feat: partially implement execution

45 files changed, 1562 insertions, 0 deletions

diff --git a/src/Execution/Allocator.php b/src/Execution/Allocator.php
new file mode 100644
index 0000000..ad62fc7
--- /dev/null
+++ b/src/Execution/Allocator.php
@@ -0,0 +1,162 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Modules\ExportDescs;
+use Nsfisis\Waddiwasi\Structure\Modules\Func;
+use Nsfisis\Waddiwasi\Structure\Modules\Module;
+use Nsfisis\Waddiwasi\Structure\Types\GlobalType;
+use Nsfisis\Waddiwasi\Structure\Types\MemType;
+use Nsfisis\Waddiwasi\Structure\Types\RefType;
+use Nsfisis\Waddiwasi\Structure\Types\TableType;
+
+final readonly class Allocator
+{
+    public function __construct(
+        private readonly Store $store,
+    ) {
+    }
+
+    /**
+     * @param list<ExternVal> $externVals
+     */
+    public function allocPreInitModule(
+        Module $module,
+        array $externVals,
+    ): ModuleInst {
+        $m = new ModuleInst($module->types, [], [], [], [], [], [], []);
+
+        foreach ($externVals as $externVal) {
+            if ($externVal instanceof ExternVals\Global_) {
+                $m->globalAddrs[] = $externVal->addr;
+            }
+        }
+        foreach ($module->funcs as $func) {
+            $m->funcAddrs[] = $this->allocFunc($func, $m);
+        }
+
+        return $m;
+    }
+
+    /**
+     * @param list<ExternVal> $externVals
+     * @param list<Val> $vals
+     * @param list<list<Ref>> $refsList
+     * @param list<FuncAddr> $preAllocatedFuncs
+     */
+    public function allocModule(
+        Module $module,
+        array $externVals,
+        array $vals,
+        array $refsList,
+        array $preAllocatedFuncs,
+    ): ModuleInst {
+        $m = new ModuleInst($module->types, [], [], [], [], [], [], []);
+
+        foreach ($externVals as $externVal) {
+            match ($externVal::class) {
+                ExternVals\Func::class => $m->funcAddrs[] = $externVal->addr,
+                ExternVals\Table::class => $m->tableAddrs[] = $externVal->addr,
+                ExternVals\Mem::class => $m->memAddrs[] = $externVal->addr,
+                ExternVals\Global_::class => $m->globalAddrs[] = $externVal->addr,
+                default => throw new \RuntimeException("unreachable"),
+            };
+        }
+
+        foreach ($preAllocatedFuncs as $funcAddr) {
+            $m->funcAddrs[] = $funcAddr;
+            $funcInst = $this->store->funcs[$funcAddr->value];
+            assert($funcInst instanceof FuncInsts\Wasm);
+            // @phpstan-ignore-next-line
+            $this->store->funcs[$funcAddr->value] = FuncInst::Wasm(
+                $funcInst->type,
+                $m,
+                $funcInst->code,
+            );
+        }
+        foreach ($module->tables as $table) {
+            $m->tableAddrs[] = $this->allocTable($table->type, Ref::RefNull($table->type->refType));
+        }
+        foreach ($module->mems as $mem) {
+            $m->memAddrs[] = $this->allocMem($mem->type);
+        }
+        foreach ($module->datas as $data) {
+            $m->dataAddrs[] = $this->allocData($data->init);
+        }
+
+        foreach ($module->globals as $i => $global) {
+            $m->globalAddrs[] = $this->allocGlobal($global->type, $vals[$i]);
+        }
+        foreach ($module->elems as $i => $elem) {
+            $m->elemAddrs[] = $this->allocElem($elem->type, $refsList[$i]);
+        }
+
+        foreach ($module->exports as $export) {
+            $value = match ($export->desc::class) {
+                ExportDescs\Func::class => ExternVal::Func($m->funcAddrs[$export->desc->func->value]),
+                ExportDescs\Table::class => ExternVal::Table($m->tableAddrs[$export->desc->table->value]),
+                ExportDescs\Mem::class => ExternVal::Mem($m->memAddrs[$export->desc->mem->value]),
+                ExportDescs\Global_::class => ExternVal::Global_($m->globalAddrs[$export->desc->global->value]),
+                default => throw new \RuntimeException("unreachable"),
+            };
+            $m->exports[] = new ExportInst($export->name, $value);
+        }
+
+        return $m;
+    }
+
+    private function allocFunc(Func $func, ModuleInst $moduleInst): FuncAddr
+    {
+        $funcType = $moduleInst->types[$func->type->value];
+        $funcInst = FuncInst::Wasm($funcType, $moduleInst, $func);
+        $this->store->funcs[] = $funcInst;
+        return new FuncAddr(count($this->store->funcs) - 1);
+    }
+
+    private function allocTable(TableType $tableType, Ref $ref): TableAddr
+    {
+        $minSize = $tableType->limits->min;
+        $elem = array_fill(0, $minSize, $ref);
+        $tableInst = new TableInst($tableType, $elem);
+        $this->store->tables[] = $tableInst;
+        return new TableAddr(count($this->store->tables) - 1);
+    }
+
+    private function allocMem(MemType $memType): MemAddr
+    {
+        $minSize = $memType->limits->min;
+        $data = array_fill(0, $minSize * 64 * 1024, 0);
+        $memInst = new MemInst($memType, $data);
+        $this->store->mems[] = $memInst;
+        return new MemAddr(count($this->store->mems) - 1);
+    }
+
+    private function allocGlobal(GlobalType $globalType, Val $val): GlobalAddr
+    {
+        $globalInst = new GlobalInst($globalType, $val);
+        $this->store->globals[] = $globalInst;
+        return new GlobalAddr(count($this->store->globals) - 1);
+    }
+
+    /**
+     * @param list<Ref> $elem
+     */
+    private function allocElem(RefType $refType, array $elem): ElemAddr
+    {
+        $elemInst = new ElemInst($refType, $elem);
+        $this->store->elems[] = $elemInst;
