Microprocessor with multiple issue queues in a microprocessor, where at least one of the issue queues is an adjustable mode queue that can be set to act as either of a priority queue, or a regular queue, with respect to intake of new instructions and/or outflow of old instructions. A set of summary bit value(s) can be set to control whether the adjustable mode queue has instruction intake priority and/or instruction outflow priority relative to the other issue queue(s).