Customized support for feedback on calls to Array.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index afea875e9e9a4da5b5f290fc57ad46189466c481..423a3765d95c95eaa16f24c2316a4ace7db1f13a 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -2934,11 +2934,13 @@ static void EmitWrapCase(MacroAssembler* masm, int argc, Label* cont) {
 }
 
 
-void CallFunctionStub::Generate(MacroAssembler* masm) {
+static void CallFunctionNoFeedback(MacroAssembler* masm,
+                                   int argc, bool needs_checks,
+                                   bool call_as_method) {
   // r1 : the function to call
   Label slow, non_function, wrap, cont;
 
-  if (NeedsChecks()) {
+  if (needs_checks) {
     // Check that the function is really a JavaScript function.
     // r1: pushed function (to be verified)
     __ JumpIfSmi(r1, &non_function);
@@ -2950,18 +2952,17 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
 
   // Fast-case: Invoke the function now.
   // r1: 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.
     __ ldr(r3, MemOperand(sp, argc * kPointerSize));
 
-    if (NeedsChecks()) {
+    if (needs_checks) {
       __ JumpIfSmi(r3, &wrap);
       __ CompareObjectType(r3, r4, r4, FIRST_SPEC_OBJECT_TYPE);
       __ b(lt, &wrap);
@@ -2974,19 +2975,24 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
 
   __ InvokeFunction(r1, actual, JUMP_FUNCTION, NullCallWrapper());
 
-  if (NeedsChecks()) {
+  if (needs_checks) {
     // Slow-case: Non-function called.
     __ bind(&slow);
     EmitSlowCase(masm, argc, &non_function);
   }
 
-  if (CallAsMethod()) {
+  if (call_as_method) {
     __ bind(&wrap);
     EmitWrapCase(masm, argc, &cont);
   }
 }
 
 
+void CallFunctionStub::Generate(MacroAssembler* masm) {
+  CallFunctionNoFeedback(masm, argc_, NeedsChecks(), CallAsMethod());
+}
+
+
 void CallConstructStub::Generate(MacroAssembler* masm) {
   // r0 : number of arguments
   // r1 : the function to call
@@ -3046,7 +3052,7 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
   __ bind(&do_call);
   // Set expected number of arguments to zero (not changing r0).
   __ mov(r2, Operand::Zero());
-  __ Jump(isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+  __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
           RelocInfo::CODE_TARGET);
 }
 
@@ -3060,6 +3066,51 @@ static void EmitLoadTypeFeedbackVector(MacroAssembler* masm, Register vector) {
 }
 
 
+void CallICStub::Generate_MonomorphicArray(MacroAssembler* masm, Label* miss) {
+  // r1 - function
+  // r2 - feedback vector
+  // r3 - slot id
+  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
+  __ cmp(r1, r4);
+  __ b(ne, miss);
+
+  __ mov(r0, Operand(arg_count()));
+  __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
+  __ ldr(r2, FieldMemOperand(r4, FixedArray::kHeaderSize));
+  // Verify that r2 contains an AllocationSite
+  __ AssertUndefinedOrAllocationSite(r2, r4);
+  ArrayConstructorStub stub(masm->isolate(), arg_count());
+  __ TailCallStub(&stub);
+}
+
+
+void CallICStub::Generate_CustomFeedbackCall(MacroAssembler* masm) {
+  // r1 - function
+  // r2 - feedback vector
+  // r3 - 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.
+  __ stop("Unexpected code address");
+}
+
+
 void CallICStub::Generate(MacroAssembler* masm) {
   // r1 - function
   // r3 - slot id (Smi)
@@ -3071,6 +3122,12 @@ void CallICStub::Generate(MacroAssembler* masm) {
 
   EmitLoadTypeFeedbackVector(masm, r2);
 
+  // the MONOMORPHIC_ARRAY case is handled with a helper function.

[danno, 2014/05/22 08:20:43]

nit: this comment is a bit misleading, all non-defaults are handled with a
helper function, MONOMORPHIC_ARRAY is just an example.

[mvstanton, 2014/05/22 09:29:47]

Cool, I removed the comment, it's self-explanatory.

+  if (state_.stub_type() != CallIC::DEFAULT) {
+    Generate_CustomFeedbackCall(masm);
+    return;
+  }
+
   // The checks. First, does r1 match the recorded monomorphic target?
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
   __ ldr(r4, FieldMemOperand(r4, FixedArray::kHeaderSize));