------- Additional Comments From dberlin at dberlin dot org 2004-12-07 22:56 ------- Subject: Re: ICE with -O1 -ftree-loop-linear on small test case
> >> There are basically two ways how to fix this: either make the code >> that changes the order of loops in the nests to also renumber the loops >> (which would in turn invalidate all scev caches, that would need to be >> flushed). Or fix the code that assumes the ordering of the loops. > > Sorry for a bit missleading formulation -- the later solution does not > avoid need for flushing the scev caches when the "linear" pass changes > order of loops; the data are invalidated anyway. > You've missed the actual bug here. The bug doesn't occur *after* linear loops, it occurs *before* it. When computing data dependence, we expect that all loop indexes in a given loop nest are sequential. In this case, they are not. The question is whether this is correct or not. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18792
