Share optimized code for closures.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
===================================================================
--- src/arm/code-stubs-arm.cc	(revision 11527)
+++ src/arm/code-stubs-arm.cc	(working copy)
@@ -85,6 +85,8 @@
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
   // Create a new closure from the given function info in new
   // space. Set the context to the current context in cp.
+  Counters* counters = masm->isolate()->counters();
+
   Label gc;
 
   // Pop the function info from the stack.
@@ -98,6 +100,8 @@
                         &gc,
                         TAG_OBJECT);
 
+  __ IncrementCounter(counters->fast_new_closure_total(), 1, r6, r7);
+
   int map_index = (language_mode_ == CLASSIC_MODE)
       ? Context::FUNCTION_MAP_INDEX
       : Context::STRICT_MODE_FUNCTION_MAP_INDEX;
@@ -106,24 +110,34 @@
   // 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(map_index)));
-  __ str(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+  __ ldr(r5, MemOperand(r2, Context::SlotOffset(map_index)));
+  __ str(r5, FieldMemOperand(r0, HeapObject::kMapOffset));
 
   // Initialize the rest of the function. We don't have to update the
   // write barrier because the allocated object is in new space.
   __ LoadRoot(r1, Heap::kEmptyFixedArrayRootIndex);
-  __ LoadRoot(r2, Heap::kTheHoleValueRootIndex);
-  __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(r5, Heap::kTheHoleValueRootIndex);
   __ str(r1, FieldMemOperand(r0, JSObject::kPropertiesOffset));
   __ str(r1, FieldMemOperand(r0, JSObject::kElementsOffset));
-  __ str(r2, FieldMemOperand(r0, JSFunction::kPrototypeOrInitialMapOffset));
+  __ str(r5, FieldMemOperand(r0, JSFunction::kPrototypeOrInitialMapOffset));
   __ str(r3, FieldMemOperand(r0, JSFunction::kSharedFunctionInfoOffset));
   __ str(cp, FieldMemOperand(r0, JSFunction::kContextOffset));
   __ str(r1, FieldMemOperand(r0, JSFunction::kLiteralsOffset));
-  __ str(r4, FieldMemOperand(r0, JSFunction::kNextFunctionLinkOffset));
 
   // Initialize the code pointer in the function to be the one
   // found in the shared function info object.
+  // But first check if there is an optimized version for our context.
+  Label check_optimized;
+  Label install_unoptimized;
+  if (FLAG_cache_optimized_code) {
+    __ ldr(r1,
+           FieldMemOperand(r3, SharedFunctionInfo::kOptimizedCodeMapOffset));
+    __ tst(r1, r1);
+    __ b(ne, &check_optimized);
+  }
+  __ bind(&install_unoptimized);
+  __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+  __ str(r4, FieldMemOperand(r0, JSFunction::kNextFunctionLinkOffset));
   __ ldr(r3, FieldMemOperand(r3, SharedFunctionInfo::kCodeOffset));
   __ add(r3, r3, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ str(r3, FieldMemOperand(r0, JSFunction::kCodeEntryOffset));
@@ -131,6 +145,73 @@
   // Return result. The argument function info has been popped already.
   __ Ret();
 
+  __ bind(&check_optimized);
+
+  __ IncrementCounter(counters->fast_new_closure_try_optimized(), 1, r6, r7);
+
+  // r2 holds global context, r1 points to fixed array of 3-element entries
+  // (global context, optimized code, literals).
+  // The optimized code map must never be empty, so check the first elements.
+  Label install_optimized;
+  const int kEntryLength = 3;
+  // Speculatively move code object into r4.
+  __ ldr(r4, FieldMemOperand(r1, FixedArray::kHeaderSize + kPointerSize));
+  __ ldr(r5, FieldMemOperand(r1, FixedArray::kHeaderSize));
+  __ cmp(r2, r5);
+  __ b(eq, &install_optimized);
+  __ b(&install_unoptimized);
+
+  // Iterate through the rest of map backwards.  r4 holds an index as a Smi.
+  Label loop;
+  __ ldr(r4, FieldMemOperand(r1, FixedArray::kLengthOffset));
+  __ bind(&loop);
+  // Do not double check first entry.
+
+  __ cmp(r4, Operand(Smi::FromInt(kEntryLength)));
+  __ b(eq, &install_unoptimized);
+  __ sub(r4, r4, Operand(Smi::FromInt(kEntryLength)));  // Skip an entry.
+  __ add(r5, r1, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(r5, r5, Operand(r4, LSL, kPointerSizeLog2 - kSmiTagSize));
+  __ ldr(r5, MemOperand(r5));
+  __ cmp(r2, r5);
+  __ b(ne, &loop);
+  // Hit: fetch the optimized code.
+  __ add(r5, r1, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(r5, r5, Operand(r4, LSL, kPointerSizeLog2 - kSmiTagSize));
+  __ add(r5, r5, Operand(kPointerSize));
+  __ ldr(r4, MemOperand(r5));
+
+  __ bind(&install_optimized);
+  __ IncrementCounter(counters->fast_new_closure_install_optimized(),
+                      1, r6, r7);
+
+  // TODO(fschneider): Idea: store proper code pointers in the map and either
+  // unmangle them on marking or do nothing as the whole map is discarded on
+  // major GC anyway.
+  __ add(r4, r4, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ str(r4, FieldMemOperand(r0, JSFunction::kCodeEntryOffset));
+
+  // Now link a function into a list of optimized functions.
+  __ ldr(r4, ContextOperand(r2, Context::OPTIMIZED_FUNCTIONS_LIST));
+
+  __ str(r4, FieldMemOperand(r0, JSFunction::kNextFunctionLinkOffset));
+  // No need for write barrier as JSFunction (eax) is in the new space.
+
+  __ str(r0, ContextOperand(r2, Context::OPTIMIZED_FUNCTIONS_LIST));
+  // Store JSFunction (eax) into edx before issuing write barrier as
+  // it clobbers all the registers passed.
+  __ mov(r4, r0);
+  __ RecordWriteContextSlot(
+      r2,
+      Context::SlotOffset(Context::OPTIMIZED_FUNCTIONS_LIST),
+      r4,
+      r1,
+      kLRHasNotBeenSaved,
+      kDontSaveFPRegs);
+
+  // Return result. The argument function info has been popped already.
+  __ Ret();
+
   // Create a new closure through the slower runtime call.
   __ bind(&gc);
   __ LoadRoot(r4, Heap::kFalseValueRootIndex);
@@ -7105,6 +7186,8 @@
   { REG(r2), REG(r6), REG(r9), EMIT_REMEMBERED_SET },
   // StoreArrayLiteralElementStub::Generate
   { REG(r5), REG(r0), REG(r6), EMIT_REMEMBERED_SET },
+  // FastNewClosureStub::Generate
+  { REG(r2), REG(r4), REG(r1), EMIT_REMEMBERED_SET },
   // Null termination.
   { REG(no_reg), REG(no_reg), REG(no_reg), EMIT_REMEMBERED_SET}
 };