Abstract:
A processor includes a plurality of execution pipes and a distributed scheduler coupled to the plurality of execution pipes. The distributed scheduler includes a first queue to buffer instruction operations from a front end of an instruction pipeline of the processor and a plurality of second queues, wherein each second queue is to buffer instruction operations allocated from the first queue for a corresponding separate subset of execution pipes of the plurality of execution pipes. The distributed scheduler further includes a queue controller to select an allocation mode from a plurality of allocation modes based on whether at least one indicator of an imbalance at the distributed scheduler is detected, and further to control the distributed scheduler to allocate instruction operations from the first queue among the plurality of second queues in accordance with the selected allocation mode.
Abstract:
A floating point unit includes a non-pickable scheduler queue (NSQ) that offers a load operation concurrently with a load store unit retrieving load data for an operand that is to be loaded by the load operation. The floating point unit also includes a renamer that renames architectural registers used by the load operation and allocates physical register numbers to the load operation in response to receiving the load operation from the NSQ. The floating point unit further includes a set of pickable scheduler queues that receive the load operation from the renamer and store the load operation prior to execution. A physical register file is implemented in the floating point unit and a free list is used to store physical register numbers of entries in the physical register file that are available for allocation.
Abstract:
An approach is provided for implementing register based single instruction, multiple data (SIMD) lookup table operations. According to the approach, an instruction set architecture (ISA) can support one or more SIMD instructions that enable vectors or multiple values in source data registers to be processed in parallel using a lookup table or truth table stored in one or more function registers. The SIMD instructions can be flexibly configured to support functions with inputs and outputs of various sizes and data formats. Various approaches are also described for supporting very large lookup tables that span multiple registers.
Abstract:
An approach is provided for implementing register based single instruction, multiple data (SIMD) lookup table operations. According to the approach, an instruction set architecture (ISA) can support one or more SIMD instructions that enable vectors or multiple values in source data registers to be processed in parallel using a lookup table or truth table stored in one or more function registers. The SIMD instructions can be flexibly configured to support functions with inputs and outputs of various sizes and data formats. Various approaches are also described for supporting very large lookup tables that span multiple registers.
Abstract:
In some implementations, a processor includes a plurality of parallel instruction pipes, a register file includes at least one shared read port configured to be shared across multiple pipes of the plurality of parallel instruction pipes. Control logic controls multiple parallel instruction pipes to read from the at least one shared read port. In certain examples, the at least one shared register file read port is coupled as a single read port for one of the parallel instruction pipes and as a shared register file read port for a plurality of other parallel instruction pipes.
Abstract:
The disclosed computer-implemented method for interpolating register-based lookup tables can include identifying, within a set of registers, a lookup table that has been encoded for storage within the set of registers. The method can also include receiving a request to look up a value in the lookup table and responding to the request by interpolating, from the encoded lookup table stored in the set of registers, a representation of the requested value. Various other methods, systems, and computer-readable media are also disclosed.
Abstract:
An apparatus includes a plurality of load buses and a load store unit that includes a plurality of load ports to access the plurality of load buses. The load store unit performs a gather operation to concurrently gather a plurality of subsets of data from a memory via the plurality of load buses in a first mode. The apparatus also includes a register that is partitioned into a plurality of portions to hold the plurality of subsets of data provided by the load store unit. The load store unit ignores exceptions or faults while performing the gather operation in the first mode and transitions to a second mode in response to an exception or fault. Two lanes are dispatched to concurrently perform the gather operation per clock cycle in the first mode and a single lane is dispatched to perform the gather operation per clock cycle in the second mode.
Abstract:
A method includes undoing, in reverse program order, changes in a state of a processing device caused by speculative instructions previously dispatched for execution in the processing device and concurrently deallocating resources previously allocated to the speculative instructions in response to interruption of dispatch of instructions due to a flush of the speculative instructions. A processor device comprises a retire queue to store entries for instructions that are awaiting retirement and a finite state machine. The finite state machine is to interrupt dispatch of instructions in response to a flush of speculative instructions previously dispatched for execution in the processing device and to undo, in reverse program order, changes in a state of the processing device caused by the speculative instructions while concurrently deallocating resources previously allocated to the speculative instructions.
Abstract:
A processor includes one or more processor cores configured to perform accumulate top (ACCT) and accumulate bottom (ACCB) instructions. To perform such instructions, at least one processor core of the processor includes an ACCT data path that adds a first portion of a block of data to a first lane of a set of lanes of a top accumulator and adds a carry-out bit to a second lane of the set of lanes of the top accumulator. Further, the at least one processor core includes an ACCB data path that adds a second portion of the block of data to a first lane of a set of lanes of a bottom accumulator and adds a carry-out bit to a second lane of the set of lanes of the bottom accumulator.
Abstract:
A processing unit includes a plurality of adders and a plurality of carry bit generation circuits. The plurality of adders add first and second X bit binary portion values of a first Y bit binary value and a second Y bit binary value. Y is a multiple of X. The plurality of adders further generate first carry bits. The plurality of carry bit generation circuits is coupled to the plurality of adders, respectively, and receive the first carry bits. The plurality of carry bit generation circuits generate second carry bits based on the first carry bits. The plurality of adders use the second carry bits to add the first and second X bit binary portions of the first and second Y bit binary values, respectively.