static __inline int
rowcol_parse_variable_compat(struct _citrus_mapper_std_rowcol *rc,
        struct _region *r)
{
        const struct _citrus_mapper_std_rowcol_info_compat_x *rcx;
        struct _citrus_mapper_std_linear_zone *lz;
        u_int32_t m, n;
        int ret; 
 
        _DIAGASSERT(rc != NULL);
        _DIAGASSERT(r != NULL && _region_size(r) == sizeof(*rcx));
        rcx = _region_head(r);
 
        rc->rc_dst_invalid = be32toh(rcx->rcx_dst_invalid);
        rc->rc_dst_unit_bits = be32toh(rcx->rcx_dst_unit_bits);   
        m = be32toh(rcx->rcx_src_col_bits);
        n = 1 << (m - 1);  /// <- here
        n |= n - 1;
        rc->rc_src_rowcol_bits = m;
        rc->rc_src_rowcol_mask = n;

# nm /usr/lib/libc.so|grep sanit                                                                                                                            
/public/src.git/lib/libc/citrus/modules/citrus_mapper_std.c:173:8: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'