[wasm] A few small cleanups

Change-Id: Ie07e626900f8fc8218944be2b33da6fc109adf92
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3168273
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76930}

src/compiler/machine-operator-reducer.cc

@@ -1254,17 +1254,12 @@ Reduction MachineOperatorReducer::ReduceUint32Mod(Node* node) {
 
 Reduction MachineOperatorReducer::ReduceStore(Node* node) {
   NodeMatcher nm(node);
-  MachineRepresentation rep;
-  int value_input;
-  if (nm.IsStore()) {
-    rep = StoreRepresentationOf(node->op()).representation();
-    value_input = 2;
-  } else {
-    DCHECK(nm.IsUnalignedStore());
-    rep = UnalignedStoreRepresentationOf(node->op());
-    value_input = 2;
-  }
+  DCHECK(nm.IsStore() || nm.IsUnalignedStore());
+  MachineRepresentation rep =
+      nm.IsStore() ? StoreRepresentationOf(node->op()).representation()
+                   : UnalignedStoreRepresentationOf(node->op());
 
+  const int value_input = 2;
   Node* const value = node->InputAt(value_input);
 
   switch (value->opcode()) {

src/compiler/wasm-compiler.cc

@@ -2905,8 +2905,8 @@ Node* WasmGraphBuilder::BuildWasmCall(const wasm::FunctionSig* sig,
   const Operator* op = mcgraph()->common()->Call(call_descriptor);
   Node* call =
       BuildCallNode(sig, args, position, instance_node, op, frame_state);
-  // TODO(manoskouk): Don't always set control if we ever add properties to wasm
-  // calls.
+  // TODO(manoskouk): If we have kNoThrow calls, do not set them as control.
+  DCHECK_GT(call->op()->ControlOutputCount(), 0);
   SetControl(call);
 
   size_t ret_count = sig->return_count();
@@ -2935,8 +2935,8 @@ Node* WasmGraphBuilder::BuildWasmReturnCall(const wasm::FunctionSig* sig,
   const Operator* op = mcgraph()->common()->TailCall(call_descriptor);
   Node* call = BuildCallNode(sig, args, position, instance_node, op);
 
-  // TODO(manoskouk): {call} will not always be a control node if we ever add
-  // properties to wasm calls.
+  // TODO(manoskouk): If we have kNoThrow calls, do not merge them to end.
+  DCHECK_GT(call->op()->ControlOutputCount(), 0);
   gasm_->MergeControlToEnd(call);
 
   return call;

src/diagnostics/objects-printer.cc

@@ -1899,10 +1899,11 @@ void WasmStruct::WasmStructPrint(std::ostream& os) {
         os << Brief(base::ReadUnalignedValue<Object>(field_address));
         break;
       case wasm::kS128:
-      case wasm::kBottom:
-      case wasm::kVoid:
         os << "UNIMPLEMENTED";  // TODO(7748): Implement.
         break;
+      case wasm::kBottom:
+      case wasm::kVoid:
+        UNREACHABLE();
     }
   }
   os << "\n";

src/wasm/function-body-decoder-impl.h

@@ -2725,19 +2725,19 @@ class WasmFullDecoder : public WasmDecoder<validate, decoding_mode> {
         // the stack as it is.
         break;
       case kOptRef: {
-          Value result = CreateValue(
-              ValueType::Ref(ref_object.type.heap_type(), kNonNullable));
-          // The result of br_on_null has the same value as the argument (but a
-          // non-nullable type).
-          if (V8_LIKELY(current_code_reachable_and_ok_)) {
-            CALL_INTERFACE(BrOnNull, ref_object, imm.depth);
-            CALL_INTERFACE(Forward, ref_object, &result);
-            c->br_merge()->reached = true;
-          }
-          // In unreachable code, we still have to push a value of the correct
-          // type onto the stack.
-          Drop(ref_object);
-          Push(result);
+        Value result = CreateValue(
+            ValueType::Ref(ref_object.type.heap_type(), kNonNullable));
+        // The result of br_on_null has the same value as the argument (but a
+        // non-nullable type).
+        if (V8_LIKELY(current_code_reachable_and_ok_)) {
+          CALL_INTERFACE(BrOnNull, ref_object, imm.depth);
+          CALL_INTERFACE(Forward, ref_object, &result);
+          c->br_merge()->reached = true;
+        }
+        // In unreachable code, we still have to push a value of the correct
+        // type onto the stack.
+        Drop(ref_object);
+        Push(result);
         break;
       }
       default:

src/wasm/module-instantiate.cc

@@ -653,7 +653,8 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     Handle<FixedArray> tables = isolate_->factory()->NewFixedArray(table_count);
     for (int i = module_->num_imported_tables; i < table_count; i++) {
       const WasmTable& table = module_->tables[i];
-      // TODO(9495): Initialize with initializer from module if present.
+      // Initialize tables with null for now. We will initialize non-defaultable
+      // tables later, in {InitializeIndirectFunctionTables}.
       Handle<WasmTableObject> table_obj = WasmTableObject::New(
           isolate_, instance, table.type, table.initial_size,
           table.has_maximum_size, table.maximum_size, nullptr,

src/wasm/value-type.h

@@ -284,8 +284,8 @@ constexpr bool is_defaultable(ValueKind kind) {
 // representation (for reference types), and an inheritance depth (for rtts
 // only). Those are encoded into 32 bits using base::BitField. The underlying
 // ValueKind enumeration includes four elements which do not strictly correspond
-// to value types: the two packed types i8 and i16, the type of void blocks
-// (stmt), and a bottom value (for internal use).
+// to value types: the two packed types i8 and i16, the void type (for control
+// structures), and a bottom value (for internal use).
 class ValueType {
  public:
   /******************************* Constructors *******************************/

test/fuzzer/wasm-fuzzer-common.cc

@@ -294,7 +294,6 @@ std::ostream& operator<<(std::ostream& os, WasmElemSegment::Entry entry) {
 
 // Appends an initializer expression encoded in {wire_bytes}, in the offset
 // contained in {expr}.
-// TODO(7748): Find a way to implement other expressions here.
 void AppendInitExpr(std::ostream& os, ModuleWireBytes wire_bytes,
                     WireBytesRef expr) {
   Decoder decoder(wire_bytes.module_bytes());