------- Comment #2 from guillaume dot melquiond at ens-lyon dot fr 2006-04-28
09:03 -------
I tried setting the nonnull attribute, it indeed allowed the optimization. In
particular, codes containing dynamic casts are now straight lines. This is a
nice improvement. Unfortunately GCC was not able to go further and use this
information in the caller in order to optimize it:
struct A { bool g() __attribute__((nonnull)); }
bool f(A *a) {
a->g();
return a;
}
Am I expecting too much from the nonnull attribute? (The documentation does not
seem to cover this point.) Or would it be reasonnable for the middle-end to
implement such an optimization?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27336
