Method int_sub

crates/vm/src/frame.rs:7097–7105

(&self, a: &BigInt, b: &BigInt, vm: &VirtualMachine)

    /// Int subtraction with i64 fast path to avoid BigInt heap allocation.
    #[inline]
    fn int_sub(&self, a: &BigInt, b: &BigInt, vm: &VirtualMachine) -> PyObjectRef {
        use num_traits::ToPrimitive;
        if let (Some(av), Some(bv)) = (a.to_i64(), b.to_i64())
            && let Some(result) = av.checked_sub(bv)
        {
            return vm.ctx.new_int(result).into();
        }
        vm.ctx.new_int(a - b).into()
    }

    #[cold]
    fn setup_annotations(&mut self, vm: &VirtualMachine) -> FrameResult {