register dancing

	This is the JargonFile ^(V4.00) entry for register dancing - Next: reincarnation cycle of, Prev: regexp
:register dancing: /n./ Many older processor architectures suffer from a serious shortage of general-purpose registers. This is especially a problem for compiler-writers, because their generated code needs places to store temporaries for things like intermediate values in expression evaluation. Some designs with this problem, like the Intel 80x86, do have a handful of special-purpose registers that can be pressed into service, providing suitable care is taken to avoid unpleasant side effects on the state of the processor: while the special-purpose register is being used to hold an intermediate value, a delicate minuet is required in which the previous value of the register is saved and then restored just before the official function (and value) of the special-purpose register is again needed.
* (text is auto-included via JargonExtension by mutante using jargon with VERSION 4.0.0, 24 JUL 1996* - JargonFile by Eric S. Raymond is in the public domain)*