Method alloc_slot_for_alloc

crates/ir-to-asm/src/compiler/function_context.rs:84–98

Allocate a stack slot for an `Alloc` (`stack_alloc`) instruction. Uses the actual inner type size rather than pointer size so structs get enough space.

(
        &mut self,
        reg: &IrRegister,
        ty: &IrType,
        count: Option<usize>,
    )

    ) -> usize {
        let elem_size = self.frame.type_size(ty, &self.type_aliases);
        let total_size = (elem_size * count.unwrap_or(1)).max(8);
        let alignment = self.frame.type_alignment(ty, &self.type_aliases).max(8);
        let slot = self.frame.alloc_slot(total_size, alignment);
        self.reg_slots.insert(reg.clone(), slot);
        self.reg_types
            .insert(reg.clone(), IrType::Pointer(Box::new(ty.clone())));
        slot
    }

    /// Reserve space for saving `ra`.
    pub fn save_ra(&mut self) {
        self.frame.save_ra();
    }

    /// Reserve space for saving a callee-saved register.
    pub fn save_reg(&mut self, reg: u8) {
        self.frame.save_reg(reg);
    }