From there, the Helium system then replaces the original bit-rotted components with the re-optimized ones. The net result: Helium can improve the performance of certain Photoshop filters by 75 percent, and the performance of less optimized programs such as Microsoft Windows’ IrfanView by 400 to 500 percent.

“We’ve found that Helium can make updates in one day that would take human engineers upwards of three months,” says Amarasinghe. “A system like this can help companies make sure that the next generation of code is faster, and save them the trouble of putting 100 people on these sorts of problems.”

Source: Computer program fixes old code faster than expert engineers | MIT News

Having the ability to automatically fix bad code is like when they introduced auto focus on cameras to automatically fix bad focus or auto tunes to fix bad singing.  The downside might be that development chooses to do less code reviews releasing more bad code into the wild relying on these automatic techniques to fix everything.

Here’s another article recently published by MIT News about this concept.

Remarkably, the system, dubbed CodePhage, doesn’t require access to the source code of the applications whose functionality it’s borrowing. Instead, it analyzes the applications’ execution and characterizes the types of security checks they perform. As a consequence, it can import checks from applications written in programming languages other than the one in which the program it’s repairing was written.

Source: Automatic bug repair | MIT News