If you want to guarantee a size use the corresponding type. uint8_t uint16_t uint32_t uint64_t uint128_t or the signed varients int8_t int16_t int32_t int64_t int128_t On Wed, 2018-10-03 at 10:00 -0500, sundaresh wrote: > Thanks to all of you. The __attribute__ worked but later came to know > about > #pragma pack also and tried that and simpler. However I am using > compile > option -m32 but I would like long to be 64 bit rather than 32 bit. Is > using > long long the only way to go about doing it. What is the best way to > make > long a 64 bit irrespective of whether it is compiled for a 32-bit or > for a > 64-bit architecture ? > > > > -- > Sent from: http://gcc.1065356.n8.nabble.com/gcc-Help-f629689.html