm19BranchOffset(dest, next);
+    buffer_.Store<int32_t>(position, encoded);
+    label->position_ = DecodeImm19BranchOffset(next);
+  }
+  label->BindTo(bound_pc);
+}
+
+
 static int CountLeadingZeros(uint64_t value, int width) {
   ASSERT((width == 32) || (width == 64));
   if (value == 0) {
     return width;
   }
   int count = 0;
   do {
     count++;
   } while (value >>= 1);
   return width - count;
@@ skipping 112 matching lines @@
     }
 
     // 6. Otherwise, the value can't be encoded.
     return false;
   }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64