Next:Code Iterators, Up:Iterators [Contents][Index]
Ports often need to define similar patterns for two or more different modes.For example:
SFmode patterns tend to bevery similar to theDFmode ones.SImode pointers in one configuration andDImode pointers in another, it will usually have very similarSImode andDImode patterns for manipulating pointers.Mode iterators allow several patterns to be instantiated from one.md file template. They can be used with any type ofrtx-based construct, such as adefine_insn,define_split, ordefine_peephole2.