[Atomics] Remove Atomics code stubs; use TF ops

src/compiler/arm/code-generator-arm.cc

 // Copyright 2014 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-generator.h"
 
 #include "src/arm/macro-assembler-arm.h"
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
@@ skipping 370 matching lines @@
     if (instr->InputAt(1)->IsRegister()) {        \
       __ cmp(offset, i.InputRegister(1));         \
     } else {                                      \
       __ cmp(offset, i.InputImmediate(1));        \
     }                                             \
     auto value = i.InputRegister(2);              \
     __ asm_instr(value, i.InputOffset(3), lo);    \
     DCHECK_EQ(LeaveCC, i.OutputSBit());           \
   } while (0)
 
+#define ASSEMBLE_ATOMIC_LOAD_INTEGER(asm_instr)                       \
+  do {                                                                \
+    __ asm_instr(i.OutputRegister(),                                  \
+                 MemOperand(i.InputRegister(0), i.InputRegister(1))); \
+    __ dmb(ISH);                                                      \
+  } while (0)
+
 void CodeGenerator::AssembleDeconstructFrame() {
   __ LeaveFrame(StackFrame::MANUAL);
 }
 
 void CodeGenerator::AssembleSetupStackPointer() {}
 
 void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
   int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
   if (sp_slot_delta > 0) {
     __ add(sp, sp, Operand(sp_slot_delta * kPointerSize));
@@ skipping 842 matching lines @@
     case kCheckedStoreFloat32:
       ASSEMBLE_CHECKED_STORE_FLOAT(32);
       break;
     case kCheckedStoreFloat64:
       ASSEMBLE_CHECKED_STORE_FLOAT(64);
       break;
     case kCheckedLoadWord64:
     case kCheckedStoreWord64:
       UNREACHABLE();  // currently unsupported checked int64 load/store.
       break;
+
+    case kAtomicLoadInt8:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ldrsb);
+      break;
+    case kAtomicLoadUint8:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ldrb);
+      break;
+    case kAtomicLoadInt16:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ldrsh);
+      break;
+    case kAtomicLoadUint16:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ldrh);
+      break;
+    case kAtomicLoadWord32:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ldr);
+      break;
   }
 }  // NOLINT(readability/fn_size)
 
 
 // Assembles branches after an instruction.
 void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
   ArmOperandConverter i(this, instr);
   Label* tlabel = branch->true_label;
   Label* flabel = branch->false_label;
   Condition cc = FlagsConditionToCondition(branch->condition);
@@ skipping 372 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8