Do not emit debug check in optimized IC stubs

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 1362 matching lines @@
 // - If receiver is Smi -> load Smi class.
 // - If receiver is not-Smi -> load receiver's class.
 // - Check if 'num_args' (including receiver) match any IC data group.
 // - Match found -> jump to target.
 // - Match not found -> jump to IC miss.
 void StubCode::GenerateNArgsCheckInlineCacheStub(
     Assembler* assembler,
     intptr_t num_args,
     const RuntimeEntry& handle_ic_miss,
     Token::Kind kind,
-    RangeCollectionMode range_collection_mode) {
+    RangeCollectionMode range_collection_mode,
+    bool optimized) {
   ASSERT(num_args > 0);
 #if defined(DEBUG)
   { Label ok;
     // Check that the IC data array has NumArgsTested() == num_args.
     // 'NumArgsTested' is stored in the least significant bits of 'state_bits'.
     __ LoadFromOffset(R6, R5, ICData::state_bits_offset() - kHeapObjectTag,
                       kNoPP, kUnsignedWord);
     ASSERT(ICData::NumArgsTestedShift() == 0);  // No shift needed.
     __ andi(R6, R6, Immediate(ICData::NumArgsTestedMask()));
     __ CompareImmediate(R6, num_args, kNoPP);
     __ b(&ok, EQ);
     __ Stop("Incorrect stub for IC data");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
   Label stepping, done_stepping;
-  if (FLAG_support_debugger) {
+  if (FLAG_support_debugger && !optimized) {
     __ Comment("Check single stepping");
     __ LoadIsolate(R6, kNoPP);
     __ LoadFromOffset(
         R6, R6, Isolate::single_step_offset(), kNoPP, kUnsignedByte);
     __ CompareRegisters(R6, ZR);
     __ b(&stepping, NE);
     __ Bind(&done_stepping);
   }
 
   __ Comment("Range feedback collection");
@@ skipping 151 matching lines @@
     Label done;
     __ ldr(R5, Address(FP, kFirstLocalSlotFromFp * kWordSize));
     __ UpdateRangeFeedback(R0, 2, R5, R1, R4, &done);
     __ Bind(&done);
     __ LeaveStubFrame();
     __ ret();
   } else {
     __ br(R2);
   }
 
-  if (FLAG_support_debugger) {
+  if (FLAG_support_debugger && !optimized) {
     __ Bind(&stepping);
     __ EnterStubFrame();
     __ Push(R5);  // Preserve IC data.
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
     __ Pop(R5);
     __ LeaveStubFrame();
     __ b(&done_stepping);
   }
 }
 
@@ skipping 66 matching lines @@
       Token::kILLEGAL,
       kCollectRanges);
 }
 
 
 void StubCode::GenerateOneArgOptimizedCheckInlineCacheStub(
     Assembler* assembler) {
   GenerateOptimizedUsageCounterIncrement(assembler);
   GenerateNArgsCheckInlineCacheStub(assembler, 1,
       kInlineCacheMissHandlerOneArgRuntimeEntry, Token::kILLEGAL,
-      kIgnoreRanges);
+      kIgnoreRanges, true /* optimized */);
 }
 
 
 void StubCode::GenerateTwoArgsOptimizedCheckInlineCacheStub(
     Assembler* assembler) {
   GenerateOptimizedUsageCounterIncrement(assembler);
   GenerateNArgsCheckInlineCacheStub(assembler, 2,
       kInlineCacheMissHandlerTwoArgsRuntimeEntry, Token::kILLEGAL,
-      kIgnoreRanges);
+      kIgnoreRanges, true /* optimized */);
 }
 
 
 void StubCode::GenerateZeroArgsUnoptimizedStaticCallStub(Assembler* assembler) {
   GenerateUsageCounterIncrement(assembler, R6);
 #if defined(DEBUG)
   { Label ok;
     // Check that the IC data array has NumArgsTested() == 0.
     // 'NumArgsTested' is stored in the least significant bits of 'state_bits'.
     __ LoadFromOffset(R6, R5, ICData::state_bits_offset() - kHeapObjectTag,
@@ skipping 472 matching lines @@
 // Result:
 //  R1: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, R0, R1, R1);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64