Intel Corporation

Virtutech Ab

Bengt Werner

Fredrik Larsson

Samuel Rydh

Peter Magnusson

Peter S Magnusson

A method and system for simulating in software a digital computer system by performing virtual to physical translations of simulated instructions is disclosed. The number of virtual to physical translations using hash lookups is reduced by analyzing sequences of the instructions for determining with high probability whether the memory accesses made by the instructions perform the same virtual to physical translation in order to reduce the number of necessary hash lookups to enable faster simulation performance.

Method and system for partial evaluation of virtual address translations in a simulator

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.

Devices, methods and computer program products for reverse execution of a simulation

The invention relates to a computer program interpreter and a method for the same, using statistics to group (SR, SR. . . SR; SR, SR. . . SR) frequently used service routines (SR) in the same program function and to control encoding of instructions. Frequently used service routines are assigned shorter codes thus enhancing the performance of a simulator or emulator.

Interpreter for executing computer programs and method for collecting statistics

The invention is a technique that allows very efficient execution of an instruction set simulator (ISS) when certain code fragments are simulated. They occur frequently in operating systems, when a processor waits for something to occur. These loops perform very little, if any, computation. An automatic analysis of the code fragments is performed to determine whether they can be transformed to 'fast forward' when execution loops through the code fragment. This is done by the creation of a function g, that takes a number of state changes as an input and can compute the state at a time T by a single application of the function, rather than applying the next state function repeatedly until time T is reached. An important aspect of the resulting optimization is that it produces exactly the same simulated result as compared to when it is not applied, i.e. the optimization is non-intrusive.

Growing community of inventors

Åkersberga, Sweden

Bengt Werner