https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96351
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2020-07-28
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
VRP doesn't work "backwards", it also does an incredibly bad job at
tracking pointer ranges where it simply prefers to track non-NULL.
Here we'd need to track symbolic [str_7 + [2, +INF] ] or so which
it cannot do either.
Eventually other analyses (SCEV?) could derive sth for
# pszTmp_8 = PHI <pszTmp_19(8)>
_14 = pszTmp_8 - str_7;
_15 = _14 /[ex] 2;
but even there, since we do not know the number of iterations, the
representation will have its limits.
