You may aware or not that there is a nice optimization (more effective if you have some registers to spare) based on how you access memory thought variables. Since it wasn't that effective and didn't break anything it is enabled since -O2.
Problem: recent gcc are doing some quite smart tricks with aliasing and as result they will break in subtle way your code if you use strict-aliasing rules optimization on type puns. Quick solution: enforce -fno-strict-aliasing as global cflag. Side effect: you may lose a bit in performance, but better safe than sorry: the first package showing issues was openssl[1] mismatching hashes, guess how discovered that and how (hint: ssh was refusing logins...) Long term solution: 1- check your new package for aliasing compliance, and if you have time fix it in the code or in the makefile, if you haven't append -fno-strict-aliasing to the cflags and maybe send a notice about it upstream 2- append -fno-strict-aliasing to every source known to have such issue. I'll do 2 on all packages in the tree showing the issue if you think is ok, arches not yet affected will be in the future. lu [1]http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14725 -- Luca Barbato Gentoo/linux Gentoo/PPC http://dev.gentoo.org/~lu_zero -- gentoo-dev@gentoo.org mailing list
