4 ms·
Since RISC has a much smaller set of instruction compared to CISC, doesn't this mean any RISC software is about at least twice the size? Isn't there any study a
by jokoon 6y ago
Since RISC has a much smaller set of instruction compared to CISC, doesn't this mean any RISC software is about at least twice the size? Isn't there any study about average executable size when comparing CISC vs RISC?
If you look at smartphones, you always notice how much memory apps require. It's not a secret. It's odd that nobody seems to mention this.
Anyways, Wirth's law is relevant again. Nobody wants to hear it, but I really believe a new era of lightweight software will soon begin. I put a lot of hope in WASM, and I hope it will work well on smartphones.
I'm using tinder on a 3 year old android, and everyday it's slower and slower.
It's almost like software companies and hardware vendors have the opposite interests. Software wants to be faster, but hardware vendors wants to increase their margin, so they want software to be slower or be more feature-rich.
- cesarb 6y ago> Isn't there any study about average executable size when comparing CISC vs RISC? The RISC-V people have done a few while developing their RVC (compressed instructions) extension; see for instance slide 16 of https://riscv.org/wp-content/uploads/2015/06/riscv-compressed-workshop-june2015.pdf https://riscv.org/wp-content/uploads/2015/06/riscv-compresse... which shows, on 64-bit, x86-64 (CISC) being slightly bigger than ARMv8 (RISC), and on 32-bit, x86 (CISC) being much bigger than ARM Thumb2 (RISC). The main reason is that the encoding of x86 instructions is not very efficient, with rare instructions having shorter encodings than common instructions; an infamous example being the "ASCII adjust" single-byte instructions which nobody uses.
- jokoon 6y agoInteresting, thanks! Are compressed instructions always enabled by default?