X87
From Wikipedia, the free encyclopedia
- The correct title of this article is x87. The initial letter is shown capitalized due to technical restrictions.
x87 is a math-related instruction subset of the Intel x86 family line of processors. It is so called because initially such instructions were processed by an external chip with a name ending in 87.
Like other extensions to the basic processor instruction set, these instructions are not strictly needed for programs to work. Instead, they provide hardware support for common mathematical tasks, allowing these tasks to be performed in fewer instructions. For example, the x87 instruction set includes instructions to calculate the sine or cosine of a value.
Modern compilers, including GCC, use these expanded instruction sets to make code faster, in code optimization.
[edit] List of x87 generations
- 8087
- 80187 - apparently not released
- 80287
- 80387
- 80487 - actually a full-blown 80486DX processor
- 80587 - the only member is NexGen's Nx587
