------- Comment #8 from zadeck at naturalbridge dot com 2008-03-20 13:59 ------- Subject: Re: heisenbug in tree vectorizer
bonzini at gnu dot org wrote: > ------- Comment #7 from bonzini at gnu dot org 2008-03-20 13:51 ------- > Indeed my patch exposes additional vectorization abilities (which was > unexpected). > > Kenny, can you run the failing testcase under valgrind? > > > I did run it under valgrind and found no problems. However, i am a little skeptical about regression hunting for these failures. I have found that they come and go based on small changes to other parts of the compiler, i.e. they are symptomatic of some uninitialized variable problem or a storage overwriting. in particular, with the release that i specified in message 1, the failures were there if the compiler was not bootstrapped and were there if it was bootstrapped. Also, changes that i made to that release in the register allocator, which is far downstream of the tree vectorizer caused the problems to hit for both bootstrapped and not bootstrapped builds. I would suggest that you go roll back to that release mentioned in message 1, where you have exactly the same code base for bootstrapped and non bootstrapped compiler and run the two compilers in parallel until you find the place where they diverge. It could very well be that this may be that this is a problem with someone elses code, but you are the occam's razor first choice. kenny -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35642
