> > LOAD inode = next.dentry->inode > > if (inode != NULL) > > LOAD inode->f_op > > > > What is there the compiler can optimize? > > Those two loads depend on each other, I don't think any implementation > can re-order them. In fact, such data dependency is typically what is > used to avoid having barriers in some cases. The second load cannot be > issued until the value from the first one is returned. Actually I've met several compilers which will optimise them but not gcc and not in a Linux environment. Some compilers know how to optimise the == NULL case for pointer dereferences providing their programming environment has a couple of low pages mapped read only and reading 0. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
