[Atomics] code stubs for atomic operations

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 9cb6ebb8e922d6b8bf7d985ec6412180dcdadfad..81fa29b911a0eea55090215bf75df2b6356cb7a6 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -5564,6 +5564,169 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
                            NULL);
 }
 
+namespace {
+
+void GetTypedArrayBackingStore(MacroAssembler* masm, Register backing_store,
+                               Register object, Register scratch) {
+  Label offset_is_not_smi, done;
+  __ movp(scratch, FieldOperand(object, JSTypedArray::kBufferOffset));
+  __ movp(backing_store,
+          FieldOperand(scratch, JSArrayBuffer::kBackingStoreOffset));
+
+  __ movp(scratch, FieldOperand(object, JSArrayBufferView::kByteOffsetOffset));
+  __ JumpIfNotSmi(scratch, &offset_is_not_smi, Label::kNear);
+  // offset is smi
+  __ SmiToInteger32(scratch, scratch);
+  __ addp(backing_store, scratch);
+  __ jmp(&done, Label::kNear);
+
+  // offset is a heap number
+  __ bind(&offset_is_not_smi);
+  __ Movsd(xmm0, FieldOperand(scratch, HeapNumber::kValueOffset));
+  __ Cvttsd2siq(scratch, xmm0);
+  __ addp(backing_store, scratch);
+  __ bind(&done);
+}
+
+void TypedArrayJumpTablePrologue(MacroAssembler* masm, Register object,
+                                 Register scratch, Register scratch2,
+                                 Label* table) {
+  __ movp(scratch, FieldOperand(object, JSObject::kElementsOffset));
+  __ movp(scratch, FieldOperand(scratch, HeapObject::kMapOffset));
+  __ movzxbl(scratch, FieldOperand(scratch, Map::kInstanceTypeOffset));
+  __ subl(scratch, Immediate(static_cast<uint8_t>(FIXED_INT8_ARRAY_TYPE)));
+  __ Assert(above_equal, kOffsetOutOfRange);
+  __ leaq(scratch2, Operand(table));
+  __ jmp(Operand(scratch2, scratch, times_8, 0));
+}
+
+void TypedArrayJumpTableEpilogue(MacroAssembler* masm, Label* table, Label* i8,
+                                 Label* u8, Label* i16, Label* u16, Label* i32,
+                                 Label* u32, Label* u8c) {
+  STATIC_ASSERT(FIXED_UINT8_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 1);
+  STATIC_ASSERT(FIXED_INT16_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 2);
+  STATIC_ASSERT(FIXED_UINT16_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 3);
+  STATIC_ASSERT(FIXED_INT32_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 4);
+  STATIC_ASSERT(FIXED_UINT32_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 5);
+  STATIC_ASSERT(FIXED_FLOAT32_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 6);
+  STATIC_ASSERT(FIXED_FLOAT64_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 7);
+  STATIC_ASSERT(FIXED_UINT8_CLAMPED_ARRAY_TYPE == FIXED_INT8_ARRAY_TYPE + 8);
+
+  Label abort;
+  __ bind(table);
+  __ dq(i8);      // Int8Array
+  __ dq(u8);      // Uint8Array
+  __ dq(i16);     // Int16Array
+  __ dq(u16);     // Uint16Array
+  __ dq(i32);     // Int32Array
+  __ dq(u32);     // Uint32Array
+  __ dq(&abort);  // Float32Array
+  __ dq(&abort);  // Float64Array
+  __ dq(u8c);     // Uint8ClampedArray
+
+  __ bind(&abort);
+  __ Abort(kNoReason);
+}
+
+void ReturnInteger32(MacroAssembler* masm, XMMRegister dst, Register value,
+                     Label* use_heap_number) {
+  Label not_smi;
+  if (!value.is(rax)) {
+    __ movp(rax, value);
+  }
+  __ JumpIfNotValidSmiValue(rax, &not_smi, Label::kNear);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  __ bind(&not_smi);
+  __ Cvtlsi2sd(dst, rax);
+  __ jmp(use_heap_number);
+}
+
+void ReturnUnsignedInteger32(MacroAssembler* masm, XMMRegister dst,
+                             Register value, Label* use_heap_number) {
+  Label not_smi;
+  if (!value.is(rax)) {
+    __ movp(rax, value);
+  }
+  __ JumpIfUIntNotValidSmiValue(rax, &not_smi, Label::kNear);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  __ bind(&not_smi);
+  __ Cvtqsi2sd(dst, rax);
+  __ jmp(use_heap_number);
+}
+
+void ReturnAllocatedHeapNumber(MacroAssembler* masm, XMMRegister value,
+                               Register scratch) {
+  Label call_runtime;
+  __ AllocateHeapNumber(rax, scratch, &call_runtime);
+  __ Movsd(FieldOperand(rax, HeapNumber::kValueOffset), value);
+  __ Ret();
+
+  __ bind(&call_runtime);
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
+    __ Movsd(FieldOperand(rax, HeapNumber::kValueOffset), value);
+  }
+  __ Ret();
+}
+
+}  // anonymous namespace
+
+void AtomicsLoadStub::Generate(MacroAssembler* masm) {
+  Register object = rdx;
+  Register index = rax;  // Index is an untagged word32.
+  Register backing_store = rbx;
+  Label table;
+
+  GetTypedArrayBackingStore(masm, backing_store, object, kScratchRegister);
+  TypedArrayJumpTablePrologue(masm, object, rcx, kScratchRegister, &table);
+
+  Label i8, u8, i16, u16, i32, u32;
+
+  __ bind(&i8);
+  __ movb(rax, Operand(backing_store, index, times_1, 0));
+  __ movsxbl(rax, rax);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  __ bind(&u8);
+  __ movb(rax, Operand(backing_store, index, times_1, 0));
+  __ movzxbl(rax, rax);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  __ bind(&i16);
+  __ movw(rax, Operand(backing_store, index, times_2, 0));
+  __ movsxwl(rax, rax);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  __ bind(&u16);
+  __ movw(rax, Operand(backing_store, index, times_2, 0));
+  __ movzxwl(rax, rax);
+  __ Integer32ToSmi(rax, rax);
+  __ Ret();
+
+  Label use_heap_number;
+
+  __ bind(&i32);
+  __ movl(rax, Operand(backing_store, index, times_4, 0));
+  ReturnInteger32(masm, xmm0, rax, &use_heap_number);
+
+  __ bind(&u32);
+  __ movl(rax, Operand(backing_store, index, times_4, 0));
+  ReturnUnsignedInteger32(masm, xmm0, rax, &use_heap_number);
+
+  __ bind(&use_heap_number);
+  ReturnAllocatedHeapNumber(masm, xmm0, rcx);
+
+  TypedArrayJumpTableEpilogue(masm, &table, &i8, &u8, &i16, &u16, &i32, &u32,
+                              &u8);
+}
 
 #undef __