+        return new ElemAddr(count($this->store->elems) - 1);
+    }
+
+    /**
+     * @param list<Byte> $data
+     */
+    private function allocData(array $data): DataAddr
+    {
+        $dataInst = new DataInst($data);
+        $this->store->datas[] = $dataInst;
+        return new DataAddr(count($this->store->datas) - 1);
+    }
+}
diff --git a/src/Execution/DataAddr.php b/src/Execution/DataAddr.php
new file mode 100644
index 0000000..b3c4516
--- /dev/null
+++ b/src/Execution/DataAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class DataAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/DataInst.php b/src/Execution/DataInst.php
new file mode 100644
index 0000000..0db1da5
--- /dev/null
+++ b/src/Execution/DataInst.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class DataInst
+{
+    /**
+     * @param list<Byte> $data
+     */
+    public function __construct(
+        public array $data,
+    ) {
+    }
+}
diff --git a/src/Execution/ElemAddr.php b/src/Execution/ElemAddr.php
new file mode 100644
index 0000000..e46b54f
--- /dev/null
+++ b/src/Execution/ElemAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class ElemAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/ElemInst.php b/src/Execution/ElemInst.php
new file mode 100644
index 0000000..24e655c
--- /dev/null
+++ b/src/Execution/ElemInst.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\RefType;
+
+final readonly class ElemInst
+{
+    /**
+     * @param list<Ref> $elem
+     */
+    public function __construct(
+        public RefType $type,
+        public array $elem,
+    ) {
+    }
+}
diff --git a/src/Execution/ExportInst.php b/src/Execution/ExportInst.php
new file mode 100644
index 0000000..e4521b4
--- /dev/null
+++ b/src/Execution/ExportInst.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class ExportInst
+{
+    /**
+     * @param Name $name
+     */
+    public function __construct(
+        public string $name,
+        public ExternVal $value,
+    ) {
+    }
+}
diff --git a/src/Execution/ExternAddr.php b/src/Execution/ExternAddr.php
new file mode 100644
index 0000000..954127c
--- /dev/null
+++ b/src/Execution/ExternAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class ExternAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/ExternVal.php b/src/Execution/ExternVal.php
new file mode 100644
index 0000000..f095225
--- /dev/null
+++ b/src/Execution/ExternVal.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+abstract readonly class ExternVal
+{
+    final public static function Func(FuncAddr $addr): ExternVals\Func
+    {
+        return new ExternVals\Func($addr);
+    }
+
+    final public static function Table(TableAddr $addr): ExternVals\Table
+    {
+        return new ExternVals\Table($addr);
+    }
+
+    final public static function Mem(MemAddr $addr): ExternVals\Mem
+    {
+        return new ExternVals\Mem($addr);
+    }
+
+    final public static function Global_(GlobalAddr $addr): ExternVals\Global_
+    {
+        return new ExternVals\Global_($addr);
+    }
+}
diff --git a/src/Execution/ExternVals/Func.php b/src/Execution/ExternVals/Func.php
new file mode 100644
index 0000000..314d44d
--- /dev/null
+++ b/src/Execution/ExternVals/Func.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\ExternVals;
+
+use Nsfisis\Waddiwasi\Execution\ExternVal;
+use Nsfisis\Waddiwasi\Execution\FuncAddr;
+
+final readonly class Func extends ExternVal
+{
+    protected function __construct(
+        public FuncAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/ExternVals/Global_.php b/src/Execution/ExternVals/Global_.php
new file mode 100644
index 0000000..ae38c78
--- /dev/null
+++ b/src/Execution/ExternVals/Global_.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\ExternVals;
+
+use Nsfisis\Waddiwasi\Execution\ExternVal;
+use Nsfisis\Waddiwasi\Execution\GlobalAddr;
+
+final readonly class Global_ extends ExternVal
+{
+    protected function __construct(
+        public GlobalAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/ExternVals/Mem.php b/src/Execution/ExternVals/Mem.php
new file mode 100644
index 0000000..7bded5a
--- /dev/null
+++ b/src/Execution/ExternVals/Mem.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\ExternVals;
+
+use Nsfisis\Waddiwasi\Execution\ExternVal;
+use Nsfisis\Waddiwasi\Execution\MemAddr;
+
+final readonly class Mem extends ExternVal
+{
+    protected function __construct(
+        public MemAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/ExternVals/Table.php b/src/Execution/ExternVals/Table.php
new file mode 100644
index 0000000..cd36bb2
--- /dev/null
+++ b/src/Execution/ExternVals/Table.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\ExternVals;
+
+use Nsfisis\Waddiwasi\Execution\ExternVal;
+use Nsfisis\Waddiwasi\Execution\TableAddr;
+
+final readonly class Table extends ExternVal
+{
+    protected function __construct(
+        public TableAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/FuncAddr.php b/src/Execution/FuncAddr.php
new file mode 100644
index 0000000..101c7c9
--- /dev/null
+++ b/src/Execution/FuncAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class FuncAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/FuncInst.php b/src/Execution/FuncInst.php
new file mode 100644
index 0000000..c69eb80
--- /dev/null
+++ b/src/Execution/FuncInst.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Modules\Func;
+use Nsfisis\Waddiwasi\Structure\Types\FuncType;
+
+abstract readonly class FuncInst
+{
+    final public static function Wasm(FuncType $type, ModuleInst $module, Func $code): FuncInsts\Wasm
+    {
