3 ms·
As an abstraction on the size of a CPU register, it really turned out to be more confusing than useful.
by wvenable 2y ago
As an abstraction on the size of a CPU register, it really turned out to be more confusing than useful.
- o11c 2y agoFortunately we have `register_t` these days.
- bobmcnamara 2y agoIs it 32 or 64 bits on ARM64? Why not both?
- billti 2y agoARM64 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.
- pclmulqdq 2y agoOn RISC machines, it can be very useful to have the concept of "words," because that indicates things about how the computer loads and stores data, as well as the native instruction size. In DSPs and custom hardware, it can indicate the only available datatype. The land of x86 goes to great pains to eliminate the concept of a word at a silicon cost.