feat: basic i32 loads/stores

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

Author: explodingcamera

crates/parser/src/conversion.rs

@@ -280,6 +280,8 @@ pub(crate) fn convert_memarg(memarg: wasmparser::MemArg) -> MemArg {
     MemArg {
         offset: memarg.offset,
         align: memarg.align,
+        align_max: memarg.max_align,
+        mem_addr: memarg.memory,
     }
 }
 

crates/tinywasm/src/runtime/executor/mod.rs

@@ -7,7 +7,7 @@ use crate::{
     runtime::{BlockType, LabelFrame},
     CallFrame, Error, ModuleInstance, Result, Store,
 };
-use alloc::{format, vec::Vec};
+use alloc::vec::Vec;
 use log::info;
 use tinywasm_types::Instruction;
 
@@ -302,6 +302,32 @@ fn exec_one(
             }
         }
 
+        I32Store(arg) => {
+            let mem_idx = module.resolve_mem_addr(arg.mem_addr);
+            let mem = store.get_mem(mem_idx as usize)?;
+
+            let val = stack.values.pop()?.raw_value();
+            let addr = stack.values.pop()?.raw_value();
+
+            mem.borrow_mut()
+                .store((arg.offset + addr) as usize, arg.align as usize, &val.to_le_bytes())?;
+        }
+
+        I32Load(arg) => {
+            let mem_idx = module.resolve_mem_addr(arg.mem_addr);
+            let mem = store.get_mem(mem_idx as usize)?;
+
+            let addr = stack.values.pop()?.raw_value();
+
+            let val: [u8; 4] = {
+                let mem = mem.borrow_mut();
+                let val = mem.load((arg.offset + addr) as usize, arg.align as usize, 4)?;
+                val.try_into().expect("slice with incorrect length")
+            };
+
+            stack.values.push(i32::from_le_bytes(val).into());
+        }
+
         I64Eqz => comp_zero!(==, i64, stack),
         I32Eqz => comp_zero!(==, i32, stack),
 

crates/tinywasm/src/runtime/value.rs

@@ -17,6 +17,10 @@ impl Debug for RawWasmValue {
 }
 
 impl RawWasmValue {
+    pub fn raw_value(&self) -> u64 {
+        self.0
+    }
+
     pub fn attach_type(self, ty: ValType) -> WasmValue {
         match ty {
             ValType::I32 => WasmValue::I32(self.0 as i32),

crates/tinywasm/src/store.rs

@@ -5,8 +5,8 @@ use core::{
 
 use alloc::{format, rc::Rc, string::ToString, vec, vec::Vec};
 use tinywasm_types::{
-    Addr, Data, Element, ElementKind, FuncAddr, Function, Global, GlobalType, Import, Instruction, MemAddr, MemoryArch,
-    MemoryType, ModuleInstanceAddr, TableAddr, TableType, TypeAddr, ValType,
+    Addr, Data, Element, ElementKind, FuncAddr, Function, Global, GlobalType, Import, Instruction, MemAddr, MemArg,
+    MemoryArch, MemoryType, ModuleInstanceAddr, TableAddr, TableType, TypeAddr, ValType,
 };
 
 use crate::{
@@ -343,6 +343,35 @@ impl MemoryInstance {
         }
     }
 
+    pub(crate) fn store(&mut self, addr: usize, align: usize, data: &[u8]) -> Result<()> {
+        if addr + data.len() > self.data.len() {
+            return Err(Error::Other(format!(
+                "memory store out of bounds: offset={}, len={}, mem_size={}",
+                addr,
+                data.len(),
+                self.data.len()
+            )));
+        }
+
+        // WebAssembly doesn't require alignment for stores
+        self.data[addr..addr + data.len()].copy_from_slice(data);
+        Ok(())
+    }
+
+    pub(crate) fn load(&self, addr: usize, align: usize, len: usize) -> Result<&[u8]> {
+        if addr + len > self.data.len() {
+            return Err(Error::Other(format!(
+                "memory load out of bounds: offset={}, len={}, mem_size={}",
+                addr,
+                len,
+                self.data.len()
+            )));
+        }
+
+        // WebAssembly doesn't require alignment for loads
+        Ok(&self.data[addr..addr + len])
+    }
+
     pub(crate) fn size(&self) -> i32 {
         self.page_count as i32
     }

crates/tinywasm/tests/generated/mvp.csv

@@ -10,9 +10,6 @@ fn main() -> Result<()> {
 fn test_mvp() -> Result<()> {
     let mut test_suite = TestSuite::new();
 
-    // currently hangs, so skip it for now
-    test_suite.skip(&["fac.wast"]);
-
     TestSuite::set_log_level(log::LevelFilter::Off);
     test_suite.run_spec_group(wasm_testsuite::MVP_TESTS)?;
 

crates/tinywasm/tests/generated/progress-mvp.svg

@@ -12,7 +12,9 @@ pub enum BlockArgs {
 /// Represents a memory immediate in a WebAssembly memory instruction.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct MemArg {
+    pub mem_addr: MemAddr,
     pub align: u8,
+    pub align_max: u8,
     pub offset: u64,
 }