+        return new FuncInsts\Wasm($type, $module, $code);
+    }
+
+    final public static function Host(FuncType $type, callable $code): FuncInsts\Host
+    {
+        return new FuncInsts\Host($type, $code);
+    }
+}
diff --git a/src/Execution/FuncInsts/Host.php b/src/Execution/FuncInsts/Host.php
new file mode 100644
index 0000000..e3cba4a
--- /dev/null
+++ b/src/Execution/FuncInsts/Host.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\FuncInsts;
+
+use Nsfisis\Waddiwasi\Execution\FuncInst;
+use Nsfisis\Waddiwasi\Structure\Types\FuncType;
+
+final readonly class Host extends FuncInst
+{
+    /**
+     * @param callable $code
+     */
+    public function __construct(
+        public FuncType $type,
+        public mixed $code,
+    ) {
+    }
+}
diff --git a/src/Execution/FuncInsts/Wasm.php b/src/Execution/FuncInsts/Wasm.php
new file mode 100644
index 0000000..88eea61
--- /dev/null
+++ b/src/Execution/FuncInsts/Wasm.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\FuncInsts;
+
+use Nsfisis\Waddiwasi\Execution\FuncInst;
+use Nsfisis\Waddiwasi\Execution\ModuleInst;
+use Nsfisis\Waddiwasi\Structure\Modules\Func;
+use Nsfisis\Waddiwasi\Structure\Types\FuncType;
+
+final readonly class Wasm extends FuncInst
+{
+    public function __construct(
+        public FuncType $type,
+        public ModuleInst $module,
+        public Func $code,
+    ) {
+    }
+}
diff --git a/src/Execution/GlobalAddr.php b/src/Execution/GlobalAddr.php
new file mode 100644
index 0000000..f9a08ff
--- /dev/null
+++ b/src/Execution/GlobalAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class GlobalAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/GlobalInst.php b/src/Execution/GlobalInst.php
new file mode 100644
index 0000000..47bd9a0
--- /dev/null
+++ b/src/Execution/GlobalInst.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\GlobalType;
+
+final readonly class GlobalInst
+{
+    public function __construct(
+        public GlobalType $type,
+        public Val $value,
+    ) {
+    }
+}
diff --git a/src/Execution/MemAddr.php b/src/Execution/MemAddr.php
new file mode 100644
index 0000000..5c141cc
--- /dev/null
+++ b/src/Execution/MemAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class MemAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/MemInst.php b/src/Execution/MemInst.php
new file mode 100644
index 0000000..3999052
--- /dev/null
+++ b/src/Execution/MemInst.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\MemType;
+
+final readonly class MemInst
+{
+    /**
+     * @param list<Byte> $data
+     */
+    public function __construct(
+        public MemType $type,
+        public array $data,
+    ) {
+    }
+}
diff --git a/src/Execution/ModuleInst.php b/src/Execution/ModuleInst.php
new file mode 100644
index 0000000..2cd7f08
--- /dev/null
+++ b/src/Execution/ModuleInst.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\FuncType;
+
+final class ModuleInst
+{
+    /**
+     * @param list<FuncType> $types
+     * @param list<FuncAddr> $funcAddrs
+     * @param list<TableAddr> $tableAddrs
+     * @param list<MemAddr> $memAddrs
+     * @param list<GlobalAddr> $globalAddrs
+     * @param list<ElemAddr> $elemAddrs
+     * @param list<DataAddr> $dataAddrs
+     * @param list<ExportInst> $exports
+     */
+    public function __construct(
+        public array $types,
+        public array $funcAddrs,
+        public array $tableAddrs,
+        public array $memAddrs,
+        public array $globalAddrs,
+        public array $elemAddrs,
+        public array $dataAddrs,
+        public array $exports,
+    ) {
+    }
+}
diff --git a/src/Execution/Num.php b/src/Execution/Num.php
new file mode 100644
index 0000000..03fec4f
--- /dev/null
+++ b/src/Execution/Num.php
@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+abstract readonly class Num
+{
+    /**
+     * @param S32 $value
+     */
+    final public static function I32(int $value): Nums\I32
+    {
+        return new Nums\I32($value);
+    }
+
+    /**
+     * @param S64 $value
+     */
+    final public static function I64(int $value): Nums\I64
+    {
+        return new Nums\I64($value);
+    }
+
+    /**
+     * @param F32 $value
+     */
+    final public static function F32(float $value): Nums\F32_
+    {
+        return new Nums\F32_($value);
+    }
+
+    /**
+     * @param F64 $value
+     */
+    final public static function F64(float $value): Nums\F64_
+    {
+        return new Nums\F64_($value);
+    }
+}
diff --git a/src/Execution/Nums/F32_.php b/src/Execution/Nums/F32_.php
new file mode 100644
index 0000000..5c7b749
--- /dev/null
+++ b/src/Execution/Nums/F32_.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Nums;
+
+use Nsfisis\Waddiwasi\Execution\Num;
+
+final readonly class F32_ extends Num
+{
+    /**
+     * @param F32 $value
+     */
+    public function __construct(
+        public float $value,
+    ) {
+    }
+}
diff --git a/src/Execution/Nums/F64_.php b/src/Execution/Nums/F64_.php
new file mode 100644
index 0000000..c24709e
--- /dev/null
+++ b/src/Execution/Nums/F64_.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Nums;
+
+use Nsfisis\Waddiwasi\Execution\Num;
+
+final readonly class F64_ extends Num
+{
+    /**
+     * @param F64 $value
+     */
+    public function __construct(
+        public float $value,
+    ) {
+    }
+}
diff --git a/src/Execution/Nums/I32.php b/src/Execution/Nums/I32.php
new file mode 100644
index 0000000..fbc6fab
--- /dev/null
+++ b/src/Execution/Nums/I32.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Nums;
+
+use Nsfisis\Waddiwasi\Execution\Num;
+
+final readonly class I32 extends Num
+{
+    /**
+     * @param S32 $value
