Title CS302 Spring 1999 - Regression Testing Regression testing is a common approach to testing compilers. These outputs are called the baseline . Each time the compiler is changed, it is tested with the programs in the test suite and the results are compared with the baseline. For many changes, e.g., algorithm improvements, the output is identical to the baseline.
Unexpected differences suggest errors.
For other changes, e.g., generating better code or supporting additional source-language features, the output will differ from the baseline in presumably expected ways. Once the changes are accepted as correct, the latest outputs are established as the new baseline. Details of the testing scheme depend on the compiler stage being tested. This testing scheme can be automated using a shell script. If the baseline files don't exist, dotest creates them from the current outputs.