[wasm-gc] Add packed types to ValueType

Motivation:
In the wasm-gc proposal, structs and arrays are allowed to store
elements of packed types i8 and i16.

Changes:
- Add i8 and i16 to ValueType.
- Fix all case switches to handle the new cases.
- Add a couple helper methods to ValueType and improve the
  implementation/usage of a couple more.

Bug: v8:7748
Change-Id: I527cfe5acf5d877fc38e4212174ba9f9de5c40ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2215046Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67994}

src/compiler/wasm-compiler.cc

@@ -2126,6 +2126,8 @@ Node* WasmGraphBuilder::Throw(uint32_t exception_index,
         STORE_FIXED_ARRAY_SLOT_ANY(values_array, index, value);
         ++index;
         break;
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
       case wasm::ValueType::kStmt:
       case wasm::ValueType::kBottom:
         UNREACHABLE();
@@ -2279,6 +2281,8 @@ Node* WasmGraphBuilder::GetExceptionValues(Node* except_obj,
         value = LOAD_FIXED_ARRAY_SLOT_ANY(values_array, index);
         ++index;
         break;
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
       case wasm::ValueType::kStmt:
       case wasm::ValueType::kBottom:
         UNREACHABLE();
@@ -5507,6 +5511,9 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         // TODO(7748): Implement properly. For now, we just expose the raw
         // object for testing.
         return node;
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
+        UNIMPLEMENTED();
       case wasm::ValueType::kStmt:
       case wasm::ValueType::kBottom:
         UNREACHABLE();
@@ -5616,7 +5623,14 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         DCHECK(enabled_features_.has_bigint());
         return BuildChangeBigIntToInt64(input, js_context);
 
-      default:
+      case wasm::ValueType::kS128:
+      case wasm::ValueType::kRef:
+      case wasm::ValueType::kOptRef:
+      case wasm::ValueType::kEqRef:
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
+      case wasm::ValueType::kBottom:
+      case wasm::ValueType::kStmt:
         UNREACHABLE();
         break;
     }

src/diagnostics/objects-printer.cc

@@ -1690,6 +1690,8 @@ void WasmStruct::WasmStructPrint(std::ostream& os) {  // NOLINT
       case wasm::ValueType::kF64:
         os << base::ReadUnalignedValue<double>(field_address);
         break;
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
       case wasm::ValueType::kS128:
       case wasm::ValueType::kAnyRef:
       case wasm::ValueType::kFuncRef:
@@ -1731,6 +1733,8 @@ void WasmArray::WasmArrayPrint(std::ostream& os) {  // NOLINT
       PrintTypedArrayElements(os, reinterpret_cast<double*>(data_ptr), len,
                               true);
       break;
+    case wasm::ValueType::kI8:
+    case wasm::ValueType::kI16:
     case wasm::ValueType::kS128:
     case wasm::ValueType::kAnyRef:
     case wasm::ValueType::kFuncRef:

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

@@ -333,9 +333,11 @@ ValueType read_value_type(Decoder* decoder, const byte* pc,
                      "--experimental-wasm-simd");
       return kWasmBottom;
     case kLocalVoid:
-      // Although void is included in ValueType, it is technically not a value
-      // type and is only used to indicate a void block return type. The caller
-      // of this function is responsible to check for its presence separately.
+    case kLocalI8:
+    case kLocalI16:
+      // Although these types are included in ValueType, they are technically
+      // not value types and are only used in specific contexts. The caller of
+      // this function is responsible to check for them separately.
       break;
   }
   // Malformed modules specifying invalid types can get here.
@@ -2275,7 +2277,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           Value fval = Pop();
           Value tval = Pop(0, fval.type);
           ValueType type = tval.type == kWasmBottom ? fval.type : tval.type;
-          if (type.IsSubTypeOf(kWasmAnyRef)) {
+          if (type.IsReferenceType()) {
             this->error(
                 "select without type is only valid for value type inputs");
             break;