+     */
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/Nums/I64.php b/src/Execution/Nums/I64.php
new file mode 100644
index 0000000..889b863
--- /dev/null
+++ b/src/Execution/Nums/I64.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Nums;
+
+use Nsfisis\Waddiwasi\Execution\Num;
+
+final readonly class I64 extends Num
+{
+    /**
+     * @param S64 $value
+     */
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/Ref.php b/src/Execution/Ref.php
new file mode 100644
index 0000000..4f0c3c1
--- /dev/null
+++ b/src/Execution/Ref.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\RefType;
+
+abstract readonly class Ref
+{
+    final public static function RefNull(RefType $type): Refs\RefNull
+    {
+        return new Refs\RefNull($type);
+    }
+
+    final public static function RefFunc(FuncAddr $addr): Refs\RefFunc
+    {
+        return new Refs\RefFunc($addr);
+    }
+
+    final public static function RefExtern(ExternAddr $addr): Refs\RefExtern
+    {
+        return new Refs\RefExtern($addr);
+    }
+}
diff --git a/src/Execution/Refs/RefExtern.php b/src/Execution/Refs/RefExtern.php
new file mode 100644
index 0000000..4beccb4
--- /dev/null
+++ b/src/Execution/Refs/RefExtern.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Refs;
+
+use Nsfisis\Waddiwasi\Execution\ExternAddr;
+use Nsfisis\Waddiwasi\Execution\Ref;
+
+final readonly class RefExtern extends Ref
+{
+    public function __construct(
+        public ExternAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/Refs/RefFunc.php b/src/Execution/Refs/RefFunc.php
new file mode 100644
index 0000000..449b780
--- /dev/null
+++ b/src/Execution/Refs/RefFunc.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Refs;
+
+use Nsfisis\Waddiwasi\Execution\FuncAddr;
+use Nsfisis\Waddiwasi\Execution\Ref;
+
+final readonly class RefFunc extends Ref
+{
+    public function __construct(
+        public FuncAddr $addr,
+    ) {
+    }
+}
diff --git a/src/Execution/Refs/RefNull.php b/src/Execution/Refs/RefNull.php
new file mode 100644
index 0000000..b4323d7
--- /dev/null
+++ b/src/Execution/Refs/RefNull.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Refs;
+
+use Nsfisis\Waddiwasi\Execution\Ref;
+use Nsfisis\Waddiwasi\Structure\Types\RefType;
+
+final readonly class RefNull extends Ref
+{
+    public function __construct(
+        public RefType $type,
+    ) {
+    }
+}
diff --git a/src/Execution/Result.php b/src/Execution/Result.php
new file mode 100644
index 0000000..e07752c
--- /dev/null
+++ b/src/Execution/Result.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+abstract readonly class Result
+{
+    /**
+     * @param list<Val> $values
+     */
+    final public static function Values(array $values): Results\Values
+    {
+        return new Results\Values($values);
+    }
+
+    final public static function Trap(): Results\Trap
+    {
+        return new Results\Trap();
+    }
+}
diff --git a/src/Execution/Results/Trap.php b/src/Execution/Results/Trap.php
new file mode 100644
index 0000000..eb676b2
--- /dev/null
+++ b/src/Execution/Results/Trap.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Results;
+
+use Nsfisis\Waddiwasi\Execution\Result;
+
+final readonly class Trap extends Result
+{
+}
diff --git a/src/Execution/Results/Values.php b/src/Execution/Results/Values.php
new file mode 100644
index 0000000..c3a9e36
--- /dev/null
+++ b/src/Execution/Results/Values.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Results;
+
+use Nsfisis\Waddiwasi\Execution\Result;
+use Nsfisis\Waddiwasi\Execution\Val;
+
+final readonly class Values extends Result
+{
+    /**
+     * @param list<Val> $values
+     */
+    protected function __construct(
+        public array $values,
+    ) {
+    }
+}
diff --git a/src/Execution/Runtime.php b/src/Execution/Runtime.php
new file mode 100644
index 0000000..030c46e
--- /dev/null
+++ b/src/Execution/Runtime.php
@@ -0,0 +1,561 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Instructions\Instr;
+use Nsfisis\Waddiwasi\Structure\Instructions\Instrs;
+use Nsfisis\Waddiwasi\Structure\Modules\DataModes;
+use Nsfisis\Waddiwasi\Structure\Modules\ElemModes;
+use Nsfisis\Waddiwasi\Structure\Modules\Module;
+use Nsfisis\Waddiwasi\Structure\Types\DataIdx;
+use Nsfisis\Waddiwasi\Structure\Types\ElemIdx;
+
+// @todo split this class into multiple classes
+final readonly class Runtime
+{
+    private function __construct(
+        private readonly Store $store,
+        private readonly Stack $stack,
+        private readonly ModuleInst $module,
+    ) {
+    }
+
+    /**
+     * @param list<ExternVal> $externVals
+     */
+    public static function instantiate(
+        Store $store,
+        Module $module,
+        array $externVals,
+    ): self {
+        $allocator = new Allocator($store);
+
+        $moduleInstInit = $allocator->allocPreInitModule($module, $externVals);
+
+        $stack = new Stack([]);
+        $frameInit = StackEntry::Frame(0, [], $moduleInstInit);
+        $stack->push($frameInit);
+
+        $runtimeInit = new self($store, $stack, $moduleInstInit);
+
+        $vals = [];
+        foreach ($module->globals as $global) {
+            $instrs = $global->init->instrs;
+            array_pop($instrs); // drop "end"
+            $vals[] = $runtimeInit->evalInstrs($instrs);
+            assert($stack->top() === $frameInit);
+        }
+
+        $refsList = [];
+        foreach ($module->elems as $elem) {
+            $refs = [];
+            foreach ($elem->init as $expr) {
+                $instrs = $expr->instrs;
+                array_pop($instrs); // drop "end"
+                $result = $runtimeInit->evalInstrs($instrs);
