Nice jab at Emacs ;)

Nice jab at Emacs ;)

From the article:

Building "cat" as a 64-bit application can only serve to make it bigger and slower. So a processor with native 32-bit support is a good thing.

Actually, on the x86-64 architecture, the "slower" bit is dubious.

In 32 bit mode (which is designed to run existing binaries without modification), programs only have access to the x86's eight general purpose registers, and not all of these are really general purpose. In 64 bit mode, AMD have added an extra eight.

This means that x86-64 binaries have to load and store data to (usually cache) memory less often. This means that there are usually less instructions for the processor to decode.

It also means that compilers have more registers to play with when optimising. On the x86, there is often a limit to the amount of instruction-level parallelism that compliers can get out of source, simply because there aren't enough registers to spell out that several operations can happen at the same time. The extra eight registers are supposed to make this sort of optimisation a lot easier.

James.