In the early 1980’s there was a swing away from providing architectural support for high-level hardware support for languages. Several groups started to analyse the problems of providing support for features of high-level languages and proposed simpler architectures to solve these problems. The idea of RISC was first proposed in 1980 by Patterson and Ditzel. These new proposals were not immediately accepted by all researchers however, and much debate ensued. Other research proposed a closer coupling of compilers and architectures, as opposed to architectural support for high-level language features. This shifted the emphasis for efficient implementation from the hardware to the compiler. During the 1980’s much work was done on compiler optimisation and particularly on efficient register allocation.
In the mid-1980’s processors and machines based on RISC principles started to be marketed. One of the first of these was the SPARC processor range, which was first sold in Sun equipment in 1987. Since 1987 the SPARC processor range has grown and evolved. One of the major developments was the release of the SuperSPARC processor range in 1991. More recently, in 1995, a 64-bit extension of the original SPARC architecture was released as the UltraSPARC range. We will consider these extensions to the basic SPARC architecture later in the course.
And this is the point in history where we start our story! During the rest of the course we will be referring back to some of the machines and systems referred to in this historical background, and we will see the innovations that were brought about by some of these milestones in the development of computer architecture