+                assert($result instanceof Vals\Ref);
+                $refs[] = $result->inner;
+            }
+            $refsList[] = $refs;
+        }
+
+        assert($stack->top() === $frameInit);
+        $stack->pop();
+
+        $moduleInst = $allocator->allocModule(
+            $module,
+            $externVals,
+            $vals,
+            $refsList,
+            $moduleInstInit->funcAddrs,
+        );
+
+        $runtime = new self($store, $stack, $moduleInst);
+
+        $frame = StackEntry::Frame(0, [], $moduleInst);
+        $stack->push($frame);
+
+        foreach ($module->elems as $i => $elem) {
+            if ($elem->mode instanceof ElemModes\Active) {
+                $n = count($elem->init);
+                $instrs = $elem->mode->offset->instrs;
+                array_pop($instrs); // drop "end"
+                $instrs[] = Instr::I32Const(0);
+                $instrs[] = Instr::I32Const($n);
+                $instrs[] = Instr::TableInit($elem->mode->table, new ElemIdx($i));
+                $instrs[] = Instr::ElemDrop(new ElemIdx($i));
+                $runtime->execInstrs($instrs);
+            } elseif ($elem->mode instanceof ElemModes\Declarative) {
+                $runtime->execInstrs([Instr::ElemDrop(new ElemIdx($i))]);
+            }
+        }
+        foreach ($module->datas as $i => $data) {
+            if ($data->mode instanceof DataModes\Active) {
+                assert($data->mode->memory->value === 0);
+                $n = count($data->init);
+                $instrs = $data->mode->offset->instrs;
+                array_pop($instrs); // drop "end"
+                $instrs[] = Instr::I32Const(0);
+                $instrs[] = Instr::I32Const($n);
+                $instrs[] = Instr::MemoryInit(new DataIdx($i));
+                $instrs[] = Instr::DataDrop(new DataIdx($i));
+                $runtime->execInstrs($instrs);
+            }
+        }
+
+        if ($module->start !== null) {
+            $runtime->execInstrs([Instr::Call($module->start->func)]);
+        }
+
+        assert($stack->top() === $frame);
+        $stack->pop();
+
+        return new self($store, $stack, $moduleInst);
+    }
+
+    public function invoke(): void
+    {
+    }
+
+    /**
+     * @param list<Instr> $instrs
+     */
+    private function execInstrs(array $instrs): void
+    {
+        foreach ($instrs as $i) {
+            $this->interpret($i);
+        }
+    }
+
+    /**
+     * @param list<Instr> $instrs
+     */
+    private function evalInstrs(array $instrs): Val
+    {
+        $this->execInstrs($instrs);
+        $result = $this->stack->pop();
+        assert($result instanceof StackEntries\Value);
+        return $result->inner;
+    }
+
+    private function interpret(Instr $instr): void
+    {
+        if ($instr instanceof Instrs\Numeric\F32Abs) {
+            $v = $this->stack->pop();
+            assert($v instanceof StackEntries\Value);
+            assert($v->inner instanceof Vals\Num);
+            assert($v->inner->inner instanceof Nums\F32_);
+            $this->stack->push(StackEntry::Value(Val::Num(Num::F32($v->inner->inner))));
+        } elseif ($instr instanceof Instrs\Numeric\F32Add) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Ceil) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Const) {
+            $this->stack->push(StackEntry::Value(Val::Num(Num::F32($instr->value))));
+        } elseif ($instr instanceof Instrs\Numeric\F32ConvertI32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32ConvertI32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32ConvertI64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32ConvertI64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32CopySign) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32DemoteF64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Div) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Eq) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Floor) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Ge) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Gt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Le) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Lt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Max) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Min) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Mul) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Ne) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Nearest) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Neg) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32ReinterpretI32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32ReinterpretI64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Sqrt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Sub) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F32Trunc) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Abs) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Add) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Ceil) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Const) {
+            $this->stack->push(StackEntry::Value(Val::Num(Num::F64($instr->value))));
