Optimal program execution reversal

Optimal program execution reversal

For adjoint calculations, debugging, and similar purposes one may need to reverse the execution of a computer program. The simplest option of recording a complete execution log and then reading it backwards requires massive amounts of storage. Instead one may generate the execution log piecewise by restarting the “forward” calculation repeatedly from suitably placed checkpoints. Our goal is to ...

Optimal Program Exe ution Reversal

Towards an Optimal Bit-Reversal Permutation Program

The speed of many computations is limited not by the number of arithmetic operations but by the time it takes to move and rearrange data in the increasingly complicated memory hierarchies of modern computers. Array transpose and the bit-reversal permutation – trivial operations on a RAM – present non-trivial problems when designing highly-tuned scientific library functions, particular for the F...

Multi-Amdahl: Optimal Resource Sharing with Multiple Program Execution Segments

This paper presents Multi-Amdahl, a resource allocation analytical tool for heterogeneous systems. Our model includes multiple program execution segments, where each one is accelerated by a specific hardware unit. The acceleration speedup of the specific hardware unit is a function of a limited resource, such as the unit area, power, or energy. Using the Lagrange theorem we discover the optimal...

Determining Average Program Execution

This paper presents a general framework for determining average program execution times and their variance, based on the program's interval structure and control dependence graph. Average execution times and variance values are computed using frequency information from an optimized counter-based execution proole of the program.