Before revision:  We examine energy consumption distributions of two benchmarks under a range of input data on two cache-less embedded architectures, AVR and XS1-L. We find that the worst case can be predicted with a distribution created from random data. We propose a model to obtain energy distributions for instruction sequences that can be composed , enabling WCEC analysis on program basic blocks.
After revision:  We examine probabilistic energy distributions of instructions and propose a model to obtain energy distributions for instruction sequences that can be composed , enabling WCEC analysis on program basic blocks.