Implementations of VLIW

Sounds like a homework problem to me. Did you read the textbook?

Anyhow, if the implementations aren't binary-compatible with each other, they aren't the same architecture, by definition. Computer architecture was defined by Brooks and Blaauw to be the characteristics of the computer that are visible to the programmer, so two implementations of the same architecture of necessity must be binary compatible.

The definition is not stictly adhered to in practice. For instance, people talk about the x86 architecture in general, but not all x86 implementations have SSE3 instructions, as one example. Also, the definition sometimes only refers to user-mode programs, so two implementations of the DEC PDP-10 architecure, the KA10 and KI10 processors, require some different code in the OS kernel.

Despite those laxities in the definition of architecture, I would still expect two implementations of the same VLIW architecture to be binary compatible.

A different VLIW implementation might have more (or fewer) functional units, and thus a longer (or shorter) instruction word, but then it cannot be said to be the *same* architecture.

s,

Thanx Eric. The question raised in my mind by reading text itself but is certainly not a homework/interview question kind of thing. Though it was a easy question, a simple reply (full of experience) from you will help my thought process.

Contents of your answer will certainly notbe any text book

Thanx again

Ripunjay Tripathi