chore: restructure runtime

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>

28 files changed, 396 insertions, 793 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index da8359c..54725cf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,7 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improved support for WebAssembly 2.0 features
 - Simplify and optimize the interpreter loop
 - Use a seperate stack and locals for 32, 64 and 128 bit values and references (#21)
-- Updated to latest wasmparser version
+- Updated to latest `wasmparser` version
 
 ## [0.7.0] - 2024-05-15
 
diff --git a/crates/parser/src/conversion.rs b/crates/parser/src/conversion.rs
index 1d550f3..214487f 100644
--- a/crates/parser/src/conversion.rs
+++ b/crates/parser/src/conversion.rs
@@ -225,14 +225,6 @@ pub(crate) fn convert_module_type(ty: wasmparser::RecGroup) -> Result<FuncType>
     Ok(FuncType { params, results })
 }
 
-pub(crate) fn convert_blocktype(blocktype: wasmparser::BlockType) -> BlockArgs {
-    match blocktype {
-        wasmparser::BlockType::Empty => BlockArgs::Empty,
-        wasmparser::BlockType::Type(ty) => BlockArgs::Type(convert_valtype(&ty)),
-        wasmparser::BlockType::FuncType(ty) => BlockArgs::FuncType(ty),
-    }
-}
-
 pub(crate) fn convert_reftype(reftype: &wasmparser::RefType) -> ValType {
     match reftype {
         _ if reftype.is_func_ref() => ValType::RefFunc,
diff --git a/crates/parser/src/visit.rs b/crates/parser/src/visit.rs
index 1db00ad..e9844aa 100644
--- a/crates/parser/src/visit.rs
+++ b/crates/parser/src/visit.rs
@@ -1,6 +1,6 @@
-use crate::{conversion::convert_blocktype, Result};
+use crate::Result;
 
-use crate::conversion::convert_heaptype;
+use crate::conversion::{convert_heaptype, convert_valtype};
 use alloc::string::ToString;
 use alloc::{boxed::Box, vec::Vec};
 use tinywasm_types::{Instruction, MemoryArg};
@@ -357,7 +357,13 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
     }
 
     fn visit_local_get(&mut self, idx: u32) -> Self::Output {
-        let resolved_idx = self.local_addr_map[idx as usize];
+        let Ok(resolved_idx) = self.local_addr_map[idx as usize].try_into() else {
+            self.errors.push(crate::ParseError::UnsupportedOperator(
+                "Local index is too large, tinywasm does not support local indexes that large".to_string(),
+            ));
+            return;
+        };
+
         match self.validator.get_local_type(idx) {
             Some(t) => self.instructions.push(match t {
                 wasmparser::ValType::I32 => Instruction::LocalGet32(resolved_idx),
@@ -372,7 +378,13 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
     }
 
     fn visit_local_set(&mut self, idx: u32) -> Self::Output {
-        let resolved_idx = self.local_addr_map[idx as usize];
+        let Ok(resolved_idx) = self.local_addr_map[idx as usize].try_into() else {
+            self.errors.push(crate::ParseError::UnsupportedOperator(
+                "Local index is too large, tinywasm does not support local indexes that large".to_string(),
+            ));
+            return;
+        };
+
         match self.validator.get_operand_type(0) {
             Some(Some(t)) => self.instructions.push(match t {
                 wasmparser::ValType::I32 => Instruction::LocalSet32(resolved_idx),
@@ -387,7 +399,13 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
     }
 
     fn visit_local_tee(&mut self, idx: u32) -> Self::Output {
-        let resolved_idx = self.local_addr_map[idx as usize];
+        let Ok(resolved_idx) = self.local_addr_map[idx as usize].try_into() else {
+            self.errors.push(crate::ParseError::UnsupportedOperator(
+                "Local index is too large, tinywasm does not support local indexes that large".to_string(),
+            ));
+            return;
+        };
+
         match self.validator.get_operand_type(0) {
             Some(Some(t)) => self.instructions.push(match t {
                 wasmparser::ValType::I32 => Instruction::LocalTee32(resolved_idx),
@@ -411,17 +429,29 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
 
     fn visit_block(&mut self, blockty: wasmparser::BlockType) -> Self::Output {
         self.label_ptrs.push(self.instructions.len());
-        self.instructions.push(Instruction::Block(convert_blocktype(blockty), 0))
+        self.instructions.push(match blockty {
+            wasmparser::BlockType::Empty => Instruction::Block(0),
+            wasmparser::BlockType::FuncType(idx) => Instruction::BlockWithFuncType(idx, 0),
+            wasmparser::BlockType::Type(ty) => Instruction::BlockWithType(convert_valtype(&ty), 0),
+        })
     }
 
     fn visit_loop(&mut self, ty: wasmparser::BlockType) -> Self::Output {
         self.label_ptrs.push(self.instructions.len());
-        self.instructions.push(Instruction::Loop(convert_blocktype(ty), 0))
+        self.instructions.push(match ty {
+            wasmparser::BlockType::Empty => Instruction::Loop(0),
+            wasmparser::BlockType::FuncType(idx) => Instruction::LoopWithFuncType(idx, 0),
+            wasmparser::BlockType::Type(ty) => Instruction::LoopWithType(convert_valtype(&ty), 0),
+        })
     }
 
     fn visit_if(&mut self, ty: wasmparser::BlockType) -> Self::Output {
         self.label_ptrs.push(self.instructions.len());
-        self.instructions.push(Instruction::If(convert_blocktype(ty).into(), 0, 0))
+        self.instructions.push(match ty {
+            wasmparser::BlockType::Empty => Instruction::If(0, 0),
+            wasmparser::BlockType::FuncType(idx) => Instruction::IfWithFuncType(idx, 0, 0),
+            wasmparser::BlockType::Type(ty) => Instruction::IfWithType(convert_valtype(&ty), 0, 0),
+        })
     }
 
     fn visit_else(&mut self) -> Self::Output {
@@ -451,12 +481,18 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
                 };
 
                 let if_instruction = &mut self.instructions[if_label_pointer];
-                let Instruction::If(_, else_offset, end_offset) = if_instruction else {
-                    self.errors.push(crate::ParseError::UnsupportedOperator(
-                        "Expected to end an if block, but the last label was not an if".to_string(),
-                    ));
 
-                    return;
+                let (else_offset, end_offset) = match if_instruction {
+                    Instruction::If(else_offset, end_offset)
+                    | Instruction::IfWithFuncType(_, else_offset, end_offset)
+                    | Instruction::IfWithType(_, else_offset, end_offset) => (else_offset, end_offset),
+                    _ => {
+                        self.errors.push(crate::ParseError::UnsupportedOperator(
+                            "Expected to end an if block, but the last label was not an if".to_string(),
+                        ));
+
+                        return;
+                    }
                 };
 
                 *else_offset = (label_pointer - if_label_pointer)
@@ -467,9 +503,15 @@ impl<'a, R: WasmModuleResources> wasmparser::VisitOperator<'a> for FunctionBuild
                     .try_into()
                     .expect("else_instr_end_offset is too large, tinywasm does not support blocks that large");
             }
-            Some(Instruction::Block(_, end_offset))
-            | Some(Instruction::Loop(_, end_offset))
-            | Some(Instruction::If(_, _, end_offset)) => {
+            Some(Instruction::Block(end_offset))
+            | Some(Instruction::BlockWithType(_, end_offset))
+            | Some(Instruction::BlockWithFuncType(_, end_offset))
+            | Some(Instruction::Loop(end_offset))
+            | Some(Instruction::LoopWithFuncType(_, end_offset))
+            | Some(Instruction::LoopWithType(_, end_offset))
+            | Some(Instruction::If(_, end_offset))
+            | Some(Instruction::IfWithFuncType(_, _, end_offset))
+            | Some(Instruction::IfWithType(_, _, end_offset)) => {
                 *end_offset = (current_instr_ptr - label_pointer)
                     .try_into()
                     .expect("else_instr_end_offset is too large, tinywasm does not support  blocks that large");
diff --git a/crates/tinywasm/Cargo.toml b/crates/tinywasm/Cargo.toml
index d82d850..4e15123 100644
--- a/crates/tinywasm/Cargo.toml
+++ b/crates/tinywasm/Cargo.toml
@@ -19,16 +19,6 @@ tinywasm-parser={version="0.7.0", path="../parser", default-features=false, opti
 tinywasm-types={version="0.7.0", path="../types", default-features=false}
 libm={version="0.2", default-features=false}
 
