Abstract:
A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.
Abstract:
An error handling method includes identifying a code region eligible for cumulative multiply add (CMA) optimization and translating code region instructions into interpreter code instructions, which may include translating sequences of multiply add instructions in the code region instructions into fusion code including CMA instructions. Floating point (FP) exceptions generated by the fusion code may be monitored and at least a portion of the code region instructions may be re-translated to eliminate some or all fusion code if CMA intermediate rounding exceptions exceed a threshold.
Abstract:
A processor includes allocation unit with logic to receive a logical move instruction. The logical move instruction includes a source logical register as a source parameter and a destination logical register as a destination parameter. The source logical register is assigned to a source physical register and the destination logical register is assigned to a destination physical register. The allocation unit includes logic to assign a first value of the source logical register to the destination logical register and to maintain a second value of the destination physical register before and after the assignment of the first value to the destination logical register.
Abstract:
A computer-readable storage medium, method and system for optimization-level aware branch prediction is described. A gear level is assigned to a set of application instructions that have been optimized. The gear level is also stored in a register of a branch prediction unit of a processor. Branch prediction is then performed by the processor based upon the gear level.
Abstract:
An error handling method includes identifying a code region eligible for cumulative multiply add (CMA) optimization and translating code region instructions into interpreter code instructions, which may include translating sequences of multiply add instructions in the code region instructions into fusion code including CMA instructions. Floating point (FP) exceptions generated by the fusion code may be monitored and at least a portion of the code region instructions may be re-translated to eliminate some or all fusion code if CMA intermediate rounding exceptions exceed a threshold.