Uses a conditional move for usage counter increment instead of a branch

runtime/vm/stub_code_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/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 1444 matching lines @@
   __ Pop(R4);  // Restore arguments descriptor array.
   __ LeaveStubFrame();
   Label call_target_function;
   __ b(&call_target_function);
 
   __ Bind(&found);
   // R6: pointer to an IC data check group.
   const intptr_t target_offset = ICData::TargetIndexFor(num_args) * kWordSize;
   const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
   __ LoadFromOffset(R0, R6, target_offset, kNoPP);
+
+  // Update counter.
   __ LoadFromOffset(R1, R6, count_offset, kNoPP);
   __ adds(R1, R1, Operand(Smi::RawValue(1)));
-  __ StoreToOffset(R1, R6, count_offset, kNoPP);
-  __ b(&call_target_function, VC);  // No overflow.
-  __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), kNoPP);
+  __ LoadImmediate(R2, Smi::RawValue(Smi::kMaxValue), kNoPP);
+  __ csel(R1, R2, R1, VS);  // Overflow.
   __ StoreToOffset(R1, R6, count_offset, kNoPP);
 
   __ Bind(&call_target_function);
   // R0: target function.
   __ LoadFieldFromOffset(R2, R0, Function::instructions_offset(), kNoPP);
   __ AddImmediate(
       R2, R2, Instructions::HeaderSize() - kHeapObjectTag, kNoPP);
   __ br(R2);
 }
 
@@ skipping 451 matching lines @@
   const Register right = R0;
   __ LoadFromOffset(left, SP, 1 * kWordSize, kNoPP);
   __ LoadFromOffset(right, SP, 0 * kWordSize, kNoPP);
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64