3 ms·
The cpu bus is what’s important. Bus addressing us at the byte level
by bodhiandphysics 5y ago
The cpu bus is what’s important. Bus addressing us at the byte level
- shakow 5y agoOn modern CPU, byte-level addressing is but smoke and mirrors for what is a fetch of a line-sized memory chunk followed by a mask-and-shift.
- bodhiandphysics 5y agoNot at the ISA level. Programmers don’t have access to the smoke and mirrors besides some cache management stuff
- p_l 5y agoDepends on the cpu specific, and a lot of non-x86 designs made it explicit that memory is not byte addressable without special steps. This makes those architectures incompatible with latest C and C++ though, because they require simultaneous, concurrent, atomic access to bytes at a time
- bodhiandphysics 5y agoThe most important non x86 arch is aarch64 which is in fact byte addressable (more so than x86)! So is mips64.
- bodhiandphysics 5y agoUsing c on a word machine is just a bad idea.
- shakow 5y agoBut x86_64 ISA is smoke and mirrors; proof is the large increase in performances that can obtained when one is aware of these tricks.