Preparing For Future Software: AMD's Lightweight Profiling Proposal

It's not often these days that we see AMD's name attached to new x86 instructions. While monumental to the creation of the AMD64/x86-64 standard for 64bit processors and the No-eXecute bit for buffer overflow protection, we haven't otherwise heard much out of AMD lately. It's been Intel driving new instruction sets, with standards such as SSE3, SSE4, and VT for virtualization (with AMD's own implementation, AMD-v following).

With AMD's impressive track record in recent years, we're all ears when they are announcing something new about x86 instructions. However with that said, what we're looking at today is not a new instruction set for high performance instructions, or a new safety measure. In fact AMD's proposal doesn't even directly apply to most computer users, they'll likely never use these instructions. What AMD is proposing is to our knowledge a first for the x86 instruction set: a set of instructions solely for developers.

As part of the newly-launched Extensions for Software Parallelism initiative, AMD is making its first move by announcing the Lightweight Profiling Proposal(LWP), a proposed standard for adding hardware and instructions to help fine tune their code and improve application performance by profiling the performance of their applications. With this addition to the x86 instruction set, AMD is specifically targeting managed code environments and developers producing multithreaded applications, two of the biggest areas of growth in the software industry. AMD believes that these groups stand to benefit the most from LWP given the unique difficulties faced by those two fields.

Although the hardware to come from this proposal is still some time off, we're in a position today to talk about some the benefits that can be extracted from such hardware, and some of the hurdles in bringing about such a change. Profilers can be extremely powerful tools, with special purpose platforms such as embedded computers and video game consoles having used such hardware and software to squeeze an amazing amount of performance out of what can be very limited hardware. In some ways what AMD is proposing is simply bringing the PC up to par with other systems, and what they're proposing is simply simple. But never the less, the potential performance can be huge.

So what is profiling, why does it have such a potential to improve performance, and how does AMD intend to improve profiling? Let's take a look.