Use platform specific stubs for vector-based Load/KeyedLoad.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic.h"
+#include "src/ic/stub-cache.h"
 #include "src/isolate.h"
 #include "src/jsregexp.h"
 #include "src/regexp-macro-assembler.h"
 #include "src/runtime/runtime.h"
 
 namespace v8 {
 namespace internal {
 
 
 static void InitializeArrayConstructorDescriptor(
@@ skipping 4367 matching lines @@
   __ pop(ecx);
   int additional_offset =
       function_mode() == JS_FUNCTION_STUB_MODE ? kPointerSize : 0;
   __ lea(esp, MemOperand(esp, ebx, times_pointer_size, additional_offset));
   __ jmp(ecx);  // Return to IC Miss stub, continuation still on stack.
 }
 
 
 void LoadICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
-  VectorLoadStub stub(isolate(), state());
-  __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
+  VectorRawLoadStub stub(isolate(), state());
+  stub.GenerateForTrampoline(masm);
+  // __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 void KeyedLoadICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
-  VectorKeyedLoadStub stub(isolate());
-  __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
-}
-
-
+  VectorRawKeyedLoadStub stub(isolate());
+  stub.GenerateForTrampoline(masm);
+  // __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+static void HandleArrayCases(MacroAssembler* masm, Register receiver,
+                             Register key, Register vector, Register slot,
+                             Register feedback, Label* miss) {
+  // feedback initially contains the feedback array
+  Label next, next_loop, prepare_next;
+  Label load_smi_map, compare_map;
+
+  __ push(receiver);
+  __ push(vector);
+
+  Register receiver_map = receiver;
+  Register array_map = vector;
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &load_smi_map);
+  __ mov(receiver_map, FieldOperand(receiver, 0));
+  __ bind(&compare_map);
+  __ mov(array_map, FieldOperand(feedback, FixedArray::OffsetOfElementAt(0)));
+  __ cmp(receiver_map, FieldOperand(array_map, WeakCell::kValueOffset));
+  __ j(not_equal, &next);
+  // found, now call handler.
+  __ mov(feedback, FieldOperand(feedback, FixedArray::OffsetOfElementAt(1)));

[Toon Verwaest, 2015/03/11 17:55:02]

feedback -> handler?
Maybe just do Register handler = feedback;

[mvstanton, 2015/03/12 17:05:34]

Done.

+  __ pop(vector);
+  __ pop(receiver);
+  __ lea(feedback, FieldOperand(feedback, Code::kHeaderSize));
+  __ jmp(feedback);
+
+  __ bind(&next);
+  __ cmp(FieldOperand(feedback, FixedArray::kLengthOffset),
+         Immediate(Smi::FromInt(2)));

[Toon Verwaest, 2015/03/11 17:55:01]

This isn't possible for named loads afaict.

[mvstanton, 2015/03/12 17:05:34]

I addressed this with a boolean, is_polymorphic.

+  Label start_polymorphic;
+  __ j(not_equal, &start_polymorphic);
+  __ pop(vector);
+  __ pop(receiver);
+  __ jmp(miss);
+
+  // Polymorphic, we have to loop from 2 to N
+  __ bind(&start_polymorphic);
+  __ push(key);

[Toon Verwaest, 2015/03/11 17:55:02]

As discussed, you don't need the key for named loads if you store it the next to
the feedback array on top-level; so you don't need to spill it.

[mvstanton, 2015/03/12 17:05:34]

Yeah, I don't want to load it from the array very much I think that might be
more expensive. It would introduce a lot of variations downwind (like
KeyedLoadIC::GenerateMiss(), that has to know about this case).

