[Atomics] code stubs for atomic operations

src/compiler/code-stub-assembler.cc

 // Copyright 2015 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/compiler/code-stub-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 60 matching lines @@
 Node* CodeStubAssembler::HeapConstant(Handle<HeapObject> object) {
   return raw_assembler_->HeapConstant(object);
 }
 
 
 Node* CodeStubAssembler::BooleanConstant(bool value) {
   return raw_assembler_->BooleanConstant(value);
 }
 
 
+Node* CodeStubAssembler::Load(MachineType type, Node* base) {
+  return raw_assembler_->Load(type, base);
+}
+
+
+Node* CodeStubAssembler::Load(MachineType type, Node* base, Node* index) {
+  return raw_assembler_->Load(type, base, index);
+}
+
+
 Node* CodeStubAssembler::Parameter(int value) {
   return raw_assembler_->Parameter(value);
 }
 
 
+Node* CodeStubAssembler::StackArg(Node* num_args, int value) {
+  // N = num_args
+  // Arg 0:   [sp + (N + 1) * kPointerSize]
+  // Arg 1:   [sp + N * kPointerSize]
+  // ...
+  // Arg N-1: [sp + kPointerSize]
+  RawMachineAssembler* rma = raw_assembler_.get();
+  return rma->Load(
+      MachineType::AnyTagged(), rma->LoadStackPointer(),
+      rma->Word32Shl(rma->Int32Sub(num_args, rma->Int32Constant(value - 1)),
+                     rma->Int32Constant(kPointerSizeLog2)));
+}
+
+
+Node* CodeStubAssembler::StackArgOrUndefined(Node* num_args, int value) {
+  RawMachineAssembler* rma = raw_assembler_.get();
+  RawMachineLabel ok, not_ok, done;
+  rma->Branch(rma->Int32LessThan(rma->Int32Constant(value - 1), num_args), &ok,
+              &not_ok);
+  rma->Bind(&ok);
+  Node* arg = StackArg(num_args, value);
+  rma->Goto(&done);
+  rma->Bind(&not_ok);
+  Node* undefined = rma->UndefinedConstant();
+  rma->Goto(&done);
+  rma->Bind(&done);
+  return rma->Phi(MachineRepresentation::kTagged, arg, undefined);
+}
+
+
 void CodeStubAssembler::Return(Node* value) {
   return raw_assembler_->Return(value);
 }
 
 
 Node* CodeStubAssembler::SmiShiftBitsConstant() {
   return Int32Constant(kSmiShiftSize + kSmiTagSize);
 }
 
 
@@ skipping 71 matching lines @@
 
 Graph* CodeStubAssembler::graph() { return raw_assembler_->graph(); }
 
 
 Zone* CodeStubAssembler::zone() { return raw_assembler_->zone(); }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8