Abstract:
In an embodiment, an integrated circuit may include one or more power gated blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power gated block and a block enable clock. The power gated block may generate local block enables to various power switch segments in the power gated block. In particular, the power gated block may include a set of series-connected flops that receive the block enable from the power manager circuit. The power gated block may include a set of multiplexors (muxes) that provide the local block enables for each power switch segment. One input of the muxes is coupled to the block enable, and the other input is coupled to another enable propagated through one of the other power switch segments. Accordingly, the muxes may be controlled to select the propagated enables or the input block enable.
Abstract:
Techniques are disclosed relating to ordering of load instructions in a weakly-ordered memory model. In one embodiment, a processor includes a cache with multiple cache lines and a store queue configured to maintain status information associated with a store instruction that targets a location in one of the cache lines. In this embodiment, the processor is configured to set an indicator in the status information in response to migration of the targeted cache line. The indicator may be usable to sequence performance of load instructions that are younger than the store instruction. For example, the processor may be configured to wait, based on the indicator, to perform a younger load instruction that targets the same location as the store instruction until the store instruction is removed from the store queue. This may prevent forwarding of the value of the store instruction to the younger load and preserve load-load ordering.
Abstract:
Techniques are disclosed relating to completion of load and store instructions in a weakly-ordered memory model. In one embodiment, a processor includes a load queue and a store queue and is configured to associate queue information with a load instruction in an instruction stream. In this embodiment, the queue information indicates a location of the load instruction in the load queue and one or more locations in the store queue that are associated with one or more store instructions that are older than the load instruction. The processor may determine, using the queue information, that the load instruction does not conflict with a store instruction in the store queue that is older than the load instruction. The processor may remove the load instruction from the load queue while the store instruction remains in the store queue. The queue information may include a wrap value for the load queue.