src/wasm/graph-builder-interface.cc

@@ -795,6 +795,8 @@ class WasmGraphBuildingInterface {
 
   TFNode* DefaultValue(ValueType type) {
     switch (type.kind()) {
+      case ValueType::kI8:
+      case ValueType::kI16:
       case ValueType::kI32:
         return builder_->Int32Constant(0);
       case ValueType::kI64:

src/wasm/module-instantiate.cc

@@ -815,6 +815,8 @@ void InstanceBuilder::WriteGlobalValue(const WasmGlobal& global,
     case ValueType::kStmt:
     case ValueType::kS128:
     case ValueType::kBottom:
+    case ValueType::kI8:
+    case ValueType::kI16:
       UNREACHABLE();
   }
   TRACE(", type = %s (from WebAssembly.Global)\n", global.type.type_name());

src/wasm/value-type.h

@@ -49,6 +49,8 @@ class Simd128;
   V(F32, 2, F32, Float32, 'f', "f32")                                        \
   V(F64, 3, F64, Float64, 'd', "f64")                                        \
   V(S128, 4, S128, Simd128, 's', "s128")                                     \
+  V(I8, 1, I8, Int8, 'b', "i8")                                              \
+  V(I16, 1, I16, Int16, 'h', "i16")                                          \
   V(AnyRef, kSystemPointerSizeLog2, AnyRef, TaggedPointer, 'r', "anyref")    \
   V(FuncRef, kSystemPointerSizeLog2, FuncRef, TaggedPointer, 'a', "funcref") \
   V(NullRef, kSystemPointerSizeLog2, NullRef, TaggedPointer, 'n', "nullref") \
@@ -129,9 +131,7 @@ class ValueType {
   }
 
   constexpr bool IsReferenceType() const {
-    return kind() == kAnyRef || kind() == kFuncRef || kind() == kNullRef ||
-           kind() == kExnRef || kind() == kRef || kind() == kOptRef ||
-           kind() == kEqRef;
+    return kAnyRef <= kind() && kind() <= kEqRef;
   }
 
   // TODO(7748): Extend this with struct and function subtyping.
@@ -226,6 +226,12 @@ class ValueType {
     return kTypeName[kind()];
   }
 
+  constexpr bool IsPacked() const { return kind() == kI8 || kind() == kI16; }
+
+  constexpr ValueType Unpack() const {
+    return IsPacked() ? ValueType(kI32) : *this;
+  }
+
  private:
   using KindField = base::BitField<Kind, 0, 8>;
   using RefIndexField = base::BitField<uint32_t, 8, 24>;
@@ -255,6 +261,8 @@ constexpr ValueType kWasmExnRef = ValueType(ValueType::kExnRef);
 constexpr ValueType kWasmFuncRef = ValueType(ValueType::kFuncRef);
 constexpr ValueType kWasmNullRef = ValueType(ValueType::kNullRef);
 constexpr ValueType kWasmS128 = ValueType(ValueType::kS128);
+constexpr ValueType kWasmI8 = ValueType(ValueType::kI8);
+constexpr ValueType kWasmI16 = ValueType(ValueType::kI16);
 constexpr ValueType kWasmStmt = ValueType(ValueType::kStmt);
 constexpr ValueType kWasmBottom = ValueType(ValueType::kBottom);
 

src/wasm/wasm-constants.h

@@ -35,6 +35,8 @@ enum ValueTypeCode : uint8_t {
   kLocalI31Ref = 0x6a,  // GC proposal
   kLocalRttRef = 0x69,  // GC proposal
   kLocalExnRef = 0x68,
+  kLocalI8 = 0x7a,  // GC proposal
+  kLocalI16 = 0x79  // GC proposal
 };
 // Binary encoding of other types.
 constexpr uint8_t kWasmFunctionTypeCode = 0x60;

