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Do number of instructions even matter on modern chips? intel/amd chips don't even use x86 since they break it down in to their own internal RISC via a translati
by SilverRed 5y ago
Do number of instructions even matter on modern chips? intel/amd chips don't even use x86 since they break it down in to their own internal RISC via a translation layer?
If you have a CPU that breaks one mega x86 instruction in to 100 internal instructions, is that any better than 100 external instructions generated by a compiler?
- sudosysgen 5y agoIt does and doesn't. When your CPU is breaking up that instruction you can optimize for the exact way its being broken up at the design because you know what those 100 instructions will be and in what order. You pay for that with more decode. It's a trade-off, but it does mean there is less of a need for the machinery the M1 has more of, somewhat.
- ithkuil 5y agoYou have to feed those 100 instructions to the CPU, this takes memory bandwidth, which means you need larger instruction caches. Caches take up most of the space and power on modern hardware