[turbofan] Fixes incorrect DataView setters

Having no value argument in DataView setters (e.g. setFloat64) caused
wrong behavior in compiled code.

Bug: chromium:1071190
Change-Id: I37ddba8555dafad321f8d4c1352da8a501a98453
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2170091Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Auto-Submit: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67451}

src/compiler/js-call-reducer.cc

@@ -7146,6 +7146,7 @@ uint32_t ExternalArrayElementSize(const ExternalArrayType element_type) {
 
 Reduction JSCallReducer::ReduceDataViewAccess(Node* node, DataViewAccess access,
                                               ExternalArrayType element_type) {
+  DCHECK_EQ(node->opcode(), IrOpcode::kJSCall);
   size_t const element_size = ExternalArrayElementSize(element_type);
   CallParameters const& p = CallParametersOf(node->op());
   Node* effect = NodeProperties::GetEffectInput(node);
@@ -7154,17 +7155,16 @@ Reduction JSCallReducer::ReduceDataViewAccess(Node* node, DataViewAccess access,
   Node* offset = node->op()->ValueInputCount() > 2
                      ? NodeProperties::GetValueInput(node, 2)
                      : jsgraph()->ZeroConstant();
-  Node* value = (access == DataViewAccess::kGet)
-                    ? nullptr
-                    : (node->op()->ValueInputCount() > 3
-                           ? NodeProperties::GetValueInput(node, 3)
-                           : jsgraph()->ZeroConstant());
-  Node* is_little_endian = (access == DataViewAccess::kGet)
-                               ? (node->op()->ValueInputCount() > 3
+  Node* value = nullptr;
+  if (access == DataViewAccess::kSet) {
+    value = node->op()->ValueInputCount() > 3
                 ? NodeProperties::GetValueInput(node, 3)
-                                      : jsgraph()->FalseConstant())
-                               : (node->op()->ValueInputCount() > 4
-                                      ? NodeProperties::GetValueInput(node, 4)
+                : jsgraph()->UndefinedConstant();
+  }
+  const int endian_index = (access == DataViewAccess::kGet ? 3 : 4);
+  Node* is_little_endian =
+      (node->op()->ValueInputCount() > endian_index
+           ? NodeProperties::GetValueInput(node, endian_index)
            : jsgraph()->FalseConstant());
 
   if (p.speculation_mode() == SpeculationMode::kDisallowSpeculation) {

test/mjsunit/regress/regress-1071190.js

+// Copyright 2020 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.
+
+// Flags: --allow-natives-syntax
+
+
+function test() {
+  const a = new DataView(new ArrayBuffer(32));
+  const b = new DataView(new ArrayBuffer(32));
+  a.setFloat64(0);
+  b.setFloat64(0, undefined);
+
+  for(let i = 0; i < 8; ++i) {
+    assertEquals(a.getUint8(i), b.getUint8(i));
+  }
+}
+
+%PrepareFunctionForOptimization(test);
+test();
+test();
+%OptimizeFunctionOnNextCall(test);
+test();