feat(backend): Add var align

src/backend/generator.rs

@@ -10,6 +10,7 @@ pub struct Generator {
     register_allocator: RegisterAllocator,
 }
 
+const DEFAULT_VAR_ALIGN: usize = 4;
 impl Generator {
     pub fn new() -> Self {
         Self {
@@ -32,10 +33,10 @@ impl Generator {
         let mut text = String::new();
         text.push_str(".arch armv7ve\n.arm\n.fpu vfpv4\n");
         for var in &self.var_uninited {
-            text.push_str(&format!(".comm {}, {}\n", var.name, var.size));
+            text.push_str(&format!(".comm {}, {}, {}\n", var.name, var.size, var.align));
         }
         for var in &self.var_inited {
-            text.push_str(&format!(".data\n.align 4\n.global {}\n.type {}, @object\n:{}\n", var.name, var.name, var.name));
+            text.push_str(&format!(".data\n.align {}\n.global {}\n.type {}, @object\n:{}\n", var.align, var.name, var.name, var.name));
             text.push_str(&format!(".word 0\n"));
         }
         text.push_str(".text\n");
@@ -50,6 +51,7 @@ impl Generator {
         self.var_uninited.push(ARMAsmVar {
             name: format!("global_var_{}", var.index),
             size: var.data_type.size_in_bytes(),
+            align: DEFAULT_VAR_ALIGN,
         });
     }
 

src/backend/types.rs

@@ -1,4 +1,5 @@
 pub struct ARMAsmVar {
     pub name: String,
     pub size: usize,
+    pub align: usize,
 }