Profiler experiments: fix snapshotting with count-based interrupts

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 324 matching lines @@
   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));
     }
-    __ sub(Operand::Cell(profiling_counter_), Immediate(Smi::FromInt(weight)));
+    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)));
+    }
     __ 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.
-    __ mov(Operand::Cell(profiling_counter_),
-           Immediate(Smi::FromInt(FLAG_interrupt_budget)));
+    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)));
+    }
   }
 
   __ 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) {
       // Pretend that the exit is a backwards jump to the entry.
       int weight = 1;
       if (FLAG_weighted_back_edges) {
         int distance = masm_->pc_offset();
         weight = Min(127, Max(1, distance / 100));
       }
-      __ sub(Operand::Cell(profiling_counter_),
-             Immediate(Smi::FromInt(weight)));
+      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)));
+      }
       Label ok;
       __ j(positive, &ok, Label::kNear);
       __ push(eax);
       InterruptStub stub;
       __ CallStub(&stub);
       __ pop(eax);
       // Reset the countdown.
-      __ mov(Operand::Cell(profiling_counter_),
-             Immediate(Smi::FromInt(FLAG_interrupt_budget)));
+      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)));
+      }
       __ 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 3998 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32