VM: Don't emit usage counter and range feedback code and when optimizations are disabled.

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"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/heap.h"
 #include "vm/instructions.h"
 #include "vm/object_store.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/tags.h"
 
 #define __ assembler->
 
 namespace dart {
 
 DEFINE_FLAG(bool, inline_alloc, true, "Inline allocation of objects.");
 DEFINE_FLAG(bool, use_slow_path, false,
     "Set to true for debugging & verifying the slow paths.");
 DECLARE_FLAG(bool, trace_optimized_ic_calls);
+DECLARE_FLAG(int, optimization_counter_threshold);
 
 // Input parameters:
 //   LR : return address.
 //   SP : address of last argument in argument array.
 //   SP + 4*R4 - 4 : address of first argument in argument array.
 //   SP + 4*R4 : address of return value.
 //   R5 : address of the runtime function to call.
 //   R4 : number of arguments to the call.
 void StubCode::GenerateCallToRuntimeStub(Assembler* assembler) {
   const intptr_t isolate_offset = NativeArguments::isolate_offset();
@@ skipping 1192 matching lines @@
   }
   __ ldr(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
   __ add(R7, R7, Operand(1));
   __ str(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
 }
 
 
 // Loads function into 'temp_reg'.
 void StubCode::GenerateUsageCounterIncrement(Assembler* assembler,
                                              Register temp_reg) {
-  Register ic_reg = R5;
-  Register func_reg = temp_reg;
-  ASSERT(temp_reg == R6);
-  __ Comment("Increment function counter");
-  __ ldr(func_reg, FieldAddress(ic_reg, ICData::owner_offset()));
-  __ ldr(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
-  __ add(R7, R7, Operand(1));
-  __ str(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
+  if (FLAG_optimization_counter_threshold >= 0) {
+    Register ic_reg = R5;
+    Register func_reg = temp_reg;
+    ASSERT(temp_reg == R6);
+    __ Comment("Increment function counter");
+    __ ldr(func_reg, FieldAddress(ic_reg, ICData::owner_offset()));
+    __ ldr(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
+    __ add(R7, R7, Operand(1));
+    __ str(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
+  }
 }
 
 
 // Note: R5 must be preserved.
 // Attempt a quick Smi operation for known operations ('kind'). The ICData
 // must have been primed with a Smi/Smi check that will be used for counting
 // the invocations.
 static void EmitFastSmiOp(Assembler* assembler,
                           Token::Kind kind,
                           intptr_t num_args,
@@ skipping 35 matching lines @@
   __ ldr(R1, Address(R6, 0));
   __ CompareImmediate(R1, imm_smi_cid);
   __ b(&error, NE);
   __ ldr(R1, Address(R6, kWordSize));
   __ CompareImmediate(R1, imm_smi_cid);
   __ b(&ok, EQ);
   __ Bind(&error);
   __ Stop("Incorrect IC data");
   __ Bind(&ok);
 #endif
-  // Update counter.
-  const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
-  __ LoadFromOffset(kWord, R1, R6, count_offset);
-  __ adds(R1, R1, Operand(Smi::RawValue(1)));
-  __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
-  __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  if (FLAG_optimization_counter_threshold >= 0) {
+    // Update counter.
+    const intptr_t count_offset = ICData::CountIndexFor(num_args) * kWordSize;
+    __ LoadFromOffset(kWord, R1, R6, count_offset);
+    __ adds(R1, R1, Operand(Smi::RawValue(1)));
+    __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
+    __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  }
   __ Ret();
 }
 
 
 // Generate inline cache check for 'num_args'.
 //  LR: return address.
 //  R5: inline cache data object.
 // Control flow:
 // - If receiver is null -> jump to IC miss.
 // - If receiver is Smi -> load Smi class.
@@ skipping 133 matching lines @@
   __ 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(kWord, R0, R6, target_offset);
 
-  __ Comment("Update caller's counter");
-  __ LoadFromOffset(kWord, R1, R6, count_offset);
-  __ adds(R1, R1, Operand(Smi::RawValue(1)));
-  __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
-  __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  if (FLAG_optimization_counter_threshold >= 0) {
+    __ Comment("Update caller's counter");
+    __ LoadFromOffset(kWord, R1, R6, count_offset);
+    __ adds(R1, R1, Operand(Smi::RawValue(1)));
+    __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
+    __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  }
 
   __ Comment("Call target");
   __ Bind(&call_target_function);
   // R0: target function.
   __ ldr(R2, FieldAddress(R0, Function::instructions_offset()));
   __ AddImmediate(R2, Instructions::HeaderSize() - kHeapObjectTag);
   if (range_collection_mode == kCollectRanges) {
     __ ldr(R1, Address(SP, 0 * kWordSize));
     if (num_args == 2) {
       __ ldr(R3, Address(SP, 1 * kWordSize));
@@ skipping 167 matching lines @@
   __ 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.
-  __ LoadFromOffset(kWord, R1, R6, count_offset);
-  __ adds(R1, R1, Operand(Smi::RawValue(1)));
-  __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
-  __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  if (FLAG_optimization_counter_threshold >= 0) {
+    // Increment count for this call.
+    __ LoadFromOffset(kWord, R1, R6, count_offset);
+    __ adds(R1, R1, Operand(Smi::RawValue(1)));
+    __ LoadImmediate(R1, Smi::RawValue(Smi::kMaxValue), VS);  // Overflow.
+    __ StoreIntoSmiField(Address(R6, count_offset), R1);
+  }
 
   // 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.
@@ skipping 385 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