Conditional branch instruction capable of testing a plurality of indicators in a predicate register

摘要

A method of conditionally executing branch instructions which comprise an opcode field defining a type of test to be applied to determine whether or not to execute a branch operation, a control field designating a control store holding a plurality of indicators and a destination field holding information on a branch target address. The method comprises determining from the opcode field whether or not the test will check the state of one indicator or a plurality of indicators in the designated control store, accessing the designated control store to check the state of said one or said plurality of indicators depending on the determination, and generating a branch target address using information in the destination field in dependence on the state of the or each indicator checked.