Port FastNewClosureStub introduced for ia32 in r3477 to x64 and arm.

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
===================================================================
--- src/arm/codegen-arm.cc	(revision 3577)
+++ src/arm/codegen-arm.cc	(working copy)
@@ -2299,12 +2299,21 @@
   VirtualFrame::SpilledScope spilled_scope;
   ASSERT(boilerplate->IsBoilerplate());
 
-  // Create a new closure.
-  frame_->EmitPush(cp);
   __ mov(r0, Operand(boilerplate));
-  frame_->EmitPush(r0);
-  frame_->CallRuntime(Runtime::kNewClosure, 2);
-  frame_->EmitPush(r0);
+  // Use the fast case closure allocation code that allocates in new
+  // space for nested functions that don't need literals cloning.
+  if (scope()->is_function_scope() && boilerplate->NumberOfLiterals() == 0) {
+    FastNewClosureStub stub;
+    frame_->EmitPush(r0);
+    frame_->CallStub(&stub, 1);
+    frame_->EmitPush(r0);
+  } else {
+    // Create a new closure.
+    frame_->EmitPush(cp);
+    frame_->EmitPush(r0);
+    frame_->CallRuntime(Runtime::kNewClosure, 2);
+    frame_->EmitPush(r0);
+  }
 }
 
 
@@ -4384,6 +4393,53 @@
 }
 
 
+void FastNewClosureStub::Generate(MacroAssembler* masm) {
+  // Clone the boilerplate in new space. Set the context to the
+  // current context in cp.
+  Label gc;
+
+  // Pop the boilerplate function from the stack.
+  __ pop(r3);
+
+  // Attempt to allocate new JSFunction in new space.
+  __ AllocateInNewSpace(JSFunction::kSize / kPointerSize,
+                        r0,
+                        r1,
+                        r2,
+                        &gc,
+                        TAG_OBJECT);
+
+  // Compute the function map in the current global context and set that
+  // as the map of the allocated object.
+  __ ldr(r2, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalContextOffset));
+  __ ldr(r2, MemOperand(r2, Context::SlotOffset(Context::FUNCTION_MAP_INDEX)));
+  __ str(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+
+  // Clone the rest of the boilerplate fields. We don't have to update
+  // the write barrier because the allocated object is in new space.
+  for (int offset = kPointerSize;
+       offset < JSFunction::kSize;
+       offset += kPointerSize) {
+    if (offset == JSFunction::kContextOffset) {
+      __ str(cp, FieldMemOperand(r0, offset));
+    } else {
+      __ ldr(r1, FieldMemOperand(r3, offset));
+      __ str(r1, FieldMemOperand(r0, offset));
+    }
+  }
+
+  // Return result. The argument boilerplate has been popped already.
+  __ Ret();
+
+  // Create a new closure through the slower runtime call.
+  __ bind(&gc);
+  __ push(cp);
+  __ push(r3);
+  __ TailCallRuntime(ExternalReference(Runtime::kNewClosure), 2, 1);
+}
+
+
 // Count leading zeros in a 32 bit word.  On ARM5 and later it uses the clz
 // instruction.  On pre-ARM5 hardware this routine gives the wrong answer for 0
 // (31 instead of 32).