Revert "[maglev] Support LdaModuleVariable and StaModuleVariable"

This reverts commit 532ca599.

Reason for revert: UBSan failures (integer overflow):
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20UBSan/22615/overview

Original change's description:
> [maglev] Support LdaModuleVariable and StaModuleVariable
>
> Bug: v8:7700
> Change-Id: I036ac71324e0c1c96a4da4aacdb5a6718726db31
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3821203
> Reviewed-by: Victor Gomes <victorgomes@chromium.org>
> Commit-Queue: 王澳 <wangao.james@bytedance.com>
> Cr-Commit-Position: refs/heads/main@{#82347}

Bug: v8:7700
Change-Id: Iedbcb80a2ec41f299105bb814650ec4eff30db0d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3824718
Auto-Submit: Adam Klein <adamk@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#82356}

src/maglev/maglev-graph-builder.cc

@@ -1110,59 +1110,8 @@ void MaglevGraphBuilder::VisitGetKeyedProperty() {
       AddNewNode<GetKeyedGeneric>({context, object, key}, feedback_source));
 }
 
-void MaglevGraphBuilder::VisitLdaModuleVariable() {
-  // LdaModuleVariable <cell_index> <depth>
-  int cell_index = iterator_.GetImmediateOperand(0);
-  int depth = iterator_.GetUnsignedImmediateOperand(1);
-
-  ValueNode* context = GetContext();
-  for (int i = 0; i < depth; i++) {
-    context = AddNewNode<LoadTaggedField>(
-        {context}, Context::OffsetOfElementAt(Context::PREVIOUS_INDEX));
-  }
-  ValueNode* module = AddNewNode<LoadTaggedField>(
-      {context}, Context::OffsetOfElementAt(Context::EXTENSION_INDEX));
-  ValueNode* exports_or_imports;
-  if (cell_index > 0) {
-    exports_or_imports = AddNewNode<LoadTaggedField>(
-        {module}, SourceTextModule::kRegularExportsOffset);
-    // The actual array index is (cell_index - 1).
-    cell_index -= 1;
-  } else {
-    exports_or_imports = AddNewNode<LoadTaggedField>(
-        {module}, SourceTextModule::kRegularImportsOffset);
-    // The actual array index is (-cell_index - 1).
-    cell_index = -cell_index - 1;
-  }
-  ValueNode* cell = LoadFixedArrayElement(exports_or_imports, cell_index);
-  SetAccumulator(AddNewNode<LoadTaggedField>({cell}, Cell::kValueOffset));
-}
-
-void MaglevGraphBuilder::VisitStaModuleVariable() {
-  // StaModuleVariable <cell_index> <depth>
-  int cell_index = iterator_.GetImmediateOperand(0);
-  if (V8_UNLIKELY(cell_index < 0)) {
-    BuildCallRuntime(Runtime::kAbort,
-                     {GetSmiConstant(static_cast<int>(
-                         AbortReason::kUnsupportedModuleOperation))});
-    return;
-  }
-  ValueNode* context = GetContext();
-  int depth = iterator_.GetUnsignedImmediateOperand(1);
-  for (int i = 0; i < depth; i++) {
-    context = AddNewNode<LoadTaggedField>(
-        {context}, Context::OffsetOfElementAt(Context::PREVIOUS_INDEX));
-  }
-  ValueNode* module = AddNewNode<LoadTaggedField>(
-      {context}, Context::OffsetOfElementAt(Context::EXTENSION_INDEX));
-  ValueNode* exports = AddNewNode<LoadTaggedField>(
-      {module}, SourceTextModule::kRegularExportsOffset);
-  // The actual array index is (cell_index - 1).
-  cell_index -= 1;
-  ValueNode* cell = LoadFixedArrayElement(exports, cell_index);
-  AddNewNode<StoreTaggedFieldWithWriteBarrier>({cell, GetAccumulatorTagged()},
-                                               Cell::kValueOffset);
-}
+MAGLEV_UNIMPLEMENTED_BYTECODE(LdaModuleVariable)
+MAGLEV_UNIMPLEMENTED_BYTECODE(StaModuleVariable)
 
 bool MaglevGraphBuilder::TryBuildMonomorphicStoreFromSmiHandler(
     ValueNode* object, const compiler::MapRef& map, int32_t handler) {

src/maglev/maglev-graph-builder.h

@@ -610,11 +610,6 @@ class MaglevGraphBuilder {
     return GetFloat64(iterator_.GetRegisterOperand(operand_index));
   }
 
-  ValueNode* LoadFixedArrayElement(ValueNode* node, int index) {
-    return AddNewNode<LoadTaggedField>({node},
-                                       FixedArray::OffsetOfElementAt(index));
-  }
-
   template <typename NodeT>
   void SetAccumulator(NodeT* node) {
     // Accumulator stores are equivalent to stores to the virtual accumulator

test/mjsunit/maglev/lda-module-variable-import.mjs

-// Copyright 2022 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 --maglev --no-stress-opt --no-always-turbofan
-
-const b = 1;
-export {b};

test/mjsunit/maglev/lda-module-variable.mjs

-// Copyright 2022 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 --maglev --no-stress-opt --no-always-turbofan
-
-// Test LdaModuleVariable with imports.
-import {b} from './lda-module-variable-import.mjs'
-
-function bar(y) {
-  // b = 1.
-  return b + y;
-};
-%PrepareFunctionForOptimization(bar);
-assertEquals(2, bar(1));
-assertEquals(3, bar(2));
-%OptimizeMaglevOnNextCall(bar);
-assertEquals(2, bar(1));
-assertEquals(3, bar(2));
-assertTrue(isMaglevved(bar));
-
-// Test LdaModuleVariable with exports.
-export let x = 1;
-function foo(y) { return x + y };
-
-%PrepareFunctionForOptimization(foo);
-assertEquals(2, foo(1));
-assertEquals(3, foo(2));
-%OptimizeMaglevOnNextCall(foo);
-assertEquals(2, foo(1));
-assertEquals(3, foo(2));
-assertTrue(isMaglevved(foo));
-

test/mjsunit/maglev/sta-module-variable.mjs

-// Copyright 2022 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 --maglev --no-stress-opt --no-always-turbofan
-
-export let x = 1;
-function foo(y) {
-  x = x + 1;
-  return x + y;
-};
-
-%PrepareFunctionForOptimization(foo);
-assertEquals(3, foo(1));
-assertEquals(4, foo(1));
-%OptimizeMaglevOnNextCall(foo);
-assertEquals(5, foo(1));
-assertEquals(6, foo(1));
-assertTrue(isMaglevved(foo));
-