-# maybe?
-# arrayvec={version="0.7"}          instead of the custom implementation
-# bumpalo={version="3.16"}
-# wide=                             for simd
-# vec1=                             might be useful? fast .last() and .first() access
-# https://github.com/lumol-org/soa-derive       could be useful for the memory layout of Stacks
-
-#https://alic.dev/blog/dense-enums
-# https://docs.rs/tagged-pointer/latest/tagged_pointer/
-
 [dev-dependencies]
 wasm-testsuite={path="../wasm-testsuite"}
 wast={version="212.0"}
diff --git a/crates/tinywasm/src/func.rs b/crates/tinywasm/src/func.rs
index 650f9df..3b97d93 100644
--- a/crates/tinywasm/src/func.rs
+++ b/crates/tinywasm/src/func.rs
@@ -1,4 +1,4 @@
-use crate::runtime::{CallFrame, Stack};
+use crate::interpreter::{CallFrame, Stack};
 use crate::{log, unlikely, Function};
 use crate::{Error, FuncContext, Result, Store};
 use alloc::{boxed::Box, format, string::String, string::ToString, vec, vec::Vec};
@@ -59,7 +59,7 @@ impl FuncHandle {
         };
 
         // 6. Let f be the dummy frame
-        let call_frame = CallFrame::new(wasm_func.clone(), func_inst.owner, params, 0);
+        let call_frame = CallFrame::new(wasm_func.clone(), func_inst._owner, params, 0);
 
         // 7. Push the frame f to the call stack
         // & 8. Push the values to the stack (Not needed since the call frame owns the values)
diff --git a/crates/tinywasm/src/imports.rs b/crates/tinywasm/src/imports.rs
index f24ed73..8c208f0 100644
--- a/crates/tinywasm/src/imports.rs
+++ b/crates/tinywasm/src/imports.rs
@@ -348,7 +348,7 @@ impl Imports {
     ) -> Result<ResolvedImports> {
         let mut imports = ResolvedImports::new();
 
-        for import in module.data.imports.iter() {
+        for import in module.0.imports.iter() {
             let val = self.take(store, import).ok_or_else(|| LinkingError::unknown_import(import))?;
 
             match val {
@@ -368,7 +368,7 @@ impl Imports {
                     }
                     (Extern::Function(extern_func), ImportKind::Function(ty)) => {
                         let import_func_type = module
-                            .data
+                            .0
                             .func_types
                             .get(*ty as usize)
                             .ok_or_else(|| LinkingError::incompatible_import_type(import))?;
@@ -409,7 +409,7 @@ impl Imports {
                         (ExternVal::Func(func_addr), ImportKind::Function(ty)) => {
                             let func = store.get_func(func_addr)?;
                             let import_func_type = module
-                                .data
+                                .0
                                 .func_types
                                 .get(*ty as usize)
                                 .ok_or_else(|| LinkingError::incompatible_import_type(import))?;
diff --git a/crates/tinywasm/src/instance.rs b/crates/tinywasm/src/instance.rs
index 4ad3d09..7250cf0 100644
--- a/crates/tinywasm/src/instance.rs
+++ b/crates/tinywasm/src/instance.rs
@@ -64,45 +64,39 @@ impl ModuleInstance {
 
         let idx = store.next_module_instance_idx();
         let mut addrs = imports.unwrap_or_default().link(store, &module, idx)?;
-        let data = module.data;
 
-        addrs.funcs.extend(store.init_funcs(data.funcs.into(), idx)?);
-        addrs.tables.extend(store.init_tables(data.table_types.into(), idx)?);
-        addrs.memories.extend(store.init_memories(data.memory_types.into(), idx)?);
+        addrs.funcs.extend(store.init_funcs(module.0.funcs.into(), idx)?);
+        addrs.tables.extend(store.init_tables(module.0.table_types.into(), idx)?);
+        addrs.memories.extend(store.init_memories(module.0.memory_types.into(), idx)?);
 
-        let global_addrs = store.init_globals(addrs.globals, data.globals.into(), &addrs.funcs, idx)?;
+        let global_addrs = store.init_globals(addrs.globals, module.0.globals.into(), &addrs.funcs, idx)?;
         let (elem_addrs, elem_trapped) =
-            store.init_elements(&addrs.tables, &addrs.funcs, &global_addrs, &data.elements, idx)?;
-        let (data_addrs, data_trapped) = store.init_datas(&addrs.memories, data.data.into(), idx)?;
+            store.init_elements(&addrs.tables, &addrs.funcs, &global_addrs, &module.0.elements, idx)?;
+        let (data_addrs, data_trapped) = store.init_datas(&addrs.memories, module.0.data.into(), idx)?;
 
         let instance = ModuleInstanceInner {
             failed_to_instantiate: elem_trapped.is_some() || data_trapped.is_some(),
             store_id: store.id(),
             idx,
-            types: data.func_types,
+            types: module.0.func_types,
             func_addrs: addrs.funcs.into_boxed_slice(),
             table_addrs: addrs.tables.into_boxed_slice(),
             mem_addrs: addrs.memories.into_boxed_slice(),
             global_addrs: global_addrs.into_boxed_slice(),
             elem_addrs,
             data_addrs,
-            func_start: data.start_func,
-            imports: data.imports,
-            exports: data.exports,
+            func_start: module.0.start_func,
+            imports: module.0.imports,
+            exports: module.0.exports,
         };
 
         let instance = ModuleInstance::new(instance);
         store.add_instance(instance.clone());
 
-        if let Some(trap) = elem_trapped {
-            return Err(trap.into());
-        };
-
-        if let Some(trap) = data_trapped {
-            return Err(trap.into());
-        };
-
-        Ok(instance)
+        match (elem_trapped, data_trapped) {
+            (Some(trap), _) | (_, Some(trap)) => Err(trap.into()),
+            _ => Ok(instance),
+        }
     }
 
     /// Get a export by name
@@ -224,13 +218,13 @@ impl ModuleInstance {
     /// Get a memory by address
     pub fn memory<'a>(&self, store: &'a mut Store, addr: MemAddr) -> Result<MemoryRef<'a>> {
         let mem = store.get_mem(self.resolve_mem_addr(addr)?)?;
-        Ok(MemoryRef { instance: mem.borrow() })
+        Ok(MemoryRef(mem.borrow()))
     }
 
     /// Get a memory by address (mutable)
     pub fn memory_mut<'a>(&self, store: &'a mut Store, addr: MemAddr) -> Result<MemoryRefMut<'a>> {
         let mem = store.get_mem(self.resolve_mem_addr(addr)?)?;
-        Ok(MemoryRefMut { instance: mem.borrow_mut() })
+        Ok(MemoryRefMut(mem.borrow_mut()))
     }
 
     /// Get the start function of the module
diff --git a/crates/tinywasm/src/runtime/interpreter/mod.rs b/crates/tinywasm/src/interpreter/executor.rs
index 8028e87..386099d 100644
--- a/crates/tinywasm/src/runtime/interpreter/mod.rs
+++ b/crates/tinywasm/src/interpreter/executor.rs
@@ -1,34 +1,25 @@
-mod num_helpers;
-
 #[cfg(not(feature = "std"))]
 mod no_std_floats;
 
+use interpreter::CallFrame;
 #[cfg(not(feature = "std"))]
 #[allow(unused_imports)]
 use no_std_floats::NoStdFloatExt;
 
 use alloc::{format, rc::Rc, string::ToString};
 use core::ops::ControlFlow;
-use num_helpers::*;
 use tinywasm_types::*;
 
-use super::stack::{values::StackHeight, BlockFrame, BlockType};
-use super::{values::*, InterpreterRuntime, Stack};
-use crate::runtime::CallFrame;
+use super::num_helpers::*;
+use super::stack::{values::StackHeight, BlockFrame, BlockType, Stack};
+use super::values::*;
 use crate::*;
 
-impl InterpreterRuntime {
-    pub(crate) fn exec(&self, store: &mut Store, stack: &mut Stack) -> Result<()> {
-        Executor::new(store, stack)?.run_to_completion()
-    }
-}
-
-struct Executor<'store, 'stack> {
-    store: &'store mut Store,
-    stack: &'stack mut Stack,
-
+pub(super) struct Executor<'store, 'stack> {
     cf: CallFrame,
     module: ModuleInstance,
+    store: &'store mut Store,
+    stack: &'stack mut Stack,
 }
 
 impl<'store, 'stack> Executor<'store, 'stack> {
@@ -68,10 +59,28 @@ impl<'store, 'stack> Executor<'store, 'stack> {
             Call(v) => return self.exec_call_direct(*v),
             CallIndirect(ty, table) => return self.exec_call_indirect(*ty, *table),
 
