Customized support for feedback on calls to Array.

src/arm64/code-stubs-arm64.cc

Index: src/arm64/code-stubs-arm64.cc
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
index 0bf89d89019b36ddb610a402c466f1e48dc6e921..d1185b23e131e0a1ed6565f4530a37d3750dff8b 100644
--- a/src/arm64/code-stubs-arm64.cc
+++ b/src/arm64/code-stubs-arm64.cc
@@ -3217,10 +3217,10 @@ static void EmitWrapCase(MacroAssembler* masm, int argc, Label* cont) {
 }
 
 
-void CallFunctionStub::Generate(MacroAssembler* masm) {
-  ASM_LOCATION("CallFunctionStub::Generate");
+static void CallFunctionNoFeedback(MacroAssembler* masm,
+                                   int argc, bool needs_checks,
+                                   bool call_as_method) {
   // x1  function    the function to call
-
   Register function = x1;
   Register type = x4;
   Label slow, non_function, wrap, cont;
@@ -3228,7 +3228,7 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
   // TODO(jbramley): This function has a lot of unnamed registers. Name them,
   // and tidy things up a bit.
 
-  if (NeedsChecks()) {
+  if (needs_checks) {
     // Check that the function is really a JavaScript function.
     __ JumpIfSmi(function, &non_function);
 
@@ -3238,18 +3238,17 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
 
   // Fast-case: Invoke the function now.
   // x1  function  pushed function
-  int argc = argc_;
   ParameterCount actual(argc);
 
-  if (CallAsMethod()) {
-    if (NeedsChecks()) {
+  if (call_as_method) {
+    if (needs_checks) {
       EmitContinueIfStrictOrNative(masm, &cont);
     }
 
     // Compute the receiver in sloppy mode.
     __ Peek(x3, argc * kPointerSize);
 
-    if (NeedsChecks()) {
+    if (needs_checks) {
       __ JumpIfSmi(x3, &wrap);
       __ JumpIfObjectType(x3, x10, type, FIRST_SPEC_OBJECT_TYPE, &wrap, lt);
     } else {
@@ -3263,20 +3262,25 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
                     actual,
                     JUMP_FUNCTION,
                     NullCallWrapper());
-
-  if (NeedsChecks()) {
+  if (needs_checks) {
     // Slow-case: Non-function called.
     __ Bind(&slow);
     EmitSlowCase(masm, argc, function, type, &non_function);
   }
 
-  if (CallAsMethod()) {
+  if (call_as_method) {
     __ Bind(&wrap);
     EmitWrapCase(masm, argc, &cont);
   }
 }
 
 
+void CallFunctionStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("CallFunctionStub::Generate");
+  CallFunctionNoFeedback(masm, argc_, NeedsChecks(), CallAsMethod());
+}
+
+
 void CallConstructStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("CallConstructStub::Generate");
   // x0 : number of arguments
@@ -3356,6 +3360,59 @@ static void EmitLoadTypeFeedbackVector(MacroAssembler* masm, Register vector) {
 }
 
 
+void CallICStub::Generate_MonomorphicArray(MacroAssembler* masm, Label* miss) {
+  // x1 - function
+  // x2 - feedback vector
+  // x3 - slot id
+  Register function = x1;
+  Register feedback_vector = x2;
+  Register index = x3;
+  Register scratch = x4;
+
+  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, scratch);
+  __ Cmp(function, scratch);
+  __ B(ne, miss);
+
+  Register allocation_site = feedback_vector;
+  __ Mov(x0, Operand(arg_count()));
+
+  __ Add(scratch, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ Ldr(allocation_site, FieldMemOperand(scratch, FixedArray::kHeaderSize));
+
+  // Verify that x2 contains an AllocationSite
+  __ AssertUndefinedOrAllocationSite(allocation_site, scratch);
+  ArrayConstructorStub stub(masm->isolate(), arg_count());
+  __ TailCallStub(&stub);
+}
+
+
+void CallICStub::Generate_CustomFeedbackCall(MacroAssembler* masm) {
+  // x1 - function
+  // x2 - feedback vector
+  // x3 - slot id
+  Label miss;
+
+  if (state_.stub_type() == CallIC::MONOMORPHIC_ARRAY) {
+    Generate_MonomorphicArray(masm, &miss);
+  } else {
+    // So far there is only one customer for our custom feedback scheme.
+    UNREACHABLE();
+  }
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+
+  // The slow case, we need this no matter what to complete a call after a miss.
+  CallFunctionNoFeedback(masm,
+                         arg_count(),
+                         true,
+                         CallAsMethod());
+
+  __ Unreachable();
+}
+
+
 void CallICStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("CallICStub");
 
@@ -3374,6 +3431,11 @@ void CallICStub::Generate(MacroAssembler* masm) {
 
   EmitLoadTypeFeedbackVector(masm, feedback_vector);
 
+  if (state_.stub_type() != CallIC::DEFAULT) {
+    Generate_CustomFeedbackCall(masm);
+    return;
+  }
+
   // The checks. First, does x1 match the recorded monomorphic target?
   __ Add(x4, feedback_vector,
          Operand::UntagSmiAndScale(index, kPointerSizeLog2));