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. [Jargon File]

In addition suitable contents:
[ 80x86 ] [ = ] [ ag ] [ ai ] [ al ] [ am ] [ an ] [ ar ] [ arc ] [ architecture ] [ arg ] [ as ] [ at ] [ au ] [ av ] [ b ] [ be ] [ ca ] [ cat ] [ ch ] [ ci ] [ co ] [ code ] [ com ] [ compiler ] [ de ] [ design ] [ ding ] [ do ] [ du ] [ ec ] [ ed ] [ ee ] [ eg ] [ er ] [ era ] [ es ] [ et ] [ evaluation ] [ expression ] [ fi ] [ file ] [ fo ] [ for ] [ fr ] [ function ] [ ga ] [ ge ] [ gen ] [ generate ] [ gi ] [ gn ] [ gs ] [ h ] [ hat ] [ hing ] [ hit ] [ hr ] [ id ] [ ie ] [ il ] [ in ] [ int ] [ Intel 80x86 ] [ io ] [ ir ] [ is ] [ it ] [ J ] [ Jargon File ] [ ke ] [ ken ] [ la ] [ ld ] [ Lex ] [ li ] [ lu ] [ ly ] [ M ] [ mo ] [ mod ] [ module ] [ mp ] [ na ] [ nc ] [ ne ] [ ng ] [ np ] [ ns ] [ nu ] [ om ] [ pe ] [ ph ] [ pl ] [ pr ] [ process ] [ processor ] [ query ] [ rc ] [ re ] [ register ] [ ro ] [ S ] [ sa ] [ save ] [ se ] [ service ] [ sh ] [ si ] [ sig ] [ so ] [ spec ] [ st ] [ state ] [ store ] [ su ] [ suit ] [ T ] [ table ] [ tag ] [ th ] [ to ] [ ua ] [ us ] [ va ] [ value ] [ ve ] [ vi ] [ while ] [ write ] [ x86 ]