-            If(args, el, end) => self.exec_if((*args).into(), *el, *end)?,
+            If(end, el) => self.exec_if(*end, *el, (Default::default(), Default::default()))?,
+            IfWithType(ty, end, el) => self.exec_if(*end, *el, (Default::default(), (*ty).into()))?,
+            IfWithFuncType(ty, end, el) => self.exec_if(*end, *el, self.resolve_functype(*ty))?,
             Else(end_offset) => self.exec_else(*end_offset)?,
-            Loop(args, end) => self.enter_block(self.cf.instr_ptr(), *end, BlockType::Loop, *args),
-            Block(args, end) => self.enter_block(self.cf.instr_ptr(), *end, BlockType::Block, *args),
+            Loop(end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Loop, (Default::default(), Default::default()))
+            }
+            LoopWithType(ty, end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Loop, (Default::default(), (*ty).into()))
+            }
+            LoopWithFuncType(ty, end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Loop, self.resolve_functype(*ty))
+            }
+            Block(end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Block, (Default::default(), Default::default()))
+            }
+            BlockWithType(ty, end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Block, (Default::default(), (*ty).into()))
+            }
+            BlockWithFuncType(ty, end) => {
+                self.enter_block(self.cf.instr_ptr(), *end, BlockType::Block, self.resolve_functype(*ty))
+            }
             Br(v) => return self.exec_br(*v),
             BrIf(v) => return self.exec_br_if(*v),
             BrTable(default, len) => return self.exec_brtable(*default, *len),
@@ -429,7 +438,7 @@ impl<'store, 'stack> Executor<'store, 'stack> {
             }
         };
 
-        self.exec_call(wasm_func.clone(), func_inst.owner)
+        self.exec_call(wasm_func.clone(), func_inst._owner)
     }
     fn exec_call_indirect(&mut self, type_addr: u32, table_addr: u32) -> Result<ControlFlow<()>> {
         // verify that the table is of the right type, this should be validated by the parser already
@@ -467,17 +476,22 @@ impl<'store, 'stack> Executor<'store, 'stack> {
         };
 
         if wasm_func.ty == *call_ty {
-            return self.exec_call(wasm_func.clone(), func_inst.owner);
+            return self.exec_call(wasm_func.clone(), func_inst._owner);
         }
 
         cold();
         Err(Trap::IndirectCallTypeMismatch { actual: wasm_func.ty.clone(), expected: call_ty.clone() }.into())
     }
 
-    fn exec_if(&mut self, args: BlockArgs, else_offset: u32, end_offset: u32) -> Result<()> {
+    fn exec_if(
+        &mut self,
+        else_offset: u32,
+        end_offset: u32,
+        (params, results): (StackHeight, StackHeight),
+    ) -> Result<()> {
         // truthy value is on the top of the stack, so enter the then block
         if self.stack.values.pop::<i32>()? != 0 {
-            self.enter_block(self.cf.instr_ptr(), end_offset, BlockType::If, args);
+            self.enter_block(self.cf.instr_ptr(), end_offset, BlockType::If, (params, results));
             return Ok(());
         }
 
@@ -489,7 +503,7 @@ impl<'store, 'stack> Executor<'store, 'stack> {
 
         let old = self.cf.instr_ptr();
         *self.cf.instr_ptr_mut() += else_offset as usize;
-        self.enter_block(old + else_offset as usize, end_offset - else_offset, BlockType::Else, args);
+        self.enter_block(old + else_offset as usize, end_offset - else_offset, BlockType::Else, (params, results));
         Ok(())
     }
     fn exec_else(&mut self, end_offset: u32) -> Result<()> {
@@ -497,16 +511,17 @@ impl<'store, 'stack> Executor<'store, 'stack> {
         *self.cf.instr_ptr_mut() += end_offset as usize;
         Ok(())
     }
-    fn enter_block(&mut self, instr_ptr: usize, end_instr_offset: u32, ty: BlockType, args: BlockArgs) {
-        let (params, results) = match args {
-            BlockArgs::Empty => (StackHeight::default(), StackHeight::default()),
-            BlockArgs::Type(t) => (StackHeight::default(), t.into()),
-            BlockArgs::FuncType(t) => {
-                let ty = self.module.func_ty(t);
-                ((&*ty.params).into(), (&*ty.results).into())
-            }
-        };
-
+    fn resolve_functype(&self, idx: u32) -> (StackHeight, StackHeight) {
+        let ty = self.module.func_ty(idx);
+        ((&*ty.params).into(), (&*ty.results).into())
+    }
+    fn enter_block(
+        &mut self,
+        instr_ptr: usize,
+        end_instr_offset: u32,
+        ty: BlockType,
+        (params, results): (StackHeight, StackHeight),
+    ) {
         self.stack.blocks.push(BlockFrame {
             instr_ptr,
             end_instr_offset,
diff --git a/crates/tinywasm/src/runtime/mod.rs b/crates/tinywasm/src/interpreter/mod.rs
index fca58cc..f9096f8 100644
--- a/crates/tinywasm/src/runtime/mod.rs
+++ b/crates/tinywasm/src/interpreter/mod.rs
@@ -1,4 +1,5 @@
-mod interpreter;
+mod executor;
+mod num_helpers;
 pub(crate) mod stack;
 
 #[doc(hidden)]
@@ -7,8 +8,16 @@ pub use stack::values::*;
 
 pub(crate) use stack::{CallFrame, Stack};
 
+use crate::{Result, Store};
+
 /// The main TinyWasm runtime.
 ///
 /// This is the default runtime used by TinyWasm.
 #[derive(Debug, Default)]
 pub struct InterpreterRuntime {}
+
+impl InterpreterRuntime {
+    pub(crate) fn exec(&self, store: &mut Store, stack: &mut Stack) -> Result<()> {
+        executor::Executor::new(store, stack)?.run_to_completion()
+    }
+}
diff --git a/crates/tinywasm/src/runtime/interpreter/no_std_floats.rs b/crates/tinywasm/src/interpreter/no_std_floats.rs
index 5b9471e..5b9471e 100644
--- a/crates/tinywasm/src/runtime/interpreter/no_std_floats.rs
+++ b/crates/tinywasm/src/interpreter/no_std_floats.rs
diff --git a/crates/tinywasm/src/runtime/interpreter/num_helpers.rs b/crates/tinywasm/src/interpreter/num_helpers.rs
index d0402bc..88a5e9e 100644
--- a/crates/tinywasm/src/runtime/interpreter/num_helpers.rs
+++ b/crates/tinywasm/src/interpreter/num_helpers.rs
@@ -11,7 +11,7 @@ where
 /// Rust sadly doesn't have wrapping casts for floats yet, maybe never.
 /// Alternatively, https://crates.io/crates/az could be used for this but
 /// it's not worth the dependency. 
-#[rustfmt::skip]
+#[rustfmt::skip] 
 macro_rules! float_min_max {
     (f32, i32) => {(-2147483904.0_f32, 2147483648.0_f32)};
     (f64, i32) => {(-2147483649.0_f64, 2147483648.0_f64)};
diff --git a/crates/tinywasm/src/runtime/stack/block_stack.rs b/crates/tinywasm/src/interpreter/stack/block_stack.rs
index cef536a..cef536a 100644
--- a/crates/tinywasm/src/runtime/stack/block_stack.rs
+++ b/crates/tinywasm/src/interpreter/stack/block_stack.rs
diff --git a/crates/tinywasm/src/runtime/stack/call_stack.rs b/crates/tinywasm/src/interpreter/stack/call_stack.rs
index 8e9dbe7..8e9dbe7 100644
--- a/crates/tinywasm/src/runtime/stack/call_stack.rs
+++ b/crates/tinywasm/src/interpreter/stack/call_stack.rs
diff --git a/crates/tinywasm/src/runtime/stack/mod.rs b/crates/tinywasm/src/interpreter/stack/mod.rs
index 3902bd2..3902bd2 100644
--- a/crates/tinywasm/src/runtime/stack/mod.rs
+++ b/crates/tinywasm/src/interpreter/stack/mod.rs
diff --git a/crates/tinywasm/src/runtime/stack/value_stack.rs b/crates/tinywasm/src/interpreter/stack/value_stack.rs
index 40376f1..fc23b48 100644
--- a/crates/tinywasm/src/runtime/stack/value_stack.rs
+++ b/crates/tinywasm/src/interpreter/stack/value_stack.rs
@@ -106,10 +106,19 @@ impl ValueStack {
     }
 
