But, if the OP was off topic, I would have labelled it as such. Just as I have always done.
Yes. This is directly related to my attempt to fix a bug in the 64-bit linux build of Devel::Size.
Ah! The explanation that this was related to a problem in Devel::Size would have been useful to see in the first paragraph of your original post. Without that detail, your post was an interesting technical question about C compilers on different platforms, seemingly unrelated to Perl. Hence, my consideration request to mark the node off-topic.
Alex / talexb / Toronto
"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds