Count-based profiling for primitive functions (hidden behind a flag)

src/ia32/full-codegen-ia32.cc

-// Copyright 2011 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 110 matching lines @@
   SetFunctionPosition(function());
   Comment cmnt(masm_, "[ function compiled by full code generator");
 
 #ifdef DEBUG
   if (strlen(FLAG_stop_at) > 0 &&
       info->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
     __ int3();
   }
 #endif
 
+  // Primitive functions are unlikely to be picked up by the stack-walking
+  // profiler, so they trigger their own optimization when they're called
+  // for the SharedFunctionInfo::kCallsUntilPrimitiveOptimization-th time.
+  if (FLAG_counting_profiler &&

[Erik Corry, 2012/02/08 14:09:23]

These two flags can be tested inside ShouldSelfOptimize for a reduction in
verbosity.  Perhaps the flags on the shared info can also be tested there?

[Jakob Kummerow, 2012/02/08 15:24:08]

Good idea to clean this up. I've moved ShouldSelfOptimize() to CompilationInfo,
where all the required information for this decision is accessible.

+      FLAG_crankshaft &&
+      info->function()->ShouldSelfOptimize() &&
+      !Serializer::enabled() &&
+      !(!info->shared_info().is_null() &&
+        info->shared_info()->optimization_disabled())) {
+    if (FLAG_trace_opt) {
+      PrintF("[adding self-optimization header to %s]\n",
+             *info->function()->debug_name()->ToCString());
+    }
+    MaybeObject* maybe_cell = isolate()->heap()->AllocateJSGlobalPropertyCell(
+        Smi::FromInt(Compiler::kCallsUntilPrimitiveOpt));
+    JSGlobalPropertyCell* cell;
+    if (maybe_cell->To(&cell)) {
+      __ mov(eax, Immediate(Handle<JSGlobalPropertyCell>(cell)));
+      __ sub(FieldOperand(eax, JSGlobalPropertyCell::kValueOffset),
+             Immediate(Smi::FromInt(1)));

[Erik Corry, 2012/02/08 14:09:23]

It seems you can do:

__ sub(Operand::Cell(Handle<JSGlobalPropertyCell>(cell)), Immediate(...))

[Jakob Kummerow, 2012/02/08 15:24:08]

Done.

+      Handle<Code> compile_stub(
+          isolate()->builtins()->builtin(Builtins::kLazyRecompile));
+      __ j(zero, compile_stub);

[Erik Corry, 2012/02/08 14:09:23]

There is an assumption here that the Smi tag is zero and that we decrement one
at a time.  I would prefer j(mi, ... instead.

[Jakob Kummerow, 2012/02/08 15:24:08]

I've added an ASSERT for the Smi tag.
I can't easily change the jump condition because we intentionally don't reset
the countdown. After it has fired,  should we ever come back (e.g. after deopt),
we simply ignore it (until it overflows and reaches zero again after 2 billion
executions).

+    }
+  }
+
   // 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
   // function calls.
   if (!info->is_classic_mode() || info->is_native()) {
     Label ok;
     __ test(ecx, ecx);
     __ j(zero, &ok, Label::kNear);
     // +1 for return address.
     int receiver_offset = (info->scope()->num_parameters() + 1) * kPointerSize;
@@ skipping 4243 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32