     pub(crate) fn truncate_keep(&mut self, to: &StackLocation, keep: &StackHeight) {
-        truncate_keep(&mut self.stack_32, to.s32, keep.s32);
-        truncate_keep(&mut self.stack_64, to.s64, keep.s64);
-        truncate_keep(&mut self.stack_128, to.s128, keep.s128);
-        truncate_keep(&mut self.stack_ref, to.sref, keep.sref);
+        #[inline(always)]
+        fn truncate_keep<T: Copy + Default>(data: &mut Vec<T>, n: u32, end_keep: u32) {
+            let len = data.len() as u32;
+            if len <= n {
+                return; // No need to truncate if the current size is already less than or equal to total_to_keep
+            }
+            data.drain((n as usize)..(len - end_keep) as usize);
+        }
+
+        truncate_keep(&mut self.stack_32, to.s32, keep.s32 as u32);
+        truncate_keep(&mut self.stack_64, to.s64, keep.s64 as u32);
+        truncate_keep(&mut self.stack_128, to.s128, keep.s128 as u32);
+        truncate_keep(&mut self.stack_ref, to.sref, keep.sref as u32);
     }
 
     pub(crate) fn push_dyn(&mut self, value: TinyWasmValue) {
@@ -145,42 +154,3 @@ impl ValueStack {
         }
     }
 }
-
-fn truncate_keep<T: Copy + Default>(data: &mut Vec<T>, n: u32, end_keep: u32) {
-    let total_to_keep = n + end_keep;
-    let len = data.len() as u32;
-    crate::log::error!("truncate_keep: len: {}, total_to_keep: {}, end_keep: {}", len, total_to_keep, end_keep);
-
-    if len <= n {
-        return; // No need to truncate if the current size is already less than or equal to total_to_keep
-    }
-
-    data.drain((n as usize)..(len - end_keep) as usize);
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_truncate_keep() {
-        macro_rules! test_macro {
-            ($( $n:expr, $end_keep:expr, $expected:expr ),*) => {
-            $(
-                let mut stack = alloc::vec![1,2,3,4,5];
-                truncate_keep(&mut stack, $n, $end_keep);
-                assert_eq!(stack.len(), $expected);
-            )*
-            };
-        }
-
-        test_macro! {
-            0, 0, 0,
-            1, 0, 1,
-            0, 1, 1,
-            1, 1, 2,
-            2, 1, 3,
-            2, 2, 4
-        }
-    }
-}
diff --git a/crates/tinywasm/src/interpreter/stack/values.rs b/crates/tinywasm/src/interpreter/stack/values.rs
new file mode 100644
index 0000000..6e8274f
--- /dev/null
+++ b/crates/tinywasm/src/interpreter/stack/values.rs
@@ -0,0 +1,200 @@
+#![allow(missing_docs)]
+use super::{call_stack::Locals, ValueStack};
+use crate::{Error, Result};
+use tinywasm_types::{LocalAddr, ValType, WasmValue};
+
+pub(crate) type Value32 = u32;
+pub(crate) type Value64 = u64;
+pub(crate) type Value128 = u128;
+pub(crate) type ValueRef = Option<u32>;
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+/// A untyped WebAssembly value
+pub enum TinyWasmValue {
+    Value32(Value32),
+    Value64(Value64),
+    Value128(Value128),
+    ValueRef(ValueRef),
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct StackLocation {
+    pub(crate) s32: u32,
+    pub(crate) s64: u32,
+    pub(crate) s128: u32,
+    pub(crate) sref: u32,
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub(crate) struct StackHeight {
+    pub(crate) s32: u16,
+    pub(crate) s64: u16,
+    pub(crate) s128: u16,
+    pub(crate) sref: u16,
+}
+
+impl From<ValType> for StackHeight {
+    fn from(value: ValType) -> Self {
+        match value {
+            ValType::I32 | ValType::F32 => Self { s32: 1, ..Default::default() },
+            ValType::I64 | ValType::F64 => Self { s64: 1, ..Default::default() },
+            ValType::V128 => Self { s128: 1, ..Default::default() },
+            ValType::RefExtern | ValType::RefFunc => Self { sref: 1, ..Default::default() },
+        }
+    }
+}
+
+impl From<&[ValType]> for StackHeight {
+    fn from(value: &[ValType]) -> Self {
+        let mut s32 = 0;
+        let mut s64 = 0;
+        let mut s128 = 0;
+        let mut sref = 0;
+        for val_type in value.iter() {
+            match val_type {
+                ValType::I32 | ValType::F32 => s32 += 1,
+                ValType::I64 | ValType::F64 => s64 += 1,
+                ValType::V128 => s128 += 1,
+                ValType::RefExtern | ValType::RefFunc => sref += 1,
+            }
+        }
+        Self { s32, s64, s128, sref }
+    }
+}
+
+impl TinyWasmValue {
+    pub fn unwrap_32(&self) -> Value32 {
+        match self {
+            TinyWasmValue::Value32(v) => *v,
+            _ => unreachable!("Expected Value32"),
+        }
+    }
+
+    pub fn unwrap_64(&self) -> Value64 {
+        match self {
+            TinyWasmValue::Value64(v) => *v,
+            _ => unreachable!("Expected Value64"),
+        }
+    }
+
+    pub fn unwrap_128(&self) -> Value128 {
+        match self {
+            TinyWasmValue::Value128(v) => *v,
+            _ => unreachable!("Expected Value128"),
+        }
+    }
+
+    pub fn unwrap_ref(&self) -> ValueRef {
+        match self {
+            TinyWasmValue::ValueRef(v) => *v,
+            _ => unreachable!("Expected ValueRef"),
+        }
+    }
+
+    pub fn attach_type(&self, ty: ValType) -> WasmValue {
+        match ty {
+            ValType::I32 => WasmValue::I32(self.unwrap_32() as i32),
+            ValType::I64 => WasmValue::I64(self.unwrap_64() as i64),
+            ValType::F32 => WasmValue::F32(f32::from_bits(self.unwrap_32())),
+            ValType::F64 => WasmValue::F64(f64::from_bits(self.unwrap_64())),
+            ValType::V128 => WasmValue::V128(self.unwrap_128()),
+            ValType::RefExtern => match self.unwrap_ref() {
+                Some(v) => WasmValue::RefExtern(v),
+                None => WasmValue::RefNull(ValType::RefExtern),
+            },
+            ValType::RefFunc => match self.unwrap_ref() {
+                Some(v) => WasmValue::RefFunc(v),
+                None => WasmValue::RefNull(ValType::RefFunc),
+            },
+        }
+    }
+}
+
+impl From<&WasmValue> for TinyWasmValue {
+    fn from(value: &WasmValue) -> Self {
+        match value {
+            WasmValue::I32(v) => TinyWasmValue::Value32(*v as u32),
+            WasmValue::I64(v) => TinyWasmValue::Value64(*v as u64),
+            WasmValue::V128(v) => TinyWasmValue::Value128(*v),
+            WasmValue::F32(v) => TinyWasmValue::Value32(v.to_bits()),
+            WasmValue::F64(v) => TinyWasmValue::Value64(v.to_bits()),
+            WasmValue::RefFunc(v) => TinyWasmValue::ValueRef(Some(*v)),
+            WasmValue::RefExtern(v) => TinyWasmValue::ValueRef(Some(*v)),
+            WasmValue::RefNull(_) => TinyWasmValue::ValueRef(None),
+        }
+    }
+}
+
+impl From<WasmValue> for TinyWasmValue {
+    fn from(value: WasmValue) -> Self {
+        TinyWasmValue::from(&value)
+    }
+}
+
+mod sealed {
+    #[allow(unreachable_pub)]
+    pub trait Sealed {}
+}
+
+pub(crate) trait InternalValue: sealed::Sealed {
+    fn stack_push(stack: &mut ValueStack, value: Self);
+    fn stack_pop(stack: &mut ValueStack) -> Result<Self>
+    where
+        Self: Sized;
+    fn stack_peek(stack: &ValueStack) -> Result<Self>
+    where
+        Self: Sized;
+    fn local_get(locals: &Locals, index: LocalAddr) -> Result<Self>
+    where
+        Self: Sized;
+    fn local_set(locals: &mut Locals, index: LocalAddr, value: Self) -> Result<()>;
+}
+
+macro_rules! impl_internalvalue {
+    ($( $variant:ident, $stack:ident, $locals:ident, $internal:ty, $outer:ty, $to_internal:expr, $to_outer:expr )*) => {
+        $(
+            impl sealed::Sealed for $outer {}
+
+            impl From<$outer> for TinyWasmValue {
+                fn from(value: $outer) -> Self {
+                    TinyWasmValue::$variant($to_internal(value))
+                }
+            }
+
+            impl InternalValue for $outer {
+                #[inline]
+                fn stack_push(stack: &mut ValueStack, value: Self) {
+                    stack.$stack.push($to_internal(value));
+                }
+                #[inline]
+                fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
+                    stack.$stack.pop().ok_or(Error::ValueStackUnderflow).map($to_outer)
+                }
+                #[inline]
+                fn stack_peek(stack: &ValueStack) -> Result<Self> {
+                    stack.$stack.last().copied().ok_or(Error::ValueStackUnderflow).map($to_outer)
+                }
+                #[inline]
+                fn local_get(locals: &Locals, index: LocalAddr) -> Result<Self> {
+                    Ok($to_outer(locals.$locals[index as usize]))
+                }
+                #[inline]
+                fn local_set(locals: &mut Locals, index: LocalAddr, value: Self) -> Result<()> {
+                    locals.$locals[index as usize] = $to_internal(value);
+                    Ok(())
+                }
+            }
+        )*
+    };
+}
+
+impl_internalvalue! {
+    Value32, stack_32, locals_32, u32, u32, |v| v, |v| v
+    Value64, stack_64, locals_64, u64, u64, |v| v, |v| v
+    Value32, stack_32, locals_32, u32, i32, |v| v as u32, |v: u32| v as i32
+    Value64, stack_64, locals_64, u64, i64, |v| v as u64, |v| v as i64
+    Value32, stack_32, locals_32, u32, f32, f32::to_bits, f32::from_bits
+    Value64, stack_64, locals_64, u64, f64, f64::to_bits, f64::from_bits
+    Value128, stack_128, locals_128, Value128, Value128, |v| v, |v| v
+    ValueRef, stack_ref, locals_ref, ValueRef, ValueRef, |v| v, |v| v
+}
diff --git a/crates/tinywasm/src/lib.rs b/crates/tinywasm/src/lib.rs
index 9c48ee0..c1c2549 100644
--- a/crates/tinywasm/src/lib.rs
+++ b/crates/tinywasm/src/lib.rs
@@ -108,8 +108,8 @@ mod reference;
 mod store;
 