+        } elseif ($instr instanceof Instrs\Numeric\F64ConvertI32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64ConvertI32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64ConvertI64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64ConvertI64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64CopySign) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Div) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Eq) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Floor) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Ge) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Gt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Le) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Lt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Max) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Min) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Mul) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Ne) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Nearest) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Neg) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64PromoteF32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64ReinterpretI32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64ReinterpretI64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Sqrt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Sub) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\F64Trunc) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Add) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32And) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Clz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Const) {
+            $this->stack->push(StackEntry::Value(Val::Num(Num::I32($instr->value))));
+        } elseif ($instr instanceof Instrs\Numeric\I32Ctz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32DivS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32DivU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Eq) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Eqz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Extend16S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Extend8S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32GeS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32GeU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32GtS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32GtU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32LeS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32LeU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32LtS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32LtU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Mul) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Ne) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Or) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Popcnt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32ReinterpretF32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32ReinterpretF64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32RemS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32RemU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32RotL) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32RotR) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Shl) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32ShrS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32ShrU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Sub) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncF32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncF32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncF64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncF64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncSatF32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncSatF32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncSatF64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32TruncSatF64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32WrapI64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I32Xor) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Add) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64And) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Clz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Const) {
+            $this->stack->push(StackEntry::Value(Val::Num(Num::I64($instr->value))));
+        } elseif ($instr instanceof Instrs\Numeric\I64Ctz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64DivS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64DivU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Eq) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Eqz) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Extend16S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Extend32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Extend8S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ExtendI32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ExtendI32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64GeS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64GeU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64GtS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64GtU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64LeS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64LeU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64LtS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64LtU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Mul) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Ne) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Or) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Popcnt) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ReinterpretF32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ReinterpretF64) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64RemS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64RemU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64RotL) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64RotR) