feat: all mem loads

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

Author: explodingcamera

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

@@ -2,6 +2,32 @@
 //!
 //! These macros are used to generate the actual instruction implementations.
 
+macro_rules! mem_load {
+    ($type:ty, $arg:ident, $stack:ident, $store:ident, $module:ident) => {{
+        mem_load!($type, $type, $arg, $stack, $store, $module)
+    }};
+
+    ($load_type:ty, $target_type:ty, $arg:ident, $stack:ident, $store:ident, $module:ident) => {{
+        let mem_idx = $module.resolve_mem_addr($arg.mem_addr);
+        let mem = $store.get_mem(mem_idx as usize)?;
+
+        let addr = $stack.values.pop()?.raw_value();
+
+        let val: [u8; core::mem::size_of::<$load_type>()] = {
+            let mem = mem.borrow_mut();
+            let val = mem.load(
+                ($arg.offset + addr) as usize,
+                $arg.align as usize,
+                core::mem::size_of::<$load_type>(),
+            )?;
+            val.try_into().expect("slice with incorrect length")
+        };
+
+        let loaded_value = <$load_type>::from_le_bytes(val);
+        $stack.values.push((loaded_value as $target_type).into());
+    }};
+}
+
 /// Convert the top value on the stack to a specific type
 macro_rules! conv_1 {
     ($from:ty, $to:ty, $stack:ident) => {{
@@ -10,6 +36,10 @@ macro_rules! conv_1 {
     }};
 }
 
+/// Doing the actual conversion from float to int is a bit tricky, because
+/// we need to check for overflow. This macro generates the min/max values
+/// for a specific conversion, which are then used in the actual conversion.
+/// Rust sadly doesn't have wrapping casts for floats (yet)
 macro_rules! float_min_max {
     (f32, i32) => {
         (-2147483904.0_f32, 2147483648.0_f32)
@@ -18,22 +48,22 @@ macro_rules! float_min_max {
         (-2147483649.0_f64, 2147483648.0_f64)
     };
     (f32, u32) => {
-        (-1.0_f32, 4294967296.0_f32)
+        (-1.0_f32, 4294967296.0_f32) // 2^32
     };
     (f64, u32) => {
-        (-1.0_f64, 4294967296.0_f64)
+        (-1.0_f64, 4294967296.0_f64) // 2^32
     };
     (f32, i64) => {
-        (-9223373136366403584.0_f32, 9223372036854775808.0_f32)
+        (-9223373136366403584.0_f32, 9223372036854775808.0_f32) // 2^63 + 2^40 | 2^63
     };
     (f64, i64) => {
-        (-9223372036854777856.0_f64, 9223372036854775808.0_f64)
+        (-9223372036854777856.0_f64, 9223372036854775808.0_f64) // 2^63 + 2^40 | 2^63
     };
     (f32, u64) => {
-        (-1.0_f32, 18446744073709551616.0_f32)
+        (-1.0_f32, 18446744073709551616.0_f32) // 2^64
     };
     (f64, u64) => {
-        (-1.0_f64, 18446744073709551616.0_f64)
+        (-1.0_f64, 18446744073709551616.0_f64) // 2^64
     };
     // other conversions are not allowed
     ($from:ty, $to:ty) => {
@@ -212,3 +242,4 @@ pub(super) use comp_zero;
 pub(super) use conv_1;
 pub(super) use conv_2;
 pub(super) use float_min_max;
+pub(super) use mem_load;

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

@@ -313,20 +313,20 @@ fn exec_one(
                 .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());
-        }
+        I32Load(arg) => mem_load!(i32, arg, stack, store, module),
+        I64Load(arg) => mem_load!(i64, arg, stack, store, module),
+        F32Load(arg) => mem_load!(f32, arg, stack, store, module),
+        F64Load(arg) => mem_load!(f64, arg, stack, store, module),
+        I32Load8S(arg) => mem_load!(i8, i32, arg, stack, store, module),
+        I32Load8U(arg) => mem_load!(u8, i32, arg, stack, store, module),
+        I32Load16S(arg) => mem_load!(i16, i32, arg, stack, store, module),
+        I32Load16U(arg) => mem_load!(u16, i32, arg, stack, store, module),
+        I64Load8S(arg) => mem_load!(i8, i64, arg, stack, store, module),
+        I64Load8U(arg) => mem_load!(u8, i64, arg, stack, store, module),
+        I64Load16S(arg) => mem_load!(i16, i64, arg, stack, store, module),
+        I64Load16U(arg) => mem_load!(u16, i64, arg, stack, store, module),
+        I64Load32S(arg) => mem_load!(i32, i64, arg, stack, store, module),
+        I64Load32U(arg) => mem_load!(u32, i64, arg, stack, store, module),
 
         I64Eqz => comp_zero!(==, i64, stack),
         I32Eqz => comp_zero!(==, i32, stack),