 /// Runtime for executing WebAssembly modules.
-pub mod runtime;
-pub use runtime::InterpreterRuntime;
+pub mod interpreter;
+pub use interpreter::InterpreterRuntime;
 
 #[cfg(feature = "parser")]
 /// Re-export of [`tinywasm_parser`]. Requires `parser` feature.
diff --git a/crates/tinywasm/src/module.rs b/crates/tinywasm/src/module.rs
index 5b5f0c6..f6e8e04 100644
--- a/crates/tinywasm/src/module.rs
+++ b/crates/tinywasm/src/module.rs
@@ -1,24 +1,21 @@
 use crate::{Imports, ModuleInstance, Result, Store};
 use tinywasm_types::TinyWasmModule;
 
-#[derive(Debug)]
 /// A WebAssembly Module
 ///
 /// See <https://webassembly.github.io/spec/core/syntax/modules.html#syntax-module>
-#[derive(Clone)]
-pub struct Module {
-    pub(crate) data: TinyWasmModule,
-}
+#[derive(Debug, Clone)]
+pub struct Module(pub(crate) TinyWasmModule);
 
 impl From<&TinyWasmModule> for Module {
     fn from(data: &TinyWasmModule) -> Self {
-        Self { data: data.clone() }
+        Self(data.clone())
     }
 }
 
 impl From<TinyWasmModule> for Module {
     fn from(data: TinyWasmModule) -> Self {
-        Self { data }
+        Self(data)
     }
 }
 
diff --git a/crates/tinywasm/src/reference.rs b/crates/tinywasm/src/reference.rs
index f3acc49..870de48 100644
--- a/crates/tinywasm/src/reference.rs
+++ b/crates/tinywasm/src/reference.rs
@@ -1,45 +1,40 @@
-use core::cell::{Ref, RefCell, RefMut};
+use core::cell::{Ref, RefMut};
 use core::ffi::CStr;
 
 use alloc::ffi::CString;
 use alloc::string::{String, ToString};
 use alloc::vec::Vec;
 
-use crate::{GlobalInstance, MemoryInstance, Result};
-use tinywasm_types::WasmValue;
+use crate::{MemoryInstance, Result};
 
 // This module essentially contains the public APIs to interact with the data stored in the store
 
 /// A reference to a memory instance
 #[derive(Debug)]
-pub struct MemoryRef<'a> {
-    pub(crate) instance: Ref<'a, MemoryInstance>,
-}
+pub struct MemoryRef<'a>(pub(crate) Ref<'a, MemoryInstance>);
 
 /// A borrowed reference to a memory instance
 #[derive(Debug)]
-pub struct MemoryRefMut<'a> {
-    pub(crate) instance: RefMut<'a, MemoryInstance>,
-}
+pub struct MemoryRefMut<'a>(pub(crate) RefMut<'a, MemoryInstance>);
 
 impl<'a> MemoryRefLoad for MemoryRef<'a> {
     /// Load a slice of memory
     fn load(&self, offset: usize, len: usize) -> Result<&[u8]> {
-        self.instance.load(offset, len)
+        self.0.load(offset, len)
     }
 }
 
 impl<'a> MemoryRefLoad for MemoryRefMut<'a> {
     /// Load a slice of memory
     fn load(&self, offset: usize, len: usize) -> Result<&[u8]> {
-        self.instance.load(offset, len)
+        self.0.load(offset, len)
     }
 }
 
 impl MemoryRef<'_> {
     /// Load a slice of memory
     pub fn load(&self, offset: usize, len: usize) -> Result<&[u8]> {
-        self.instance.load(offset, len)
+        self.0.load(offset, len)
     }
 
     /// Load a slice of memory as a vector
@@ -51,7 +46,7 @@ impl MemoryRef<'_> {
 impl MemoryRefMut<'_> {
     /// Load a slice of memory
     pub fn load(&self, offset: usize, len: usize) -> Result<&[u8]> {
-        self.instance.load(offset, len)
+        self.0.load(offset, len)
     }
 
     /// Load a slice of memory as a vector
@@ -61,27 +56,27 @@ impl MemoryRefMut<'_> {
 
     /// Grow the memory by the given number of pages
     pub fn grow(&mut self, delta_pages: i32) -> Option<i32> {
-        self.instance.grow(delta_pages)
+        self.0.grow(delta_pages)
     }
 
     /// Get the current size of the memory in pages
     pub fn page_count(&mut self) -> usize {
-        self.instance.page_count()
+        self.0.page_count()
     }
 
     /// Copy a slice of memory to another place in memory
     pub fn copy_within(&mut self, src: usize, dst: usize, len: usize) -> Result<()> {
-        self.instance.copy_within(src, dst, len)
+        self.0.copy_within(src, dst, len)
     }
 
     /// Fill a slice of memory with a value
     pub fn fill(&mut self, offset: usize, len: usize, val: u8) -> Result<()> {
-        self.instance.fill(offset, len, val)
+        self.0.fill(offset, len, val)
     }
 
     /// Store a slice of memory
     pub fn store(&mut self, offset: usize, len: usize, data: &[u8]) -> Result<()> {
-        self.instance.store(offset, len, data)
+        self.0.store(offset, len, data)
     }
 }
 