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Shl) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ShrS) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64ShrU) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Sub) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncF32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncF32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncF64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncF64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncSatF32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncSatF32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncSatF64S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64TruncSatF64U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Numeric\I64Xor) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Reference\RefFunc) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Reference\RefIsNull) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Reference\RefNull) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Parametric\Drop) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Parametric\Select) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Variable\GlobalGet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Variable\GlobalSet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Variable\LocalGet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Variable\LocalSet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Variable\LocalTee) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\ElemDrop) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableCopy) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableFill) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableGet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableGrow) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableInit) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableSet) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Table\TableSize) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\DataDrop) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\F32Load) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\F32Store) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\F64Load) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\F64Store) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Load) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Load16S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Load16U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Load8S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Load8U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Store) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Store16) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I32Store8) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load16S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load16U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load32S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load32U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load8S) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Load8U) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Store) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Store16) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Store32) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\I64Store8) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\MemoryCopy) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\MemoryFill) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\MemoryGrow) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\MemoryInit) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Memory\MemorySize) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Block) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Br) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\BrIf) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\BrTable) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Call) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\CallIndirect) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Else_) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\End) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\If_) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Loop) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Nop) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Return_) {
+            assert(false, "not implemented " . $instr::class);
+        } elseif ($instr instanceof Instrs\Control\Unreachable) {
+            assert(false, "not implemented " . $instr::class);
+        } else {
+            assert(false);
+        }
+    }
+}
diff --git a/src/Execution/Stack.php b/src/Execution/Stack.php
new file mode 100644
index 0000000..1fa2dae
--- /dev/null
+++ b/src/Execution/Stack.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final class Stack
+{
+    /**
+     * @param list<StackEntry> $entries
+     */
+    public function __construct(
+        private array $entries,
+    ) {
+    }
+
+    public function push(StackEntry $entry): void
+    {
+        $this->entries[] = $entry;
+    }
+
+    public function pop(): ?StackEntry
+    {
+        return array_pop($this->entries);
+    }
+
+    public function top(): ?StackEntry
+    {
+        $n = array_key_last($this->entries);
+        return $n === null ? null : $this->entries[$n];
+    }
+
+    public function count(): int
+    {
+        return count($this->entries);
+    }
+
+    public function isEmpty(): bool
+    {
+        return $this->count() === 0;
+    }
+}
diff --git a/src/Execution/StackEntries/Frame.php b/src/Execution/StackEntries/Frame.php
