search for: reduction_unrol

...d by the fact that standard output is written only at the end of the program and stderr is unbuffered, i.e. always written before stdout. A lot of tests disable stdout using either "-o /dev/null" or "-disable-output", but not all. For instance, test/Transforms/SLPVectorizer/X86/reduction_unrolled.ll does not. It checks for output from stdout and stderr using the same FileCheck. The stderr it is checking even comes from -debug, which has an additional buffering layer (circular_raw_ostream). The testing guide [1] does not mention how to test stderr. My questions: 1. Are these tests, e....