> I disagree that the tests are not obviously worth keeping. Having a large suite of regression tests is vital to stop bugs reappearing.
What I left implicit is that a non-reduced Csmith test makes a terrible regression test. It may for instance spend several seconds incrementing a counter from 0 to 4000000000 before switching to the entirely unrelated computation that once triggered a bug. The value of these randomly generated tests is in generating a new one the next time, not in saving them to run again and again. Running the same randomly generated tests again and again would find very few bugs and would be a criminal waste of electricity.
The reduced program is worth keeping as a regression test, because it is typically a few lines long and these few lines contain a construct that once tripped the compiler. Sometimes the reduced version can be rewritten by a human to be even more concise and readable than the output of C-reduce. But as I said in another comment, one compiler's regression test does not obviously make a good test for another compiler.
Sounds like we agree then :) If we assume that no (Csmith) bug will be fixed without a reduced test-case, then the choice of which one to use as a regression test is obvious.
What I left implicit is that a non-reduced Csmith test makes a terrible regression test. It may for instance spend several seconds incrementing a counter from 0 to 4000000000 before switching to the entirely unrelated computation that once triggered a bug. The value of these randomly generated tests is in generating a new one the next time, not in saving them to run again and again. Running the same randomly generated tests again and again would find very few bugs and would be a criminal waste of electricity.
The reduced program is worth keeping as a regression test, because it is typically a few lines long and these few lines contain a construct that once tripped the compiler. Sometimes the reduced version can be rewritten by a human to be even more concise and readable than the output of C-reduce. But as I said in another comment, one compiler's regression test does not obviously make a good test for another compiler.