+  Register counter = key;
+  __ mov(counter, Immediate(Smi::FromInt(2)));
+  __ bind(&next_loop);
+  __ mov(array_map, FieldOperand(feedback, counter, times_half_pointer_size,
+                                 FixedArray::kHeaderSize));
+  __ cmp(receiver_map, FieldOperand(array_map, WeakCell::kValueOffset));
+  __ j(not_equal, &prepare_next);
+  __ mov(feedback, FieldOperand(feedback, counter, times_half_pointer_size,
+                                FixedArray::kHeaderSize + kPointerSize));
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ lea(feedback, FieldOperand(feedback, Code::kHeaderSize));
+  __ jmp(feedback);
+
+  __ bind(&prepare_next);
+  __ add(counter, Immediate(Smi::FromInt(2)));
+  __ cmp(counter, FieldOperand(feedback, FixedArray::kLengthOffset));
+  __ j(less, &next_loop);
+
+  // We exhausted our array of map handler pairs.
+  __ pop(key);
+  __ pop(vector);
+  __ pop(receiver);
+  __ jmp(miss);
+
+  __ bind(&load_smi_map);
+  __ mov(receiver_map, masm->isolate()->factory()->heap_number_map());
+  __ jmp(&compare_map);
+}
+
+
+static void HandleMonomorphicCase(MacroAssembler* masm, Register receiver,
+                                  Register key, Register vector, Register slot,
+                                  Register weak_cell, Label* miss) {
+  // feedback initially contains the feedback array
+  Label compare_smi_map;
+
+  // Move the weak map into the weak_cell register.
+  __ mov(weak_cell, FieldOperand(weak_cell, WeakCell::kValueOffset));
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &compare_smi_map);
+  __ cmp(weak_cell, FieldOperand(receiver, 0));

[Toon Verwaest, 2015/03/11 17:55:02]

Register receiver_map = weak_cell;

[mvstanton, 2015/03/12 17:05:34]

Good idea, but I called it ic_map to indicate it's the map held by the ic, and
not necessary the map of the receiver.

+  __ j(not_equal, miss);
+  __ mov(weak_cell, FieldOperand(vector, slot, times_half_pointer_size,

[Toon Verwaest, 2015/03/11 17:55:02]

Register code_object = weak_cell;

[mvstanton, 2015/03/12 17:05:34]

Cool, but I called it handler per your good suggestion above.