@@ -139,21 +134,3 @@ pub trait MemoryStringExt: MemoryRefLoad {
 
 impl MemoryStringExt for MemoryRef<'_> {}
 impl MemoryStringExt for MemoryRefMut<'_> {}
-
-/// A reference to a global instance
-#[derive(Debug)]
-pub struct GlobalRef {
-    pub(crate) instance: RefCell<GlobalInstance>,
-}
-
-impl GlobalRef {
-    /// Get the value of the global
-    pub fn get(&self) -> WasmValue {
-        self.instance.borrow().get()
-    }
-
-    /// Set the value of the global
-    pub fn set(&self, val: WasmValue) -> Result<()> {
-        self.instance.borrow_mut().set(val)
-    }
-}
diff --git a/crates/tinywasm/src/runtime/stack/values.rs b/crates/tinywasm/src/runtime/stack/values.rs
deleted file mode 100644
index 606e13a..0000000
--- a/crates/tinywasm/src/runtime/stack/values.rs
+++ /dev/null
@@ -1,420 +0,0 @@
-#![allow(missing_docs)]
-use tinywasm_types::{ValType, WasmValue};
-
-use crate::{Error, Result};
-
-use super::{call_stack::Locals, ValueStack};
-
-pub type Value32 = u32;
-pub type Value64 = u64;
-pub type Value128 = u128;
-pub type ValueRef = Option<u32>;
-
-#[derive(Debug, Clone, Copy)]
-pub(crate) struct StackLocation {
-    pub(crate) s32: u32,
-    pub(crate) s64: u32,
-    pub(crate) s128: u32,
-    pub(crate) sref: u32,
-}
-
-#[derive(Debug, Clone, Copy, Default)]
-pub(crate) struct StackHeight {
-    pub(crate) s32: u32,
-    pub(crate) s64: u32,
-    pub(crate) s128: u32,
-    pub(crate) sref: u32,
-}
-
-impl From<ValType> for StackHeight {
-    fn from(value: ValType) -> Self {
-        match value {
-            ValType::I32 | ValType::F32 => Self { s32: 1, ..Default::default() },
-            ValType::I64 | ValType::F64 => Self { s64: 1, ..Default::default() },
-            ValType::V128 => Self { s128: 1, ..Default::default() },
-            ValType::RefExtern | ValType::RefFunc => Self { sref: 1, ..Default::default() },
-        }
-    }
-}
-
-impl From<&[ValType]> for StackHeight {
-    fn from(value: &[ValType]) -> Self {
-        let mut s32 = 0;
-        let mut s64 = 0;
-        let mut s128 = 0;
-        let mut sref = 0;
-        for val_type in value.iter() {
-            match val_type {
-                ValType::I32 | ValType::F32 => s32 += 1,
-                ValType::I64 | ValType::F64 => s64 += 1,
-                ValType::V128 => s128 += 1,
-                ValType::RefExtern | ValType::RefFunc => sref += 1,
-            }
-        }
-        Self { s32, s64, s128, sref }
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq)]
-pub enum TinyWasmValue {
-    Value32(Value32),
-    Value64(Value64),
-    Value128(Value128),
-    ValueRef(ValueRef),
-}
-
-impl TinyWasmValue {
-    pub fn unwrap_32(&self) -> Value32 {
-        match self {
-            TinyWasmValue::Value32(v) => *v,
-            _ => unreachable!("Expected Value32"),
-        }
-    }
-
-    pub fn unwrap_64(&self) -> Value64 {
-        match self {
-            TinyWasmValue::Value64(v) => *v,
-            _ => unreachable!("Expected Value64"),
-        }
-    }
-
-    pub fn unwrap_128(&self) -> Value128 {
-        match self {
-            TinyWasmValue::Value128(v) => *v,
-            _ => unreachable!("Expected Value128"),
-        }
-    }
-
-    pub fn unwrap_ref(&self) -> ValueRef {
-        match self {
-            TinyWasmValue::ValueRef(v) => *v,
-            _ => unreachable!("Expected ValueRef"),
-        }
-    }
-
-    pub fn attach_type(&self, ty: ValType) -> WasmValue {
-        match ty {
-            ValType::I32 => WasmValue::I32(self.unwrap_32() as i32),
-            ValType::I64 => WasmValue::I64(self.unwrap_64() as i64),
-            ValType::F32 => WasmValue::F32(f32::from_bits(self.unwrap_32())),
-            ValType::F64 => WasmValue::F64(f64::from_bits(self.unwrap_64())),
-            ValType::V128 => WasmValue::V128(self.unwrap_128()),
-            ValType::RefExtern => match self.unwrap_ref() {
-                Some(v) => WasmValue::RefExtern(v),
-                None => WasmValue::RefNull(ValType::RefExtern),
-            },
-            ValType::RefFunc => match self.unwrap_ref() {
-                Some(v) => WasmValue::RefFunc(v),
-                None => WasmValue::RefNull(ValType::RefFunc),
-            },
-        }
-    }
-}
-
-impl Default for TinyWasmValue {
-    fn default() -> Self {
-        TinyWasmValue::Value32(0)
-    }
-}
-
-impl From<WasmValue> for TinyWasmValue {
-    fn from(value: WasmValue) -> Self {
-        match value {
-            WasmValue::I32(v) => TinyWasmValue::Value32(v as u32),
-            WasmValue::I64(v) => TinyWasmValue::Value64(v as u64),
-            WasmValue::V128(v) => TinyWasmValue::Value128(v),
-            WasmValue::F32(v) => TinyWasmValue::Value32(v.to_bits()),
-            WasmValue::F64(v) => TinyWasmValue::Value64(v.to_bits()),
-            WasmValue::RefFunc(v) => TinyWasmValue::ValueRef(Some(v)),
-            WasmValue::RefExtern(v) => TinyWasmValue::ValueRef(Some(v)),
-            WasmValue::RefNull(_) => TinyWasmValue::ValueRef(None),
-        }
-    }
-}
-
-impl From<&WasmValue> for TinyWasmValue {
-    fn from(value: &WasmValue) -> Self {
-        match value {
-            WasmValue::I32(v) => TinyWasmValue::Value32(*v as u32),
-            WasmValue::I64(v) => TinyWasmValue::Value64(*v as u64),
-            WasmValue::V128(v) => TinyWasmValue::Value128(*v),
-            WasmValue::F32(v) => TinyWasmValue::Value32(v.to_bits()),
-            WasmValue::F64(v) => TinyWasmValue::Value64(v.to_bits()),
-            WasmValue::RefFunc(v) => TinyWasmValue::ValueRef(Some(*v)),
-            WasmValue::RefExtern(v) => TinyWasmValue::ValueRef(Some(*v)),
-            WasmValue::RefNull(_) => TinyWasmValue::ValueRef(None),
-        }
-    }
-}
-
-impl From<f32> for TinyWasmValue {
-    fn from(value: f32) -> Self {
-        TinyWasmValue::Value32(value.to_bits())
-    }
-}
-
-impl From<f64> for TinyWasmValue {
-    fn from(value: f64) -> Self {
-        TinyWasmValue::Value64(value.to_bits())
-    }
-}
-
-impl From<i32> for TinyWasmValue {
-    fn from(value: i32) -> Self {
-        TinyWasmValue::Value32(value as u32)
-    }
-}
-
-impl From<u32> for TinyWasmValue {
-    fn from(value: u32) -> Self {
-        TinyWasmValue::Value32(value)
-    }
-}
-
-impl From<i64> for TinyWasmValue {
-    fn from(value: i64) -> Self {
-        TinyWasmValue::Value64(value as u64)
-    }
-}
-
-impl From<u64> for TinyWasmValue {
-    fn from(value: u64) -> Self {
-        TinyWasmValue::Value64(value)
-    }
-}
-
-impl From<Value128> for TinyWasmValue {
-    fn from(value: Value128) -> Self {
-        TinyWasmValue::Value128(value)
-    }
-}
-
-impl From<ValueRef> for TinyWasmValue {
-    fn from(value: ValueRef) -> Self {
-        TinyWasmValue::ValueRef(value)
-    }
-}
-
-// TODO: this can be made a bit more maintainable by using a macro
-
-mod sealed {
-    #[allow(unreachable_pub)]
-    pub trait Sealed {}
-}
-
-impl sealed::Sealed for i32 {}
-impl sealed::Sealed for f32 {}
-impl sealed::Sealed for i64 {}
-impl sealed::Sealed for u64 {}
-impl sealed::Sealed for f64 {}
-impl sealed::Sealed for u32 {}
-impl sealed::Sealed for Value128 {}
-impl sealed::Sealed for ValueRef {}
-
-pub(crate) trait InternalValue: sealed::Sealed {
-    fn stack_push(stack: &mut ValueStack, value: Self);
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self>
-    where
-        Self: Sized;
-    fn stack_peek(stack: &ValueStack) -> Result<Self>
-    where
-        Self: Sized;
-
-    fn local_get(locals: &Locals, index: u32) -> Result<Self>
-    where
-        Self: Sized;
-
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()>;
-}
-
-impl InternalValue for i32 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_32.push(value as u32);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_32.pop().ok_or(Error::ValueStackUnderflow).map(|v| v as i32)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_32.last().ok_or(Error::ValueStackUnderflow).map(|v| *v as i32)
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_32[index as usize] as i32)
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_32[index as usize] = value as u32;
-        Ok(())
-    }
-}
-
-impl InternalValue for f32 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_32.push(value.to_bits());
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_32.pop().ok_or(Error::ValueStackUnderflow).map(f32::from_bits)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_32.last().ok_or(Error::ValueStackUnderflow).map(|v| f32::from_bits(*v))
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(f32::from_bits(locals.locals_32[index as usize]))
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_32[index as usize] = value.to_bits();
-        Ok(())
-    }
-}
-
-impl InternalValue for i64 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_64.push(value as u64);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_64.pop().ok_or(Error::ValueStackUnderflow).map(|v| v as i64)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_64.last().ok_or(Error::ValueStackUnderflow).map(|v| *v as i64)
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_64[index as usize] as i64)
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_64[index as usize] = value as u64;
-        Ok(())
-    }
-}
-
-impl InternalValue for u64 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_64.push(value);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_64.pop().ok_or(Error::ValueStackUnderflow)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_64.last().ok_or(Error::ValueStackUnderflow).copied()
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_64[index as usize])
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_64[index as usize] = value;
-        Ok(())
-    }
-}
-
-impl InternalValue for f64 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_64.push(value.to_bits());
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_64.pop().ok_or(Error::ValueStackUnderflow).map(f64::from_bits)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_64.last().ok_or(Error::ValueStackUnderflow).map(|v| f64::from_bits(*v))
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(f64::from_bits(locals.locals_64[index as usize]))
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_64[index as usize] = value.to_bits();
-        Ok(())
-    }
-}
-
-impl InternalValue for u32 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_32.push(value);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_32.pop().ok_or(Error::ValueStackUnderflow)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_32.last().ok_or(Error::ValueStackUnderflow).copied()
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_32[index as usize])
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_32[index as usize] = value;
-        Ok(())
-    }
-}
-
-impl InternalValue for Value128 {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_128.push(value);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_128.pop().ok_or(Error::ValueStackUnderflow)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_128.last().ok_or(Error::ValueStackUnderflow).copied()
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_128[index as usize])
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_128[index as usize] = value;
-        Ok(())
-    }
-}
-
-impl InternalValue for ValueRef {
-    #[inline]
-    fn stack_push(stack: &mut ValueStack, value: Self) {
-        stack.stack_ref.push(value);
-    }
-    #[inline]
-    fn stack_pop(stack: &mut ValueStack) -> Result<Self> {
-        stack.stack_ref.pop().ok_or(Error::ValueStackUnderflow)
-    }
-    #[inline]
-    fn stack_peek(stack: &ValueStack) -> Result<Self> {
-        stack.stack_ref.last().ok_or(Error::ValueStackUnderflow).copied()
-    }
-    #[inline]
-    fn local_get(locals: &Locals, index: u32) -> Result<Self> {
-        Ok(locals.locals_ref[index as usize])
-    }
-    #[inline]
-    fn local_set(locals: &mut Locals, index: u32, value: Self) -> Result<()> {
-        locals.locals_ref[index as usize] = value;
-        Ok(())
-    }
-}
diff --git a/crates/tinywasm/src/store/element.rs b/crates/tinywasm/src/store/element.rs
index 6da73c7..40301a5 100644
--- a/crates/tinywasm/src/store/element.rs
+++ b/crates/tinywasm/src/store/element.rs
@@ -9,7 +9,7 @@ use tinywasm_types::*;
 pub(crate) struct ElementInstance {
     pub(crate) kind: ElementKind,
     pub(crate) items: Option<Vec<TableElement>>, // none is the element was dropped
-    _owner: ModuleInstanceAddr,                  // index into store.module_instances
+    pub(crate) _owner: ModuleInstanceAddr,       // index into store.module_instances
 }
 
