Power Efficient Software Coding

Question

In a typical handheld/portable embedded system device Battery life is a major concern in design of H/W, S/W and the features the device can support. From the Software progra

Answer 1

Well, to the extent that your code can execute entirely in the processor cache, you'll have less bus activity and save power. To the extent that your program is small enough to fit code+data entirely in the cache, you get that benefit "for free". OTOH, if your program is too big, and you can divide your programs into modules that are more or less independent of the other, you might get some power saving by dividing it into separate programs. (I suppose it's also possible to make a toolchain that spreas out related bundles of code and data into cache-sized chunks...)

I suppose that, theoretically, you can save some amount of unnecessary work by reducing the number of pointer dereferencing, and by refactoring your jumps so that the most likely jumps are taken first -- but that's not realistic to do as a programmer.

Transmeta had the idea of letting the machine do some instruction optimization on-the-fly to save power... But that didn't seem to help enough... And look where that got them.