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

src/arm/code-stubs-arm.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_ARM
 
 #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 4291 matching lines @@
   }
   masm->LeaveFrame(StackFrame::STUB_FAILURE_TRAMPOLINE);
   __ mov(r1, Operand(r1, LSL, kPointerSizeLog2));
   __ add(sp, sp, r1);
   __ Ret();
 }
 
 
 void LoadICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
-  VectorLoadStub stub(isolate(), state());
-  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+  VectorRawLoadStub stub(isolate(), state());
+  stub.GenerateForTrampoline(masm);
 }
 
 
 void KeyedLoadICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
-  VectorKeyedLoadStub stub(isolate());
-  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+  VectorRawKeyedLoadStub stub(isolate());
+  stub.GenerateForTrampoline(masm);
 }
 
 
 void CallICTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, r2);
   CallICStub stub(isolate(), state());
   __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 void CallIC_ArrayTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, r2);
   CallIC_ArrayStub stub(isolate(), state());
   __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
+void VectorRawLoadStub::Generate(MacroAssembler* masm) {
+  GenerateImpl(masm, false);
+}
+
+
+void VectorRawLoadStub::GenerateForTrampoline(MacroAssembler* masm) {
+  GenerateImpl(masm, true);
+}
+
+
+static void HandleArrayCases(MacroAssembler* masm, Register receiver,
+                             Register key, Register vector, Register slot,
+                             Register feedback, Register scratch1,
+                             Register scratch2, Register scratch3,
+                             bool is_polymorphic, Label* miss) {
+  // feedback initially contains the feedback array
+  Label next_loop, prepare_next;
+  Label load_smi_map, compare_map;
+  Label start_polymorphic;
+
+  Register receiver_map = scratch1;
+  Register array_map = scratch2;
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &load_smi_map);
+  __ ldr(receiver_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ bind(&compare_map);
+  __ ldr(array_map,
+         FieldMemOperand(feedback, FixedArray::OffsetOfElementAt(0)));
+  __ ldr(array_map, FieldMemOperand(array_map, WeakCell::kValueOffset));
+  __ cmp(receiver_map, array_map);
+  __ b(ne, &start_polymorphic);
+  // found, now call handler.
+  Register handler = feedback;
+  __ ldr(handler, FieldMemOperand(feedback, FixedArray::OffsetOfElementAt(1)));
+  __ add(pc, handler, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+
+  Register length = scratch3;
+  __ bind(&start_polymorphic);
+  __ ldr(length, FieldMemOperand(feedback, FixedArray::kLengthOffset));
+  if (!is_polymorphic) {
+    // If the IC could be monomorphic we have to make sure we don't go past the
+    // end of the feedback array.
+    __ cmp(length, Operand(Smi::FromInt(2)));
+    __ b(eq, miss);
+  }
+
+  Register too_far = length;
+  Register pointer_reg = feedback;
+
+  // +-----+------+------+-----+-----+ ... ----+
+  // | map | len  | wm0  | h0  | wm1 |      hN |
+  // +-----+------+------+-----+-----+ ... ----+
+  //                 0      1     2        len-1
+  //                              ^              ^
+  //                              |              |
+  //                         pointer_reg      too_far
+  //                         aka feedback     scratch3
+  // also need receiver_map (aka scratch1)
+  // use array_map (scratch2) to look in the weak map values.
+  __ add(too_far, feedback, Operand::PointerOffsetFromSmiKey(length));
+  __ add(too_far, too_far, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(pointer_reg, feedback,
+         Operand(FixedArray::OffsetOfElementAt(2) - kHeapObjectTag));
+
+  __ bind(&next_loop);
+  __ ldr(array_map, MemOperand(pointer_reg));
+  __ ldr(array_map, FieldMemOperand(array_map, WeakCell::kValueOffset));
+  __ cmp(receiver_map, array_map);
+  __ b(ne, &prepare_next);
+  __ ldr(handler, MemOperand(pointer_reg, kPointerSize));
+  __ add(pc, handler, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+  __ bind(&prepare_next);
+  __ add(pointer_reg, pointer_reg, Operand(kPointerSize * 2));
+  __ cmp(pointer_reg, too_far);
+  __ b(lt, &next_loop);
+
+  // We exhausted our array of map handler pairs.
+  __ jmp(miss);
+
+  __ bind(&load_smi_map);
+  __ LoadRoot(receiver_map, Heap::kHeapNumberMapRootIndex);
+  __ jmp(&compare_map);
+}
+
+
+static void HandleMonomorphicCase(MacroAssembler* masm, Register receiver,
+                                  Register key, Register vector, Register slot,
+                                  Register weak_cell, Register scratch,
+                                  Label* miss) {
+  // feedback initially contains the feedback array
+  Label compare_smi_map;
+  Register receiver_map = scratch;
+  Register array_map = weak_cell;
+
+  // Move the weak map into the weak_cell register.
+  __ ldr(array_map, FieldMemOperand(weak_cell, WeakCell::kValueOffset));
+
+  // Receiver might not be a heap object.
+  __ JumpIfSmi(receiver, &compare_smi_map);
+  __ ldr(receiver_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ cmp(array_map, receiver_map);
+  __ b(ne, miss);
+
+  Register handler = weak_cell;
+  __ add(handler, vector, Operand::PointerOffsetFromSmiKey(slot));
+  __ ldr(handler,
+         FieldMemOperand(handler, FixedArray::kHeaderSize + kPointerSize));
+  __ add(pc, handler, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+  // 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.
+  // TODO(mvstanton): does this hold on ARM?

