On Sat, Mar 12, 2016 at 07:37:25PM +1030, Alan Modra wrote:
> > I believe Alan's point is DSE deleted the assignment to x which can't be
> > right as long as we've left in goto *&x.
> >
> > The goto *&x should be a use of x and thus should have kept the assignment
> > live.
>
> Right, I wasn't trying to say that ira.c:indirect_jump_optimize is
> OK. It needs the patch I posted or perhaps even better a test of
> DF_REF_INSN_INFO rather than !DF_REF_IS_ARTIFICIAL (simply because the
> flag test is reading another field, and we need to read
> DF_REF_INSN_INFO anyway).
Ok, that was my point. BTW, DSE isn't the only one that deletes x = 0;
cddce deletes it too. -fno-tree-dse -fno-tree-dce preserves it till
expansion.
Jakub
