The goal of this series is to get rid of false "crazy programmer" warnings. This warning is issued when a cycle is detected in the address calculation of memory operations. Such cycle can happen when simplifying phi-nodes dealing with uninitialized variables. However the very same diagnostic can also be emitted if we try to simplify phi-nodes inside an unreachable loop (because localy it's exactly the same situation: since the loop is unreachable it's very possible that the induction variables have no more an initial value). Of course, since this situation is only the consequence of trying to simplify code that is not reachable while the original may very well not contain any unitialized var, this diagnostic should not be emitted in this situation. The solution is to kill potential unreachable BBs before trying to simplify them, each time a parent is removed from a BB. --- Changes since v1: - split the patch in 3, the first 2 being small preparatory patches, the third being the meat. - try to avoid to have to call kill_unreachable_bbs() in the rare situations where the BB having a parent removed still contains another parent and thus can't be unreachable. Luc Van Oostenryck (3): introduce REPEAT_CFG_CLEANUP let kill_unreachable_bbs() clear REPEAT_CFG_CLEANUP fix: kill unreachable BBs after killing a child flow.c | 2 ++ flow.h | 1 + linearize.c | 5 ++++- validation/crazy02-not-so.c | 22 ++++++++++++++++++++++ 4 files changed, 29 insertions(+), 1 deletion(-) create mode 100644 validation/crazy02-not-so.c -- 2.12.2 -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