src/wasm/wasm-interpreter.cc

@@ -1444,6 +1444,8 @@ class ThreadImpl {
         }
         case ValueType::kStmt:
         case ValueType::kBottom:
+        case ValueType::kI8:
+        case ValueType::kI16:
           UNREACHABLE();
           break;
       }
@@ -2877,6 +2879,8 @@ class ThreadImpl {
         case ValueType::kEqRef:
           // TODO(7748): Implement these.
           UNIMPLEMENTED();
+        case ValueType::kI8:
+        case ValueType::kI16:
         case ValueType::kStmt:
         case ValueType::kBottom:
           UNREACHABLE();
@@ -2987,6 +2991,8 @@ class ThreadImpl {
         case ValueType::kEqRef:
           // TODO(7748): Implement these.
           UNIMPLEMENTED();
+        case ValueType::kI8:
+        case ValueType::kI16:
         case ValueType::kStmt:
         case ValueType::kBottom:
           UNREACHABLE();
@@ -3430,6 +3436,8 @@ class ThreadImpl {
               global_buffer->set(global_index, *ref);
               break;
             }
+            case ValueType::kI8:
+            case ValueType::kI16:
             case ValueType::kStmt:
             case ValueType::kBottom:
               UNREACHABLE();
@@ -3835,6 +3843,8 @@ class ThreadImpl {
         case ValueType::kEqRef:
           PrintF("(func|null|exn|opt|eq|)ref:unimplemented");
           break;
+        case ValueType::kI8:
+        case ValueType::kI16:
         case ValueType::kBottom:
           UNREACHABLE();
           break;

src/wasm/wasm-js.cc

@@ -1369,6 +1369,8 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
     case i::wasm::ValueType::kEqRef:
       // TODO(7748): Implement these.
       UNIMPLEMENTED();
+    case i::wasm::ValueType::kI8:
+    case i::wasm::ValueType::kI16:
     case i::wasm::ValueType::kStmt:
     case i::wasm::ValueType::kS128:
     case i::wasm::ValueType::kBottom:
@@ -1834,6 +1836,8 @@ void WebAssemblyGlobalGetValueCommon(
     case i::wasm::ValueType::kEqRef:
       // TODO(7748): Implement these.
       UNIMPLEMENTED();
+    case i::wasm::ValueType::kI8:
+    case i::wasm::ValueType::kI16:
     case i::wasm::ValueType::kBottom:
     case i::wasm::ValueType::kStmt:
     case i::wasm::ValueType::kS128:
@@ -1924,6 +1928,8 @@ void WebAssemblyGlobalSetValue(
     case i::wasm::ValueType::kEqRef:
       // TODO(7748): Implement these.
       UNIMPLEMENTED();
+    case i::wasm::ValueType::kI8:
+    case i::wasm::ValueType::kI16:
     case i::wasm::ValueType::kBottom:
     case i::wasm::ValueType::kStmt:
     case i::wasm::ValueType::kS128:

src/wasm/wasm-module-builder.cc

@@ -595,6 +595,8 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
             case ValueType::kEqRef:
               buffer->write_u8(kExprRefNull);
               break;
+            case ValueType::kI8:
+            case ValueType::kI16:
             case ValueType::kStmt:
             case ValueType::kS128:
             case ValueType::kBottom:

src/wasm/wasm-objects.cc

@@ -1738,6 +1738,8 @@ uint32_t WasmExceptionPackage::GetEncodedSize(
         break;
       case wasm::ValueType::kStmt:
       case wasm::ValueType::kBottom:
+      case wasm::ValueType::kI8:
+      case wasm::ValueType::kI16:
         UNREACHABLE();
     }
   }

test/common/wasm/wasm-module-runner.cc

@@ -112,6 +112,8 @@ bool InterpretWasmModuleForTesting(Isolate* isolate,
         arguments[i] =
             WasmValue(Handle<Object>::cast(isolate->factory()->null_value()));
         break;
+      case ValueType::kI8:
+      case ValueType::kI16:
       case ValueType::kStmt:
       case ValueType::kBottom:
       case ValueType::kS128: