[Wasm] Support packed integer class fields

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/BodyGenerator.kt

@@ -77,9 +77,22 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
     }
 
     private fun generateInstanceFieldAccess(field: IrField) {
-        body.buildStructGet(
-            context.referenceGcType(field.parentAsClass.symbol),
-            context.getStructFieldRef(field)
+        val opcode = when (field.type) {
+            irBuiltIns.charType ->
+                WasmOp.STRUCT_GET_U
+
+            irBuiltIns.booleanType,
+            irBuiltIns.byteType,
+            irBuiltIns.shortType ->
+                WasmOp.STRUCT_GET_S
+
+            else -> WasmOp.STRUCT_GET
+        }
+
+        body.buildInstr(
+            opcode,
+            WasmImmediate.GcType(context.referenceGcType(field.parentAsClass.symbol)),
+            WasmImmediate.StructFieldIdx(context.getStructFieldRef(field))
         )
     }
 

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/DeclarationGenerator.kt

@@ -194,7 +194,7 @@ class DeclarationGenerator(val context: WasmModuleCodegenContext) : IrElementVis
                 fields = declaration.allFields(irBuiltIns).map {
                     WasmStructFieldDeclaration(
                         name = it.name.toString(),
-                        type = context.transformType(it.type),
+                        type = context.transformFieldType(it.type),
                         isMutable = true
                     )
                 }

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/TypeTransformer.kt

@@ -51,6 +51,19 @@ class WasmTypeTransformer(
     fun IrType.toBoxedInlineClassType(): WasmType =
         toWasmGcRefType()
 
+    fun IrType.toWasmFieldType(): WasmType =
+        when (this) {
+            builtIns.booleanType,
+            builtIns.byteType ->
+                WasmI8
+
+            builtIns.shortType,
+            builtIns.charType ->
+                WasmI16
+
+            else -> toWasmValueType()
+        }
+
     fun IrType.toWasmValueType(): WasmType =
         when (this) {
             builtIns.booleanType,

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmBaseCodegenContext.kt

@@ -34,6 +34,8 @@ interface WasmBaseCodegenContext {
     fun referenceStringLiteral(string: String): WasmSymbol<Int>
 
     fun transformType(irType: IrType): WasmType
+    fun transformFieldType(irType: IrType): WasmType
+
     fun transformBoxedType(irType: IrType): WasmType
     fun transformValueParameterType(irValueParameter: IrValueParameter): WasmType
     fun transformResultType(irType: IrType): WasmType?

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmModuleCodegenContextImpl.kt

@@ -33,6 +33,10 @@ class WasmModuleCodegenContextImpl(
         return with(typeTransformer) { irType.toWasmValueType() }
     }
 
+    override fun transformFieldType(irType: IrType): WasmType {
+        return with(typeTransformer) { irType.toWasmFieldType() }
+    }
+
     override fun transformBoxedType(irType: IrType): WasmType {
         return with(typeTransformer) { irType.toBoxedInlineClassType() }
     }

wasm/wasm.ir/src/org/jetbrains/kotlin/wasm/ir/Types.kt

@@ -21,7 +21,7 @@ object WasmF32 : WasmType("f32", -0x3)
 object WasmF64 : WasmType("f64", -0x4)
 object WasmV128 : WasmType("v128", -0x5)
 object WasmI8 : WasmType("i8", -0x6)
-object WasmI16 : WasmType("i8", -0x7)
+object WasmI16 : WasmType("i16", -0x7)
 object WasmFuncRef : WasmType("funcref", -0x10)
 object WasmExternRef : WasmType("externref", -0x11)
 object WasmAnyRef : WasmType("anyref", -0x12)