The[/your?] article mentions two current concerns with code density, "Cache hit ratio," and "Instruction fetch bandwidth."
Does the footprint of Thumb (including total bytes, count of opcodes, speed, likely other things that I have not thought of) impact the conclusions in the paper?
Interesting that Thumb has been removed from AArch64, and that Intel never added anything like it.
My experience from Thumb was that it makes code slower. Probably because the CPU had to execute more insteuctions than in "ARM" mode.
Thumb was a thing for embedded systems with very limited RAM etc. It was not designed for optimal speed.
My guess is that ARM64 targeted higher end, and that severe memory constraints were no longer considered a big issue. ARM has its Cortex M4 (Thumb only microcontrollers) and the likes for those markets.
Does the footprint of Thumb (including total bytes, count of opcodes, speed, likely other things that I have not thought of) impact the conclusions in the paper?
Interesting that Thumb has been removed from AArch64, and that Intel never added anything like it.