ranjith kumar <ranjit_kumar_b4u@xxxxxxxxxxx> writes: > 1)What is an "issues group" ? > > I think its definition is : > " Processors contain more than one > execution units like integer execution unit, floating > exection unit, memory read/write execution > units.....etc. > An issue group is a list of assembly instructions > which can be issued simultaneously to different > execution units at same time so that all execution > units are busy." > > > Am I right??? More or less. An issue group is a group of instructions which can all be issued at the same time. It is not a requirement that *all* execution units be busy. > 2) Compilers can make use of it by reodering > instructions so that all execution units are busy. > Is GCC exploiting such feature???? In general, this is target dependent: it requires somebody to write the scheduler description in the MD file. It has been done for most targets, though, including all popular targets. Ian
