Do not emit debug check in optimized IC stubs

runtime/vm/stub_code_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/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 1316 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'.
     __ movl(RCX, FieldAddress(RBX, ICData::state_bits_offset()));
     ASSERT(ICData::NumArgsTestedShift() == 0);  // No shift needed.
     __ andq(RCX, Immediate(ICData::NumArgsTestedMask()));
     __ cmpq(RCX, Immediate(num_args));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ 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(RAX);
     __ cmpb(Address(RAX, Isolate::single_step_offset()), Immediate(0));
     __ j(NOT_EQUAL, &stepping);
     __ Bind(&done_stepping);
   }
 
   __ Comment("Range feedback collection");
   Label not_smi_or_overflow;
   if (range_collection_mode == kCollectRanges) {
@@ skipping 139 matching lines @@
     __ movq(RDX, RAX);
     __ movq(RBX, Address(RBP, kFirstLocalSlotFromFp * kWordSize));
     __ UpdateRangeFeedback(RDX, 2, RBX, RCX, &done);
     __ Bind(&done);
     __ LeaveStubFrame();
     __ ret();
   } else {
     __ jmp(RCX);
   }
 
-  if (FLAG_support_debugger) {
+  if (FLAG_support_debugger && !optimized) {
     __ Bind(&stepping);
     __ EnterStubFrame();
     __ pushq(RBX);
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
     __ popq(RBX);
     __ LeaveStubFrame();
     __ jmp(&done_stepping);
   }
 }
 
@@ skipping 83 matching lines @@
 // 1: N, number of arguments checked.
 // 2 .. (length - 1): group of checks, each check containing:
 //   - N classes.
 //   - 1 target function.
 void StubCode::GenerateOneArgOptimizedCheckInlineCacheStub(
     Assembler* assembler) {
   GenerateOptimizedUsageCounterIncrement(assembler);
   GenerateNArgsCheckInlineCacheStub(assembler, 1,
       kInlineCacheMissHandlerOneArgRuntimeEntry,
       Token::kILLEGAL,
-      kIgnoreRanges);
+      kIgnoreRanges, true);
 }
 
 
 void StubCode::GenerateTwoArgsOptimizedCheckInlineCacheStub(
     Assembler* assembler) {
   GenerateOptimizedUsageCounterIncrement(assembler);
   GenerateNArgsCheckInlineCacheStub(assembler, 2,
       kInlineCacheMissHandlerTwoArgsRuntimeEntry,
       Token::kILLEGAL,
-      kIgnoreRanges);
+      kIgnoreRanges, true);
 }
 
 
 // Intermediary stub between a static call and its target. ICData contains
 // the target function and the call count.
 // RBX: ICData
 void StubCode::GenerateZeroArgsUnoptimizedStaticCallStub(Assembler* assembler) {
   GenerateUsageCounterIncrement(assembler, RCX);
 #if defined(DEBUG)
   { Label ok;
@@ skipping 522 matching lines @@
 // Result:
 //  RCX: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, RDI, RBX, RCX);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64