Agner`s CPU blog

why do we still use conventional -- and enormous -- memory addresses?

We use 64-bit (or 48 actual I think on x64). Since it's a program's exclusive virtual memory space, a universe of our own, why can't we use arbitrary and much, much smaller addresses? Like 1, 2, 3, etc., basically a byte or two.

Separately, I think it would be fruitful to think about how an ISA could be designed to help JITs, and common parsing workloads like the web. If we designed an ISA to increase the performance of browser JS engines,. NET and Java VMs, etc. what would that look like? Would it be instruction selection that mattered most, or other aspects of the architecture?

My proposal includes variable-length vector registers that enable the software to adapt automatically to the different vector sizes of different processors without recompiling. If one compiled executable file fits all variants of the processor, why do we need JIT compilers at all?

Interpreters for byte code languages have a lot of jump tables or tables of function pointers. My proposal has an instruction for efficient handling of jump/call tables of 32-bit pointers relative to an arbitrary reference point.

Intel rolled out some great instructions for string parsing in SSE 4.2, but my impression is that hardly any developers know about them or use then