 impl ElementInstance {
diff --git a/crates/tinywasm/src/store/function.rs b/crates/tinywasm/src/store/function.rs
index ef370c2..f3f1df0 100644
--- a/crates/tinywasm/src/store/function.rs
+++ b/crates/tinywasm/src/store/function.rs
@@ -8,11 +8,11 @@ use tinywasm_types::*;
 /// See <https://webassembly.github.io/spec/core/exec/runtime.html#function-instances>
 pub(crate) struct FunctionInstance {
     pub(crate) func: Function,
-    pub(crate) owner: ModuleInstanceAddr, // index into store.module_instances, none for host functions
+    pub(crate) _owner: ModuleInstanceAddr, // index into store.module_instances, none for host functions
 }
 
 impl FunctionInstance {
     pub(crate) fn new_wasm(func: WasmFunction, owner: ModuleInstanceAddr) -> Self {
-        Self { func: Function::Wasm(Rc::new(func)), owner }
+        Self { func: Function::Wasm(Rc::new(func)), _owner: owner }
     }
 }
diff --git a/crates/tinywasm/src/store/global.rs b/crates/tinywasm/src/store/global.rs
index a18e43d..b7a47d6 100644
--- a/crates/tinywasm/src/store/global.rs
+++ b/crates/tinywasm/src/store/global.rs
@@ -1,10 +1,7 @@
+use crate::interpreter::TinyWasmValue;
 use core::cell::Cell;
-
-use alloc::{format, string::ToString};
 use tinywasm_types::*;
 
-use crate::{runtime::TinyWasmValue, unlikely, Error, Result};
-
 /// A WebAssembly Global Instance
 ///
 /// See <https://webassembly.github.io/spec/core/exec/runtime.html#global-instances>
@@ -19,55 +16,4 @@ impl GlobalInstance {
     pub(crate) fn new(ty: GlobalType, value: TinyWasmValue, owner: ModuleInstanceAddr) -> Self {
         Self { ty, value: value.into(), _owner: owner }
     }
-
-    #[inline]
-    pub(crate) fn get(&self) -> WasmValue {
-        self.value.get().attach_type(self.ty.ty)
-    }
-
-    pub(crate) fn set(&mut self, val: WasmValue) -> Result<()> {
-        if unlikely(val.val_type() != self.ty.ty) {
-            return Err(Error::Other(format!(
-                "global type mismatch: expected {:?}, got {:?}",
-                self.ty.ty,
-                val.val_type()
-            )));
-        }
-
-        if unlikely(!self.ty.mutable) {
-            return Err(Error::Other("global is immutable".to_string()));
-        }
-
-        self.value.set(val.into());
-        Ok(())
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_global_instance_get_set() {
-        let global_type = GlobalType { ty: ValType::I32, mutable: true };
-        let initial_value = TinyWasmValue::from(10i32);
-        let owner = 0;
-
-        let mut global_instance = GlobalInstance::new(global_type, initial_value, owner);
-
-        // Test `get`
-        assert_eq!(global_instance.get(), WasmValue::I32(10), "global value should be 10");
-
-        // Test `set` with correct type
-        assert!(global_instance.set(WasmValue::I32(20)).is_ok(), "set should succeed");
-        assert_eq!(global_instance.get(), WasmValue::I32(20), "global value should be 20");
-
-        // Test `set` with incorrect type
-        assert!(matches!(global_instance.set(WasmValue::F32(1.0)), Err(Error::Other(_))), "set should fail");
-
-        // Test `set` on immutable global
-        let immutable_global_type = GlobalType { ty: ValType::I32, mutable: false };
-        let mut immutable_global_instance = GlobalInstance::new(immutable_global_type, initial_value, owner);
-        assert!(matches!(immutable_global_instance.set(WasmValue::I32(30)), Err(Error::Other(_))));
-    }
 }
diff --git a/crates/tinywasm/src/store/mod.rs b/crates/tinywasm/src/store/mod.rs
index 9ebd82e..b427497 100644
--- a/crates/tinywasm/src/store/mod.rs
+++ b/crates/tinywasm/src/store/mod.rs
@@ -3,7 +3,7 @@ use core::cell::RefCell;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use tinywasm_types::*;
 
