Loading Up the Stores

By Jim Turley  |  Posted 2002-02-11 Print this article Print

IA-64 is surprisingly stingy with memory-addressing modes. It has precisely one: register-indirect with optional post-increment. This seems horribly limiting but is very RISC-like in philosophy. Addresses are calculated just like any other number and deposited in a general-purpose register. By avoiding special addressing modes, Itanium avoids specialized hardware in the critical path. VLIW pushes complexity onto the compiler instead of the hardware. Loads can be pretty uninteresting, but IA-64 manages to spice them up a bit. Loads can "hint" to the cache that it would be beneficial to preload additional data after the load, whether that data is likely to be reused, and if so, which of the three cache levels is most appropriate to hold it. These are not the kinds of things even dedicated assembly-language programmers are likely to know, but large-scale commercial developers might profile a new operating system or major application extensively, and use the feedback to provide prefetch and caching hints. These are just hints, too--the processor is under no obligation to act on the hints or the caching information.

Jim Turley is a semiconductor industry analyst, editor, and presenter working in Silicon Valley. Focus technologies are 32-bit microprocessors and semiconductor intellectual property (SIP).

Most recently Jim was the Senior Vice President of Strategy & Technology at ARC International plc (LSE:ARK), where he set the Company's strategic direction and guided its technical developments at five locations worldwide. With headquarters in London (UK) and development centers in New Hampshire, Canada, and California, ARC International is an innovative leader in the semiconductor IP (intellectual property) industry.

Previously, Jim was senior analyst for MicroDesign Resources (a unit of Cahners/Reed Elsevier) as well as the Senior Editor of the prestigious industry journal Microprocessor Report (a three-time winner of the Computer Press Award), and Editor-in-Chief of Embedded Processor Watch. He also hosted and directed the yearly Embedded Processor Forum conference, the industry's annual showcase for new microprocessors. As an analyst and editor, Turley consulting with leading semiconductor firms, providing informed advice on technology trends and market requirements, and was often called on to participate in new product reviews, strategy sessions, and technology development for large semiconductor companies.

Turley is the author of six popular books including Advanced 80386 Programming Techniques, the best-selling PCs Made Easy and others published by McGraw-Hill and Academic Press. He's served as technical editor for several of McGraw-Hill's computer and programming books. In addition, he was a regular technology columnist for Embedded System Programming, Computer Design, and Supermicro magazines, and contributed articles to dozens more. Earlier in his career, Turley held engineering or marketing positions at Adept Technology, Force Computers, TeleVideo, and other high-technology firms in Europe and the United States.

Turley has created and presented numerous seminars and training sessions around the world covering technology trends and the competitive microprocessor market. He is also a well-known speaker at industry events such as the Embedded Systems Conference and Microprocessor Forum, is frequently quoted in the Wall Street Journal, New York Times, USA Today, San Francisco Chronicle, and San Jose Mercury News, and has appeared frequently on television, radio, and Internet broadcasts. Jim volunteers for Recording for the Blind and recently earned his amateur auto-racing license. He has a talented and stunningly attractive wife, two overachieving children, an apparently brain-damaged dog, and an opossum living under the house.

Jim can be contacted at info@jimturley.com or by calling (408) 226-8086.

For additional information, visit http://www.jimturley.com.


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