Moves SingleStepHandler runtime calls

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 1433 matching lines @@
     ASSERT(ICData::NumArgsTestedShift() == 0);  // No shift needed.
     __ and_(R6, R6, Operand(ICData::NumArgsTestedMask()));
     __ CompareImmediate(R6, 0);
     __ b(&ok, EQ);
     __ Stop("Incorrect IC data for unoptimized static call");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
   // Check single stepping.
-  Label not_stepping;
+  Label stepping, done_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);
 
   // R5: IC data object (preserved).
   __ ldr(R6, FieldAddress(R5, ICData::ic_data_offset()));
   // R6: ic_data_array with entries: target functions and count.
   __ AddImmediate(R6, R6, Array::data_offset() - kHeapObjectTag);
   // R6: points directly to the first ic data array element.
   const intptr_t target_offset = ICData::TargetIndexFor(0) * kWordSize;
   const intptr_t count_offset = ICData::CountIndexFor(0) * kWordSize;
 
   // Increment count for this call.
-  Label increment_done;
   __ 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);
-  __ b(&increment_done, VC);  // No overflow.
-  __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue));
-  __ StoreToOffset(kWord, R1, R6, count_offset);
-  __ Bind(&increment_done);
 
   // Load arguments descriptor into R4.
   __ ldr(R4, FieldAddress(R5, ICData::arguments_descriptor_offset()));
 
   // Get function and call it, if possible.
   __ LoadFromOffset(kWord, R0, R6, target_offset);
   __ ldr(R2, FieldAddress(R0, Function::instructions_offset()));
 
   // R0: function.
   // R2: target instructions.
   __ AddImmediate(R2, Instructions::HeaderSize() - kHeapObjectTag);
   __ bx(R2);
+
+  __ Bind(&stepping);
+  __ EnterStubFrame();
+  __ Push(R5);  // Preserve IC data.
+  __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
+  __ Pop(R5);
+  __ LeaveStubFrame();
+  __ b(&done_stepping);
 }
 
 
 void StubCode::GenerateTwoArgsUnoptimizedStaticCallStub(Assembler* assembler) {
   GenerateUsageCounterIncrement(assembler, R6);
   GenerateNArgsCheckInlineCacheStub(
       assembler, 2, kStaticCallMissHandlerTwoArgsRuntimeEntry);
 }
 
 
@@ skipping 54 matching lines @@
   __ PopList((1 << R0));
   __ LeaveStubFrame();
   __ bx(R0);
 }
 
 
 // Called only from unoptimized code. All relevant registers have been saved.
 void StubCode::GenerateDebugStepCheckStub(
     Assembler* assembler) {
   // Check single stepping.
-  Label not_stepping;
+  Label stepping, done_stepping;
   __ ldr(R1, FieldAddress(CTX, Context::isolate_offset()));
   __ ldrb(R1, Address(R1, Isolate::single_step_offset()));
   __ CompareImmediate(R1, 0);
-  __ b(&not_stepping, EQ);
+  __ b(&stepping, NE);
+  __ Bind(&done_stepping);
+  __ Ret();
+
+  __ Bind(&stepping);
   __ EnterStubFrame();
   __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
   __ LeaveStubFrame();
-  __ Bind(&not_stepping);
-
-  __ Ret();
+  __ b(&done_stepping);
 }
 
 
 // Used to check class and type arguments. Arguments passed in registers:
 // LR: return address.
 // R0: instance (must be preserved).
 // R1: instantiator type arguments or NULL.
 // R2: cache array.
 // Result in R1: null -> not found, otherwise result (true or false).
 static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
@@ skipping 227 matching lines @@
 
 
 // Called only from unoptimized code. All relevant registers have been saved.
 // LR: return address.
 // SP + 4: left operand.
 // SP + 0: right operand.
 // Return Zero condition flag set if equal.
 void StubCode::GenerateUnoptimizedIdenticalWithNumberCheckStub(
     Assembler* assembler) {
   // Check single stepping.
-  Label not_stepping;
+  Label stepping, done_stepping;
   __ ldr(R1, FieldAddress(CTX, Context::isolate_offset()));
   __ ldrb(R1, Address(R1, Isolate::single_step_offset()));
   __ CompareImmediate(R1, 0);
-  __ b(&not_stepping, EQ);
-  __ EnterStubFrame();
-  __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
-  __ LeaveStubFrame();
-  __ Bind(&not_stepping);
+  __ b(&stepping, NE);
+  __ Bind(&done_stepping);
 
   const Register temp = R2;
   const Register left = R1;
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
+
+  __ Bind(&stepping);
+  __ EnterStubFrame();
+  __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
+  __ LeaveStubFrame();
+  __ b(&done_stepping);
 }
 
 
 // Called from optimized code only.
 // LR: return address.
 // SP + 4: left operand.
 // SP + 0: right operand.
 // Return Zero condition flag set if equal.
 void StubCode::GenerateOptimizedIdenticalWithNumberCheckStub(
     Assembler* assembler) {
   const Register temp = R2;
   const Register left = R1;
   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