+                                 FixedArray::kHeaderSize + kPointerSize));
+  __ lea(weak_cell, FieldOperand(weak_cell, Code::kHeaderSize));
+  __ jmp(weak_cell);
+
+  // In microbenchmarks, it made sense to unroll this code so that the call to
+  // the handler is duplicated for a HeapObject receiver and a Smi receiver.
+  __ bind(&compare_smi_map);
+  __ cmp(weak_cell, masm->isolate()->factory()->heap_number_map());
+  __ j(not_equal, miss);
+  __ mov(weak_cell, FieldOperand(vector, slot, times_half_pointer_size,
+                                 FixedArray::kHeaderSize + kPointerSize));
+  __ lea(weak_cell, FieldOperand(weak_cell, Code::kHeaderSize));
+  __ jmp(weak_cell);
+}
+
+
+void VectorRawLoadStub::Generate(MacroAssembler* masm) {
+  GenerateImpl(masm, false);
+}
+
+
+void VectorRawLoadStub::GenerateForTrampoline(MacroAssembler* masm) {
+  GenerateImpl(masm, true);
+}
+
+
+void VectorRawLoadStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
+  Register receiver = VectorLoadICDescriptor::ReceiverRegister();  // edx
+  Register name = VectorLoadICDescriptor::NameRegister();          // ecx
+  Register vector = VectorLoadICDescriptor::VectorRegister();      // ebx
+  Register slot = VectorLoadICDescriptor::SlotRegister();          // eax
+  Factory* factory = masm->isolate()->factory();
+  Register scratch = edi;
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize));
+
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay, miss;
+  __ cmp(FieldOperand(scratch, 0), factory->weak_cell_map());
+  __ j(not_equal, &try_array);
+  HandleMonomorphicCase(masm, receiver, name, vector, slot, scratch, &miss);
+  __ int3();  // We shouldn't get here.
+
+  // Is it a fixed array?
+  __ bind(&try_array);
+  __ cmp(FieldOperand(scratch, 0), factory->fixed_array_map());
+  __ j(not_equal, &not_array);
+  HandleArrayCases(masm, receiver, name, vector, slot, scratch, &miss);
+  __ int3();  // We shouldn't get here.
+
+  __ bind(&not_array);
+  __ cmp(scratch, factory->megamorphic_symbol());
+  __ j(not_equal, &miss);
+  __ push(slot);
+  __ push(vector);
+  Code::Flags code_flags = Code::RemoveTypeAndHolderFromFlags(
+      Code::ComputeHandlerFlags(Code::LOAD_IC));
+  masm->isolate()->stub_cache()->GenerateProbe(
+      masm, Code::LOAD_IC, code_flags, false, receiver, name, vector, scratch);
+  __ pop(vector);
+  __ pop(slot);
+
+  __ bind(&miss);
+  LoadIC::GenerateMiss(masm);
+}
+
+
+void VectorRawKeyedLoadStub::Generate(MacroAssembler* masm) {
+  GenerateImpl(masm, false);
+}
+
+
+void VectorRawKeyedLoadStub::GenerateForTrampoline(MacroAssembler* masm) {
+  GenerateImpl(masm, true);
+}
+
+
+void VectorRawKeyedLoadStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
+  Register receiver = VectorLoadICDescriptor::ReceiverRegister();  // edx
+  Register key = VectorLoadICDescriptor::NameRegister();           // ecx
+  Register vector = VectorLoadICDescriptor::VectorRegister();      // ebx
+  Register slot = VectorLoadICDescriptor::SlotRegister();          // eax
+  Factory* factory = masm->isolate()->factory();
+  Register scratch = edi;
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize));
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay, miss;
+  __ cmp(FieldOperand(scratch, 0), factory->weak_cell_map());
+  __ j(not_equal, &try_array);
+  __ JumpIfNotSmi(key, &miss);
+  HandleMonomorphicCase(masm, receiver, key, vector, slot, scratch, &miss);
+  __ int3();  // We shouldn't get here.
+
+  __ bind(&try_array);
+  // Is it a fixed array?
+  __ cmp(FieldOperand(scratch, 0), factory->fixed_array_map());
+  __ j(not_equal, &not_array);
+  // We have a polymorphic element handler.
+  __ JumpIfNotSmi(key, &miss);
+
+  Label polymorphic, try_poly_name;
+  __ bind(&polymorphic);
+  HandleArrayCases(masm, receiver, key, vector, slot, scratch, &miss);
+  __ int3();  // We shouldn't get here.
+
+  __ bind(&not_array);
+  // Is it generic?
+  __ cmp(scratch, factory->megamorphic_symbol());
+  __ j(not_equal, &try_poly_name);
+  Handle<Code> megamorphic_stub =
+      KeyedLoadIC::ChooseMegamorphicStub(masm->isolate());
+  __ jmp(megamorphic_stub, RelocInfo::CODE_TARGET);
+  __ int3();  // We shouldn't get here.

[Toon Verwaest, 2015/03/11 17:55:01]

drop int3(), I presume we can trust __jmp to do the right thing :)

[mvstanton, 2015/03/12 17:05:34]

Done.

+
+  __ bind(&try_poly_name);
+  // We might have a name in scratch, and a fixed array in the next slot.
+  __ cmp(key, scratch);
+  __ j(not_equal, &miss);
+  // If the name comparison succeeded, we know we have a fixed array with
+  // at least one map/handler pair.
+  __ mov(scratch, FieldOperand(vector, slot, times_half_pointer_size,
+                               FixedArray::kHeaderSize + kPointerSize));
+  __ jmp(&polymorphic);
+
+  __ bind(&miss);
+  KeyedLoadIC::GenerateMiss(masm);
+}
+
+
 void CallICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, ebx);
   CallICStub stub(isolate(), state());
   __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 void CallIC_ArrayTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, ebx);
   CallIC_ArrayStub stub(isolate(), state());
@@ skipping 763 matching lines @@
                            ApiParameterOperand(2), kStackSpace, nullptr,
                            Operand(ebp, 7 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32