摘要:
In one embodiment, the present invention includes a method for receiving control in a kernel mode via a ring transition from a user thread during execution of an unbounded transactional memory (UTM) transaction, updating a state of a transaction status register (TSR) associated with the user thread and storing the TSR with a context of the user thread, and later restoring the context during a transition from the kernel mode to the user thread. In this way, the UTM transaction may continue on resumption of the user thread. Other embodiments are described and claimed.
摘要:
Monitoring performance of one or more architecturally significant processor caches coupled to a processor. The methods include executing an application on one or more processors coupled to one or more architecturally significant processor caches, where the application utilizes the architecturally significant portions of the architecturally significant processor caches. The methods further include at least one of generating metrics related to performance of the architecturally significant processor caches; implementing one or more debug exceptions related to performance of the architecturally significant processor caches; or implementing one or more transactional breakpoints related to performance of the architecturally significant processor caches as a result of utilizing the architecturally significant portions of the architecturally significant processor caches.
摘要:
Minimizing code duplication in an unbounded transactional memory system. A computing apparatus including one or more processors in which it is possible to use a set of common mode-agnostic TM barrier sequences that runs on legacy ISA and extended ISA processors, and that employs hardware filter indicators (when available) to filter redundant applications of TM barriers, and that enables a compiled binary representation of the subject code to run correctly in any of the currently implemented set of transactional memory execution modes, including running the code outside of a transaction, and that enables the same compiled binary to continue to work with future TM implementations which may introduce as yet unknown future TM execution modes.
摘要:
A method and apparatus for extending cache coherency to hold buffered data to support transactional execution is herein described. A transactional store operation referencing an address associated with a data item is performed in a buffered manner. Here, the coherency state associated with cache lines to hold the data item are transitioned to a buffered state. In response to local requests for the buffered data item, the data item is provided to ensure internal transactional sequential ordering. However, in response to external access requests, a miss response is provided to ensure the transactionally updated data item is not made globally visible until commit. Upon commit, the buffered lines are transitioned to a modified state to make the data item globally visible.
摘要:
Methods, apparatus and systems for memory access obscuration are provided. A first embodiment provides memory access obscuration in conjunction with deadlock avoidance. Such embodiment utilizes processor features including an instruction to enable monitoring of specified cache lines and an instruction that sets a status bit responsive to any foreign access (e.g., write or eviction due to a read) to the specified lines. A second embodiment provides memory access obscuration in conjunction with deadlock detection. Such embodiment utilizes the monitoring feature, as well as handler registration. A user-level handler may be asynchronously invoked responsive to a foreign write to any of the specified lines. Invocation of the handler more frequently than expected indicates that a deadlock may have been encountered. In such case, a deadlock policy may be enforced. Other embodiments are also described and claimed.
摘要:
Controlling a reorder buffer (ROB) to selectively perform functional hardware lock disabling (HLD) is described. One apparatus embodiment includes a unit to enable an ROB to selectively disable a lock upon Identifying a lock acquire operation (LAO) associated with a critical section (CS) entry point, a unit to selectively retire the LAO, a unit to cause the ROB to selectively disable the lock, and a unit to snoop a buffer. The apparatus may, based on the snooping, selectively abort a transaction associated with the CS.
摘要:
The present invention relates to a method and system for providing a variable width, at least six-way addition instruction in a processor. The method includes decoding an instruction as a variable width, at least six-way addition instruction, where the variable width, at least six-way addition instruction includes a plurality of operands. The method also includes adding the plurality of operands to obtain a plurality of sums. The method further includes outputting the plurality of sums and optionally storing carry results from the adding operation.
摘要:
The present invention relates to a method and system for providing sine and cosine value pairs in a processor. The method includes decoding a sine and cosine instruction having a predetermined source angle and generating an index value for a sine cosine table (SCT) using a sine cosine control register (SCCR). The method also includes generating a plurality of quadrant bits using the SCCR, reading a sine and a cosine value pair from the SCT using the index value, and adjusting a sign of each value of the sine and the cosine value pair using the plurality of quadrant bits, if necessary. The method further includes incrementing the SCCR, if the SCCR is to be incremented, executing the sine and cosine instruction using the sine and cosine value pair, and outputting at least one result.
摘要:
How a first result of a first operation compares to a second result of a second operation is identified. The identification may be performed without producing the first result or the second result. The first result or the second result may be selected in response to the identification, and the first operation or the second operation may be performed in response to the selection to produce the selected result. Alternatively, the first operation may be performed to produce the first result and the second operation may be performed to produce the second result. The produced first result or the produced second result may be selected in response to the identification.
摘要:
A method and apparatus for hybrid pre and post-retire tentative access tracking is herein described. Access tracking is often performed during execution of critical sections, which may be defined by traditional locks or transactional memory instructions. Pre-retire accesses to memory are performed to update tracking information for access during execution of a critical section. However, post-retire updates to tracking information are performed for subsequent consecutive critical section accesses in a pipeline when a previous end critical section operation is retired.