Current sparse code doesn't handle very gracefully code with undefined pseudos. These can occurs, of course because the dev has not initialize them, maybe by error, but they can also occurs when they are only set (and used) in a single path or even worse, hen initiializing a bitfield. The origin of the problem is the single store shortcut in simplify_one_symbol() which doesn't take in account the (absence of) dominance when loads exist without stores. Fix this by removing this single-store shortcut and leave all the work for the general case which handle this situation quite well (and/but set those variables to 0). Warning: this change impact the performance (but not too much) Note: This patch will also avoid internal infinite loops occuring when processing undefined vars present during the SSA construction. Note: This patch will not avoid all similar problems because they can also be created after the SSA construction, for example when processing code that really is unreachable (then, typically, some of the involved pseudos are, in fact, not defined). It shouldn't be a problem since the code is unreachable. But if we process the code anyway (possibly because we simply don't know that the code is unreachable) then we create the same situation with the same consequences. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>