Moves infrequently used debugger code in CheckInlineCachestub.

runtime/vm/stub_code_arm.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_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 1234 matching lines @@
     __ ldr(R6, FieldAddress(R5, ICData::state_bits_offset()));
     ASSERT(ICData::NumArgsTestedShift() == 0);  // No shift needed.
     __ and_(R6, R6, Operand(ICData::NumArgsTestedMask()));
     __ CompareImmediate(R6, num_args);
     __ b(&ok, EQ);
     __ Stop("Incorrect stub for IC data");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
+  Label stepping, done_stepping;
   if (FLAG_enable_debugger) {
     // Check single stepping.
-    Label not_stepping;
     __ ldr(R6, FieldAddress(CTX, Context::isolate_offset()));
     __ ldrb(R6, Address(R6, Isolate::single_step_offset()));
     __ CompareImmediate(R6, 0);
-    __ b(&not_stepping, EQ);
-    __ EnterStubFrame();
-    __ Push(R5);  // Preserve IC data.
-    __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
-    __ Pop(R5);
-    __ LeaveStubFrame();
-    __ Bind(&not_stepping);
+    __ b(&stepping, NE);
+    __ Bind(&done_stepping);
   }
 
   // Load arguments descriptor into R4.
   __ ldr(R4, FieldAddress(R5, ICData::arguments_descriptor_offset()));
   // Preserve return address, since LR is needed for subroutine call.
   __ mov(R8, Operand(LR));
   // Loop that checks if there is an IC data match.
   Label loop, update, test, found;
   // R5: IC data object (preserved).
   __ ldr(R6, FieldAddress(R5, ICData::ic_data_offset()));
@@ skipping 89 matching lines @@
   __ LoadFromOffset(kWord, R1, R6, count_offset);
   __ adds(R1, R1, Operand(Smi::RawValue(1)));
   __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
   __ StoreToOffset(kWord, R1, R6, count_offset);
 
   __ Bind(&call_target_function);
   // R0: target function.
   __ ldr(R2, FieldAddress(R0, Function::instructions_offset()));
   __ AddImmediate(R2, Instructions::HeaderSize() - kHeapObjectTag);
   __ bx(R2);
+
+  if (FLAG_enable_debugger) {
+    __ Bind(&stepping);
+    __ EnterStubFrame();
+    __ Push(R5);  // Preserve IC data.
+    __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
+    __ Pop(R5);
+    __ LeaveStubFrame();
+    __ b(&done_stepping);
+  }
 }
 
 
 // Use inline cache data array to invoke the target or continue in inline
 // cache miss handler. Stub for 1-argument check (receiver class).
 //  LR: return address.
 //  R5: inline cache data object.
 // Inline cache data object structure:
 // 0: function-name
 // 1: N, number of arguments checked.
@@ skipping 445 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM