Broadcom Corporation

Oracle America, Inc.

Sun Microsystems, Inc.

Sun Microsystems Technology Ltd.

Joseph Byron Rowlands

John Gregory Favor

Laurent Rene Moll

Richard Win Thaik

James Y Cho

Leonard Eric Shar

Manu Gulati

Graham Ricketson Murphy

Paul G Chan

Mark Hayter

Matthew Ashcraft

James B Keller

Peter N Glaskowsky

Barton Sano

Koray Oner

Ivan Pavle Radivojevic

Michael P Dickman

Christopher Patrick Nelson

David L Anderson

David A Kruckemyer

Mark Pearce

Chun Hung Ning

Shailendra S Desai

Daniel Fung

Michael D Carlson

Seungyoon Peter Song

James D Kelly

Yu Qing Cheng

Carlos Puchol

Rohini Krishna Kaza

A method and apparatus for optimizing a sequence of operations adapted for execution by a processor is disclosed to include associating with each register a symbolic expression selected from a set of possible symbolic expressions, locating an operation, if any, that is next within the sequence of operations and setting that operation to be a working operation, where the working operation has associated therewith a destination register and zero or more source registers, and processing the working operation when the working operation and any symbolic expressions of its source registers, if any, match at least one of a set of rules, where each rule specifies that the working operation must match a subset of the operation set, where each rule also specifies that the symbolic expressions, if any, of any source registers of the working operation must match a subset of the possible symbolic expressions, and where the rule also specifies a result, then posting the result as the symbolic expression of the destination register.

Symbolic renaming optimization of a trace

An embodiment of the present invention includes a circuit for tracking memory operations with trace-based execution. Each trace includes a sequence of operations that includes zero or more of the memory operations. At least some of the active memory operations access the memory in an execution order that is different from the program order. The circuit includes a first memory that caches data accessed by the memory operations. This memory is partitioned into N banks. Checkpoint entries, which are stored in a second memory also partitioned into N banks, are associated with each trace. Each entry refers to a checkpoint location in the first memory. A sub-circuit receives rollback requests and responds by overwriting checkpoint locations. Each of the N memory units consisting of a bank in the first memory and the corresponding bank in the second memory may be rolled back independently and concurrently with other memory units.

Cache rollback acceleration via a bank based versioning cache ciruit

This invention includes a circuit for tracking memory operations with trace-based execution. Each trace includes a sequence of operations that includes zero or more of the memory operations. The memory operations being executed form a set of active memory operations that have a predefined program order among them and corresponding ordering constraints. At least some of the active memory operations access the memory in an execution order that is different from the program order. Checkpoint entries are associated with each trace. Each entry refers to a checkpoint location. Memory operation ordering entries correspond to each one of the active memory operations. Violations of the ordering constraints result in overwriting the checkpoint locations associated with the selected trace as well as the checkpoint locations associated with traces that are younger than the selected trace.

Data cache rollbacks for failed speculative traces with memory operations

A virtual core management system including a physical core and a first virtual core including a collection of logical states associated with execution of a first program. The first virtual core is mapped to the physical core. The virtual core management system further includes a second virtual core including a collection of logical states associated with execution of a second program, and a virtual core management component configured to unmap the first virtual core from the physical core and map the second virtual core to the physical core in response to the virtual core management component detecting that the physical core is idle.

Virtual core management

A circuit for tracking memory operations with trace-based execution is disclosed. Each trace includes a sequence of operations that includes zero or more of the memory operations. The memory operations being executed form a set of active memory operations that have a predefined program order among them. At least some of the active memory operations access the memory in an execution order that is different from the program order. Checkpoint entries are associated with each trace. Each entry refers to a checkpoint location. Executing one of the active memory operations updates a checkpoint location. During the operation of the circuit, none of the operations of a given trace has any effect on the execution unit's architectural state prior to committing that trace. Each trace becomes eligible for commitment after all operations in the trace complete executing. After the trace is committed, all of the checkpoint entries associated with the trace are invalidated.

Trace based deallocation of entries in a versioning cache circuit

An instruction processing circuit includes a decoder circuit operable to receive a sequence of instructions and to decode the received sequence of instructions into a first type of sequence of operations, and a trace builder circuit operable to receive at least a portion of the sequence of operations of the first type and to generate, based thereon, a second type of sequence of operations, where the at least a portion of the sequence of operations of the first type represents a first portion of the sequence of instructions, where the first portion of the sequence of instructions includes at most one conditional control transfer instruction that, when present, ends the first portion of the sequence of instructions, and where the sequence of operations of the second type also represents the first portion of the sequence of instructions.

Trace unit

A method and system of ensuring coherency of a sequence of instructions to be executed by a processor having a trace unit and an execution unit includes grouping at least a portion of the sequence of instructions to form at least one trace where a status of the at least one trace is set to a verified status when the at least one trace is formed; holding in the at least one trace a coherency component that includes a pointer to a physical address of the at least one trace; receiving, based on the coherency component, the pointer to the physical address as associated with an invalidating event, and in response thereto, setting the status of the at least one trace to be an unverified status; and preventing the at least one trace from being executed when the status of the at least one trace is the unverified status.

