Profiler experiments: merge self-optimization code into interrupt-at-exit

src/ia32/full-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 109 matching lines @@
 // frames-ia32.h for its layout.
 void FullCodeGenerator::Generate() {
   CompilationInfo* info = info_;
   handler_table_ =
       isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
   profiling_counter_ = isolate()->factory()->NewJSGlobalPropertyCell(
       Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget)));
   SetFunctionPosition(function());
   Comment cmnt(masm_, "[ function compiled by full code generator");
 
-  // We can optionally optimize based on counters rather than statistical
-  // sampling.
-  if (info->ShouldSelfOptimize()) {
-    if (FLAG_trace_opt_verbose) {
-      PrintF("[adding self-optimization header to %s]\n",
-             *info->function()->debug_name()->ToCString());
-    }
-    has_self_optimization_header_ = true;
-    MaybeObject* maybe_cell = isolate()->heap()->AllocateJSGlobalPropertyCell(
-        Smi::FromInt(Compiler::kCallsUntilPrimitiveOpt));
-    JSGlobalPropertyCell* cell;
-    if (maybe_cell->To(&cell)) {
-      __ sub(Operand::Cell(Handle<JSGlobalPropertyCell>(cell)),
-             Immediate(Smi::FromInt(1)));
-      Handle<Code> compile_stub(
-          isolate()->builtins()->builtin(Builtins::kLazyRecompile));
-      STATIC_ASSERT(kSmiTag == 0);
-      __ j(zero, compile_stub);
-      ASSERT(masm_->pc_offset() == self_optimization_header_size());
-    }
-  }
-
 #ifdef DEBUG
   if (strlen(FLAG_stop_at) > 0 &&
       info->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
     __ int3();
   }
 #endif
 
   // Strict mode functions and builtins need to replace the receiver
   // with undefined when called as functions (without an explicit
   // receiver object). ecx is zero for method calls and non-zero for
@@ skipping 161 matching lines @@
     EmitReturnSequence();
   }
 }
 
 
 void FullCodeGenerator::ClearAccumulator() {
   __ Set(eax, Immediate(Smi::FromInt(0)));
 }
 
 
+void FullCodeGenerator::EmitProfilingCounterDecrement(int delta) {
+  __ mov(ebx, Immediate(profiling_counter_));
+  __ sub(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
+         Immediate(Smi::FromInt(delta)));
+}
+
+
+void FullCodeGenerator::EmitProfilingCounterReset() {
+  int reset_value = FLAG_interrupt_budget;
+  if (info_->ShouldSelfOptimize() && !FLAG_retry_self_opt) {
+    // Self-optimization is a one-off thing: if it fails, don't try again.
+    reset_value = Smi::kMaxValue;
+  }
+  __ mov(ebx, Immediate(profiling_counter_));
+  __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
+         Immediate(Smi::FromInt(reset_value)));
+}
+
+
 void FullCodeGenerator::EmitStackCheck(IterationStatement* stmt,
                                        Label* back_edge_target) {
   Comment cmnt(masm_, "[ Stack check");
   Label ok;
 
   if (FLAG_count_based_interrupts) {
     int weight = 1;
     if (FLAG_weighted_back_edges) {
       ASSERT(back_edge_target->is_bound());
       int distance = masm_->SizeOfCodeGeneratedSince(back_edge_target);
       weight = Min(127, Max(1, distance / 100));
     }
-    if (Serializer::enabled()) {
-      __ mov(ebx, Immediate(profiling_counter_));
-      __ sub(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
-             Immediate(Smi::FromInt(weight)));
-    } else {
-      // This version is slightly faster, but not snapshot safe.
-      __ sub(Operand::Cell(profiling_counter_),
-             Immediate(Smi::FromInt(weight)));
-    }
+    EmitProfilingCounterDecrement(weight);
     __ j(positive, &ok, Label::kNear);
     InterruptStub stub;
     __ CallStub(&stub);
   } else {
     // Count based interrupts happen often enough when they are enabled
     // that the additional stack checks are not necessary (they would
     // only check for interrupts).
     ExternalReference stack_limit =
         ExternalReference::address_of_stack_limit(isolate());
     __ cmp(esp, Operand::StaticVariable(stack_limit));
     __ j(above_equal, &ok, Label::kNear);
     StackCheckStub stub;
     __ CallStub(&stub);
   }
 
