4 ms·
It's not too surprising. Load, store, move, add, subtract, shift, branch, jump. These are definitely the most common instructions used. Put it side-by-side wit
by hajile 5y ago
It's not too surprising. Load, store, move, add, subtract, shift, branch, jump. These are definitely the most common instructions used.
Put it side-by-side with Thumb and it also looks pretty similar (thumb has a multiply instruction IIRC).
Put it side-by-side with short x86 instructions accounting for the outdated ones and the list is pretty similar (down to having 8 registers).
All in all, when old and new instruction sets are taking the same approach, you can be reasonably sure it's not the absolute worst choice.
- zamadatix 5y agoIt was more a question of the way it was handled (i.e. it's not a different mode and can be mixed) than what the opcode list looked like.
- hajile 5y agoMode switching bloats the instruction count by shifting in and out. RISC-V does well here. If there's a criticism, it's that the two bytes on 32-bit instructions mean the total instruction range is MUCH smaller overall until you switch to 48-bit instructions which are then much bigger.