Optimization of conditional access to globals: thread-unsafe?

[Diego Novillo]

On 26 Oct 2007 14:24:21 -0700, Ian Lance Taylor <iant@google.com> wrote:

> What do people think of this patch?  This seems to fix the problem
> case without breaking Michael's case.  It basically avoids store
> speculation: we don't write to a MEM unless the function
> unconditionally writes to the MEM anyhow.

I think it couldn't hurt.  Providing it as a QOI feature might be
good.  However, we should predicate these changes on a -fthread-safe
flag.  More and more of these corner cases will start popping up.