[etaioinshrdlu]

I had assumed the opposite, that ARM was better in terms of Op/J. Can you provide a reference to make it certain?

Also, I wonder if the low density of RISC could be countered by introducing execution of compressed/zipped machine code. Some compressors like brotli are highly tuned to the expected type of data to be compressed and are very compact. All entry points to basic blocks in the code are generally known at compile time, so it can be ensured that the jump destinations are decompressible without any context, avoiding the slow process of needing to scan backwards to start decompressing...

[kevin_thibedeau]

Arm Thumb is a compressed ISA. Intel has been decompressing x86 instructions into an internal RISC machine since the Pentium Pro. The benefit is getting more instructions through the chokepoint from DRAM to L1 cache.