New approach to Crankshaft decision-making

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 24df20ba767bd76df3fe06cbae9109d56afe6512..2fa8065931645e8724845f402e9b47ecba1699dd 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -129,6 +129,23 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
   }
 #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_crankshaft &&
+      !info->shared_info().is_null() &&
+      info->function()->is_primitive()) {
+    info->shared_info()->set_call_counter(
+        SharedFunctionInfo::kCallsUntilPrimitiveOptimization);
+    __ movq(rax, info->shared_info(), RelocInfo::EMBEDDED_OBJECT);
+    // rax: shared function info
+    __ SmiAddConstant(FieldOperand(rax, SharedFunctionInfo::kCallCounterOffset),
+                      Smi::FromInt(-1));
+    Handle<Code> compile_stub(
+        isolate()->builtins()->builtin(Builtins::kLazyRecompile));
+    __ j(zero, compile_stub, RelocInfo::CODE_TARGET);
+  }
+
   // Strict mode functions and builtins need to replace the receiver
   // with undefined when called as functions (without an explicit
   // receiver object). rcx is zero for method calls and non-zero for