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US 7,849,450 B1Granted
Devices, methods and computer program products for reverse execution of a simulation
AssigneeIntel Corporation
InventorsSamuel Rydh, Peter S. Magnusson, Bengt Werner
Life of this patent
Estimating the term…
Abstract
Devices, methods, and software program products for reverse execution of a simulation and/or tracing a value are provided. A state of a preceding checkpoint may be restored and a simulation may be run forward. Break points or watch points may be noted and the state of the last occurring breakpoint or watch point preceding the current simulation position may be restored. If no breakpoint or watch point occurred, an earlier checkpoint may be loaded and the previous steps may be repeated.
Claims57
A device comprising:
- a processor adapted to,
- first restore a state of a preceding checkpoint relative to a current simulation position, the current simulation position being a point of interest in a simulation,
- simulate the entire simulation forward from the preceding checkpoint by replaying recorded events and noting breakpoints or watch points regardless of breakpoints or watch points encountered while simulating from the preceding checkpoint to the current simulation position, the recorded events including non-deterministic events, and the simulating forward from the preceding checkpoint to the current simulation position having a same instruction flow as an initial simulation,
- second restore the state of a last occurring breakpoint or watch point preceding the current simulation position, after reaching the current simulation position,
- load the state of an earlier checkpoint;
- and
- repeat the first restoring, the simulating, the noting, the second restoring, and the loading, if no breakpoint or watch point occurred between the preceding checkpoint and the current simulation position to form an iterative process in which successively earlier checkpoints are restored, the earlier checkpoint being prior to the preceding checkpoint in the simulation.
4 more elements
A method for reverse execution of a simulation, the method comprising:
- first restoring a state of a preceding checkpoint relative to a current simulation position, the current simulation position being a point of interest in the simulation;
- simulating the entire simulation forward from the preceding checkpoint by replaying recorded events, regardless of breakpoints or watch points encountered while simulating from the preceding checkpoint to the current simulation position, the recorded events including non-deterministic events, and the simulating forward from the preceding checkpoint to the current simulation position having a same instruction flow as an initial simulation;
- noting breakpoints or watch points;
- second restoring a state of a last occurring breakpoint or watch point preceding the current simulation position when having reached the current simulation position;
- loading the state of an earlier checkpoint;
- and
- repeating the first restoring, the simulating, the noting, the second restoring, and the loading if no breakpoint or watch point occurred between the preceding checkpoint and the current simulation position to form an iterative process in which successively earlier checkpoints are restored, the earlier checkpoint being prior to the preceding checkpoint in the simulation.
4 more elements
Dependencies are inferred from the claim text.