System and method for ensuring coherency in trace execution

A processor includes a circuit for tracking memory operations with trace-based execution. Each trace includes a sequence of operations that includes zero or more of the memory operations. The memory operations being executed form a set of active memory operations that have a predefined program order among them. At least some of the active memory operations access the memory in an execution order that is different from the program order. During the operation of the circuit, none of the operations of a given trace has any effect on the execution unit's architectural state prior to committing that trace. Each trace becomes eligible for commitment after all operations in the trace complete executing. The circuit also includes a sub-circuit that holds memory operation ordering information corresponding to the active memory operations. The sub-circuit detects violations of ordering constraints. After each trace is committed, the sub-circuit invalidates all of the memory operation ordering information associated with the trace.

Memory ordering queue/versioning cache circuit

An embodiment of the present invention includes a circuit for tracking memory operations with trace-based execution. Each trace includes a sequence of operations that includes zero or more of the memory operations. The memory operations being executed form a set of active memory operations that have a predefined program order among them and corresponding ordering constraints. At least some of the active memory operations access the memory in an execution order that is different from the program order. Checkpoint entries are associated with each trace. Violations of the ordering constraints may be signaled too late to prevent an update of the cached data associated with the memory operations. A sub-circuit detects this condition and invalidates the checkpoint locations indicated by the checkpoint entries associated with the trace experiencing the violation and all younger traces.

Checking for a memory ordering violation after a speculative cache write

An instruction processing circuit for a processor is disclosed. The instruction processing circuit is adapted to provide one or more sequence of operations, based on one or more sequence of instructions, to an execution unit of the processor. The instruction processing circuit comprises at least one cache circuit and the processing circuit includes a sequencer and a page translation buffer coupled to the sequencer for trace verification and maintaining coherency between a memory and the at least one cache.

Method and system for utilizing a common structure for trace verification and maintaining coherency in an instruction processing circuit

An embodiment of the present invention includes a circuit for tracking memory operations with trace-based execution. Each trace includes a sequence of operations that includes zero or more of the memory operations. The memory operations being executed form a set of active memory operations that have a predefined program order among them and corresponding ordering constraints. At least some of the active memory operations access the memory in an execution order that is different from the program order. Checkpoint entries are associated with each trace. When a memory operation attempts to update a cache line that may not be updated, the circuit attempts to upgrade the cache line. If this fails, a rollback request is generated that indicates the trace involved. The checkpoint locations associated with the indicated trace are overwritten along with those locations associated with all younger traces.

Rolling back a speculative update of a non-modifiable cache line

A system on a chip for network devices. In one implementation, the system on a chip may include (integrated onto a single integrated circuit), a processor and one or more I/O devices for networking applications. For example, the I/O devices may include one or more network interface circuits for coupling to a network interface. In one embodiment, coherency may be enforced within the boundaries of the system on a chip but not enforced outside of the boundaries.

System on a chip for networking

An instruction processing circuit for a processor, where the instruction processing circuit is adapted to provide one or more sequence of operations, based on one or more sequence of instructions, to an execution circuit of the processor. The instruction processing circuit includes a cache circuit operable to store a second type of sequence of operations that represents at least a portion of a first type of sequence of operations, where the sequence of operations of the second type includes at most one control transfer that, when present, ends a first portion of a sequence of instructions, where the cache circuit is further configured to store a third type of sequence of operations that represents a set of at least two sequences of operations.

Trace unit with a decoder, a basic-block cache, a multi-block cache, and sequencer

An instruction processing circuit includes a decoder circuit, a basic block builder circuit, a multi-block builder circuit, first and second predictor circuits, and a sequencer circuit, where the sequencer circuit is operable, in a first environment, to cause the first predictor circuit to generate a prediction for a particular conditional branch op concurrently with the second predictor circuit generating a prediction for another particular conditional branch op, where the sequencer circuit is also operable, in a second environment, to cause the first predictor circuit to generate a prediction for the particular conditional branch op sequentially with the second predictor circuit generating a prediction for the another particular conditional branch operation.

Concurrent vs. low power branch prediction

An instruction processing circuit includes an instruction cache, a decoder configured to receive at least one of the instructions and to generate, based thereon, a decoder sequence of at least one operation. The circuit includes a basic block cache that includes a basic block sequence of at least one of the operations. The basic block sequence is derived from at least one of the decoder sequences and includes at most one conditional control transfer operation. The circuit includes a multi-block cache that includes a multi-block sequence consisting of at least one of the operations derived from two or more smaller op sequences. A sequencer is configured to generate a prediction for the result of a conditional control transfer operation, select the next sequence of operations, and provide an indication of the next sequence to the instructions cache, the basic block cache, and the multi-block cache.

Growing community of inventors

Santa Clara, CA, United States of America

Joseph Byron Rowlands