FLiT
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PRUNERS
Bisect difference threshold
The current, and I think desired default behavior of flit bisect is to look for files and functions that have any influence on variability according to the comparison function. However, it may show too many things that have very little influence on the final result, and consequently not being as helpful as desired.
Instead, we would like to add an option for the user to provide
- a relative error threshold (
--relative-threshold) or - a threshold of the number of equal digits (
--digit-threshold) or - an absolute threshold (
--absolute-threshold)
This would only trigger bisect to identify when the variability exceeds the threshold.
A word of caution: The assumption that all variability is independently identifiable has a higher risk of being violated when using this functionality. The flit bisect tool will only be able to isolate instances where the variability is so extreme, that its presence causes the total variability to exceed the threshold regardless of how the rest of the application is compiled. But be assured that if the assumption is violated, then that violation will be identified and bisect will immediately stop. So, at worst, you have a chance to get no results, which is much better than getting misleading results.
