Instruction Groups
Itanium® processors execute several instructions in parallel. Instructions
that are allowed to execute in parallel are organized in instruction groups.
An instruction group is a set of consecutive instructions that should
have no interdependencies. The instruction group is terminated by a stop
(;;). IAS supports
explicit stops as defined in the Intel®
Itanium® Architecture Assembly Language Reference Guide.
IAS checks for data dependencies in instruction
groups. An example of a data dependency is a write instruction following
a read instruction to the same register. For more details on dependency
violations, see Dependency Violations and Assembly Modes.