new file mode 100644
index 0000000..f8bd68e
--- /dev/null
+++ b/src/Execution/StackEntries/Frame.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\StackEntries;
+
+use Nsfisis\Waddiwasi\Execution\ModuleInst;
+use Nsfisis\Waddiwasi\Execution\StackEntry;
+use Nsfisis\Waddiwasi\Execution\Val;
+
+final readonly class Frame extends StackEntry
+{
+    /**
+     * @param int<0, max> $arity
+     * @param list<Val> $locals
+     */
+    public function __construct(
+        public int $arity,
+        public array $locals,
+        public ModuleInst $module,
+    ) {
+    }
+}
diff --git a/src/Execution/StackEntries/Label.php b/src/Execution/StackEntries/Label.php
new file mode 100644
index 0000000..b83fb0f
--- /dev/null
+++ b/src/Execution/StackEntries/Label.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\StackEntries;
+
+use Nsfisis\Waddiwasi\Execution\StackEntry;
+use Nsfisis\Waddiwasi\Structure\Instructions\Instr;
+
+final readonly class Label extends StackEntry
+{
+    /**
+     * @param int<0, max> $arity
+     * @param list<Instr> $target
+     */
+    public function __construct(
+        public int $arity,
+        public array $target,
+    ) {
+    }
+}
diff --git a/src/Execution/StackEntries/Value.php b/src/Execution/StackEntries/Value.php
new file mode 100644
index 0000000..1cd1146
--- /dev/null
+++ b/src/Execution/StackEntries/Value.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\StackEntries;
+
+use Nsfisis\Waddiwasi\Execution\StackEntry;
+use Nsfisis\Waddiwasi\Execution\Val;
+
+final readonly class Value extends StackEntry
+{
+    public function __construct(
+        public Val $inner,
+    ) {
+    }
+}
diff --git a/src/Execution/StackEntry.php b/src/Execution/StackEntry.php
new file mode 100644
index 0000000..8a9d7dd
--- /dev/null
+++ b/src/Execution/StackEntry.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Instructions\Instr;
+
+abstract readonly class StackEntry
+{
+    final public static function Value(Val $inner): StackEntries\Value
+    {
+        return new StackEntries\Value($inner);
+    }
+
+    /**
+     * @param int<0, max> $arity
+     * @param list<Instr> $target
+     */
+    final public static function Label(
+        int $arity,
+        array $target,
+    ): StackEntries\Label {
+        return new StackEntries\Label($arity, $target);
+    }
+
+    /**
+     * @param int<0, max> $arity
+     * @param list<Val> $locals
+     */
+    final public static function Frame(
+        int $arity,
+        array $locals,
+        ModuleInst $module,
+    ): StackEntries\Frame {
+        return new StackEntries\Frame($arity, $locals, $module);
+    }
+}
diff --git a/src/Execution/Store.php b/src/Execution/Store.php
new file mode 100644
index 0000000..b7b0dfc
--- /dev/null
+++ b/src/Execution/Store.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final class Store
+{
+    /**
+     * @param list<FuncInst> $funcs
+     * @param list<TableInst> $tables
+     * @param list<MemInst> $mems
+     * @param list<GlobalInst> $globals
+     * @param list<ElemInst> $elems
+     * @param list<DataInst> $datas
+     */
+    public function __construct(
+        public array $funcs,
+        public array $tables,
+        public array $mems,
+        public array $globals,
+        public array $elems,
+        public array $datas,
+    ) {
+    }
+
+    public static function empty(): self
+    {
+        return new self([], [], [], [], [], []);
+    }
+}
diff --git a/src/Execution/TableAddr.php b/src/Execution/TableAddr.php
new file mode 100644
index 0000000..e41eef1
--- /dev/null
+++ b/src/Execution/TableAddr.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+final readonly class TableAddr
+{
+    public function __construct(
+        public int $value,
+    ) {
+    }
+}
diff --git a/src/Execution/TableInst.php b/src/Execution/TableInst.php
new file mode 100644
index 0000000..5a6766d
--- /dev/null
+++ b/src/Execution/TableInst.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+use Nsfisis\Waddiwasi\Structure\Types\TableType;
+
+final readonly class TableInst
+{
+    /**
+     * @param list<Ref> $elem
+     */
+    public function __construct(
+        public TableType $type,
+        public array $elem,
+    ) {
+    }
+}
diff --git a/src/Execution/Val.php b/src/Execution/Val.php
new file mode 100644
index 0000000..287f441
--- /dev/null
+++ b/src/Execution/Val.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution;
+
+abstract readonly class Val
+{
+    final public static function Num(Num $inner): Vals\Num
+    {
+        return new Vals\Num($inner);
+    }
+
+    final public static function Ref(Ref $inner): Vals\Ref
+    {
+        return new Vals\Ref($inner);
+    }
+}
diff --git a/src/Execution/Vals/Num.php b/src/Execution/Vals/Num.php
new file mode 100644
index 0000000..15b4433
--- /dev/null
+++ b/src/Execution/Vals/Num.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Vals;
+
+use Nsfisis\Waddiwasi\Execution\Num as OrigNum;
+use Nsfisis\Waddiwasi\Execution\Val;
+
+final readonly class Num extends Val
+{
+    public function __construct(
+        public OrigNum $inner,
+    ) {
+    }
+}
diff --git a/src/Execution/Vals/Ref.php b/src/Execution/Vals/Ref.php
new file mode 100644
index 0000000..8ea8a94
--- /dev/null
+++ b/src/Execution/Vals/Ref.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nsfisis\Waddiwasi\Execution\Vals;
+
+use Nsfisis\Waddiwasi\Execution\Ref as OrigRef;
+use Nsfisis\Waddiwasi\Execution\Val;
+
+final readonly class Ref extends Val
+{
+    public function __construct(
+        public OrigRef $inner,
+    ) {
+    }
+}