←back to thread

C++ proposal: There are exactly 8 bits in a byte

(www.open-std.org)
288 points Twirrim | 2 comments | 17 Oct 24 22:21 UTC | HN request time: 0.425s | source
Show context
throwaway889900 ◴[17 Oct 24 23:18 UTC] No.41874794[source]▶
But how many bytes are there in a word?
replies(4): >>41874796 #>>41874838 #>>41875260 #>>41875413 #
wvenable ◴[17 Oct 24 23:27 UTC] No.41874838[source]▶
"Word" is an outdated concept we should try to get rid of.
replies(4): >>41874888 #>>41874892 #>>41874933 #>>41875850 #
pclmulqdq ◴[17 Oct 24 23:32 UTC] No.41874888[source]▶
It's very useful on hardware that is not an x86 CPU.
replies(2): >>41874937 #>>41874988 #
wvenable ◴[17 Oct 24 23:39 UTC] No.41874937[source]▶
As an abstraction on the size of a CPU register, it really turned out to be more confusing than useful.
replies(3): >>41874993 #>>41875003 #>>41875078 #
1. bobmcnamara ◴[17 Oct 24 23:49 UTC] No.41874993[source]▶
Is it 32 or 64 bits on ARM64? Why not both?
replies(1): >>41876643 #
2. billti ◴[18 Oct 24 05:42 UTC] No.41876643[source]▶
ARM64 has a 32-bit word, even though the native pointer size and general register size is 64 bits. To access just the lower 32 bits of a register Xn you refer to it as Wn.