------- Comment #18 from changpeng dot fang at amd dot com 2010-03-17 00:22 ------- (In reply to comment #16) > > In this case, the loop itself is "empty" and we can replace every use of the > > phi with "n" (exit value of the iv). > > I don't think that is done by remove_empty_loop anyways and it is already done > by sccp (Propagation of constants using scev) which is enabled at -O1. >
But n "is" not a constant. Of course we can modify the pass to compute the exit value of iv (integer overflow may be an issue). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42906
