The latest news to leak out of the tightly wound Merced community makes it abundantly clear that software will be the linchpin of Intel Corp.'s upcoming 64-bit architecture. Sure, the silicon itself will be significant. But without smart compiler technology, which can turn complex applications programs into uninterrupted parallel streams of machine instructions, Merced won't outperform today's superscalar architectures.

Now, a first glimpse of that technology is available thanks to Hewlett-Packard, which has authorized the release of a research compiler called Trimaran and a related set of performance-monitoring tools.

There are a few major caveats. The compiler itself doesn't actually use the IA-64 instruction set implemented by Merced. Nor does it run on Intel hardware.

But Trimaran does support predication and speculation-the two software techniques at the heart of the microprocessor. (Predication removes unnecessary branches from a program; speculation masks memory latency by executing load instructions as early as possible.)

Now, anyone with a well-equipped lab and a bunch of experienced computer scientists in their employ will be able to assess whether Intel is barking up the right tree.

Trimaran, which can be downloaded for free from www.trimaran.org, is based heavily on the pioneering Impact compiler research conducted by Wen-mei Hwu at the University of Illinois at Urbana-Champaign. It also includes contributions from researchers at HP and at New York University. "The only constraint is that you can't sell products directly based on the research," Hwu told me.

Officially, HP said it's offering Trimaran to spur academic study into code-optimization algorithms that can boost IA-64 performance.

"It's an architecture that doesn't like surprises," said Tom Christian, a compiler expert at HP Labs. "Things like branches that go the wrong way or loads that miss the cache are bad news. You can stall the processor or have to completely unload the stack and start over again."

For his part, Hwu said compilers will be crucial to Merced's success. "Once IA-64 is released, there will be a long period of rapid performance improvements," Hwu said. "We have lots of room for researchers to contribute new algorithms."

Currently, Trimaran runs only on workstations equipped with the HP-UX operating system. Ports to Windows NT and Sun OS are expected soon, however.

Intel watchers hoping for a glimpse at shipping software will be disappointed: Trimaran won't be part of the Merced's production compiler.