On 10/17/14 14:41, Marc Glisse wrote:
On Thu, 16 Oct 2014, Jeff Law wrote:
BTW, I dislike having multiple DCE implementations...
Similarly. The proposal above was just to determine if we should
schedule DCE or not.
Thinking about it some more, I don't think we should need any kind of
DCE here. The rewriting in update_ssa already does a form of forward
propagation that avoids generating dead assignments, the problem only
occurs if we explicitly introduce this new assignment. So I believe we
should go back to an earlier version, like the attached, which is less
work for the compiler.
And now I can go re-read the old discussion (apparently I should avoid
gsi_replace, and there may be other ways to handle the coalescing).
I'm starting to agree -- a later message indicated you wanted to drop
the unlink_stmt_vdef call and you wanted to avoid gsi_replace, that
seems fine. I'll approve once those things are taken care of.
jeff
