Add i32 literals support.

src/backend.rs

@@ -261,7 +261,7 @@ pub fn get_local_i32(ctx: &mut Context, local_idx: u32) {
     push_i32(ctx, gpr);
 }
 
-pub fn store_i32(ctx: &mut Context, local_idx: u32) {
+pub fn set_local_i32(ctx: &mut Context, local_idx: u32) {
     let gpr = pop_i32(ctx);
     let offset = sp_relative_offset(ctx, local_idx);
     dynasm!(ctx.asm
@@ -270,6 +270,14 @@ pub fn store_i32(ctx: &mut Context, local_idx: u32) {
     ctx.regs.release_scratch_gpr(gpr);
 }
 
+pub fn literal_i32(ctx: &mut Context, imm: i32) {
+    let gpr = ctx.regs.take_scratch_gpr();
+    dynasm!(ctx.asm
+        ; mov Rd(gpr), imm
+    );
+    push_i32(ctx, gpr);
+}
+
 pub fn relop_eq_i32(ctx: &mut Context) {
     let right = pop_i32(ctx);
     let left = pop_i32(ctx);

src/function_body.rs

@@ -217,6 +217,9 @@ pub fn translate(
             Operator::GetLocal { local_index } => {
                 get_local_i32(&mut ctx, local_index);
             }
+            Operator::I32Const { value } => {
+                literal_i32(&mut ctx, value);
+            }
             Operator::Call { function_index } => {
                 let callee_ty = translation_ctx.func_type(function_index);
                 assert!(callee_ty.returns.len() == 0, "is not supported");

src/tests.rs

@@ -129,4 +129,18 @@ fn function_call() {
     assert_eq!(execute_wat(code, 2, 0), 2);
 }
 
+#[test]
+fn literals() {
+    let code = r#"
+(module
+  (func (param i32) (param i32) (result i32)
+    (i32.const 228)
+  )
+)
+    "#;
+
+    assert_eq!(execute_wat(code, 0, 0), 228);
+}
+
+
 // TODO: Add a test that checks argument passing via the stack.