-use crate::runtime::{self, InterpreterRuntime, TinyWasmValue};
+use crate::interpreter::{self, InterpreterRuntime, TinyWasmValue};
 use crate::{Error, Function, ModuleInstance, Result, Trap};
 
 mod data;
@@ -57,7 +57,7 @@ impl Store {
     }
 
     /// Create a new store with the given runtime
-    pub(crate) fn runtime(&self) -> runtime::InterpreterRuntime {
+    pub(crate) fn runtime(&self) -> interpreter::InterpreterRuntime {
         match self.runtime {
             Runtime::Default => InterpreterRuntime::default(),
         }
@@ -381,7 +381,7 @@ impl Store {
     }
 
     pub(crate) fn add_func(&mut self, func: Function, idx: ModuleInstanceAddr) -> Result<FuncAddr> {
-        self.data.funcs.push(FunctionInstance { func, owner: idx });
+        self.data.funcs.push(FunctionInstance { func, _owner: idx });
         Ok(self.data.funcs.len() as FuncAddr - 1)
     }
 
diff --git a/crates/types/src/archive.rs b/crates/types/src/archive.rs
index 52146e7..0a57f4c 100644
--- a/crates/types/src/archive.rs
+++ b/crates/types/src/archive.rs
@@ -57,11 +57,7 @@ impl TinyWasmModule {
     /// Creates a TinyWasmModule from a slice of bytes.
     pub fn from_twasm(wasm: &[u8]) -> Result<TinyWasmModule, TwasmError> {
         let len = validate_magic(wasm)?;
-        let root = check_archived_root::<Self>(&wasm[len..]).map_err(|_e| {
-            crate::log::error!("Invalid archive: {}", _e);
-            TwasmError::InvalidArchive
-        })?;
-
+        let root = check_archived_root::<Self>(&wasm[len..]).map_err(|_e| TwasmError::InvalidArchive)?;
         Ok(root.deserialize(&mut rkyv::Infallible).unwrap())
     }
 
diff --git a/crates/types/src/instructions.rs b/crates/types/src/instructions.rs
index d19326d..dd201ad 100644
--- a/crates/types/src/instructions.rs
+++ b/crates/types/src/instructions.rs
@@ -1,50 +1,6 @@
 use super::{FuncAddr, GlobalAddr, LabelAddr, LocalAddr, TableAddr, TypeAddr, ValType};
 use crate::{DataAddr, ElemAddr, MemAddr};
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "archive", derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize), archive(check_bytes))]
-pub enum BlockArgs {
-    Empty,
-    Type(ValType),
-    FuncType(u32),
-}
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "archive", derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize), archive(check_bytes))]
-/// A packed representation of BlockArgs
-/// This is needed to keep the size of the Instruction enum small.
-/// Sadly, using #[repr(u8)] on BlockArgs itself is not possible because of the FuncType variant.
-pub struct BlockArgsPacked([u8; 5]); // Modifying this directly can cause runtime errors, but no UB
-
-impl From<BlockArgs> for BlockArgsPacked {
-    fn from(args: BlockArgs) -> Self {
-        let mut packed = [0; 5];
-        match args {
-            BlockArgs::Empty => packed[0] = 0,
-            BlockArgs::Type(t) => {
-                packed[0] = 1;
-                packed[1] = t.to_byte();
-            }
-            BlockArgs::FuncType(t) => {
-                packed[0] = 2;
-                packed[1..].copy_from_slice(&t.to_le_bytes());
-            }
-        }
-        Self(packed)
-    }
-}
-
-impl From<BlockArgsPacked> for BlockArgs {
-    fn from(packed: BlockArgsPacked) -> Self {
-        match packed.0[0] {
-            0 => BlockArgs::Empty,
-            1 => BlockArgs::Type(ValType::from_byte(packed.0[1]).unwrap()),
-            2 => BlockArgs::FuncType(u32::from_le_bytes(packed.0[1..].try_into().unwrap())),
-            _ => unreachable!(),
-        }
-    }
-}
-
 /// Represents a memory immediate in a WebAssembly memory instruction.
 #[derive(Debug, Copy, Clone, PartialEq)]
 #[cfg_attr(feature = "archive", derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize), archive(check_bytes))]
@@ -106,9 +62,19 @@ pub enum Instruction {
     // See <https://webassembly.github.io/spec/core/binary/instructions.html#control-instructions>
     Unreachable,
     Nop,
-    Block(BlockArgs, EndOffset),
-    Loop(BlockArgs, EndOffset),
-    If(BlockArgsPacked, ElseOffset, EndOffset), // If else offset is 0 if there is no else block
+    
+    Block(EndOffset),
+    BlockWithType(ValType, EndOffset),
+    BlockWithFuncType(TypeAddr, EndOffset),
+
+    Loop(EndOffset),
+    LoopWithType(ValType, EndOffset),
+    LoopWithFuncType(TypeAddr, EndOffset),
+
+    If(ElseOffset, EndOffset),
+    IfWithType(ValType, ElseOffset, EndOffset),
+    IfWithFuncType(TypeAddr, ElseOffset, EndOffset),
+
     Else(EndOffset),
     EndBlockFrame,
     Br(LabelAddr),
@@ -233,44 +199,3 @@ pub enum Instruction {
     DataDrop(DataAddr),
     ElemDrop(ElemAddr),
 }
-
-#[cfg(test)]
-mod test_blockargs_packed {
-    use super::*;
-
-    #[test]
-    fn test_empty() {
-        let packed: BlockArgsPacked = BlockArgs::Empty.into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::Empty);
-    }
-
-    #[test]
-    fn test_val_type_i32() {
-        let packed: BlockArgsPacked = BlockArgs::Type(ValType::I32).into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::Type(ValType::I32));
-    }
-
-    #[test]
-    fn test_val_type_i64() {
-        let packed: BlockArgsPacked = BlockArgs::Type(ValType::I64).into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::Type(ValType::I64));
-    }
-
-    #[test]
-    fn test_val_type_f32() {
-        let packed: BlockArgsPacked = BlockArgs::Type(ValType::F32).into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::Type(ValType::F32));
-    }
-
-    #[test]
-    fn test_val_type_f64() {
-        let packed: BlockArgsPacked = BlockArgs::Type(ValType::F64).into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::Type(ValType::F64));
-    }
-
-    #[test]
-    fn test_func_type() {
-        let packed: BlockArgsPacked = BlockArgs::FuncType(0x12345678).into();
-        assert_eq!(BlockArgs::from(packed), BlockArgs::FuncType(0x12345678));
-    }
-}
diff --git a/crates/types/src/lib.rs b/crates/types/src/lib.rs
index 785b13b..cdee7e6 100644
--- a/crates/types/src/lib.rs
+++ b/crates/types/src/lib.rs
@@ -14,7 +14,7 @@ use core::{fmt::Debug, ops::Range};
 
 // log for logging (optional).
 #[cfg(feature = "logging")]
-#[allow(clippy::single_component_path_imports)]
+#[allow(clippy::single_component_path_imports, unused)]
 use log;
 
 #[cfg(not(feature = "logging"))]
@@ -125,7 +125,7 @@ pub type ExternAddr = Addr;
 
 // additional internal addresses
 pub type TypeAddr = Addr;
-pub type LocalAddr = Addr;
+pub type LocalAddr = u16; // there can't be more than 50.000 locals in a function
 pub type LabelAddr = Addr;
 pub type ModuleInstanceAddr = Addr;
 
diff --git a/crates/types/src/value.rs b/crates/types/src/value.rs
index 6c422d0..c418338 100644
--- a/crates/types/src/value.rs
+++ b/crates/types/src/value.rs
@@ -146,31 +146,6 @@ impl ValType {
     pub fn is_simd(&self) -> bool {
         matches!(self, ValType::V128)
     }
-
-    pub(crate) fn to_byte(self) -> u8 {
-        match self {
-            ValType::I32 => 0x7F,
-            ValType::I64 => 0x7E,
-            ValType::F32 => 0x7D,
-            ValType::F64 => 0x7C,
-            ValType::V128 => 0x7B,
-            ValType::RefFunc => 0x70,
-            ValType::RefExtern => 0x6F,
-        }
-    }
-
-    pub(crate) fn from_byte(byte: u8) -> Option<Self> {
-        match byte {
-            0x7F => Some(ValType::I32),
-            0x7E => Some(ValType::I64),
-            0x7D => Some(ValType::F32),
-            0x7C => Some(ValType::F64),
-            0x7B => Some(ValType::V128),
-            0x70 => Some(ValType::RefFunc),
-            0x6F => Some(ValType::RefExtern),
-            _ => None,
-        }
-    }
 }
 
 macro_rules! impl_conversion_for_wasmvalue {
@@ -202,9 +177,4 @@ macro_rules! impl_conversion_for_wasmvalue {
     }
 }
 
-impl_conversion_for_wasmvalue! {
-    i32 => I32,
-    i64 => I64,
-    f32 => F32,
-    f64 => F64
-}
+impl_conversion_for_wasmvalue! { i32 => I32, i64 => I64, f32 => F32, f64 => F64, u128 => V128 }