static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg,
				 struct bpf_reg_state *src_reg)
{
	bool src_known = tnum_subreg_is_const(src_reg->var_off);
	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
	s32 smin_val = src_reg->s32_min_value;

	if (src_known && dst_known) {
		__mark_reg32_known(dst_reg, var32_off.value);
		return;
	}

	/* We get both minimum and maximum from the var32_off. */
	dst_reg->u32_min_value = var32_off.value;
	dst_reg->u32_max_value = var32_off.value | var32_off.mask;

	if (dst_reg->s32_min_value >= 0 && smin_val >= 0) {
		/* XORing two positive sign numbers gives a positive,
		 * so safe to cast u32 result into s32.
		 */
		dst_reg->s32_min_value = dst_reg->u32_min_value;
		dst_reg->s32_max_value = dst_reg->u32_max_value;
	} else {
		dst_reg->s32_min_value = S32_MIN;
		dst_reg->s32_max_value = S32_MAX;
	}
}