[Bug tree-optimization/63185] Improve DSE with branches

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63185

--- Comment #12 from Marc Glisse <glisse at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #11)
> I guess you meant (notice the bogus memset size above):

True. And while it shouldn't make a difference in checking if the stores to c
are dead, it could (but doesn't, symbolic bounds are not so easy to handle)
make a difference for the reads since we could notice that the reads from a and
b are necessarily 0 (thus we write 0 to c[i], thus this loop is a memset, etc).