   // Record a mapping of this PC offset to the OSR id.  This is used to find
   // the AST id from the unoptimized code in order to use it as a key into
   // the deoptimization input data found in the optimized code.
   RecordStackCheck(stmt->OsrEntryId());
 
   // Loop stack checks can be patched to perform on-stack replacement. In
   // order to decide whether or not to perform OSR we embed the loop depth
   // in a test instruction after the call so we can extract it from the OSR
   // builtin.
   ASSERT(loop_depth() > 0);
   __ test(eax, Immediate(Min(loop_depth(), Code::kMaxLoopNestingMarker)));
 
   if (FLAG_count_based_interrupts) {
-    // Reset the countdown.
-    if (Serializer::enabled()) {
-      __ mov(ebx, Immediate(profiling_counter_));
-      __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
-             Immediate(Smi::FromInt(FLAG_interrupt_budget)));
-    } else {
-      __ mov(Operand::Cell(profiling_counter_),
-             Immediate(Smi::FromInt(FLAG_interrupt_budget)));
-    }
+    EmitProfilingCounterReset();
   }
 
   __ bind(&ok);
   PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
   // Record a mapping of the OSR id to this PC.  This is used if the OSR
   // entry becomes the target of a bailout.  We don't expect it to be, but
   // we want it to work if it is.
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
   if (return_label_.is_bound()) {
     __ jmp(&return_label_);
   } else {
     // Common return label
     __ bind(&return_label_);
     if (FLAG_trace) {
       __ push(eax);
       __ CallRuntime(Runtime::kTraceExit, 1);
     }
-    if (FLAG_interrupt_at_exit) {
+    if (FLAG_interrupt_at_exit || FLAG_self_optimization) {
       // Pretend that the exit is a backwards jump to the entry.
       int weight = 1;
-      if (FLAG_weighted_back_edges) {
+      if (info_->ShouldSelfOptimize()) {
+        weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+      } else if (FLAG_weighted_back_edges) {
         int distance = masm_->pc_offset();
         weight = Min(127, Max(1, distance / 100));
       }
-      if (Serializer::enabled()) {
-        __ mov(ebx, Immediate(profiling_counter_));
-        __ sub(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
-               Immediate(Smi::FromInt(weight)));
-      } else {
-        // This version is slightly faster, but not snapshot safe.
-        __ sub(Operand::Cell(profiling_counter_),
-               Immediate(Smi::FromInt(weight)));
-      }
+      EmitProfilingCounterDecrement(weight);
       Label ok;
       __ j(positive, &ok, Label::kNear);
       __ push(eax);
-      InterruptStub stub;
-      __ CallStub(&stub);
+      if (info_->ShouldSelfOptimize() && FLAG_direct_self_opt) {
+        __ push(Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
+        __ CallRuntime(Runtime::kOptimizeFunctionOnNextCall, 1);
+      } else {
+        InterruptStub stub;
+        __ CallStub(&stub);
+      }
       __ pop(eax);
-      // Reset the countdown.
-      if (Serializer::enabled()) {
-        __ mov(ebx, Immediate(profiling_counter_));
-        __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
-               Immediate(Smi::FromInt(FLAG_interrupt_budget)));
-      } else {
-        __ mov(Operand::Cell(profiling_counter_),
-               Immediate(Smi::FromInt(FLAG_interrupt_budget)));
-      }
+      EmitProfilingCounterReset();
       __ bind(&ok);
     }
 #ifdef DEBUG
     // Add a label for checking the size of the code used for returning.
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
     SetSourcePosition(function()->end_position() - 1);
     __ RecordJSReturn();
     // Do not use the leave instruction here because it is too short to
@@ skipping 4012 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32