[Benedikt Meurer, 2015/03/16 10:30:17]

I guess it does not matter.

[mvstanton, 2015/03/16 13:59:40]

Okay, I removed the TODO for now. Certainly there will be more looks at this
code in future.

+  __ bind(&compare_smi_map);
+  __ CompareRoot(weak_cell, Heap::kHeapNumberMapRootIndex);
+  __ b(ne, miss);
+  __ add(handler, vector, Operand::PointerOffsetFromSmiKey(slot));
+  __ ldr(handler,
+         FieldMemOperand(handler, FixedArray::kHeaderSize + kPointerSize));
+  __ add(pc, handler, Operand(Code::kHeaderSize - kHeapObjectTag));
+}
+
+
+void VectorRawLoadStub::GenerateImpl(MacroAssembler* masm, bool in_frame) {
+  Register receiver = VectorLoadICDescriptor::ReceiverRegister();  // r1
+  Register name = VectorLoadICDescriptor::NameRegister();          // r2
+  Register vector = VectorLoadICDescriptor::VectorRegister();      // r3
+  Register slot = VectorLoadICDescriptor::SlotRegister();          // r0
+  Register feedback = r4;
+  Register scratch1 = r5;
+
+  __ add(feedback, vector, Operand::PointerOffsetFromSmiKey(slot));
+  __ ldr(feedback, FieldMemOperand(feedback, FixedArray::kHeaderSize));
+
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay, miss;
+  __ ldr(scratch1, FieldMemOperand(feedback, HeapObject::kMapOffset));
+  __ CompareRoot(scratch1, Heap::kWeakCellMapRootIndex);
+  __ b(ne, &try_array);
+  HandleMonomorphicCase(masm, receiver, name, vector, slot, feedback, scratch1,
+                        &miss);
+
+  // Is it a fixed array?
+  __ bind(&try_array);
+  __ CompareRoot(scratch1, Heap::kFixedArrayMapRootIndex);
+  __ b(ne, &not_array);
+  HandleArrayCases(masm, receiver, name, vector, slot, feedback, scratch1, r8,
+                   r9, true, &miss);
+
+  __ bind(&not_array);
+  __ CompareRoot(feedback, Heap::kmegamorphic_symbolRootIndex);
+  __ b(ne, &miss);
+  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, feedback,
+                                               scratch1, r8, r9);
+
+  __ 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();  // r1
+  Register key = VectorLoadICDescriptor::NameRegister();           // r2
+  Register vector = VectorLoadICDescriptor::VectorRegister();      // r3
+  Register slot = VectorLoadICDescriptor::SlotRegister();          // r0
+  Register feedback = r4;
+  Register scratch1 = r5;
+
+  __ add(feedback, vector, Operand::PointerOffsetFromSmiKey(slot));
+  __ ldr(feedback, FieldMemOperand(feedback, FixedArray::kHeaderSize));
+
+  // Is it a weak cell?
+  Label try_array;
+  Label not_array, smi_key, key_okay, miss;
+  __ ldr(scratch1, FieldMemOperand(feedback, HeapObject::kMapOffset));
+  __ CompareRoot(scratch1, Heap::kWeakCellMapRootIndex);
+  __ b(ne, &try_array);
+  __ JumpIfNotSmi(key, &miss);
+  HandleMonomorphicCase(masm, receiver, key, vector, slot, feedback, scratch1,
+                        &miss);
+
+  __ bind(&try_array);
+  // Is it a fixed array?
+  __ CompareRoot(scratch1, Heap::kFixedArrayMapRootIndex);
+  __ b(ne, &not_array);
+  // We have a polymorphic element handler.
+  __ JumpIfNotSmi(key, &miss);
+
+  Label polymorphic, try_poly_name;
+  __ bind(&polymorphic);
+  HandleArrayCases(masm, receiver, key, vector, slot, feedback, scratch1, r8,
+                   r9, true, &miss);
+
+  __ bind(&not_array);
+  // Is it generic?
+  __ CompareRoot(feedback, Heap::kmegamorphic_symbolRootIndex);
+  __ b(ne, &try_poly_name);
+  Handle<Code> megamorphic_stub =
+      KeyedLoadIC::ChooseMegamorphicStub(masm->isolate());
+  __ Jump(megamorphic_stub, RelocInfo::CODE_TARGET);
+
+  __ bind(&try_poly_name);
+  // We might have a name in feedback, and a fixed array in the next slot.
+  __ cmp(key, feedback);
+  __ b(ne, &miss);
+  // If the name comparison succeeded, we know we have a fixed array with
+  // at least one map/handler pair.
+  __ add(feedback, vector, Operand::PointerOffsetFromSmiKey(slot));
+  __ ldr(feedback,
+         FieldMemOperand(feedback, FixedArray::kHeaderSize + kPointerSize));
+  HandleArrayCases(masm, receiver, key, vector, slot, feedback, scratch1, r8,
+                   r9, false, &miss);
+
+  __ bind(&miss);
+  KeyedLoadIC::GenerateMiss(masm);
+}
+
+
 void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
   if (masm->isolate()->function_entry_hook() != NULL) {
     ProfileEntryHookStub stub(masm->isolate());
     int code_size = masm->CallStubSize(&stub) + 2 * Assembler::kInstrSize;
     PredictableCodeSizeScope predictable(masm, code_size);
     __ push(lr);
     __ CallStub(&stub);
     __ pop(lr);
   }
 }
@@ skipping 692 matching lines @@
                            kStackUnwindSpace, NULL,
                            MemOperand(fp, 6 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM