2016-12-25 16:33 GMT-05:00 His Shadow <[email protected]>: > I thought that only addresses doubled, not the instruction opcodes.
This is mostly right. Instructions that use 64 bit operands, or registers with absolute value larger than 7 also need a prefix https://en.wikipedia.org/wiki/VEX_prefix#REX Running in 32 bit mode also uses only 8 from the 16 registers. It is possible to have a 32 bit distro enabled, just that some directories will conflict, e.g. there is no /bin32 or /bin64. About the upper 32 bits, some instructions do not touch the upper 32 bit, some zero fill and other sign fill the result, and most have some encoding to tell if using 32 or 64 input operands. Some distros have a x32 version: https://en.wikipedia.org/wiki/X32_ABI that uses 32 bit pointers. Thanks, Paulo _______________________________________________ OM-Cooker mailing list [email protected] http://ml.openmandriva.org/mailman/listinfo/om-cooker_ml.openmandriva.org
