cp_normalize_timestamps() can produce negative timestamps in log()

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:26

The cp_normalize_timestamps() function was added recently in trunk to normalize all timestamps in the log relative to MPI_Init() time. It doesn't check to see if a timestamp was unused, though, in which case subtracting the offset from 0 produces a negative value.

This function should be fixed to avoid touching 0 values, and maybe also add a check after that to make sure that normalized values are positive.

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:26

Fixed in trunk; only deduct init time from timestamps if timestamp is greater than init time.